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Chaim OM, Miki S, Prager BC, Ma J, Jeong AY, Lara J, Tran NK, Smith JM, Rich JN, Gutkind JS, Miyamoto S, Furnari FB, Brown JH. Gα12 signaling regulates transcriptional and phenotypic responses that promote glioblastoma tumor invasion. Sci Rep 2023; 13:22412. [PMID: 38104152 PMCID: PMC10725435 DOI: 10.1038/s41598-023-49164-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023] Open
Abstract
In silico interrogation of glioblastoma (GBM) in The Cancer Genome Atlas (TCGA) revealed upregulation of GNA12 (Gα12), encoding the alpha subunit of the heterotrimeric G-protein G12, concomitant with overexpression of multiple G-protein coupled receptors (GPCRs) that signal through Gα12. Glioma stem cell lines from patient-derived xenografts also showed elevated levels of Gα12. Knockdown (KD) of Gα12 was carried out in two different human GBM stem cell (GSC) lines. Tumors generated in vivo by orthotopic injection of Gα12KD GSC cells showed reduced invasiveness, without apparent changes in tumor size or survival relative to control GSC tumor-bearing mice. Transcriptional profiling of GSC-23 cell tumors revealed significant differences between WT and Gα12KD tumors including reduced expression of genes associated with the extracellular matrix, as well as decreased expression of stem cell genes and increased expression of several proneural genes. Thrombospondin-1 (THBS1), one of the genes most repressed by Gα12 knockdown, was shown to be required for Gα12-mediated cell migration in vitro and for in vivo tumor invasion. Chemogenetic activation of GSC-23 cells harboring a Gα12-coupled DREADD also increased THBS1 expression and in vitro invasion. Collectively, our findings implicate Gα12 signaling in regulation of transcriptional reprogramming that promotes invasiveness, highlighting this as a potential signaling node for therapeutic intervention.
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Affiliation(s)
- Olga Meiri Chaim
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA.
- Department of Cell Biology, Federal University of Paraná, Curitiba, Brazil.
| | - Shunichiro Miki
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA
| | - Briana C Prager
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
- Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH, USA
| | - Jianhui Ma
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA
| | - Anthony Y Jeong
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA
| | - Jacqueline Lara
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA
| | - Nancy K Tran
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA
| | - Jeffrey M Smith
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA
| | - Jeremy N Rich
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
- UPMC Hillman Cancer Center, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - J Silvio Gutkind
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA
- Moores Cancer Center, University of California at San Diego, La Jolla, CA, USA
| | - Shigeki Miyamoto
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA
| | - Frank B Furnari
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA
| | - Joan Heller Brown
- Department of Pharmacology, University of California San Diego, Biomedical Sciences Building, 9500 Gilman Drive #0636, La Jolla, CA, 92093-0636, USA
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Rasheed SAK, Subramanyan LV, Lim WK, Udayappan UK, Wang M, Casey PJ. The emerging roles of Gα12/13 proteins on the hallmarks of cancer in solid tumors. Oncogene 2022; 41:147-158. [PMID: 34689178 PMCID: PMC8732267 DOI: 10.1038/s41388-021-02069-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 09/28/2021] [Accepted: 10/06/2021] [Indexed: 01/14/2023]
Abstract
G12 proteins comprise a subfamily of G-alpha subunits of heterotrimeric GTP-binding proteins (G proteins) that link specific cell surface G protein-coupled receptors (GPCRs) to downstream signaling molecules and play important roles in human physiology. The G12 subfamily contains two family members: Gα12 and Gα13 (encoded by the GNA12 and GNA13 genes, respectively) and, as with all G proteins, their activity is regulated by their ability to bind to guanine nucleotides. Increased expression of both Gα12 and Gα13, and their enhanced signaling, has been associated with tumorigenesis and tumor progression of multiple cancer types over the past decade. Despite these strong associations, Gα12/13 proteins are underappreciated in the field of cancer. As our understanding of G protein involvement in oncogenic signaling has evolved, it has become clear that Gα12/13 signaling is pleotropic and activates specific downstream effectors in different tumor types. Further, the expression of Gα12/13 proteins is regulated through a series of transcriptional and post-transcriptional mechanisms, several of which are frequently deregulated in cancer. With the ever-increasing understanding of tumorigenic processes driven by Gα12/13 proteins, it is becoming clear that targeting Gα12/13 signaling in a context-specific manner could provide a new strategy to improve therapeutic outcomes in a number of solid tumors. In this review, we detail how Gα12/13 proteins, which were first discovered as proto-oncogenes, are now known to drive several "classical" hallmarks, and also play important roles in the "emerging" hallmarks, of cancer.
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Affiliation(s)
| | | | - Wei Kiang Lim
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, 169857, Singapore
| | - Udhaya Kumari Udayappan
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, 169857, Singapore
| | - Mei Wang
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, 169857, Singapore
| | - Patrick J Casey
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, 169857, Singapore.
- Dept. of Pharmacology and Cancer Biology, Duke Univ. Medical Center, Durham, NC, 27710, USA.
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Martin TD, Patel RS, Cook DR, Choi MY, Patil A, Liang AC, Li MZ, Haigis KM, Elledge SJ. The adaptive immune system is a major driver of selection for tumor suppressor gene inactivation. Science 2021; 373:1327-1335. [PMID: 34529489 DOI: 10.1126/science.abg5784] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During tumorigenesis, tumors must evolve to evade the immune system and do so by disrupting the genes involved in antigen processing and presentation or up-regulating inhibitory immune checkpoint genes. We performed in vivo CRISPR screens in syngeneic mouse tumor models to examine requirements for tumorigenesis both with and without adaptive immune selective pressure. In each tumor type tested, we found a marked enrichment for the loss of tumor suppressor genes (TSGs) in the presence of an adaptive immune system relative to immunocompromised mice. Nearly one-third of TSGs showed preferential enrichment, often in a cancer- and tissue-specific manner. These results suggest that clonal selection of recurrent mutations found in cancer is driven largely by the tumor’s requirement to avoid the adaptive immune system.
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MESH Headings
- Animals
- CRISPR-Cas Systems
- Carcinogenesis
- Cell Line, Tumor
- Chemokine CCL2/metabolism
- Female
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- Gene Silencing
- Genes, Tumor Suppressor
- Humans
- Immune Evasion/genetics
- Mammary Neoplasms, Experimental/genetics
- Mammary Neoplasms, Experimental/immunology
- Mammary Neoplasms, Experimental/pathology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, SCID
- Neoplasm Transplantation
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/immunology
- Neoplasms, Experimental/pathology
- Selection, Genetic
- Tumor Microenvironment
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Affiliation(s)
- Timothy D Martin
- Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Rupesh S Patel
- Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Danielle R Cook
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Mei Yuk Choi
- Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Ajinkya Patil
- Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Anthony C Liang
- Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Mamie Z Li
- Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Kevin M Haigis
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Stephen J Elledge
- Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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Zhang T, Shen Y, Guo Y, Yao J. Identification of key transcriptome biomarkers based on a vital gene module associated with pathological changes in Alzheimer's disease. Aging (Albany NY) 2021; 13:14940-14967. [PMID: 34031265 PMCID: PMC8221319 DOI: 10.18632/aging.203017] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 04/05/2021] [Indexed: 12/22/2022]
Abstract
Dysregulation of transcriptome expression has been reported to play an increasingly significant role in AD. In this study, we firstly identified a vital gene module associated with the accumulation of β-amyloid (Aβ) and phosphorylated tau (p-tau) using the WGCNA method. The vital module, named target module, was then employed for the identification of key transcriptome biomarkers. For coding RNA, GNA13 and GJA1 were identified as key biomarkers based on ROC analysis. As for non-coding RNA, MEG3, miR-106a-3p, and miR-24-3p were determined as key biomarkers based on analysis of a ceRNA network and ROC analysis. Experimental analyses firstly confirmed that GNA13, GJA1, and ROCK2, a downstream effector of GNA13, were all increased in 5XFAD mice, compared to littermate mice. Moreover, their expression was increased with aging in 5XFAD mice, as Aβ and p-tau pathology developed. Besides, the expression of key ncRNA biomarkers was verified to be decreased in 5XFAD mice. GSEA results indicated that GNA13 and GJA1 were respectively involved in ribosome and spliceosome dysfunction. MEG3, miR-106a-3p, and miR-24-3p were identified to be involved in MAPK pathway and PI3K-Akt pathway based on enrichment analysis. In summary, we identified several key transcriptome biomarkers, which promoted the prediction and diagnosis of AD.
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Affiliation(s)
- Tong Zhang
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yang Shen
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yiqing Guo
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Junyan Yao
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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5
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Xu Z, Liang Y, Delaney MK, Zhang Y, Kim K, Li J, Bai Y, Cho J, Ushio-Fukai M, Cheng N, Du X. Shear and Integrin Outside-In Signaling Activate NADPH-Oxidase 2 to Promote Platelet Activation. Arterioscler Thromb Vasc Biol 2021; 41:1638-1653. [PMID: 33691478 PMCID: PMC8057529 DOI: 10.1161/atvbaha.120.315773] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 03/01/2021] [Indexed: 11/18/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Zheng Xu
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
| | - Ying Liang
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
| | - M. Keegan Delaney
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
- Dupage Medical Technology, Inc (M.K.D.)
| | - Yaping Zhang
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
| | - Kyungho Kim
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
- Korean Medicine-Application Center, Korea Institute of Oriental Medicine, Daegu (K.K.)
| | - Jing Li
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
| | - Yanyan Bai
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
| | - Jaehyung Cho
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
| | - Masuko Ushio-Fukai
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
- Department of Medicine (Cardiology), Vascular Biology Center, Medical College of Georgia at Augusta University (M.U.-F.)
| | - Ni Cheng
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
| | - Xiaoping Du
- Department of Pharmacology, University of Illinois at Chicago (Z.X., Y.L., M.K.D., Y.Z., K.K., J.L., Y.B., J.C., M.U.-F., N.C., X.D.)
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Mosquera Orgueira A, Ferreiro Ferro R, Díaz Arias JÁ, Aliste Santos C, Antelo Rodríguez B, Bao Pérez L, Alonso Vence N, Bendaña López Á, Abuin Blanco A, Melero Valentín P, Peleteiro Raindo A, Cid López M, Pérez Encinas MM, González Pérez MS, Fraga Rodríguez MF, Bello López JL. Detection of new drivers of frequent B-cell lymphoid neoplasms using an integrated analysis of whole genomes. PLoS One 2021; 16:e0248886. [PMID: 33945543 PMCID: PMC8096002 DOI: 10.1371/journal.pone.0248886] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 01/19/2021] [Indexed: 12/21/2022] Open
Abstract
B-cell lymphoproliferative disorders exhibit a diverse spectrum of diagnostic entities with heterogeneous behaviour. Multiple efforts have focused on the determination of the genomic drivers of B-cell lymphoma subtypes. In the meantime, the aggregation of diverse tumors in pan-cancer genomic studies has become a useful tool to detect new driver genes, while enabling the comparison of mutational patterns across tumors. Here we present an integrated analysis of 354 B-cell lymphoid disorders. 112 recurrently mutated genes were discovered, of which KMT2D, CREBBP, IGLL5 and BCL2 were the most frequent, and 31 genes were putative new drivers. Mutations in CREBBP, TNFRSF14 and KMT2D predominated in follicular lymphoma, whereas those in BTG2, HTA-A and PIM1 were more frequent in diffuse large B-cell lymphoma. Additionally, we discovered 31 significantly mutated protein networks, reinforcing the role of genes such as CREBBP, EEF1A1, STAT6, GNA13 and TP53, but also pointing towards a myriad of infrequent players in lymphomagenesis. Finally, we report aberrant expression of oncogenes and tumor suppressors associated with novel noncoding mutations (DTX1 and S1PR2), and new recurrent copy number aberrations affecting immune check-point regulators (CD83, PVR) and B-cell specific genes (TNFRSF13C). Our analysis expands the number of mutational drivers of B-cell lymphoid neoplasms, and identifies several differential somatic events between disease subtypes.
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Affiliation(s)
- Adrián Mosquera Orgueira
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
- University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
- * E-mail:
| | - Roi Ferreiro Ferro
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - José Ángel Díaz Arias
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - Carlos Aliste Santos
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Pathology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - Beatriz Antelo Rodríguez
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Pathology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - Laura Bao Pérez
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - Natalia Alonso Vence
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - Ággeles Bendaña López
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
- University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - Aitor Abuin Blanco
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - Paula Melero Valentín
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - And´res Peleteiro Raindo
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
- University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - Miguel Cid López
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
- University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - Manuel Mateo Pérez Encinas
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
- University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - Marta Sonia González Pérez
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - Máximo Francisco Fraga Rodríguez
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
- Department of Pathology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
| | - José Luis Bello López
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain
- Department of Hematology, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, Galicia, Spain
- University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
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7
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Hou L, Zhang Z, Yang L, Chang N, Zhao X, Zhou X, Yang L, Li L. NLRP3 inflammasome priming and activation in cholestatic liver injury via the sphingosine 1-phosphate/S1P receptor 2/Gα (12/13)/MAPK signaling pathway. J Mol Med (Berl) 2021; 99:273-288. [PMID: 33388881 DOI: 10.1007/s00109-020-02032-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 12/04/2020] [Accepted: 12/23/2020] [Indexed: 12/19/2022]
Abstract
NLRP3 inflammasome-driven inflammation represents a key trigger for hepatic fibrogenesis during cholestatic liver injury. However, whether sphingosine 1-phosphate (S1P) plays a role in NLRP3 inflammasome priming and activation remains unknown. Here, we found that the expression of NLRP3 in macrophages and NLRP3 inflammasome activation were significantly elevated in the liver injured by bile duct ligation (BDL). In vitro, S1P promoted the NLRP3 inflammasome priming and activation via S1P receptor 2 (S1PR2) in bone marrow-derived monocyte/macrophages (BMMs). Focusing on BMMs, the gene silencing of Gα12 or Gα13 by specific siRNA suppressed NLRP3 inflammasome priming and pro-inflammatory cytokine (IL-1β and IL-18) secretion, whereas Gα(i/o) and Gαq were not involved in this process. The MAPK signaling pathways (P38, ERK, and JNK) mediated NLRP3 inflammasome priming and IL-1β and IL-18 secretion, whereas blockage of PI3K, ROCK, and Rho family had no such effect. Moreover, JTE-013 (S1PR2 inhibitor) treatment markedly reduced NLRP3 inflammasome priming and activation in BDL-injured liver. Collectively, S1P promotes NLRP3 inflammasome priming and pro-inflammatory cytokines (IL-1β and IL-18) secretion via the S1PR2/Gα(12/13)/MAPK pathway, which may represent an effective therapeutic strategy for liver disease. KEY MESSAGE: • Hepatic NLRP3 expression was significantly elevated in BMMs of BDL-injured mouse liver. • S1P promoted NLRP3 inflammasome priming and activation in BMMs, depending on the S1PR2/Gα(12/13)/MAPK pathway. • Blockade of S1PR2 by JTE-013 reduced NLRP3 inflammasome priming and activation inflammasome in vivo.
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Affiliation(s)
- Lei Hou
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China
| | - Zhi Zhang
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China
| | - Le Yang
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China
| | - Na Chang
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China
| | - Xinhao Zhao
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China
| | - Xuan Zhou
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China
| | - Lin Yang
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China
| | - Liying Li
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing, 100069, China.
- , Beijing, China.
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8
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Maziarz M, Federico A, Zhao J, Dujmusic L, Zhao Z, Monti S, Varelas X, Garcia-Marcos M. Naturally occurring hotspot cancer mutations in Gα 13 promote oncogenic signaling. J Biol Chem 2020; 295:16897-16904. [PMID: 33109615 PMCID: PMC7864081 DOI: 10.1074/jbc.ac120.014698] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 10/07/2020] [Indexed: 12/15/2022] Open
Abstract
Heterotrimeric G-proteins are signaling switches broadly divided into four families based on the sequence and functional similarity of their Gα subunits: Gs, Gi/o, Gq/11, and G12/13 Artificial mutations that activate Gα subunits of each of these families have long been known to induce oncogenic transformation in experimental systems. With the advent of next-generation sequencing, activating hotspot mutations in Gs, Gi/o, or Gq/11 proteins have also been identified in patient tumor samples. In contrast, patient tumor-associated G12/13 mutations characterized to date lead to inactivation rather than activation. By using bioinformatic pathway analysis and signaling assays, here we identified cancer-associated hotspot mutations in Arg-200 of Gα13 (encoded by GNA13) as potent activators of oncogenic signaling. First, we found that components of a G12/13-dependent signaling cascade that culminates in activation of the Hippo pathway effectors YAP and TAZ is frequently altered in bladder cancer. Up-regulation of this signaling cascade correlates with increased YAP/TAZ activation transcriptional signatures in this cancer type. Among the G12/13 pathway alterations were mutations in Arg-200 of Gα13, which we validated to promote YAP/TAZ-dependent (TEAD) and MRTF-A/B-dependent (SRE.L) transcriptional activity. We further showed that this mechanism relies on the same RhoGEF-RhoGTPase cascade components that are up-regulated in bladder cancers. Moreover, Gα13 Arg-200 mutants induced oncogenic transformation in vitro as determined by focus formation assays. In summary, our findings on Gα13 mutants establish that naturally occurring hotspot mutations in Gα subunits of any of the four families of heterotrimeric G-proteins are putative cancer drivers.
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Affiliation(s)
- Marcin Maziarz
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Anthony Federico
- Section of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Jingyi Zhao
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Lorena Dujmusic
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Zhiming Zhao
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Stefano Monti
- Section of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Xaralabos Varelas
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Mikel Garcia-Marcos
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA.
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9
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Mathiasen S, Palmisano T, Perry NA, Stoveken HM, Vizurraga A, McEwen DP, Okashah N, Langenhan T, Inoue A, Lambert NA, Tall GG, Javitch JA. G12/13 is activated by acute tethered agonist exposure in the adhesion GPCR ADGRL3. Nat Chem Biol 2020; 16:1343-1350. [PMID: 32778842 PMCID: PMC7990041 DOI: 10.1038/s41589-020-0617-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 07/08/2020] [Indexed: 02/06/2023]
Abstract
The adhesion G-protein-coupled receptor (GPCR) latrophilin 3 (ADGRL3) has been associated with increased risk of attention deficit hyperactivity disorder (ADHD) and substance use in human genetic studies. Knockdown in multiple species leads to hyperlocomotion and altered dopamine signaling. Thus, ADGRL3 is a potential target for treatment of neuropsychiatric disorders that involve dopamine dysfunction, but its basic signaling properties are poorly understood. Identification of adhesion GPCR signaling partners has been limited by a lack of tools to acutely activate these receptors in living cells. Here, we design a novel acute activation strategy to characterize ADGRL3 signaling by engineering a receptor construct in which we could trigger acute activation enzymatically. Using this assay, we found that ADGRL3 signals through G12/G13 and Gq, with G12/13 the most robustly activated. Gα12/13 is a new player in ADGRL3 biology, opening up unexplored roles for ADGRL3 in the brain. Our methodological advancements should be broadly useful in adhesion GPCR research.
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MESH Headings
- Activating Transcription Factor 6/agonists
- Activating Transcription Factor 6/chemistry
- Activating Transcription Factor 6/genetics
- Activating Transcription Factor 6/metabolism
- Animals
- Arrestin/chemistry
- Arrestin/genetics
- Arrestin/metabolism
- CRISPR-Cas Systems
- Cell Engineering
- GTP-Binding Protein alpha Subunits, G12-G13/chemistry
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/chemistry
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Gene Expression
- HEK293 Cells
- Humans
- Kinetics
- Mice
- Mitogen-Activated Protein Kinase 1/chemistry
- Mitogen-Activated Protein Kinase 1/genetics
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/chemistry
- Mitogen-Activated Protein Kinase 3/genetics
- Mitogen-Activated Protein Kinase 3/metabolism
- Peptides/chemistry
- Peptides/metabolism
- Peptides/pharmacology
- Protein Binding
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Peptide/chemistry
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Signal Transduction
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Affiliation(s)
- Signe Mathiasen
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA
| | - Tiago Palmisano
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA
| | - Nicole A Perry
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA
| | - Hannah M Stoveken
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Alex Vizurraga
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Dyke P McEwen
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Najeah Okashah
- Department of Pharmacology and Toxicology, Augusta University Medical College of Georgia, Augusta, GA, USA
| | - Tobias Langenhan
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Nevin A Lambert
- Department of Pharmacology and Toxicology, Augusta University Medical College of Georgia, Augusta, GA, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Jonathan A Javitch
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA.
- Department of Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
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10
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Xiang B, Yang J, Zhang J, Yu M, Huang C, He W, Lei W, Chen J, Liu K. The role of genes affected by human evolution marker GNA13 in schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2020; 98:109764. [PMID: 31676466 DOI: 10.1016/j.pnpbp.2019.109764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/04/2019] [Accepted: 09/20/2019] [Indexed: 11/20/2022]
Abstract
Numerous variants associated with increased risk for SCZ have undergone positive selection and were associated with human brain development, but which brain regions and developmental stages were influenced by the positive selection for SCZ risk alleles are unclear. We analyzed SCZ using summary statistics from a genome-wide association study (GWAS) from the Psychiatric Genomics Consortium (PGC). Machine-learning scores were used to investigate two natural-selection scenarios: complete selection (loci where a selected allele has reached fixation) and incomplete selection (loci where a selected allele has not yet reached fixation). Based on the p value of single nucleotide polymorphisms (SNPs) with selection scores in the top 5%, we formed five subgroups: p < 0.0001, 0.001, 0.01, 0.05, or 0.1. We found that 48 and 29 genes (p < 0.0001) in complete and incomplete selection, respectively, were enrichedfor the transcriptionalco-expressionprofilein theprenatal dorsolateral prefrontal cortex (DFC), inferior parietal cortex (IPC), and ventrolateral prefrontal cortex (VFC). Core genes (GNA13, TBC1D19, and ZMYM4) involved in regulating early brain development were identified in these three brain regions. RNA sequencing for primary cortical neurons that were transfected Gna13 overexpressed lentivirus demonstrated that 135 gene expression levels changed in the Gna13 overexpressed groups compared with the controls. Gene-set analysis identified important associations among common variants of these 13 genes, which were associated with neurodevelopment and putamen volume [p = 0.031; family-wise error correction (FWEC)], SCZ (p = 0.022; FWEC). The study indicate that certain SCZ risk alleles were likely to undergo positive selection during human evolution due to their involvement in the development of prenatal DFC, IPC and VFC, and suggest that SCZ is related to abnormal neurodevelopment.
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Affiliation(s)
- Bo Xiang
- Department of Psychiatry, Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China.
| | - Juanjuan Yang
- Department of cell Biology, School of Biology and Basic Medical, Soochow University, Suzhou, Jiangsu Province, China
| | - Jin Zhang
- Department of Psychiatry, Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Minglan Yu
- Medical Laboratory Center, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Chaohua Huang
- Department of Psychiatry, Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Wenying He
- Department of Psychiatry, Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Wei Lei
- Department of Psychiatry, Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Jing Chen
- Department of Psychiatry, Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Kezhi Liu
- Department of Psychiatry, Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China.
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Hendrickx G, Boudin E, Verbeek M, Fransen E, Mortier G, Van Hul W. WNT16 Requires Gα Subunits as Intracellular Partners for Both Its Canonical and Non-Canonical WNT Signalling Activity in Osteoblasts. Calcif Tissue Int 2020; 106:294-302. [PMID: 31760436 DOI: 10.1007/s00223-019-00633-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/11/2019] [Indexed: 01/08/2023]
Abstract
In the past years, WNT16 became an interesting target in the field of skeletal research, as it was identified as an essential regulator of the cortical bone compartment, with the ability to increase both cortical and trabecular bone mass and strength in vivo. Even though there are indications that these advantageous effects are coming from canonical and non-canonical WNT-signalling activity, a clear model of WNT signalling by WNT16 is not yet depicted. We, therefore, investigated the modulation of canonical (WNT/β-catenin) and non-canonical [WNT/calcium, WNT/planar cell polarity (PCP)] signalling in human embryonic kidney (HEK) 293 T and SaOS2 cells. Here, we demonstrated that WNT16 activates all WNT-signalling pathways in osteoblasts, whereas only WNT/calcium signalling was activated in HEK293T cells. In osteoblasts, we therefore, additionally investigated the role of Gα subunits as intracellular partners in WNT16's mechanism of action by performing knockdown of Gα12, Gα13 and Gαq. These studies point out that the above-mentioned Gα subunits might be involved in the WNT/β-catenin and WNT/calcium-signalling activity by WNT16 in osteoblasts, and for Gα12 in its WNT/PCP-signalling activity, illustrating a novel possible mechanism of interplay between the different WNT-signalling pathways in osteoblasts. Additional studies are needed to demonstrate whether this mechanism is specific for WNT16 signalling or relevant for all other WNT ligands as well. Altogether, we further defined WNT16's mechanism of action in osteoblasts that might underlie the well-known beneficial effects of WNT16 on skeletal homeostasis. These findings on WNT16 and the activity of specific Gα subunits in osteoblasts could definitely contribute to the development of novel therapeutic approaches for fragility fractures in the future.
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Affiliation(s)
- Gretl Hendrickx
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Marinus Verbeek
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Erik Fransen
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Geert Mortier
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium.
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium.
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12
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Nakano S, Inoue K, Xu C, Deng Z, Syrovatkina V, Vitone G, Zhao L, Huang XY, Zhao B. G-protein Gα 13 functions as a cytoskeletal and mitochondrial regulator to restrain osteoclast function. Sci Rep 2019; 9:4236. [PMID: 30862896 PMCID: PMC6414604 DOI: 10.1038/s41598-019-40974-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 02/19/2019] [Indexed: 12/13/2022] Open
Abstract
Excessive osteoclastic bone erosion disrupts normal bone remodeling and leads to bone loss in many skeletal diseases, including inflammatory arthritis, such as rheumatoid arthritis (RA) and psoriatic arthritis, periodontitis and peri-prosthetic loosening. Functional control of osteoclasts is critical for the maintenance of bone homeostasis. However, the mechanisms that restrain osteoclast resorptive function are not fully understood. In this study, we identify a previously unrecognized role for G-protein Gα13 in inhibition of osteoclast adhesion, fusion and bone resorptive function. Gα13 is highly expressed in mature multinucleated osteoclasts, but not during early differentiation. Deficiency of Gα13 in myeloid osteoclast lineage (Gα13ΔM/ΔM mice) leads to super spread morphology of multinucleated giant osteoclasts with elevated bone resorptive capacity, corroborated with an osteoporotic bone phenotype in the Gα13ΔM/ΔM mice. Mechanistically, Gα13 functions as a brake that restrains the c-Src, Pyk2, RhoA-Rock2 mediated signaling pathways and related gene expressions to control the ability of osteoclasts in fusion, adhesion, actin cytoskeletal remodeling and resorption. Genome wide analysis reveals cytoskeleton related genes that are suppressed by Gα13, identifying Gα13 as a critical cytoskeletal regulator in osteoclasts. We also identify a genome wide regulation of genes responsible for mitochondrial biogenesis and function by Gα13 in osteoclasts. Furthermore, the significant correlation between Gα13 expression levels, TNF activity and RA disease activity in RA patients suggests that the Gα13 mediated mechanisms represent attractive therapeutic targets for diseases associated with excessive bone resorption.
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Affiliation(s)
- Shinichi Nakano
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
| | - Kazuki Inoue
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Cheng Xu
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
| | - Zhonghao Deng
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
- Department of Orthopedic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Viktoriya Syrovatkina
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
| | - Gregory Vitone
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
| | - Liang Zhao
- Department of Orthopedic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xin-Yun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
| | - Baohong Zhao
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA.
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA.
- Graduate Program in Cell & Developmental Biology, Weill Cornell Graduate School of Medical Sciences, New York, New York, USA.
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13
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Guo X, Riobo-Del Galdo NA, Kim EJ, Grant GR, Manning DR. Overlap in signaling between Smoothened and the α subunit of the heterotrimeric G protein G13. PLoS One 2018; 13:e0197442. [PMID: 29763457 PMCID: PMC5953476 DOI: 10.1371/journal.pone.0197442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/02/2018] [Indexed: 01/20/2023] Open
Abstract
The Hedgehog family of morphogens has long been known to utilize, through the 7-transmembrane protein Smoothened (Smo), the heterotrimeric G protein Gi in both canonical and noncanonical forms of signaling. Other G proteins, while not specifically utilized by Smo, may nonetheless provide access to some of the events controlled by it. We reported several years ago that the G protein G13 activates one or more forms of the Gli family of transcription factors. While the Gli transcription factors are well known targets for Smo, the uncertain mechanism of activation by G13 and the identity of the targeted Gli(s) limited predictions as to the extent to which G13 might mimic Smo's actions. We evaluate here the potential for overlap in G13 and Smo signaling using C3H10T1/2 and 3T3-L1 cells as models of osteogenesis and adipogenesis, respectively. We find in C3H10T1/2 cells that a constitutively active form of Gα13 (Gα13QL) increases Gli1 mRNA, as does a constitutively active form of Smo (SmoA1). We find as well that Gα13QL induces alkaline phosphatase activity, a marker of osteogenesis, albeit the induction is far less substantial than that achieved by SmoA1. In 3T3-L1 cells both Gα13QL and SmoA1 markedly suppress adipogenic differentiation as determined by triglyceride accumulation. RNA sequencing reveals that Gα13QL and SmoA1 regulate many of the same genes but that quantitative and qualitative differences exist. Differences also exist, we find, between SmoA1 and purmorphamine, an agonist for Smo. Therefore, while comparisons of constitutively active proteins are informative, extrapolations to the setting of agonists require care.
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Affiliation(s)
- Xueshui Guo
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Natalia A. Riobo-Del Galdo
- Leeds Institute of Cancer and Pathology and School of Molecular and Cellular Biology, University of Leeds, United Kingdom
| | - Eun Ji Kim
- Institute of Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gregory R. Grant
- Institute of Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - David R. Manning
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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14
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Yoo EJ, Cao G, Koziol‐White CJ, Ojiaku CA, Sunder K, Jude JA, Michael JV, Lam H, Pushkarsky I, Damoiseaux R, Di Carlo D, Ahn K, An SS, Penn RB, Panettieri RA. Gα 12 facilitates shortening in human airway smooth muscle by modulating phosphoinositide 3-kinase-mediated activation in a RhoA-dependent manner. Br J Pharmacol 2017; 174:4383-4395. [PMID: 28921504 PMCID: PMC5715591 DOI: 10.1111/bph.14040] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 09/12/2017] [Accepted: 09/12/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND AND PURPOSE PI3K-dependent activation of Rho kinase (ROCK) is necessary for agonist-induced human airway smooth muscle cell (HASMC) contraction, and inhibition of PI3K promotes bronchodilation of human small airways. The mechanisms driving agonist-mediated PI3K/ROCK axis activation, however, remain unclear. Given that G12 family proteins activate ROCK pathways in other cell types, their role in M3 muscarinic acetylcholine receptor-stimulated PI3K/ROCK activation and contraction was examined. EXPERIMENTAL APPROACH Gα12 coupling was evaluated using co-immunoprecipitation and serum response element (SRE)-luciferase reporter assays. siRNA and pharmacological approaches, as well as overexpression of a regulator of G-protein signaling (RGS) proteins were applied in HASMCs. Phosphorylation levels of Akt, myosin phosphatase targeting subunit-1 (MYPT1), and myosin light chain-20 (MLC) were measured. Contraction and shortening were evaluated using magnetic twisting cytometry (MTC) and micro-pattern deformation, respectively. Human precision-cut lung slices (hPCLS) were utilized to evaluate bronchoconstriction. KEY RESULTS Knockdown of M3 receptors or Gα12 attenuated activation of Akt, MYPT1, and MLC phosphorylation. Gα12 coimmunoprecipitated with M3 receptors, and p115RhoGEF-RGS overexpression inhibited carbachol-mediated induction of SRE-luciferase reporter. p115RhoGEF-RGS overexpression inhibited carbachol-induced activation of Akt, HASMC contraction, and shortening. Moreover, inhibition of RhoA blunted activation of PI3K. Lastly, RhoA inhibitors induced dilation of hPCLS. CONCLUSIONS AND IMPLICATIONS Gα12 plays a crucial role in HASMC contraction via RhoA-dependent activation of the PI3K/ROCK axis. Inhibition of RhoA activation induces bronchodilation in hPCLS, and targeting Gα12 signaling may elucidate novel therapeutic targets in asthma. These findings provide alternative approaches to the clinical management of airway obstruction in asthma.
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Affiliation(s)
- Edwin J Yoo
- Rutgers Institute for Translational Medicine and Science, Child Health InstituteRutgers UniversityNew BrunswickNJUSA
| | - Gaoyuan Cao
- Rutgers Institute for Translational Medicine and Science, Child Health InstituteRutgers UniversityNew BrunswickNJUSA
| | - Cynthia J Koziol‐White
- Rutgers Institute for Translational Medicine and Science, Child Health InstituteRutgers UniversityNew BrunswickNJUSA
| | - Christie A Ojiaku
- Rutgers Institute for Translational Medicine and Science, Child Health InstituteRutgers UniversityNew BrunswickNJUSA
| | - Krishna Sunder
- Rutgers Institute for Translational Medicine and Science, Child Health InstituteRutgers UniversityNew BrunswickNJUSA
| | - Joseph A Jude
- Rutgers Institute for Translational Medicine and Science, Child Health InstituteRutgers UniversityNew BrunswickNJUSA
| | - James V Michael
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Center for Translational Medicine, Jane and Leonard Korman Lung CenterThomas Jefferson UniversityPhiladelphiaPAUSA
| | - Hong Lam
- Department of Environmental Health and EngineeringJohns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA
| | - Ivan Pushkarsky
- Department of BioengineeringUniversity of CaliforniaLos AngelesCAUSA
| | - Robert Damoiseaux
- Department of Molecular and Medicinal PharmacologyUniversity of CaliforniaLos AngelesCAUSA
- California NanoSystems InstituteUniversity of CaliforniaLos AngelesCAUSA
| | - Dino Di Carlo
- Department of BioengineeringUniversity of CaliforniaLos AngelesCAUSA
- California NanoSystems InstituteUniversity of CaliforniaLos AngelesCAUSA
- Department of Mechanical EngineeringUniversity of CaliforniaLos AngelesCAUSA
| | - Kwangmi Ahn
- National Institute of Mental HealthBethesdaMDUSA
| | - Steven S An
- Department of Environmental Health and EngineeringJohns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA
- Department of Chemical and Biomolecular EngineeringJohns Hopkins UniversityBaltimoreMDUSA
| | - Raymond B Penn
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Center for Translational Medicine, Jane and Leonard Korman Lung CenterThomas Jefferson UniversityPhiladelphiaPAUSA
| | - Reynold A Panettieri
- Rutgers Institute for Translational Medicine and Science, Child Health InstituteRutgers UniversityNew BrunswickNJUSA
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15
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Lee HJ, Lee EJ, Seo M. Galpha12 Protects Vascular Endothelial Cells from Serum Withdrawal-Induced Apoptosis through Regulation of miR-155. Yonsei Med J 2016; 57:247-53. [PMID: 26632408 PMCID: PMC4696961 DOI: 10.3349/ymj.2016.57.1.247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 01/15/2023] Open
Abstract
PURPOSE Apoptosis of vascular endothelial cells is a type of endothelial damage that is associated with the pathogenesis of cardiovascular diseases such as atherosclerosis. Heterotrimeric GTP-binding proteins (G proteins), including the alpha 12 subunit of G protein (Gα12), have been found to modulate cellular proliferation, differentiation, and apoptosis of numerous cell types. However, the role of Gα12 in the regulation of apoptosis of vascular cells has not been elucidated. We investigated the role of Gα12 in serum withdrawal-induced apoptosis of human umbilical vein endothelial cells (HUVECs) and its underlying mechanisms. MATERIALS AND METHODS HUVECs were transfected with Gα12 small-interfering RNA (siRNA) to knockdown the endogenous Gα12 expression and were serum-deprived for 6 h to induce apoptosis. The apoptosis of HUVECs were assessed by Western blotting and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The expressions of microRNAs were analyzed by quantitative real-time PCR. RESULTS Knockdown of Gα12 with siRNA augmented the serum withdrawal-induced apoptosis of HUVECs and markedly repressed the expression of microRNA-155 (miR-155). Serum withdrawal-induced apoptosis of HUVECs was inhibited by the overexpression of miR-155 and increased significantly due to the inhibition of miR-155. Notably, the elevation of miR-155 expression prevented increased apoptosis of Gα12-deficient HUVECs. CONCLUSION From these results, we conclude that Gα12 protects HUVECs from serum withdrawal-induced apoptosis by retaining miR-155 expression. This suggests that Gα12 might play a protective role in vascular endothelial cells by regulating the expression of microRNAs.
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Affiliation(s)
- Hyeon Jeong Lee
- Department of Endocrinology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Jig Lee
- Department of Endocrinology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
| | - MiRan Seo
- Severance Hospital Integrative Research Institute for Cerebral & Cardiovascular Disease, Yonsei University College of Medicine, Seoul, Korea.
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16
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Montgomery ER, Temple BRS, Peters KA, Tolbert CE, Booker BK, Martin JW, Hamilton TP, Tagliatela AC, Smolski WC, Rogers SL, Jones AM, Meigs TE. Gα12 structural determinants of Hsp90 interaction are necessary for serum response element-mediated transcriptional activation. Mol Pharmacol 2014; 85:586-97. [PMID: 24435554 PMCID: PMC3965892 DOI: 10.1124/mol.113.088443] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 01/16/2014] [Indexed: 12/31/2022] Open
Abstract
The G12/13 class of heterotrimeric G proteins, comprising the α-subunits Gα12 and Gα13, regulates multiple aspects of cellular behavior, including proliferation and cytoskeletal rearrangements. Although guanine nucleotide exchange factors for the monomeric G protein Rho (RhoGEFs) are well characterized as effectors of this G protein class, a variety of other downstream targets has been reported. To identify Gα12 determinants that mediate specific protein interactions, we used a structural and evolutionary comparison between the G12/13, Gs, Gi, and Gq classes to identify "class-distinctive" residues in Gα12 and Gα13. Mutation of these residues in Gα12 to their deduced ancestral forms revealed a subset necessary for activation of serum response element (SRE)-mediated transcription, a G12/13-stimulated pathway implicated in cell proliferative signaling. Unexpectedly, this subset of Gα12 mutants showed impaired binding to heat-shock protein 90 (Hsp90) while retaining binding to RhoGEFs. Corresponding mutants of Gα13 exhibited robust SRE activation, suggesting a Gα12-specific mechanism, and inhibition of Hsp90 by geldanamycin or small interfering RNA-mediated lowering of Hsp90 levels resulted in greater downregulation of Gα12 than Gα13 signaling in SRE activation experiments. Furthermore, the Drosophila G12/13 homolog Concertina was unable to signal to SRE in mammalian cells, and Gα12:Concertina chimeras revealed Gα12-specific determinants of SRE activation within the switch regions and a C-terminal region. These findings identify Gα12 determinants of SRE activation, implicate Gα12:Hsp90 interaction in this signaling mechanism, and illuminate structural features that arose during evolution of Gα12 and Gα13 to allow bifurcated mechanisms of signaling to a common cell proliferative pathway.
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Affiliation(s)
- Ellyn R Montgomery
- Department of Biology, University of North Carolina at Asheville, Asheville, North Carolina (E.R.M., B.K.B., J.W.M., T.P.H., A.C.T., W.C.S., T.E.M.); Departments of Biology (K.A.P., S.L.R., A.M.J.), Biochemistry and Biophysics (B.R.S.T.), Cell Biology and Physiology (C.E.T.), and Pharmacology (A.M.J.), R. L. Juliano Structural Bioinformatics Core Facility (B.R.S.T.), and Carolina Center for Genome Sciences (S.L.R.), University of North Carolina, and the Lineberger Comprehensive Cancer Center, (S.L.R., T.E.M.), Chapel Hill, North Carolina
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17
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Kempf A, Tews B, Arzt ME, Weinmann O, Obermair FJ, Pernet V, Zagrebelsky M, Delekate A, Iobbi C, Zemmar A, Ristic Z, Gullo M, Spies P, Dodd D, Gygax D, Korte M, Schwab ME. The sphingolipid receptor S1PR2 is a receptor for Nogo-a repressing synaptic plasticity. PLoS Biol 2014; 12:e1001763. [PMID: 24453941 PMCID: PMC3891622 DOI: 10.1371/journal.pbio.1001763] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 12/02/2013] [Indexed: 01/11/2023] Open
Abstract
This study identifies a GPCR, S1PR2, as a receptor for the Nogo-A-Δ20 domain of the membrane protein Nogo-A, which inhibits neuronal growth and synaptic plasticity. Nogo-A is a membrane protein of the central nervous system (CNS) restricting neurite growth and synaptic plasticity via two extracellular domains: Nogo-66 and Nogo-A-Δ20. Receptors transducing Nogo-A-Δ20 signaling remained elusive so far. Here we identify the G protein-coupled receptor (GPCR) sphingosine 1-phosphate receptor 2 (S1PR2) as a Nogo-A-Δ20-specific receptor. Nogo-A-Δ20 binds S1PR2 on sites distinct from the pocket of the sphingolipid sphingosine 1-phosphate (S1P) and signals via the G protein G13, the Rho GEF LARG, and RhoA. Deleting or blocking S1PR2 counteracts Nogo-A-Δ20- and myelin-mediated inhibition of neurite outgrowth and cell spreading. Blockade of S1PR2 strongly enhances long-term potentiation (LTP) in the hippocampus of wild-type but not Nogo-A−/− mice, indicating a repressor function of the Nogo-A/S1PR2 axis in synaptic plasticity. A similar increase in LTP was also observed in the motor cortex after S1PR2 blockade. We propose a novel signaling model in which a GPCR functions as a receptor for two structurally unrelated ligands, a membrane protein and a sphingolipid. Elucidating Nogo-A/S1PR2 signaling platforms will provide new insights into regulation of synaptic plasticity. Recent studies have demonstrated an important role of Nogo-A signaling in the repression of structural and synaptic plasticity in mature neuronal networks of the central nervous system. These insights extended our understanding of Nogo-A's inhibitory function far beyond its well-studied role as axonal-growth inhibitor. Repression is mediated via two different Nogo-A extracellular domains: Nogo-66 and Nogo-A-Δ20. Here, we identify the G-protein coupled receptor S1PR2 as a high-affinity receptor for Nogo-A-Δ20 and demonstrate that S1PR2 binds this domain with sites different from the recently proposed S1P binding pocket. Interfering with S1PR2 activity, either pharmacologically or genetically, prevented Nogo-A-Δ20-mediated inhibitory effects. Similar results were obtained when we blocked G13, LARG, and RhoA, components of the downstream signaling pathway. These findings revealed a strong increase in hippocampal and cortical synaptic plasticity when acutely interfering with Nogo-A/S1PR2 signaling, similar to previous results obtained by blocking Nogo-A. We thus provide a novel biological concept of multi-ligand GPCR signaling in which this sphingolipid-activated GPCR is also bound and activated by the high molecular weight membrane protein Nogo-A.
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Affiliation(s)
- Anissa Kempf
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Bjoern Tews
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Michael E. Arzt
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Oliver Weinmann
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Franz J. Obermair
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Vincent Pernet
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Marta Zagrebelsky
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig, Germany
| | - Andrea Delekate
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig, Germany
| | - Cristina Iobbi
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig, Germany
| | - Ajmal Zemmar
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Zorica Ristic
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Miriam Gullo
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Peter Spies
- School of Life Sciences, University of Applied Life Sciences Northwestern Switzerland, Muttenz, Switzerland
| | - Dana Dodd
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Daniel Gygax
- School of Life Sciences, University of Applied Life Sciences Northwestern Switzerland, Muttenz, Switzerland
| | - Martin Korte
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig, Germany
| | - Martin E. Schwab
- Brain Research Institute, University of Zurich, and Dept. of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
- * E-mail:
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18
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Kwon MS, Park BO, Kim HM, Kim S. Leucine-rich repeat-containing G-protein coupled receptor 5/GPR49 activates G12/13-Rho GTPase pathway. Mol Cells 2013; 36:267-72. [PMID: 23912594 PMCID: PMC3887977 DOI: 10.1007/s10059-013-0173-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 06/27/2013] [Accepted: 06/27/2013] [Indexed: 10/26/2022] Open
Abstract
Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5/GPR49) is highly expressed in adult stem cells of various tissues, such as intestine, hair follicles, and stomach. LGR5 is also overexpressed in some colon and ovarian tumors. Recent reports show that R-spondin (RSPO) family ligands bind to and activate LGR5, enhancing canonical Wnt signaling via the interaction with LRP5/6 and Frizzled. The identity of heterotrimeric G-proteins coupled to LGR5, however, remains unclear. Here, we show that Rho GTPase is a downstream target of LGR5. Overexpression of LGR5 induced SRF-RE luciferase activity, a reporter of Rho signaling. RSPOs, ligands for LGR4, LGR5, and LGR6, however, did not induce SRF-RE reporter activity in the presence of LGR5. Consistently, LGR5-induced activity of the SRF-RE reporter was inhibited by Rho inhibitor C3 transferase and RhoA N19 mutant, and knockdown of Gα12/13 genes blocked the reporter activity induced by LGR5. In addition, focal adhesion kinase, NF-κB and c-fos, targets of Rho GTPase, were shown to be regulated by LGR5. Here, we have demonstrated, for the first time, that LGR5 is coupled to the Rho pathway through G12/13 signaling.
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Affiliation(s)
- Mi So Kwon
- Targeted Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon 363-883, Korea
- Biomolecular Science Major, University of Science and Technology, Daejeon 305-350, Korea
| | - Bi-oh Park
- Targeted Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon 363-883, Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
| | - Sunhong Kim
- Targeted Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon 363-883, Korea
- Biomolecular Science Major, University of Science and Technology, Daejeon 305-350, Korea
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19
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Jian SL, Hsieh HY, Liao CT, Yen TC, Nien SW, Cheng AJ, Juang JL. Gα₁₂ drives invasion of oral squamous cell carcinoma through up-regulation of proinflammatory cytokines. PLoS One 2013; 8:e66133. [PMID: 23762476 PMCID: PMC3676329 DOI: 10.1371/journal.pone.0066133] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/01/2013] [Indexed: 11/21/2022] Open
Abstract
Oral squamous cell carcinoma (OSCC) ranks among the top ten most prevalent cancers worldwide. Like most head and neck squamous cell carcinomas (HNSCCs), OSCC is highly inflammatory and aggressive. However, the signaling pathways triggering the activation of its inflammatory processes remain elusive. G protein-coupled receptor signaling regulates the inflammatory response and invasiveness of cancers, but it remains unclear whether Gα12 is a critical player in the inflammatory cytokine pathway during the tumorigenesis of OSCC. This study was undertaken to determine the role of Gα12 signaling in the regulation of proinflammatory cytokines in their mediation of OSCC invasion. We found that both the transcription and protein levels of Gα12 are up-regulated in OSCC tumors. The elevated Gα12 expressions in OSCC patients also correlated with extra-capsular spread, an indicator of tumor invasiveness in HNSCCs. This clinical finding was supported by the studies of overexpression and RNAi knockdown of Gα12 in OSCC cells, which demonstrated that Gα12 promoted tumor cell migration and invasion. To understand how Gα12 modulates OSCC invasiveness, we analyzed key biological processes in microarray data upon depletion of Gα12 and found that cytokine- and other immune-related pathways were severely impaired. Importantly, the mRNA levels of IL-6 and IL-8 proinflammatory cytokines in clinical samples were found to be significantly correlated with the increased Gα12 levels, suggesting a potential role of Gα12 in modulating the IL-6 and IL-8 expressions. Supporting this hypothesis, overexpression or RNAi knockdown of Gα12 in OSCC cell lines both showed that Gα12 positively regulated the mRNA and protein levels of IL-6 and IL-8. Finally, we demonstrated that the Gα12 promotion of tumor cell invasiveness was suppressed by the neutralization of IL-6 and IL-8 in OSCC cells. Together, these findings suggest that Gα12 drives OSCC invasion through the up-regulation of IL-6 and IL-8 cytokines.
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Affiliation(s)
- Shiou-Ling Jian
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Hsin-Yi Hsieh
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Chun-Ta Liao
- Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Tzu-Chen Yen
- Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Shu-Wei Nien
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Ann-Joy Cheng
- Graduate School of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
| | - Jyh-Lyh Juang
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
- Ph.D. Program for Aging, China Medical University, Taichung, Taiwan
- * E-mail:
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20
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Chen Z, Guo L, Hadas J, Gutowski S, Sprang SR, Sternweis PC. Activation of p115-RhoGEF requires direct association of Gα13 and the Dbl homology domain. J Biol Chem 2012; 287:25490-500. [PMID: 22661716 PMCID: PMC3408165 DOI: 10.1074/jbc.m111.333716] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 05/30/2012] [Indexed: 01/05/2023] Open
Abstract
RGS-containing RhoGEFs (RGS-RhoGEFs) represent a direct link between the G(12) class of heterotrimeric G proteins and the monomeric GTPases. In addition to the canonical Dbl homology (DH) and pleckstrin homology domains that carry out the guanine nucleotide exchange factor (GEF) activity toward RhoA, these RhoGEFs also possess RGS homology (RH) domains that interact with activated α subunits of G(12) and G(13). Although the GEF activity of p115-RhoGEF (p115), an RGS-RhoGEF, can be stimulated by Gα(13), the exact mechanism of the stimulation has remained unclear. Using combined studies with small angle x-ray scattering, biochemistry, and mutagenesis, we identify an additional binding site for activated Gα(13) in the DH domain of p115. Small angle x-ray scattering reveals that the helical domain of Gα(13) docks onto the DH domain, opposite to the surface of DH that binds RhoA. Mutation of a single tryptophan residue in the α3b helix of DH reduces binding to activated Gα(13) and ablates the stimulation of p115 by Gα(13). Complementary mutations at the predicted DH-binding site in the αB-αC loop of the helical domain of Gα(13) also affect stimulation of p115 by Gα(13). Although the GAP activity of p115 is not required for stimulation by Gα(13), two hydrophobic motifs in RH outside of the consensus RGS box are critical for this process. Therefore, the binding of Gα(13) to the RH domain facilitates direct association of Gα(13) to the DH domain to regulate its exchange activity. This study provides new insight into the mechanism of regulation of the RGS-RhoGEF and broadens our understanding of G protein signaling.
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Affiliation(s)
- Zhe Chen
- From the Departments of Biochemistry and
| | - Liang Guo
- BioCAT, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, and
| | - Jana Hadas
- Pharmacology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Stephen Gutowski
- Pharmacology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Stephen R. Sprang
- Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, Montana 59812
| | - Paul C. Sternweis
- Pharmacology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
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21
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Obara Y, Ueno S, Yanagihata Y, Nakahata N. Lysophosphatidylinositol causes neurite retraction via GPR55, G13 and RhoA in PC12 cells. PLoS One 2011; 6:e24284. [PMID: 21904624 PMCID: PMC3164175 DOI: 10.1371/journal.pone.0024284] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 08/08/2011] [Indexed: 12/26/2022] Open
Abstract
GPR55 was recently identified as a putative receptor for certain cannabinoids, and lysophosphatidylinositol (LPI). Recently, the role of cannabinoids as GPR55 agonists has been disputed by a number of reports, in part, because studies investigating GPR55 often utilized overexpression systems, such as the GPR55-overexpressing HEK293 cells, which make it difficult to deduce the physiological role of endogenous GPR55. In the present study, we found that PC12 cells, a neural model cell line, express endogenous GPR55, and by using these cells, we were able to examine the role of endogenous GPR55. Although GPR55 mRNA and protein were expressed in PC12 cells, neither CB1 nor CB2 mRNA was expressed in these cells. GPR55 was predominantly localized on the plasma membrane in undifferentiated PC12 cells. However, GPR55 was also localized in the growth cones or the ruffled border in differentiated PC12 cells, suggesting a potential role for GPR55 in the regulation of neurite elongation. LPI increased intracellular Ca2+ concentration and RhoA activity, and induced ERK1/2 phosphorylation, whereas endogenous and synthetic cannabinoids did not, thereby suggesting that cannabinoids are not GPR55 agonists. LPI also caused neurite retraction in a time-dependent manner accompanied by the loss of neurofilament light chain and redistribution of actin in PC12 cells differentiated by NGF. This LPI-induced neurite retraction was found to be Gq-independent and G13-dependent. Furthermore, inactivation of RhoA function via C3 toxin and GPR55 siRNA knockdown prevented LPI-induced neurite retraction. These results suggest that LPI, and not cannabinoids, causes neurite retraction in differentiated PC12 cells via a GPR55, G13 and RhoA signaling pathway.
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Affiliation(s)
- Yutaro Obara
- Department of Cellular Signaling, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
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22
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Hajicek N, Kukimoto-Niino M, Mishima-Tsumagari C, Chow CR, Shirouzu M, Terada T, Patel M, Yokoyama S, Kozasa T. Identification of critical residues in G(alpha)13 for stimulation of p115RhoGEF activity and the structure of the G(alpha)13-p115RhoGEF regulator of G protein signaling homology (RH) domain complex. J Biol Chem 2011; 286:20625-36. [PMID: 21507947 PMCID: PMC3121507 DOI: 10.1074/jbc.m110.201392] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 04/08/2011] [Indexed: 01/28/2023] Open
Abstract
RH-RhoGEFs are a family of guanine nucleotide exchange factors that contain a regulator of G protein signaling homology (RH) domain. The heterotrimeric G protein Gα(13) stimulates the guanine nucleotide exchange factor (GEF) activity of RH-RhoGEFs, leading to activation of RhoA. The mechanism by which Gα(13) stimulates the GEF activity of RH-RhoGEFs, such as p115RhoGEF, has not yet been fully elucidated. Here, specific residues in Gα(13) that mediate activation of p115RhoGEF are identified. Mutation of these residues significantly impairs binding of Gα(13) to p115RhoGEF as well as stimulation of GEF activity. These data suggest that the exchange activity of p115RhoGEF is stimulated allosterically by Gα(13) and not through its interaction with a secondary binding site. A crystal structure of Gα(13) bound to the RH domain of p115RhoGEF is also presented, which differs from a previously crystallized complex with a Gα(13)-Gα(i1) chimera. Taken together, these data provide new insight into the mechanism by which p115RhoGEF is activated by Gα(13).
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Affiliation(s)
- Nicole Hajicek
- Department of Pharmacology, College of Medicine, University of Illinois, Chicago, Illinois 60612, USA
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23
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Tisch D, Kubicek CP, Schmoll M. New insights into the mechanism of light modulated signaling by heterotrimeric G-proteins: ENVOY acts on gna1 and gna3 and adjusts cAMP levels in Trichoderma reesei (Hypocrea jecorina). Fungal Genet Biol 2011; 48:631-40. [PMID: 21220037 PMCID: PMC3082050 DOI: 10.1016/j.fgb.2010.12.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/23/2010] [Accepted: 12/30/2010] [Indexed: 11/26/2022]
Abstract
Sensing of environmental signals is often mediated by G-protein coupled receptors and their cognate heterotrimeric G-proteins. In Trichoderma reesei (Hypocrea jecorina) the signals transmitted via the G-protein alpha subunits GNA1 and GNA3 cause considerable modulation of cellulase transcript levels and the extent of this adjustment is dependent on the light status. We therefore intended to elucidate the underlying mechanism connecting light response and heterotrimeric G-protein signaling. Analysis of double mutant strains showed that constitutive activation of GNA1 or GNA3 in the absence of the PAS/LOV domain protein ENVOY (ENV1) leads to the phenotype of constitutive G-alpha activation in darkness. In light, however the deletion-phenotype of Δenv1 was observed with respect to growth, conidiation and cellulase gene transcription. Additionally deletion of env1 causes decreased intracellular cAMP accumulation, even upon constitutive activation of GNA1 or GNA3. While supplementation of cAMP caused an even more severe growth phenotype of all strains lacking env1 in light, addition of the phosphodiesterase inhibitor caffeine rescued the growth phenotype of these strains. ENV1 is consequently suggested to connect the light response pathway with nutrient signaling by the heterotrimeric G-protein cascade by adjusting transcript levels of gna1 and gna3 and action on cAMP levels - presumably through inhibition of a phosphodiesterase.
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Affiliation(s)
| | | | - Monika Schmoll
- Research Area of Gene Technology and Applied Biochemistry, Institute for Chemical Engineering, Vienna University of Technology, Gumpendorfer Strasse 1a/1665, A-1060 Wien, Austria
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24
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Kim YM, Lim SC, Han CY, Kay HY, Cho IJ, Ki SH, Lee MY, Kwon HM, Lee CH, Kim SG. G(alpha)12/13 induction of CYR61 in association with arteriosclerotic intimal hyperplasia: effect of sphingosine-1-phosphate. Arterioscler Thromb Vasc Biol 2011; 31:861-9. [PMID: 21212405 DOI: 10.1161/atvbaha.110.218552] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Gα(12/13) play a role in oncogenic transformation and tumor growth. Cysteine-rich protein 61 (CYR61) is a growth-factor-inducible angiogenic factor. In view of potential overlapping functions between Gα(12/13) and CYR61, this study investigated the role of these G proteins in CYR61 induction in association with hyperplastic vascular abnormality. METHODS AND RESULTS Overexpression of activated Gα(12) or Gα(13) induced CYR61 expression in vascular smooth muscle cells (VSMCs). Gene knockdown and knockout experiments revealed that sphingosine-1-phosphate (S1P) treatment induced CYR61 via Gα(12/13). JunD/activator protein-1 (AP-1) was identified as a transcription factor required for CYR61 transactivation by S1P. Deficiencies in Gα(12/13) abrogated AP-1 activation and AP-1-mediated CYR61 induction. c-Jun N-terminal kinase was responsible for CYR61 induction. Moreover, deficiencies of Gα(12/13) abolished c-Jun N-terminal kinase-dependent CYR61 induction by S1P. N-acetyl-l-cysteine or NADPH oxidase inhibitor treatment reversed CYR61 induction by S1P, indicating that reactive oxygen species are responsible for this process. The levels of Gα(12/13) were increased within thickened intimas and medias in wire-injured mouse femoral arteries, which was accompanied by simultaneous CYR61 induction. Moreover, Gα(12/13) and CYR61 were costained in the arteriosclerotic lesions immediately adjacent to human tumor tissues. CONCLUSIONS Gα(12/13) regulate AP-1-dependent CYR61 induction in VSMCs and promote VSMC migration, and they are upregulated with CYR61 in arteriosclerotic lesions.
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MESH Headings
- Aged
- Animals
- Arteriosclerosis/genetics
- Arteriosclerosis/metabolism
- Arteriosclerosis/pathology
- Cell Movement
- Cysteine-Rich Protein 61/genetics
- Cysteine-Rich Protein 61/metabolism
- Disease Models, Animal
- Enzyme Activation
- Female
- GTP-Binding Protein alpha Subunits, G12-G13/deficiency
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- HEK293 Cells
- Humans
- Hyperplasia
- JNK Mitogen-Activated Protein Kinases/metabolism
- Lysophospholipids/metabolism
- Male
- Mice
- Mice, Inbred ICR
- Mice, Knockout
- Middle Aged
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Mutation
- NADPH Oxidases/metabolism
- Promoter Regions, Genetic
- Proto-Oncogene Proteins c-jun/metabolism
- RNA Interference
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
- Signal Transduction
- Sphingosine/analogs & derivatives
- Sphingosine/metabolism
- Transcription Factor AP-1/metabolism
- Transfection
- Tunica Intima/metabolism
- Tunica Intima/pathology
- Up-Regulation
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Affiliation(s)
- Young Mi Kim
- Innovative Drug Research Center for Metabolic and Inflammatory Disease, College of Pharmacy and Research Institute of PharmaceuticalSciences, Seoul, South Korea
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Nolan T, Petris E, Müller HM, Cronin A, Catteruccia F, Crisanti A. Analysis of two novel midgut-specific promoters driving transgene expression in Anopheles stephensi mosquitoes. PLoS One 2011; 6:e16471. [PMID: 21326609 PMCID: PMC3033896 DOI: 10.1371/journal.pone.0016471] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 12/17/2010] [Indexed: 01/21/2023] Open
Abstract
Background Tissue-specific promoters controlling the expression of transgenes in Anopheles mosquitoes represent a valuable tool both for studying the interaction between these malaria vectors and the Plasmodium parasites they transmit and for novel malaria control strategies based on developing Plasmodium-refractory mosquitoes by expressing anti-parasitic genes. With this aim we have studied the promoter regions of two genes from the most important malaria vector, Anopheles gambiae, whose expression is strongly induced upon blood feeding. Results We analysed the A. gambiae Antryp1 and G12 genes, which we have shown to be midgut-specific and maximally expressed at 24 hours post-bloodmeal (PBM). Antryp1, required for bloodmeal digestion, encodes one member of a family of 7 trypsin genes. The G12 gene, of unknown function, was previously identified in our laboratory in a screen for genes induced in response to a bloodmeal. We fused 1.1 kb of the upstream regions containing the putative promoter of these genes to reporter genes and transformed these into the Indian malaria vector A. stephensi to see if we could recapitulate the expression pattern of the endogenous genes. Both the Antryp1 and G12 upstream regions were able to drive female-predominant, midgut-specific expression in transgenic mosquitoes. Expression of the Antryp1-driven reporter in transgenic A. stephensi lines was low, undetectable by northern blot analysis, and failed to fully match the induction kinetics of the endogenous Antryp1 gene in A. gambiae. This incomplete conservation of expression suggests either subtle differences in the transcriptional machinery between A. stephensi and A. gambiae or that the upstream region chosen lacked all the control elements. In contrast, the G12 upstream region was able to faithfully reproduce the expression profile of the endogenous A. gambiae gene, showing female midgut specificity in the adult mosquito and massive induction PBM, peaking at 24 hours. Conclusions Our studies on two putative blood-meal induced, midgut-specific promoters validate the use of G12 upstream regulatory regions to drive targeted transgene expression coinciding spatially and temporally with pre-sporogonic stages of Plasmodium parasites in the mosquito, offering the possibility of manipulating vector competence or performing functional studies on vector-parasite interactions.
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Affiliation(s)
- Tony Nolan
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Elisa Petris
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Hans-Michael Müller
- Heidelberg University Biochemistry Centre, Heidelberg University, Heidelberg, Germany
| | - Ann Cronin
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Flaminia Catteruccia
- Department of Life Sciences, Imperial College London, London, United Kingdom
- University of Perugia, Perugia, Italy
- * E-mail: (FC); (ACrisanti)
| | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail: (FC); (ACrisanti)
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Ye D, Yang Q, Li Y, Huang X, Hu J, Qian S, Tan Z, Song P. Gα13 is closely related to hematopoiesis in zebrafish. Mol Biol Rep 2010; 38:2685-94. [PMID: 21113681 DOI: 10.1007/s11033-010-0411-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2010] [Accepted: 11/08/2010] [Indexed: 02/02/2023]
Abstract
Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) function as signal transducers and control many different physiologic processes. G proteins can be grouped into four families: Gs, Gi, Gq and G12. Gα13 belongs to the G12 family. In zebrafish, there are two isoforms of Gα13: Gα13a and Gα13b. We show here that knockdown of Gα13b in zebrafish results in hematopoietic and angiogenic defects. The Gα13b morphants don't show complete loss of expression of gata1, pu.1 or flk until 35 hpf suggests that Gα13b is closely related to the development of hematopoietic cells. Further studies reveal that blood cells and vascular endothelial cells have undergone apoptosis through a p53-dependent pathway in Gα13b-depleted embryos. Injection of p53 morpholino could partially rescue the phenotype of Gα13b morphants. These data possibly demonstrate a new role for Gα13 in cell survival.
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Affiliation(s)
- Ding Ye
- Laboratory of Molecular Genetics and Developmental Biology, College of Life Sciences, Wuhan University, Department of Gynaecology, South Central Hospital, Wuhan, 430072, People's Republic of China
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27
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Won HY, Min HJ, Lee WH, Kim SG, Hwang ES. Galpha12 is critical for TCR-induced IL-2 production and differentiation of T helper 2 and T helper 17 cells. Biochem Biophys Res Commun 2010; 394:811-6. [PMID: 20233578 DOI: 10.1016/j.bbrc.2010.03.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 03/11/2010] [Indexed: 11/18/2022]
Abstract
G12 family have been known to modulate a variety of cellular events such as cell migration, B cell activation and maturation, cytokine production, and cell differentiation. In particular, Galpha12 modulates IgG production, thus induces IgG antibody-mediated immune responses. However, it is largely unknown whether Galpha12 is required for T cell-mediated immune functions. In this study, we investigated the effects of Galpha12 in the activation and differentiation of CD4+ T cells. While PMA plus ionomycin induced equal levels of IL-2 production in WT and Galpha12-deficient lymphocytes, TCR-triggered IL-2 production was significantly attenuated in Galpha12 KO lymphocytes. In particular, CD4+ T cells and effector Th cells lacking of Galpha12 revealed diminished IL-2 production, but not IFNgamma production, upon TCR stimulation. In addition, supplement of IL-2 preferentially induced Galpha12-deficient CD4+ T cells into Th2 and Th17 cells; however, the expression of specific transcription factors was unchanged in Galpha12 KO Th cells. While IL-2 expression was still diminished by the re-stimulation with anti-CD3, PMA plus ionomycin restored IL-2 production in Galpha12-deficient Th1 and Th2 cells. These results suggest that Galpha12 may be a critical signaling molecule in TCR-induced IL-2 production and also relay a signal to suppress Th2 and Th17 cell differentiation.
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Affiliation(s)
- Hee Yeon Won
- College of Pharmacy, Division of Life and Pharmaceutical Sciences and Center for Cell Signaling & Drug Discovery Research, Ewha Womans University, Seoul 120-750, Republic of Korea
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28
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Bunda S, Wang Y, Mitts TF, Liu P, Arab S, Arabkhari M, Hinek A. Aldosterone stimulates elastogenesis in cardiac fibroblasts via mineralocorticoid receptor-independent action involving the consecutive activation of Galpha13, c-Src, the insulin-like growth factor-I receptor, and phosphatidylinositol 3-kinase/Akt. J Biol Chem 2009; 284:16633-16647. [PMID: 19372600 PMCID: PMC2713569 DOI: 10.1074/jbc.m109.008748] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 04/15/2009] [Indexed: 11/06/2022] Open
Abstract
We previously demonstrated that aldosterone, which stimulates collagen production through the mineralocorticoid receptor (MR)-dependent pathway, also induces elastogenesis via a parallel MR-independent mechanism involving insulin-like growth factor-I receptor (IGF-IR) signaling. The present study provides a more detailed explanation of this signaling pathway. Our data demonstrate that small interfering RNA-driven elimination of MR in cardiac fibroblasts does not inhibit aldosterone-induced IGF-IR phosphorylation and subsequent increase in elastin production. These results exclude the involvement of the MR in aldosterone-induced increases in elastin production. Results of further experiments aimed at identifying the upstream signaling component(s) that might be activated by aldosterone also eliminate the putative involvement of pertussis toxin-sensitive Galphai proteins, which have previously been shown to be responsible for some MR-independent effects of aldosterone. Instead, we found that small interfering RNA-dependent elimination of another heterotrimeric G protein, Galpha13, eliminates aldosterone-induced elastogenesis. We further demonstrate that aldosterone first engages Galpha13 and then promotes its transient interaction with c-Src, which constitutes a prerequisite step for aldosterone-dependent activation of the IGF-IR and propagation of consecutive downstream elastogenic signaling involving phosphatidylinositol 3-kinase/Akt. In summary, the data we present reveal new details of an MR-independent cellular signaling pathway through which aldosterone stimulates elastogenesis in human cardiac fibroblasts.
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Affiliation(s)
- Severa Bunda
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Yanting Wang
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Thomas F Mitts
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Peter Liu
- Heart and Stroke/Richard Lewar Centre for Excellence, University of Toronto, Toronto, Ontario M5G 1X8, Canada; Toronto General Hospital/University Health Network, Toronto, Ontario M5G 1X8, Canada
| | - Sara Arab
- Toronto General Hospital/University Health Network, Toronto, Ontario M5G 1X8, Canada
| | - Majid Arabkhari
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Aleksander Hinek
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada; Heart and Stroke/Richard Lewar Centre for Excellence, University of Toronto, Toronto, Ontario M5G 1X8, Canada.
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Liu X, Zha X, Xiao Y, Yang J, Li N. [Efficient fusion expression of G13 domain derived from granulysin in Escherichia coli]. Sheng Wu Gong Cheng Xue Bao 2009; 25:235-241. [PMID: 19459329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The G13 domain derived from granulysin shows high antimicrobial activities against Gram-positive and Gram-negative bacteria but does not lyse Jurkat cells or liposomes. To explore a new approach for high expression of the G13 domain, we fused the sequence encoding G13 to thioredoxin (Trx) gene to construct the recombinant expression vector (pThioHisA-G13). A cyanogen bromide (CNBr) cleavage site was introduced between the Trx and G13 to facilitate final release of the recombinant G13. The recombinant expression vector, pThioHisA-G13, was transformed into E. coli BL21 (DE3). Upon induction by IPTG Trx-G13 fusion protein was expressed and took the form of inclusion bodies counting 58% (W/W) of total cellular proteins. The inclusion body was solved by urea (8 mol/L) and then cleaved by CNBr. We purified the recombinant peptide G13 by one-step cation exchange chromatography. Results of agarose diffuse assay analysis indicated that the recombinant G13 exhibited antibacterial activity. The procedure described in this study will provide a reliable and simple method for highly efficient production of some cationic antimicrobial peptides.
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Affiliation(s)
- Xiaoqiang Liu
- Key Laboratory of Ecological Engineering and Biotechnology of Anhui Province, School of Life Science, Anhui University, Hefei 230039, China
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30
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Kawanabe Y, Okamoto Y, Hashimoto N, Masaki T. Molecular mechanisms for activation of voltage-independent Ca2+ channels by endothelin-1/endothelin-A receptors. J Cardiovasc Pharmacol 2008; 44 Suppl 1:S219-23. [PMID: 15838284 DOI: 10.1097/01.fjc.0000166252.66486.06] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Endothelin-1 (ET-1) activates two types of Ca2+- permeable non-selective cation channels (designated NSCC-1 and NSCC-2) and a store-operated Ca2+ channel (SOCC) in Chinese hamster ovary cells expressing endothelin-A receptors (CHOETAR), which couple with Gq, Gs and G12. The purpose of this study was to identify the G proteins involved in the activation of these Ca channels, using mutated ETARs with coupling to either Gq or Gs/G12 (designated ETAR(Delta)385 and SerETAR, respectively) and a dominant negative mutant of G12 (G12G228A). ETAR(Delta)385 is truncated downstream of Cys385 in the C-terminal as palmitoylation sites, whereas SerET(A)R is unpalmitoylated because of substitution of all the cysteine residues to serine (CysCys --> SerSer). ET-1 activated SOCC in CHO-ET(A)R(Delta)385. In CHO-SerET(A)R or CHO-ET(A)R pretreated with U73122, an inhibitor of phospholipase C, ET-1 activated NSCC-1. ET-1 activated SOCC in CHO-ETAR microinjected with G12G228A. Moreover, ET-1 activated NSCC-1 in CHO-ETAR treated with LY 294002, the phosphoinositide 3-kinase inhibitor. These results indicate that NSCC-1 is activated via a G12-dependent pathway, NSCC-2 via Gq/phospholipase C-dependent and G12-dependent pathways, and SOCC via a Gq-phospholipase C-dependent pathway. In addition, NSCC-2 and SOCC are stimulated by ET-1 via a phosphoinositide 3-kinase-dependent cascade, whereas NSCC-1 is stimulated via a phosphoinositide 3-kinase-independent cascade.
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Affiliation(s)
- Yoshifumi Kawanabe
- Department of Neurosurgery and Pharmacology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
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31
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Liao Z, Seye CI, Weisman GA, Erb L. The P2Y2 nucleotide receptor requires interaction with alpha v integrins to access and activate G12. J Cell Sci 2007; 120:1654-62. [PMID: 17452627 PMCID: PMC2713722 DOI: 10.1242/jcs.03441] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The P2Y2 nucleotide receptor (P2Y2R) interacts with alpha v integrins to activate G(o) and induce chemotaxis in human 1321N1 astrocytoma cells. In this study, it was determined that the P2Y2R also requires interaction with alpha v integrins to activate G12 and associated signaling pathways that control chemotaxis in 1321N1 cells. Mutation of the Arg-Gly-Asp (RGD) integrin-binding sequence in the first extracellular loop of the human P2Y2R to Arg-Gly-Glu (RGE), which prevents integrin interaction, did not inhibit G(q) or ERK1/2 signaling by the P2Y2R agonist UTP but completely inhibited activation of G12 and G12-mediated events, including Rho activation, cofilin and myosin light chain-2 phosphorylation, stress fiber formation and chemotaxis towards UTP. The involvement of G12 in all these events was verified by using a dominant negative G alpha12 construct. G12 activation by the P2Y2R also was inhibited by anti-alpha v beta5 integrin antibodies and alpha v integrin antisense oligonucleotides, suggesting that alpha v integrin activity and expression are required for the P2Y2R to activate G12. Co-immunoprecipitation experiments confirmed that G alpha12 protein associates with the wild-type P2Y2R and with alpha v integrins but not with the RGE mutant P2Y2R or with alpha3 integrins. Collectively, these results suggest that alpha v integrin complexes provide the P2Y2R with access to G12, thereby allowing activation of this heterotrimeric G protein that controls actin cytoskeletal rearrangements required for chemotaxis.
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MESH Headings
- Amides/pharmacology
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacology
- Cardiac Myosins/metabolism
- Cell Line, Tumor
- Cell Movement/drug effects
- Cofilin 1/metabolism
- Enzyme Inhibitors/pharmacology
- Extracellular Signal-Regulated MAP Kinases/metabolism
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Humans
- Integrin alphaV/genetics
- Integrin alphaV/immunology
- Integrin alphaV/metabolism
- Integrins/immunology
- Integrins/metabolism
- Mutation
- Myosin Light Chains/metabolism
- Oligonucleotides, Antisense/genetics
- Pertussis Toxin/pharmacology
- Phosphorylation/drug effects
- Protein Binding
- Pyridines/pharmacology
- Receptors, Purinergic P2/genetics
- Receptors, Purinergic P2/metabolism
- Receptors, Purinergic P2Y2
- Receptors, Vitronectin/immunology
- Receptors, Vitronectin/metabolism
- Signal Transduction/genetics
- Signal Transduction/physiology
- Stress Fibers/metabolism
- Transfection
- Uridine Triphosphate/pharmacology
- rho GTP-Binding Proteins/metabolism
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32
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Cho MK, Kim WD, Ki SH, Hwang JI, Choi S, Lee CH, Kim SG. Role of Galpha12 and Galpha13 as novel switches for the activity of Nrf2, a key antioxidative transcription factor. Mol Cell Biol 2007; 27:6195-208. [PMID: 17591699 PMCID: PMC1952151 DOI: 10.1128/mcb.02065-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Galpha12 and Galpha13 function as molecular regulators responding to extracellular stimuli. NF-E2-related factor 2 (Nrf2) is involved in a protective adaptive response to oxidative stress. This study investigated the regulation of Nrf2 by Galpha12 and Galpha13. A deficiency of Galpha12, but not of Galpha13, enhanced Nrf2 activity and target gene transactivation in embryo fibroblasts. In mice, Galpha12 knockout activated Nrf2 and thereby facilitated heme catabolism to bilirubin and its glucuronosyl conjugations. An oligonucleotide microarray demonstrated the transactivation of Nrf2 target genes by Galpha12 gene knockout. Galpha12 deficiency reduced Jun N-terminal protein kinase (JNK)-dependent Nrf2 ubiquitination required for proteasomal degradation, and so did Galpha13 deficiency. The absence of Galpha12, but not of Galpha13, increased protein kinase C delta (PKC delta) activation and the PKC delta-mediated serine phosphorylation of Nrf2. Galpha13 gene knockout or knockdown abrogated the Nrf2 phosphorylation induced by Galpha12 deficiency, suggesting that relief from Galpha12 repression leads to the Galpha13-mediated activation of Nrf2. Constitutive activation of Galpha13 promoted Nrf2 activity and target gene induction via Rho-mediated PKC delta activation, corroborating positive regulation by Galpha13. In summary, Galpha12 and Galpha13 transmit a JNK-dependent signal for Nrf2 ubiquitination, whereas Galpha13 regulates Rho-PKC delta-mediated Nrf2 phosphorylation, which is negatively balanced by Galpha12.
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Affiliation(s)
- Min Kyung Cho
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Sillim-dong, Gwanak-gu, Seoul, South Korea
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33
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Vanni C, Mancini P, Ottaviano C, Ognibene M, Parodi A, Merello E, Russo C, Varesio L, Zheng Y, Torrisi MR, Eva A. Galpha13 regulation of proto-Dbl signaling. Cell Cycle 2007; 6:2058-70. [PMID: 17721084 DOI: 10.4161/cc.6.16.4574] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Rho family GTPases play important roles in the regulation of intracellular signals induced by activated heterotrimeric G proteins of the alpha(12/13) family. The alpha(12/13) subunits activate Rho GTPases through direct binding to a group of Rho guanine nucleotide exchange factors (GEFs) characterized by the presence of a G protein signaling-like (RGL) domain. The Rho GEF proto-Dbl, that does not contain a RGL domain, was also found to link Galpha(12/13) signals to Rho. We have explored the effects of activated Galpha(13) and Galpha(13)-associated G protein-coupled receptor (GPCR) agonists on proto-Dbl regulation. We show that activated Galpha(13), but not Galpha(12) or Galpha(q), induces translocation of proto-Dbl to the cell membrane with consequent enlargement of cell body and membrane ruffling. These effects were evident also when Galpha(13)-associated GPCR agonists were used on cells expressing proto-Dbl and were accompanied by the activation of Cdc42 and RhoA GTPases and further downstream effector JNK and p38 kinases. Moreover, we show that both activated Galpha(13) and GPCR agonists stimulate proto-Dbl interaction with ezrin to promote ezrin translocation to the plasma membrane. These results suggest a mechanism by which proto-Dbl and its effector pathways are regulated by Galpha(13)-mediated signals through association with ezrin.
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Affiliation(s)
- Cristina Vanni
- Laboratorio di Biologia Molecolare, Istituto G. Gaslini, Genova, Italy
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Lee CW, Rivera R, Dubin AE, Chun J. LPA(4)/GPR23 is a lysophosphatidic acid (LPA) receptor utilizing G(s)-, G(q)/G(i)-mediated calcium signaling and G(12/13)-mediated Rho activation. J Biol Chem 2006; 282:4310-4317. [PMID: 17166850 DOI: 10.1074/jbc.m610826200] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Lysophosphatidic acid (LPA) is a bioactive lysophospholipid that signals through G protein-coupled receptors (GPCRs) to produce a range of biological responses. A recently reported fourth receptor, LPA(4)/GPR23, was notable for its low homology to the previously identified receptors LPA(1-3) and for its ability to increase intracellular concentrations of cAMP and calcium. However, the signaling pathways leading to LPA(4)-mediated induction of cAMP and calcium levels have not been reported. Using epitope-tagged LPA(4), pharmacological intervention, and G protein mini-genes, we provide independent confirmatory evidence that supports LPA(4) as a fourth LPA receptor, including LPA concentration-dependent responses and specific membrane binding. Importantly, we further demonstrate new LPA-dependent activities of LPA(4) that include the following: receptor internalization; G(12/13)- and Rho-mediated neurite retraction and stress fiber formation; G(q) protein and pertussis toxin-sensitive calcium mobilization and activation of a nonselective cation conductance; and cAMP increases mediated by G(s). The receptor is broadly expressed in embryonic tissues, including brain, as determined by Northern blot and reverse transcription-PCR analysis. Adult tissues have increased expression in skin, heart, and to a lesser extent, thymus. These data confirm the identification and extend the functionality of LPA(4) as an LPA receptor, bringing the number of independently verified LPA receptors to five, with both overlapping and distinct signaling properties and tissue expression.
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MESH Headings
- Adult
- Animals
- Calcium Signaling/drug effects
- Calcium Signaling/physiology
- Cell Line, Tumor
- Cyclic AMP/genetics
- Cyclic AMP/metabolism
- Dose-Response Relationship, Drug
- Embryo, Mammalian/metabolism
- Enzyme Activation
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- GTP-Binding Protein alpha Subunits, G12-G13/physiology
- GTP-Binding Protein alpha Subunits, Gi-Go/genetics
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- GTP-Binding Protein alpha Subunits, Gs/genetics
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- GTP-Binding Proteins/genetics
- GTP-Binding Proteins/metabolism
- Gene Expression Regulation/physiology
- Humans
- Lysophospholipids/metabolism
- Lysophospholipids/pharmacology
- Mice
- Neurites/metabolism
- Organ Specificity/physiology
- Receptors, Lysophosphatidic Acid/genetics
- Receptors, Lysophosphatidic Acid/metabolism
- Receptors, Purinergic P2/genetics
- Receptors, Purinergic P2/metabolism
- Stress Fibers/genetics
- Stress Fibers/metabolism
- rho GTP-Binding Proteins/genetics
- rho GTP-Binding Proteins/metabolism
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Affiliation(s)
- Chang-Wook Lee
- Department of Molecular Biology, Helen L. Dorris Institute for Neurological and Psychiatric Disorders, The Scripps Research Institute, La Jolla, California 92037
| | - Richard Rivera
- Department of Molecular Biology, Helen L. Dorris Institute for Neurological and Psychiatric Disorders, The Scripps Research Institute, La Jolla, California 92037
| | - Adrienne E Dubin
- Department of Molecular Biology, Helen L. Dorris Institute for Neurological and Psychiatric Disorders, The Scripps Research Institute, La Jolla, California 92037
| | - Jerold Chun
- Department of Molecular Biology, Helen L. Dorris Institute for Neurological and Psychiatric Disorders, The Scripps Research Institute, La Jolla, California 92037.
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35
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Affiliation(s)
- O Dereure
- Service de Dermatologie, Hôpital Saint-Eloi, 80, avenue Augustin Fliche, 34295 Montpellier Cedex 5, France.
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36
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Rieken S, Sassmann A, Herroeder S, Wallenwein B, Moers A, Offermanns S, Wettschureck N. G12/G13 family G proteins regulate marginal zone B cell maturation, migration, and polarization. J Immunol 2006; 177:2985-93. [PMID: 16920934 DOI: 10.4049/jimmunol.177.5.2985] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
G protein-coupled receptors play an important role in the regulation of lymphocyte functions such as migration, adhesion, proliferation, and differentiation. Although the role of G(i) family G proteins has been intensively studied, no in vivo data exist with respect to G12/G13 family G proteins. We show in this study that mice that lack the G protein alpha-subunits G alpha12 and G alpha13 selectively in B cells show significantly reduced numbers of splenic marginal zone B (MZB) cells, resulting in a delay of Ab production in response to thymus-independent Ags. Basal and chemokine-induced adhesion to ICAM-1 and VCAM-1, two adhesion molecules critically involved in MZB localization, is normal in mutant B cells, and the same is true for chemokine-induced migration. However, migration in response to serum and sphingosine 1-phosphate is strongly increased in mutant MZB cells, but not in mutant follicular B cells. Live-cell imaging studies revealed that G alpha12/G alpha13-deficient MZB cells assumed more frequently an ameboid form than wild-type cells, and pseudopod formation was enhanced. In addition to their regulatory role in serum- and sphingosine 1-phosphate-induced migration, G12/G13 family G proteins seem to be involved in peripheral MZB cell maturation, because also splenic MZB cell precursors are reduced in mutant mice, although less prominently than mature MZB cells. These data suggest that G12/G13 family G proteins contribute to the formation of the mature MZB cell compartment both by controlling MZB cell migration and by regulating MZB cell precursor maturation.
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Affiliation(s)
- Stefan Rieken
- Institute of Pharmacology, University of Heidelberg, Germany
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37
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Shin KJ, Wall EA, Zavzavadjian JR, Santat LA, Liu J, Hwang JI, Rebres R, Roach T, Seaman W, Simon MI, Fraser IDC. A single lentiviral vector platform for microRNA-based conditional RNA interference and coordinated transgene expression. Proc Natl Acad Sci U S A 2006; 103:13759-64. [PMID: 16945906 PMCID: PMC1557799 DOI: 10.1073/pnas.0606179103] [Citation(s) in RCA: 253] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
RNAi is proving to be a powerful experimental tool for the functional annotation of mammalian genomes. The full potential of this technology will be realized through development of approaches permitting regulated manipulation of endogenous gene expression with coordinated reexpression of exogenous transgenes. We describe the development of a lentiviral vector platform, pSLIK (single lentivector for inducible knockdown), which permits tetracycline-regulated expression of microRNA-like short hairpin RNAs from a single viral infection of any naïve cell system. In mouse embryonic fibroblasts, the pSLIK platform was used to conditionally deplete the expression of the heterotrimeric G proteins Galpha12 and Galpha13 both singly and in combination, demonstrating the Galpha13 dependence of serum response element-mediated transcription. In RAW264.7 macrophages, regulated knockdown of Gbeta2 correlated with a reduced Ca(2+) response to C5a. Insertion of a GFP transgene upstream of the Gbeta2 microRNA-like short hairpin RNA allowed concomitant reexpression of a heterologous mRNA during tetracycline-dependent target gene knockdown, significantly enhancing the experimental applicability of the pSLIK system.
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Affiliation(s)
- Kum-Joo Shin
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
| | - Estelle A. Wall
- Alliance for Cell Signaling Molecular Biology Laboratory and
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
| | - Joelle R. Zavzavadjian
- Alliance for Cell Signaling Molecular Biology Laboratory and
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
| | - Leah A. Santat
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
| | - Jamie Liu
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
| | - Jong-Ik Hwang
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
| | - Robert Rebres
- Alliance for Cell Signaling Macrophage Biology Laboratory, Department of Veterans Affairs Medical Center, University of California, 4150 Clement Street, San Francisco, CA 94121
| | - Tamara Roach
- Alliance for Cell Signaling Macrophage Biology Laboratory, Department of Veterans Affairs Medical Center, University of California, 4150 Clement Street, San Francisco, CA 94121
| | - William Seaman
- Alliance for Cell Signaling Macrophage Biology Laboratory, Department of Veterans Affairs Medical Center, University of California, 4150 Clement Street, San Francisco, CA 94121
| | - Melvin I. Simon
- Alliance for Cell Signaling Molecular Biology Laboratory and
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
| | - Iain D. C. Fraser
- Alliance for Cell Signaling Molecular Biology Laboratory and
- *Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; and
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Kelly P, Stemmle LN, Madden JF, Fields TA, Daaka Y, Casey PJ. A Role for the G12 Family of Heterotrimeric G Proteins in Prostate Cancer Invasion. J Biol Chem 2006; 281:26483-90. [PMID: 16787920 DOI: 10.1074/jbc.m604376200] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many studies have suggested a role for the members of the G12 family of heterotrimeric G proteins (Galpha12 and Galpha13) in oncogenesis and tumor cell growth. However, few studies have examined G12 signaling in actual human cancers. In this study, we examined the role of G12 signaling in prostate cancer. We found that expression of the G12 proteins is significantly elevated in prostate cancer. Interestingly, expression of the activated forms of Galpha12 or Galpha13 in the PC3 and DU145 prostate cancer cell lines did not promote cancer cell growth. Instead, expression of the activated forms of Galpha12 or Galpha13 in these cell lines induced cell invasion through the activation of the RhoA family of G proteins. Furthermore, inhibition of G12 signaling by expression of the RGS domain of the p115-Rho-specific guanine nucleotide exchange factor (p115-RGS) in the PC3 and DU145 cell lines did not reduce cancer cell growth. However, inhibition of G12 signaling with p115-RGS in these cell lines blocked thrombin- and thromboxane A2-stimulated cell invasion. These observations identify the G12 family proteins as important regulators of prostate cancer invasion and suggest that these proteins may be targeted to limit invasion- and metastasis-induced prostate cancer patient mortality.
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Affiliation(s)
- Patrick Kelly
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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39
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Shan D, Chen L, Wang D, Tan YC, Gu JL, Huang XY. The G protein G alpha(13) is required for growth factor-induced cell migration. Dev Cell 2006; 10:707-18. [PMID: 16740474 DOI: 10.1016/j.devcel.2006.03.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Revised: 11/17/2005] [Accepted: 03/23/2006] [Indexed: 01/25/2023]
Abstract
Heterotrimeric G proteins are critical cellular signal transducers. They are known to directly relay signals from seven-transmembrane G protein-coupled receptors (GPCRs) to downstream effectors. On the other hand, receptor tyrosine kinases (RTKs), a different family of membrane receptors, signal through docking sites in their carboxy-terminal tails created by autophosphorylated tyrosine residues. Here we show that a heterotrimeric G protein, G alpha(13), is essential for RTK-induced migration of mouse fibroblast and endothelial cells. G alpha(13) activity in cell migration is retained in a C-terminal mutant that is defective in GPCR coupling, suggesting that the migration function is independent of GPCR signaling. Thus, G alpha(13) appears to be a critical signal transducer for RTKs as well as GPCRs. This broader role of G alpha(13) in cell migration initiated by two types of receptors could provide a molecular basis for the vascular system defects exhibited by G alpha(13) knockout mice.
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MESH Headings
- Animals
- Cell Line
- Cell Movement/drug effects
- Cell Movement/physiology
- Cells, Cultured
- Embryo, Mammalian
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Enzyme Activation
- Epidermal Growth Factor/pharmacology
- Fibroblasts/drug effects
- Fibroblasts/physiology
- GTP-Binding Protein alpha Subunits, G12-G13/deficiency
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- GTP-Binding Protein alpha Subunits, G12-G13/physiology
- Gene Deletion
- Glutathione Transferase/metabolism
- Humans
- Mice
- Mice, Knockout
- Mitogen-Activated Protein Kinase 3/metabolism
- Models, Biological
- Platelet-Derived Growth Factor/pharmacology
- Receptor Protein-Tyrosine Kinases/metabolism
- Recombinant Proteins/metabolism
- rac GTP-Binding Proteins/metabolism
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Affiliation(s)
- Dandan Shan
- Department of Physiology, Weill Medical College, Cornell University, New York, New York 10021, USA
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40
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Mariggiò S, Bavec A, Natale E, Zizza P, Salmona M, Corda D, Di Girolamo M. Galpha13 mediates activation of the cytosolic phospholipase A2alpha through fine regulation of ERK phosphorylation. Cell Signal 2006; 18:2200-8. [PMID: 16806823 DOI: 10.1016/j.cellsig.2006.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Accepted: 05/09/2006] [Indexed: 11/20/2022]
Abstract
Heterotrimeric GTP-binding (G) proteins transduce hormone-induced signals to their effector enzymes, which include several phospholipases. In particular, the G(o)/G(i) and G(q) protein families have been shown to couple signaling to phospholipase A(2) (PLA(2)), phospholipase C, and phospholipase D, while the G(12)/G(13) family has been linked to the activation of small GTPases of the Rho family, and hence, to phospholipase D activation. Here, we demonstrate that in CHO cells, the G(12)/G(13) family is also able to activate cPLA(2)alpha, through the activation of RhoA and, subsequently, ERK1/2. Hormone-induced arachidonic acid release increased as a consequence of Galpha(13) overexpression, and was inhibited through inhibition of Galpha(13) signaling. The Galpha(13)-mediated cPLA(2)alpha activation was inhibited by pharmacological blockade of ERK1/2 with either U0126 or PD98059, and by RhoA inactivation with C3 toxin or a dominant-negative RhoA (N19RhoA), and was stimulated by the serine-threonine phosphatase inhibitor calyculin A. Our data thus identify a pathway of cPLA(2)alpha regulation that is initiated by thrombin and purinergic receptor activation, and that signals through Galpha(13), RhoA and ERK1/2, with the involvement of a calyculin-sensitive phosphatase.
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Affiliation(s)
- Stefania Mariggiò
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Via Nazionale, 66030 Santa Maria Imbaro, Chieti, Italy
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41
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Kumar RN, Ha JH, Radhakrishnan R, Dhanasekaran DN. Transactivation of platelet-derived growth factor receptor alpha by the GTPase-deficient activated mutant of Galpha12. Mol Cell Biol 2006; 26:50-62. [PMID: 16354679 PMCID: PMC1317640 DOI: 10.1128/mcb.26.1.50-62.2006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The GTPase-deficient, activated mutant of Galpha12 (Galpha12Q229L, or Galpha12QL) induces neoplastic growth and oncogenic transformation of NIH 3T3 cells. Using microarray analysis, we have previously identified a role for platelet-derived growth factor receptor alpha (PDGFRalpha) in Galpha12-mediated cell growth (R. N. Kumar et al., Cell Biochem. Biophys. 41:63-73, 2004). In the present study, we report that Galpha12QL stimulates the functional expression of PDGFRalpha and demonstrate that the expression of PDGFRalpha by Galpha12QL is dependent on the small GTPase Rho. Our results indicate that it is cell type independent as the transient expression of Galpha12QL or the activation of Galpha12-coupled receptors stimulates the expression of PDGFRalpha in NIH 3T3 as well as in human astrocytoma 1321N1 cells. Furthermore, we demonstrate the presence of an autocrine loop involving PDGF-A and PDGFRalpha in Galpha12QL-transformed cells. Analysis of the functional consequences of the Galpha12-PDGFRalpha signaling axis indicates that Galpha12 stimulates the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway through PDGFR. In addition, we show that Galpha12QL stimulates the phosphorylation of forkhead transcription factor FKHRL1 via AKT in a PDGFRalpha- and PI3K-dependent manner. Since AKT promotes cell growth by blocking the transcription of antiproliferative genes through the inhibitory phosphorylation of forkhead transcription factors, our results describe for the first time a PDGFRalpha-dependent signaling pathway involving PI3K-AKT-FKHRL1, regulated by Galpha12QL in promoting cell growth. Consistent with this view, we demonstrate that the expression of a dominant negative mutant of PDGFRalpha attenuated Galpha12-mediated neoplastic transformation of NIH 3T3 cells.
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Affiliation(s)
- Rashmi N. Kumar
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Ji Hee Ha
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Rangasudhagar Radhakrishnan
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Danny N. Dhanasekaran
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
- Corresponding author. Mailing address: Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, 3307 N. Broad Street, 556 AHB, Philadelphia, PA 19140. Phone: (215) 707-1941. Fax: (215) 707-5963. E-mail:
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42
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Abstract
Galpha(12), the alpha-subunit of G12, which has been referred to as the gep oncogene, stimulates mitogenic pathways in different cell types and readily induces neoplastic transformation of fibroblast cell lines. Recently, we have shown that the oncogenic pathway activated by Galpha(12) involves the receptor tyrosine kinase platelet derived growth factor receptor-alpha (PDGFRalpha) and JAK3. In the present study, we demonstrate that the GTPase-deficient activated mutant of Galpha(12) activates signal transducer and activator of transcription 3 (STAT3) via PDGFRalpha as well as JAK3. Here we show that Galpha(12) stimulates the phosphorylation of STAT3 at both Tyrosine-705 and Serine-727 residues. Studies to delineate the mechanism by which Galpha(12) stimulates STAT3 have indicated that the Tyrosine-705-phosphorylation of STAT3 involves the tyrosine kinases, Janus Kinase-3 as well as Src kinase, whereas the Serine-727 phosphorylation of STAT3 occurs via the receptor tyrosine kinase, PDGFRalpha and phosphatidylinositol 3-OH kinase pathway. Our results also indicate that the coexpression of the dominant negative, DNA binding mutant of STAT3 (STAT3DB) inhibits the foci formation as well as anchorage-independent growth of Galpha(12)QL-transfectants, thereby establishing the critical role of STAT3 in Galpha(12)QL-mediated neoplastic cell growth. The results presented here demonstrate, for the first time, the ability of Galpha(12) to recruit multiple receptor-, nonreceptor-, and Ser/Thr kinases to stimulate STAT3-signaling to promote neoplastic transformation.
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Affiliation(s)
- R N Kumar
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, 3307 N. Broad Street, Philadelphia, PA 19140, USA
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43
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Kvachnina E, Liu G, Dityatev A, Renner U, Dumuis A, Richter DW, Dityateva G, Schachner M, Voyno-Yasenetskaya TA, Ponimaskin EG. 5-HT7 receptor is coupled to G alpha subunits of heterotrimeric G12-protein to regulate gene transcription and neuronal morphology. J Neurosci 2006; 25:7821-30. [PMID: 16120784 PMCID: PMC6725246 DOI: 10.1523/jneurosci.1790-05.2005] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The neurotransmitter serotonin (5-HT) plays an important role in the regulation of multiple events in the CNS. We demonstrated recently a coupling between the 5-HT4 receptor and the heterotrimeric G13-protein resulting in RhoA-dependent neurite retraction and cell rounding (Ponimaskin et al., 2002). In the present study, we identified G12 as an additional G-protein that can be activated by another member of serotonin receptors, the 5-HT7 receptor. Expression of 5-HT7 receptor induced constitutive and agonist-dependent activation of a serum response element-mediated gene transcription through G12-mediated activation of small GTPases. In NIH3T3 cells, activation of the 5-HT7 receptor induced filopodia formation via a Cdc42-mediated pathway correlating with RhoA-dependent cell rounding. In mouse hippocampal neurons, activation of the endogenous 5-HT7 receptors significantly increased neurite length, whereas stimulation of 5-HT4 receptors led to a decrease in the length and number of neurites. These data demonstrate distinct roles for 5-HT7R/G12 and 5-HT4R/G13 signaling pathways in neurite outgrowth and retraction, suggesting that serotonin plays a prominent role in regulating the neuronal cytoarchitecture in addition to its classical role as neurotransmitter.
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MESH Headings
- Animals
- Cells, Cultured
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- Mice
- NIH 3T3 Cells
- Neurites/physiology
- Neurons/cytology
- Neurons/metabolism
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Serotonin/genetics
- Receptors, Serotonin/metabolism
- Serotonin/physiology
- Serotonin Antagonists/pharmacology
- Signal Transduction/physiology
- Transcription, Genetic/physiology
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Affiliation(s)
- Elena Kvachnina
- Abteilung Neurologie und Sinnesphysiologie, Physiologisches Institut, Universität Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
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44
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Kashef K, Lee CM, Ha JH, Reddy EP, Dhanasekaran DN. JNK-interacting leucine zipper protein is a novel scaffolding protein in the Galpha13 signaling pathway. Biochemistry 2006; 44:14090-6. [PMID: 16245925 DOI: 10.1021/bi050604l] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Scaffolding proteins play a critical role in conferring specificity and fidelity to signaling pathways. The JNK-interacting leucine zipper protein (JLP) has been identified as a scaffolding protein involved in linking components of the JNK signaling module. Galpha(12) and Galpha(13), the alpha-subunits of heterotrimeric G proteins G12 and G13, respectively, stimulate the JNK module in diverse cell types. Here, we report that Galpha(13) physically interacts with JLP, and this interaction enhances Galpha(13)-mediated JNK activation. We also demonstrate endogenous interaction between JLP and Galpha(13) in MCF-7 cells. JLP interaction is specific to the G12 family of alpha-subunits via its C-terminal domain (termed GID-JLP), spanning amino acids 1165-1307, and this interaction is more pronounced with the mutationally or functionally activated form of Galpha(13) compared to that of wild-type Galpha(13). The presence of a ternary complex consisting of Galpha(13), JLP, and JNK suggests a role for JLP in tethering Galpha(13) to the signaling components involved in JNK activation. Coexpression of GID-JLP disrupts ternary complex formation in addition to attenuating Galpha(13)-stimulated JNK activity. These findings identify JLP as a novel scaffolding protein in the Galpha(13)-mediated JNK signaling pathway.
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Affiliation(s)
- Kimia Kashef
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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45
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Kreutz B, Yau DM, Nance M, Tanabe S, Tesmer JJG, Kozasa T. A new approach to producing functional G alpha subunits yields the activated and deactivated structures of G alpha(12/13) proteins. Biochemistry 2006; 45:167-74. [PMID: 16388592 PMCID: PMC2688741 DOI: 10.1021/bi051729t] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The oncogenic G(12/13) subfamily of heterotrimeric G proteins transduces extracellular signals that regulate the actin cytoskeleton, cell cycle progression, and gene transcription. Previously, structural analyses of fully functional G alpha(12/13) subunits have been hindered by insufficient amounts of homogeneous, functional protein. Herein, we report that substitution of the N-terminal helix of G alpha(i1) for the corresponding region of G alpha12 or G alpha13 generated soluble chimeric subunits (G alpha(i/12) and G alpha(i/13)) that could be purified in sufficient amounts for crystallographic studies. Each chimera bound guanine nucleotides, G betagamma subunits, and effector proteins and exhibited GAP responses to p115RhoGEF and leukemia-associated RhoGEF. Like their wild-type counterparts, G alpha(i/13), but not G alpha(i/12), stimulated the activity of p115RhoGEF. Crystal structures of the G alpha(i/12) x GDP x AlF4(-) and G alpha(i/13) x GDP complexes were determined using diffraction data extending to 2.9 and 2.0 A, respectively. These structures reveal not only the native structural features of G alpha12 and G alpha13 subunits, which are expected to be important for their interactions with GPCRs and effectors such as G alpha-regulated RhoGEFs, but also novel conformational changes that are likely coupled to GTP hydrolysis in the G alpha(12/13) class of heterotrimeric G proteins.
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Affiliation(s)
| | | | | | | | - John J. G. Tesmer
- To whom correspondence should be addressed. E-mail: . Telephone: (734) 615-9544. Fax: (734) 763-6492. . Telephone: (312)-413-0111. FAX: (312)-996-1225
| | - Tohru Kozasa
- To whom correspondence should be addressed. E-mail: . Telephone: (734) 615-9544. Fax: (734) 763-6492. . Telephone: (312)-413-0111. FAX: (312)-996-1225
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46
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Abstract
In this issue of Molecular Pharmacology, Andreeva et al. (p. 975) report a novel functional link between the heterotrimeric G protein G alpha12 and endothelial nitric-oxide synthase (eNOS). Based on studies characterizing the interaction of G alpha12 and the molecular chaperone Hsp90 and the interaction of eNOS and Hsp90, the group proposed an interaction between G alpha12 and eNOS and sought to determine the regulatory mechanisms, including the inferred dependence on Hsp90. Their experiments using an overexpression model lead to the observation that the cotransfection of G alpha12 and eNOS expression vectors increased overall eNOS expression. Additional studies in the overexpression model and in human umbilical vein endothelial cells (HUVEC) provide evidence for a mechanism that involves G alpha12-dependent stabilization of eNOS protein and possibly mRNA. These data present yet another paradigm by which heterotrimeric G proteins, through stabilization of target proteins, can regulate the activity of downstream signaling pathways.
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Affiliation(s)
- Matthew L Bilodeau
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232-6600, USA
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47
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Andreeva AV, Vaiskunaite R, Kutuzov MA, Profirovic J, Skidgel RA, Voyno-Yasenetskaya T. Novel mechanisms of G protein-dependent regulation of endothelial nitric-oxide synthase. Mol Pharmacol 2005; 69:975-82. [PMID: 16326932 DOI: 10.1124/mol.105.018846] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endothelial nitric-oxide synthase (eNOS) plays a crucial role in the regulation of a variety of cardiovascular and pulmonary functions in both normal and pathological conditions. Multiple signaling inputs, including calcium, caveolin-1, phosphorylation by several kinases, and binding to the 90-kDa heat shock protein (Hsp90), regulate eNOS activity. Here, we report a novel mechanism of G protein-dependent regulation of eNOS. We demonstrate that in mammalian cells, the alpha subunit of heterotrimeric G12 protein (G alpha12) can form a complex with eNOS in an activation- and Hsp90-independent manner. Our data show that G alpha12 does not affect eNOS-specific activity, but it strongly enhances total eNOS activity by increasing cellular levels of eNOS. Experiments using inhibition of protein or mRNA synthesis show that G alpha12 increases the expression of eNOS by increasing half-life of both eNOS protein and eNOS mRNA. Small interfering RNA-mediated depletion of endogenous G alpha12 decreases eNOS levels. A quantitative correlation can be detected between the extent of down-regulation of G alpha12 and eNOS in endothelial cells after prolonged treatment with thrombin. G protein-dependent increase of eNOS expression represents a novel mechanism by which heterotrimeric G proteins can regulate the activity of downstream signaling molecules.
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MESH Headings
- Animals
- Cells, Cultured
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- Enzyme Activation
- Enzyme Stability
- GTP-Binding Protein alpha Subunits, G12-G13/antagonists & inhibitors
- GTP-Binding Protein alpha Subunits, G12-G13/genetics
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- HSP90 Heat-Shock Proteins/metabolism
- Humans
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- RNA Stability
- RNA, Messenger/analysis
- RNA, Messenger/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/pharmacology
- Thrombin/pharmacology
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Affiliation(s)
- Alexandra V Andreeva
- Department of Pharmacology, University of Illinois, College of Medicine, Chicago, IL 60612, USA
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48
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Abstract
The ERM (ezrin, radixin, moesin) proteins function as cross-linkers between cell membrane and cytoskeleton by binding to membrane proteins via their N-terminal domain and to F-actin via their C-terminal domain. Previous studies from our laboratory have shown that the alpha-subunit of heterotrimeric G(13) protein induces conformational activation of radixin via interaction with its N-terminal domain (Vaiskunaite, R., Adarichev, V., Furthmayr, H., Kozasa, T., Gudkov, A., and Voyno-Yasenetskaya, T. A. (2000) J. Biol. Chem. 275, 26206-26212). In the present study, we tested whether radixin can regulate Galpha(13)-mediated signaling pathways. We determined the effects of the N-terminal domain (amino acids 1-318) and C-terminal domain (amino acids 319-583) of radixin on serum response element (SRE)-dependent gene transcription initiated by a constitutively activated Galpha(13)Q226L. The N-terminal domain potentiated SRE activation induced by Galpha(13)Q226L; RhoGDI inhibited this effect. Surprisingly, the C-terminal domain also stimulated the SRE-dependent gene transcription. When co-transfected with Galpha(13)Q226L, the C-terminal domain of radixin synergistically stimulated the SRE activation; RhoGDI inhibited this effect. Using in vivo pull-down assays, we have determined that the C-terminal domain of radixin activated Rac1 but not RhoA or Cdc42 proteins. By contrast, Galpha(13)Q226L activated RhoA but not Rac1 or Cdc42. We have also shown that both the C-terminal domain of radixin and Galpha(13)Q226L can stimulate Ca(2+)/calmodulin-dependent kinase, CaMKII. Activated mutant that mimics the phosphorylated state of radixin (T564E) stimulated Rac1, induced the phosphorylation of CaMKII, and stimulated SRE-dependent gene transcription. Down-regulation of endogenous radixin using small interference RNA inhibited SRE-dependent gene transcription and phosphorylation of CaMKII induced by Galpha(13)Q226L. Overall, our results indicated that radixin via its C-terminal domain mediates SRE-dependent gene transcription through activation of Rac1 and CaMKII. In addition, the radixin-CaMKII signaling pathway is involved in Galpha(13)-mediated SRE-dependent gene transcription, suggesting that radixin could be involved in novel signaling pathway regulated by G(13) protein.
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Affiliation(s)
- Guoquan Liu
- Department of Pharmacology, University of Illinois, Chicago, Illinois 60612, USA
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49
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Orth JHC, Lang S, Taniguchi M, Aktories K. Pasteurella multocida Toxin-induced Activation of RhoA Is Mediated via Two Families of Gα Proteins, Gαq and Gα12/13. J Biol Chem 2005; 280:36701-7. [PMID: 16141214 DOI: 10.1074/jbc.m507203200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pasteurella multocida toxin (PMT) is a potent mitogen, which is known to activate phospholipase Cbeta by stimulating the alpha-subunit of the heterotrimeric G protein G(q). PMT also activates RhoA and RhoA-dependent pathways. Using YM-254890, a specific inhibitor of G(q/11), we studied whether activation of RhoA involves G proteins other than G(q/11). YM-254890 inhibited PMT or muscarinic M3-receptor-mediated stimulation of phospholipase Cbeta at similar concentrations in HEK293m3 cells. In these cells, PMT-induced RhoA activation and enhancement of RhoA-dependent luciferase activity were partially inhibited by YM-254890. In Galpha(q/11)-deficient fibroblasts, PMT induced activation of RhoA, increase in RhoA-dependent luciferase activity, and increase in ERK phosphorylation. None of these effects were influenced by YM-254890. However, RhoA activation by PMT was inhibited by RGS2, RGS16, lscRGS, and dominant negative G(13)(GA), indicating involvement of Galpha(12/13) in the PMT effect on RhoA. In Galpha(12/13) gene-deficient cells, PMT-induced stimulation of RhoA, luciferase activity, and ERK phosphorylation were blocked by YM-254890, indicating the involvement of G(q). Infection with a virus harboring the gene of Galpha(13) reconstituted the increase in RhoA-dependent luciferase activity by PMT even in the presence of YM-254890. The data show that YM-254890 is able to block PMT activation of Galpha(q) and indicate that, in addition to Galpha(q), the Galpha(12/13) G proteins are targets of PMT.
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Affiliation(s)
- Joachim H C Orth
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs Universität Freiburg, D-79104 Freiburg, Germany
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Sgourakis NG, Bagos PG, Hamodrakas SJ. Prediction of the coupling specificity of GPCRs to four families of G-proteins using hidden Markov models and artificial neural networks. Bioinformatics 2005; 21:4101-6. [PMID: 16174684 DOI: 10.1093/bioinformatics/bti679] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
MOTIVATION G-protein coupled receptors are a major class of eukaryotic cell-surface receptors. A very important aspect of their function is the specific interaction (coupling) with members of four G-protein families. A single GPCR may interact with members of more than one G-protein families (promiscuous coupling). To date all published methods that predict the coupling specificity of GPCRs are restricted to three main coupling groups G(i/o), G(q/11) and G(s), not including G(12/13)-coupled or other promiscuous receptors. RESULTS We present a method that combines hidden Markov models and a feed-forward artificial neural network to overcome these limitations, while producing the most accurate predictions currently available. Using an up-to-date curated dataset, our method yields a 94% correct classification rate in a 5-fold cross-validation test. The method predicts also promiscuous coupling preferences, including coupling to G(12/13), whereas unlike other methods avoids overpredictions (false positives) when non-GPCR sequences are encountered. AVAILABILITY A webserver for academic users is available at http://bioinformatics.biol.uoa.gr/PRED-COUPLE2
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Affiliation(s)
- Nikolaos G Sgourakis
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Greece
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