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Chen Y, Ren L, Xu X, Sun Z, Dai M, Li Y, Ma X, Li J. RAF1 in AgRP neurons involved in the regulation of energy metabolism via the MAPK signaling pathway. J Biomed Res 2025; 39:1-19. [PMID: 40432214 DOI: 10.7555/jbr.39.20250114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2025] Open
Abstract
V-raf-leukemia viral oncogene 1(RAF1), a serine/threonine protein kinase, is universally acknowledged to play a crucial role in tumorigenesis and cell development. However, the specific role of hypothalamic RAF1 in regulating energy metabolism remains unknown. In this study, we found that the expression of RAF1 was significantly increased in hypothalamic AgRP neurons of diet induced obesity (DIO) mice. Under normal chow diet (NCD) feeding, over-expression of Raf1 in AgRP neurons leads to obesity in mice characterized by increased body weight, fat mass, and impaired glucose tolerance. Conversely, knock-out of the Raf1 gene in AgRP neurons protects against DIO, reducing fat mass and improving glucose tolerance. Mechanistically, Raf1 activates the MAPK signaling pathway, culminating in cAMP response element-binding protein (CREB) phosphorylation, which enhances transcription of Agrp and Npy. Insulin stimulation further potentiates the RAF1-MEK1/2-ERK1/2-CREB axis, highlighting RAF1's role in integrating hormonal and nutritional signals to regulate energy balance. Collectively, these findings underscore the important role of RAF1 in AgRP neurons in maintaining the energy homeostasis and obesity pathogenesis, positioning it and its downstream pathways as potential therapeutic targets for innovative strategies to combat obesity and related metabolic diseases.
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Affiliation(s)
- Yuqian Chen
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Jiangsu Provincial Key Laboratory of Molecular Targets and Intervention of Metabolic Disease Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Lianci Ren
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Clinical Center for Reproductive Medicine, First Afffliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xinyi Xu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Jiangsu Provincial Key Laboratory of Molecular Targets and Intervention of Metabolic Disease Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Zhenning Sun
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Jiangsu Provincial Key Laboratory of Molecular Targets and Intervention of Metabolic Disease Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Mingxi Dai
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yin Li
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Jiangsu Provincial Key Laboratory of Molecular Targets and Intervention of Metabolic Disease Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Xiang Ma
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Clinical Center for Reproductive Medicine, First Afffliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Juxue Li
- State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Jiangsu Provincial Key Laboratory of Molecular Targets and Intervention of Metabolic Disease Nanjing Medical University, Nanjing, Jiangsu 211166, China
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China
- The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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2
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Wang P, Laster K, Jia X, Dong Z, Liu K. Targeting CRAF kinase in anti-cancer therapy: progress and opportunities. Mol Cancer 2023; 22:208. [PMID: 38111008 PMCID: PMC10726672 DOI: 10.1186/s12943-023-01903-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023] Open
Abstract
The RAS/mitogen-activated protein kinase (MAPK) signaling cascade is commonly dysregulated in human malignancies by processes driven by RAS or RAF oncogenes. Among the members of the RAF kinase family, CRAF plays an important role in the RAS-MAPK signaling pathway, as well as in the progression of cancer. Recent research has provided evidence implicating the role of CRAF in the physiological regulation and the resistance to BRAF inhibitors through MAPK-dependent and MAPK-independent mechanisms. Nevertheless, the effectiveness of solely targeting CRAF kinase activity remains controversial. Moreover, the kinase-independent function of CRAF may be essential for lung cancers with KRAS mutations. It is imperative to develop strategies to enhance efficacy and minimize toxicity in tumors driven by RAS or RAF oncogenes. The review investigates CRAF alterations observed in cancers and unravels the distinct roles of CRAF in cancers propelled by diverse oncogenes. This review also seeks to summarize CRAF-interacting proteins and delineate CRAF's regulation across various cancer hallmarks. Additionally, we discuss recent advances in pan-RAF inhibitors and their combination with other therapeutic approaches to improve treatment outcomes and minimize adverse effects in patients with RAF/RAS-mutant tumors. By providing a comprehensive understanding of the multifaceted role of CRAF in cancers and highlighting the latest developments in RAF inhibitor therapies, we endeavor to identify synergistic targets and elucidate resistance pathways, setting the stage for more robust and safer combination strategies for cancer treatment.
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Affiliation(s)
- Penglei Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Kyle Laster
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Xuechao Jia
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Zigang Dong
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
| | - Kangdong Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
- Basic Medicine Sciences Research Center, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450052, Henan, China.
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450000, Henan, China.
- Provincial Cooperative Innovation Center for Cancer Chemoprevention, Zhengzhou University, Zhengzhou, 450000, Henan, China.
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3
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Santos EW, Dias CC, Fock RA, Paredes-Gamero EJ, Zheng YM, Wang YX, Borelli P. Protein restriction impairs the response activation/responsivity of MAPK signaling pathway of hematopoietic stem cells. Nutr Res 2023; 116:12-23. [PMID: 37320947 DOI: 10.1016/j.nutres.2023.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/11/2023] [Accepted: 05/20/2023] [Indexed: 06/17/2023]
Abstract
Protein restriction (PR) leads to bone marrow hypoplasia with changes in stromal cellularity components of the extracellular matrix in hematopoietic stem cells (HSCs). However, the underlying signaling mechanisms are poorly understood. We hypothesize that PR impairs the HSC mitogen-activated protein kinase (MAPK) signaling pathway response activation. Our aim is to evaluate the activation of MAPK and interleukin-3 (IL-3) proteins in HSC to explain PR-induced bone marrow hypoplasia, which causes altered proliferation and differentiation. C57BL/6 male mice were subjected to a low-protein diet (2% protein) or normoproteic (12% protein). PKC, PLCγ2, CaMKII, AKT, STAT3/5, ERK1/2, JNK, and p38d phosphorylation were evaluated by flow cytometry, and GATA1/2, PU.1, C/EBPα, NF-E2, and Ikz-3 genes (mRNAs) assessed by quantitative real-time-polymerase chain reaction. Pathway proteins, such as PLCγ2, JAK2, STAT3/5, PKC, and RAS do not respond to the IL-3 stimulus in PR, leading to lower activation of ERK1/2 and Ca2+ signaling pathways, consequently lowering the production of hematopoietic transcription factors. Colony forming units granulocyte-macrophage and colony forming units macrophage formation are impaired in PR even after being stimulated with IL-3. Long-term hematopoietic stem cells, short-term hematopoietic stem cells, granulocyte myeloid progenitor, and megakaryocyte-erythroid progenitor cells were significantly reduced in PR animals. This study shows for the first time that activation of MAPK pathway key proteins in HSCs is impaired in cases of PR. Several pathway proteins, such as PLCγ2, JAK2, STAT3, PKC, and RAS do not respond to IL-3 stimulation, leading to lower activation of extracellular signal-regulated protein kinase 1/2 and consequently lower production of hematopoietic transcription factors GATA1/2, PU.1, C/EBPa, NF-E2, and Ikz3. These changes result in a reduction in colony-forming units, proliferation, and differentiation, leading to hypocellularity.
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Affiliation(s)
- Ed Wilson Santos
- Department of Molecular and Cellular Physiology, Albany Medical College, NY, USA; Experimental Hematology Laboratory, Department of Clinical e Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
| | - Carolina Carvalho Dias
- Experimental Hematology Laboratory, Department of Clinical e Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
| | - Ricardo Ambrósio Fock
- Experimental Hematology Laboratory, Department of Clinical e Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
| | - Edgar Julian Paredes-Gamero
- Faculty of Pharmaceutical Sciences, Food and Nutrition (FACFAN), Federal University of Mato Grosso do Sul, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil.
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, NY, USA.
| | - Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, NY, USA.
| | - Primavera Borelli
- Experimental Hematology Laboratory, Department of Clinical e Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
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Zeng R, Ke TC, Ou MT, Duan LL, Li Y, Chen ZJ, Xing ZB, Fu XC, Huang CY, Wang J. Identification of a potential diagnostic signature for postmenopausal osteoporosis via transcriptome analysis. Front Pharmacol 2022; 13:944735. [PMID: 36105211 PMCID: PMC9464864 DOI: 10.3389/fphar.2022.944735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
Purpose: We aimed to establish the transcriptome diagnostic signature of postmenopausal osteoporosis (PMOP) to identify diagnostic biomarkers and score patient risk to prevent and treat PMOP. Methods: Peripheral blood mononuclear cell (PBMC) expression data from PMOP patients were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were screened using the “limma” package. The “WGCNA” package was used for a weighted gene co-expression network analysis to identify the gene modules associated with bone mineral density (BMD). Least absolute shrinkage and selection operator (LASSO) regression was used to construct a diagnostic signature, and its predictive ability was verified in the discovery cohort. The diagnostic values of potential biomarkers were evaluated by receiver operating characteristic curve (ROC) and coefficient analysis. Network pharmacology was used to predict the candidate therapeutic molecules. PBMCs from 14 postmenopausal women with normal BMD and 14 with low BMD were collected, and RNA was extracted for RT-qPCR validation. Results: We screened 2420 differentially expressed genes (DEGs) from the pilot cohort, and WGCNA showed that the blue module was most closely related to BMD. Based on the genes in the blue module, we constructed a diagnostic signature with 15 genes, and its ability to predict the risk of osteoporosis was verified in the discovery cohort. RT-qPCR verified the expression of potential biomarkers and showed a strong correlation with BMD. The functional annotation results of the DEGs showed that the diagnostic signature might affect the occurrence and development of PMOP through multiple biological pathways. In addition, 5 candidate molecules related to diagnostic signatures were screened out. Conclusion: Our diagnostic signature can effectively predict the risk of PMOP, with potential application for clinical decisions and drug candidate selection.
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Affiliation(s)
- Rui Zeng
- Department of Physiology, School of Medicine, Jinan University, Guangzhou, China
| | - Tian-Cheng Ke
- Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Mao-Ta Ou
- Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Li-Liang Duan
- Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Yi Li
- Department of Radiology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Zhi-Jing Chen
- Department of Plastic Surgery, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Zhi-Bin Xing
- Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xiao-Chen Fu
- Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Cheng-Yu Huang
- Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Jing Wang
- Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, China
- *Correspondence: Jing Wang,
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5
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Zhang JF, Mehta S, Zhang J. Signaling Microdomains in the Spotlight: Visualizing Compartmentalized Signaling Using Genetically Encoded Fluorescent Biosensors. Annu Rev Pharmacol Toxicol 2021; 61:587-608. [PMID: 33411579 DOI: 10.1146/annurev-pharmtox-010617-053137] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
How cells muster a network of interlinking signaling pathways to faithfully convert diverse external cues to specific functional outcomes remains a central question in biology. Through their ability to convert dynamic biochemical activities to rapid and precise optical readouts, genetically encoded fluorescent biosensors have become instrumental in unraveling the molecular logic controlling the specificity of intracellular signaling. In this review, we discuss how the use of genetically encoded fluorescent biosensors to visualize dynamic signaling events within their native cellular context is elucidating the different strategies employed by cells to organize signaling activities into discrete compartments, or signaling microdomains, to ensure functional specificity.
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Affiliation(s)
- Jin-Fan Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, USA; .,Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, USA
| | - Sohum Mehta
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, USA;
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, USA; .,Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, USA.,Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
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6
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Soni H, Kumar R, Kanthakumar P, Adebiyi A. Interleukin 1 beta-induced calcium signaling via TRPA1 channels promotes mitogen-activated protein kinase-dependent mesangial cell proliferation. FASEB J 2021; 35:e21729. [PMID: 34143493 DOI: 10.1096/fj.202100367r] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/23/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022]
Abstract
Glomerular mesangial cell (GMC)-derived pleiotropic cytokine, interleukin-1 (IL-1), contributes to hypercellularity in human and experimental proliferative glomerulonephritis. IL-1 promotes mesangial proliferation and may stimulate extracellular matrix accumulation, mechanisms of which are unclear. The present study shows that the beta isoform of IL-1 (IL-1β) is a potent inducer of IL-1 type I receptor-dependent Ca2+ entry in mouse GMCs. We also demonstrate that the transient receptor potential ankyrin 1 (TRPA1) is an intracellular store-independent diacylglycerol-sensitive Ca2+ channel in the cells. IL-1β-induced Ca2+ and Ba2+ influxes in the cells were negated by pharmacological inhibition and siRNA-mediated knockdown of TRPA1 channels. IL-1β did not stimulate fibronectin production in cultured mouse GMCs and glomerular explants but promoted Ca2+ -dependent cell proliferation. IL-1β also stimulated TRPA1-dependent ERK mitogen-activated protein kinase (MAPK) phosphorylation in the cells. Concomitantly, IL-1β-induced GMC proliferation was attenuated by TRPA1 and RAF1/ MEK/ERK inhibitors. These findings suggest that IL-1β-induced Ca2+ entry via TRPA1 channels engenders MAPK-dependent mesangial cell proliferation. Hence, TRPA1-mediated Ca2+ signaling could be of pathological significance in proliferative glomerulonephritis.
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Affiliation(s)
- Hitesh Soni
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Ravi Kumar
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Praghalathan Kanthakumar
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Adebowale Adebiyi
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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7
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McBrearty N, Arzumanyan A, Bichenkov E, Merali S, Merali C, Feitelson M. Short chain fatty acids delay the development of hepatocellular carcinoma in HBx transgenic mice. Neoplasia 2021; 23:529-538. [PMID: 33945993 PMCID: PMC8111251 DOI: 10.1016/j.neo.2021.04.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 12/17/2022] Open
Abstract
Chronic infection with hepatitis B virus (HBV) is a major risk factor for the development of hepatocellular carcinoma (HCC). The HBV encoded oncoprotein, HBx, alters the expression of host genes and the activity of multiple signal transduction pathways that contribute to the pathogenesis of HCC by multiple mechanisms independent of HBV replication. However, it is not clear which pathways are the most relevant therapeutic targets in hepatocarcinogenesis. Short chain fatty acids (SCFAs) have strong anti-inflammatory and anti-neoplastic properties, suggesting that they may block the progression of chronic liver disease (CLD) to HCC, thereby identifying the mechanisms relevant to HCC development. This hypothesis was tested in HBx transgenic (HBxTg) mice fed SCFAs. Groups of HBxTg mice were fed with SCFAs or vehicle from 6 to 9 months of age and then assessed for dysplasia, and from 9 to 12 months of age and then assessed for HCC. Livers from 12 month old mice were then analyzed for changes in gene expression by mass spectrometry-based proteomics. SCFA-fed mice had significantly fewer dysplastic and HCC nodules compared to controls at 9 and 12 months, respectively. Pathway analysis of SCFA-fed mice showed down-regulation of signaling pathways altered by HBx in human CLD and HCC, including those involved in inflammation, phosphatidylinositol 3-kinase, epidermal growth factor, and Ras. SCFA treatment promoted increased expression of the tumor suppressor, disabled homolog 2 (DAB2). DAB2 depresses Ras pathway activity, which is constitutively activated by HBx. SCFAs also reduced cell viability in HBx-transfected cell lines in a dose-dependent manner while the viability of primary human hepatocytes was unaffected. These unique findings demonstrate that SCFAs delay the pathogenesis of CLD and development of HCC, and provide insight into some of the underlying mechanisms that are relevant to pathogenesis in that they are responsive to treatment.
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Affiliation(s)
- Noreen McBrearty
- Department of Biology, College of Science and Technology, Philadelphia, PA, USA
| | - Alla Arzumanyan
- Department of Biology, College of Science and Technology, Philadelphia, PA, USA
| | - Eugene Bichenkov
- Department of Biology, College of Science and Technology, Philadelphia, PA, USA
| | - Salim Merali
- Department of Pharmaceutical Sciences, School of Pharmacy, Temple University, Philadelphia, PA, USA
| | - Carmen Merali
- Department of Pharmaceutical Sciences, School of Pharmacy, Temple University, Philadelphia, PA, USA
| | - Mark Feitelson
- Department of Biology, College of Science and Technology, Philadelphia, PA, USA.
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Imaging dynamic mTORC1 pathway activity in vivo reveals marked shifts that support time-specific inhibitor therapy in AML. Nat Commun 2021; 12:245. [PMID: 33431855 PMCID: PMC7801403 DOI: 10.1038/s41467-020-20491-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 12/01/2020] [Indexed: 12/13/2022] Open
Abstract
Acute myeloid leukemia (AML) is a high remission, high relapse fatal blood cancer. Although mTORC1 is a master regulator of cell proliferation and survival, its inhibitors have not performed well as AML treatments. To uncover the dynamics of mTORC1 activity in vivo, fluorescent probes are developed to track single cell proliferation, apoptosis and mTORC1 activity of AML cells in the bone marrow of live animals and to quantify these activities in the context of microanatomical localization and intra-tumoral heterogeneity. When chemotherapy drugs commonly used clinically are given to mice with AML, apoptosis is rapid, diffuse and not preferentially restricted to anatomic sites. Dynamic measurement of mTORC1 activity indicated a decline in mTORC1 activity with AML progression. However, at the time of maximal chemotherapy response, mTORC1 signaling is high and positively correlated with a leukemia stemness transcriptional profile. Cell barcoding reveals the induction of mTORC1 activity rather than selection of mTORC1 high cells and timed inhibition of mTORC1 improved the killing of AML cells. These data define the real-time dynamics of AML and the mTORC1 pathway in association with AML growth, response to and relapse after chemotherapy. They provide guidance for timed intervention with pathway-specific inhibitors. The role of mTORC1 in AML has not yet been proven due to the mixed results of its inhibitors in clinical trials. Here the authors show the real-time dynamics of the mTORC1 pathway in association with AML growth and response to chemotherapy with fluorescent markers, providing guidance for timed intervention with pathway-specific inhibitors.
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9
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Pleiotropic Roles of Calmodulin in the Regulation of KRas and Rac1 GTPases: Functional Diversity in Health and Disease. Int J Mol Sci 2020; 21:ijms21103680. [PMID: 32456244 PMCID: PMC7279331 DOI: 10.3390/ijms21103680] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 12/21/2022] Open
Abstract
Calmodulin is a ubiquitous signalling protein that controls many biological processes due to its capacity to interact and/or regulate a large number of cellular proteins and pathways, mostly in a Ca2+-dependent manner. This complex interactome of calmodulin can have pleiotropic molecular consequences, which over the years has made it often difficult to clearly define the contribution of calmodulin in the signal output of specific pathways and overall biological response. Most relevant for this review, the ability of calmodulin to influence the spatiotemporal signalling of several small GTPases, in particular KRas and Rac1, can modulate fundamental biological outcomes such as proliferation and migration. First, direct interaction of calmodulin with these GTPases can alter their subcellular localization and activation state, induce post-translational modifications as well as their ability to interact with effectors. Second, through interaction with a set of calmodulin binding proteins (CaMBPs), calmodulin can control the capacity of several guanine nucleotide exchange factors (GEFs) to promote the switch of inactive KRas and Rac1 to an active conformation. Moreover, Rac1 is also an effector of KRas and both proteins are interconnected as highlighted by the requirement for Rac1 activation in KRas-driven tumourigenesis. In this review, we attempt to summarize the multiple layers how calmodulin can regulate KRas and Rac1 GTPases in a variety of cellular events, with biological consequences and potential for therapeutic opportunities in disease settings, such as cancer.
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10
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TAKAHASHI C, YAZAKI T, SUGIYAMA N, ISHIHAMA Y. Selected Reaction Monitoring of Kinase Activity-Targeted Phosphopeptides. CHROMATOGRAPHY 2019. [DOI: 10.15583/jpchrom.2019.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | - Tatsuya YAZAKI
- Graduate School of Pharmaceutical Science, Kyoto University
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11
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Greenwald EC, Mehta S, Zhang J. Genetically Encoded Fluorescent Biosensors Illuminate the Spatiotemporal Regulation of Signaling Networks. Chem Rev 2018; 118:11707-11794. [PMID: 30550275 PMCID: PMC7462118 DOI: 10.1021/acs.chemrev.8b00333] [Citation(s) in RCA: 359] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular signaling networks are the foundation which determines the fate and function of cells as they respond to various cues and stimuli. The discovery of fluorescent proteins over 25 years ago enabled the development of a diverse array of genetically encodable fluorescent biosensors that are capable of measuring the spatiotemporal dynamics of signal transduction pathways in live cells. In an effort to encapsulate the breadth over which fluorescent biosensors have expanded, we endeavored to assemble a comprehensive list of published engineered biosensors, and we discuss many of the molecular designs utilized in their development. Then, we review how the high temporal and spatial resolution afforded by fluorescent biosensors has aided our understanding of the spatiotemporal regulation of signaling networks at the cellular and subcellular level. Finally, we highlight some emerging areas of research in both biosensor design and applications that are on the forefront of biosensor development.
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Affiliation(s)
- Eric C Greenwald
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Sohum Mehta
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Jin Zhang
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
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12
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Villalobo A, Ishida H, Vogel HJ, Berchtold MW. Calmodulin as a protein linker and a regulator of adaptor/scaffold proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1865:507-521. [PMID: 29247668 DOI: 10.1016/j.bbamcr.2017.12.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 01/29/2023]
Abstract
Calmodulin (CaM) is a universal regulator for a huge number of proteins in all eukaryotic cells. Best known is its function as a calcium-dependent modulator of the activity of enzymes, such as protein kinases and phosphatases, as well as other signaling proteins including membrane receptors, channels and structural proteins. However, less well known is the fact that CaM can also function as a Ca2+-dependent adaptor protein, either by bridging between different domains of the same protein or by linking two identical or different target proteins together. These activities are possible due to the fact that CaM contains two independently-folded Ca2+ binding lobes that are able to interact differentially and to some degree separately with targets proteins. In addition, CaM can interact with and regulates several proteins that function exclusively as adaptors. This review provides an overview over our present knowledge concerning the structural and functional aspects of the role of CaM as an adaptor protein and as a regulator of known adaptor/scaffold proteins.
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Affiliation(s)
- Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, E-28029 Madrid, Spain.
| | - Hiroaki Ishida
- Department of Biological Sciences, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta T2N 1N4, Canada
| | - Hans J Vogel
- Department of Biological Sciences, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta T2N 1N4, Canada.
| | - Martin W Berchtold
- Department of Biology, University of Copenhagen, 13 Universitetsparken, DK-2100 Copenhagen Ø, Denmark.
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13
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Cardoso MDFS, Castelletti CHM, Lima-Filho JLD, Martins DBG, Teixeira JAC. Putative biomarkers for cervical cancer: SNVs, methylation and expression profiles. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2017; 773:161-173. [PMID: 28927526 DOI: 10.1016/j.mrrev.2017.06.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 02/08/2023]
Abstract
Cervical cancer is primarily caused by Human papillomavirus (HPV) infection, but other factors such as smoking habits, co-infections and genetic background, can also contribute to its development. Although this cancer is avoidable, it is the fourth most frequent type of cancer in females worldwide and can only be treated with chemotherapy and radical surgery. There is a need for biomarkers that will enable early diagnosis and targeted therapy for this type of cancer. Therefore, a systems biology pipeline was applied in order to identify potential biomarkers for cervical cancer, which show significant reports in three molecular aspects: DNA sequence variants, DNA methylation pattern and alterations in mRNA/protein expression levels. CDH1, CDKN2A, RB1 and TP53 genes were selected as putative biomarkers, being involved in metastasis, cell cycle regulation and tumour suppression. Other ten genes (CDH13, FHIT, PTEN, MLH1, TP73, CDKN1A, CACNA2D2, TERT, WIF1, APC) seemed to play a role in cervical cancer, but the lack of studies prevented their inclusion as possible biomarkers. Our results highlight the importance of these genes. However, further studies should be performed to elucidate the impact of DNA sequence variants and/or epigenetic deregulation and altered expression of these genes in cervical carcinogenesis and their potential as biomarkers for cervical cancer diagnosis and prognosis.
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Affiliation(s)
- Maria de Fátima Senra Cardoso
- Molecular Prospection and Bioinformatics Group (ProspecMol), Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego s/n, Recife - PE, 50670-901, Brazil.
| | - Carlos Henrique Madeiros Castelletti
- Molecular Prospection and Bioinformatics Group (ProspecMol), Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego s/n, Recife - PE, 50670-901, Brazil; Agronomic Institute of Pernambuco (IPA), Av. General San Martin 1371, Bongi, Recife - PE, 50761-000, Brazil
| | - José Luiz de Lima-Filho
- Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego s/n, Recife - PE, 50670-901, Brazil; Biochemistry Department, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego s/n, Recife - PE, 50670-901, Brazil
| | - Danyelly Bruneska Gondim Martins
- Molecular Prospection and Bioinformatics Group (ProspecMol), Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego s/n, Recife - PE, 50670-901, Brazil; Biochemistry Department, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego s/n, Recife - PE, 50670-901, Brazil
| | - José António Couto Teixeira
- Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego s/n, Recife - PE, 50670-901, Brazil; Department of Biological Engineering, University of Minho (UM), Campus de Gualtar, 4710-057 Braga, Portugal
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14
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Li WQ, Zhong NZ, He J, Li YM, Hou LJ, Liu HM, Xia CY, Wang LZ, Lu YC. High ATP2A2 expression correlates with better prognosis of diffuse astrocytic tumor patients. Oncol Rep 2017; 37:2865-2874. [PMID: 28339043 DOI: 10.3892/or.2017.5528] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 03/03/2017] [Indexed: 11/05/2022] Open
Abstract
Novel molecular markers are required for defining subsets of diffuse astrocytic tumor patients with differing prognoses. Here, we examined ATP2A2 expression in 109 human diffuse astrocytic tumor samples (39 grade II diffuse astrocytoma (DA), 19 grade III anaplastic astrocytoma (AA), 51 grade IV glioblastoma) and its correlation with patient clinicopathologic characteristics. ATP2A2 expression significantly correlated with tumor grade and survival (P<0.05). High ATP2A2 expression was detected in 35.3% (18/51) of glioblastoma patients, compared to 61.5% (24/39) in grade II, and 52.6% (10/19) in grade III astrocytoma patients (P=0.043). The median survival was 45±5.3 (95% CI, 34.7-55.3) months in patients with high ATP2A2 expression and 16±5.0 (95% CI, 6.3-25.7) months in patients with low ATP2A2 expression (P<0.0001). Additionally, high grade astrocytoma patients with high ATP2A2 expression showed longer survival (median, 31.0±4.9 months, 95% CI, 21.4-40.7) than those with low ATP2A2 expression (median: 13.0±1.6 months, 95% CI, 9.9-16.1; P=0.027). Furthermore, both ATP2A2 overexpression and IDH1 mutation were detected in secondary glioblastoma, AA developed from DA and oligodendrogiomas with IDH1 mutation. The MTT assays showed that lentiviral ATP2A2 overexpression significantly suppressed the clonogenic growth of glioblastoma U251MG cells (P<0.05). Xenografts stably overexpressing ATP2A2 were markedly smaller in size 4 weeks post inoculation (P<0.05). Our findings identified high ATP2A2 expression in a subset of astrocytoma patients that was associated with better prognosis and ATP2A2 suppressed astrocytoma growth.
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Affiliation(s)
- Wei-Qing Li
- Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Nan-Zhe Zhong
- Department of Orthopedic Oncology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Jin He
- Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Yi-Ming Li
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Li-Jun Hou
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Hui-Min Liu
- Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Chun-Yan Xia
- Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Liang-Zhe Wang
- Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
| | - Yi-Cheng Lu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
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15
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Kinoshita A, Niwa Y, Onai K, Yamano T, Fukuzawa H, Ishiura M, Matsuo T. CSL encodes a leucine-rich-repeat protein implicated in red/violet light signaling to the circadian clock in Chlamydomonas. PLoS Genet 2017; 13:e1006645. [PMID: 28333924 PMCID: PMC5363811 DOI: 10.1371/journal.pgen.1006645] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/20/2017] [Indexed: 01/12/2023] Open
Abstract
The green alga Chlamydomonas reinhardtii shows various light responses in behavior and physiology. One such photoresponse is the circadian clock, which can be reset by external light signals to entrain its oscillation to daily environmental cycles. In a previous report, we suggested that a light-induced degradation of the clock protein ROC15 is a trigger to reset the circadian clock in Chlamydomonas. However, light signaling pathways of this process remained unclear. Here, we screened for mutants that show abnormal ROC15 diurnal rhythms, including the light-induced protein degradation at dawn, using a luciferase fusion reporter. In one mutant, ROC15 degradation and phase resetting of the circadian clock by light were impaired. Interestingly, the impairments were observed in response to red and violet light, but not to blue light. We revealed that an uncharacterized gene encoding a protein similar to RAS-signaling-related leucine-rich repeat (LRR) proteins is responsible for the mutant phenotypes. Our results indicate that a previously uncharacterized red/violet light signaling pathway is involved in the phase resetting of circadian clock in Chlamydomonas. The unicellular green alga Chlamydomonas reinhardtii is used as a model system in many biological researches. Although blue light responses of this alga (e.g., phototaxis) are well known and well characterized, far less is understood about responses to other wavelengths. One such photoresponse is the circadian clock, which can be reset by various wavelengths of light, ranging from violet to red, to entrain its oscillation to daily environmental cycles. In this study, we identified a gene responsible for red and violet light responses of the circadian clock by a forward genetic screen. Our results shed light on a previously unrecognized red/violet light signaling pathway in green algae.
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Affiliation(s)
- Ayumi Kinoshita
- Center for Gene Research, Nagoya University, Nagoya, Japan
- Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Yoshimi Niwa
- Center for Gene Research, Nagoya University, Nagoya, Japan
- Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Kiyoshi Onai
- Center for Gene Research, Nagoya University, Nagoya, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Masahiro Ishiura
- Center for Gene Research, Nagoya University, Nagoya, Japan
- Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Takuya Matsuo
- Center for Gene Research, Nagoya University, Nagoya, Japan
- Graduate School of Science, Nagoya University, Nagoya, Japan
- * E-mail:
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16
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Jeoung M, Jang ER, Liu J, Wang C, Rouchka EC, Li X, Galperin E. Shoc2-tranduced ERK1/2 motility signals--Novel insights from functional genomics. Cell Signal 2016; 28:448-459. [PMID: 26876614 DOI: 10.1016/j.cellsig.2016.02.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 02/05/2016] [Accepted: 02/08/2016] [Indexed: 12/19/2022]
Abstract
The extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway plays a central role in defining various cellular fates. Scaffold proteins modulating ERK1/2 activity control growth factor signals transduced by the pathway. Here, we analyzed signals transduced by Shoc2, a critical positive modulator of ERK1/2 activity. We found that loss of Shoc2 results in impaired cell motility and delays cell attachment. As ERKs control cellular fates by stimulating transcriptional response, we hypothesized that the mechanisms underlying changes in cell adhesion could be revealed by assessing the changes in transcription of Shoc2-depleted cells. Using quantitative RNA-seq analysis, we identified 853 differentially expressed transcripts. Characterization of the differentially expressed genes showed that Shoc2 regulates the pathway at several levels, including expression of genes controlling cell motility, adhesion, crosstalk with the transforming growth factor beta (TGFβ) pathway, and expression of transcription factors. To understand the mechanisms underlying delayed attachment of cells depleted of Shoc2, changes in expression of the protein of extracellular matrix (lectin galactoside-binding soluble 3-binding protein; LGALS3BP) were functionally analyzed. We demonstrated that delayed adhesion of the Shoc2-depleted cells is a result of attenuated expression and secretion of LGALS3BP. Together our results suggest that Shoc2 regulates cell motility by modulating ERK1/2 signals to cell adhesion.
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Affiliation(s)
- Myoungkun Jeoung
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, United States
| | - Eun Ryoung Jang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, United States
| | - Jinpeng Liu
- Markey Cancer Center and Department of Biostatistics, University of Kentucky, Lexington, KY 40536, United States
| | - Chi Wang
- Markey Cancer Center and Department of Biostatistics, University of Kentucky, Lexington, KY 40536, United States
| | - Eric C Rouchka
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, United States
| | - Xiaohong Li
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, United States; Department of Bioinformatics and Biostatistics, University of Louisville, Louisville, KY 40292, United States
| | - Emilia Galperin
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, United States.
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17
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Jang ER, Jang H, Shi P, Popa G, Jeoung M, Galperin E. Spatial control of Shoc2-scaffold-mediated ERK1/2 signaling requires remodeling activity of the ATPase PSMC5. J Cell Sci 2015; 128:4428-41. [PMID: 26519477 DOI: 10.1242/jcs.177543] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/21/2015] [Indexed: 12/13/2022] Open
Abstract
The scaffold protein Shoc2 accelerates activity of the ERK1 and ERK2 (ERK1/2, also known as MAPK3 and MAPK1) pathway. Mutations in Shoc2 result in Noonan-like RASopathy, a developmental disorder with a wide spectrum of symptoms. The amplitude of the ERK1/2 signals transduced through the complex is fine-tuned by the HUWE1-mediated ubiquitylation of Shoc2 and its signaling partner RAF-1. Here, we provide a mechanistic basis of how ubiquitylation of Shoc2 and RAF-1 is controlled. We demonstrate that the newly identified binding partner of Shoc2, the (AAA+) ATPase PSMC5, triggers translocation of Shoc2 to endosomes. At the endosomes, PSMC5 displaces the E3 ligase HUWE1 from the scaffolding complex to attenuate ubiquitylation of Shoc2 and RAF-1. We show that a RASopathy mutation that changes the subcellular distribution of Shoc2 leads to alterations in Shoc2 ubiquitylation due to the loss of accessibility to PSMC5. In summary, our results demonstrate that PSMC5 is a new and important player involved in regulating ERK1/2 signal transmission through the remodeling of Shoc2 scaffold complex in a spatially-defined manner.
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Affiliation(s)
- Eun Ryoung Jang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - HyeIn Jang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Ping Shi
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Gabriel Popa
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Myoungkun Jeoung
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Emilia Galperin
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
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18
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Abstract
The Shoc2 protein has been implicated in the positive regulation of the Ras-ERK pathway by increasing the functional binding interaction between Ras and Raf, leading to increased ERK activity. Here we found that Shoc2 overexpression induced sustained ERK phosphorylation, notably in the case of EGF stimulation, and Shoc2 knockdown inhibited ERK activation. We demonstrate that ectopic overexpression of human Shoc2 in PC12 cells significantly promotes neurite extension in the presence of EGF, a stimulus that induces proliferation rather than differentiation in these cells. Finally, Shoc2 depletion reduces both NGF-induced neurite outgrowth and ERK activation in PC12 cells. Our data indicate that Shoc2 is essential to modulate the Ras-ERK signaling outcome in cell differentiation processes involved in neurite outgrowth.
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19
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HUWE1 is a molecular link controlling RAF-1 activity supported by the Shoc2 scaffold. Mol Cell Biol 2014; 34:3579-93. [PMID: 25022756 DOI: 10.1128/mcb.00811-14] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Scaffold proteins play a critical role in controlling the activity of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway. Shoc2 is a leucine-rich repeat scaffold protein that acts as a positive modulator of ERK1/2 signaling. However, the precise mechanism by which Shoc2 modulates the activity of the ERK1/2 pathway is unclear. Here we report the identification of the E3 ubiquitin ligase HUWE1 as a binding partner and regulator of Shoc2 function. HUWE1 mediates ubiquitination and, consequently, the levels of Shoc2. Additionally, we show that both Shoc2 and HUWE1 are necessary to control the levels and ubiquitination of the Shoc2 signaling partner, RAF-1. Depletion of HUWE1 abolishes RAF-1 ubiquitination, with corresponding changes in ERK1/2 pathway activity occurring. Our results indicate that the HUWE1-mediated ubiquitination of Shoc2 is the switch that regulates the transition from an active to an inactive state of the RAF-1 kinase. Taken together, our results demonstrate that HUWE1 is a novel player involved in regulating ERK1/2 signal transmission through the Shoc2 scaffold complex.
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20
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Quantitative in vivo fluorescence cross-correlation analyses highlight the importance of competitive effects in the regulation of protein-protein interactions. Mol Cell Biol 2014; 34:3272-90. [PMID: 24958104 DOI: 10.1128/mcb.00087-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Computer-assisted simulation is a promising approach for clarifying complicated signaling networks. However, this approach is currently limited by a deficiency of kinetic parameters determined in living cells. To overcome this problem, we applied fluorescence cross-correlation spectrometry (FCCS) to measure dissociation constant (Kd) values of signaling molecule complexes in living cells (in vivo Kd). Among the pairs of fluorescent molecules tested, that of monomerized enhanced green fluorescent protein (mEGFP) and HaloTag-tetramethylrhodamine was most suitable for the measurement of in vivo Kd by FCCS. Using this pair, we determined 22 in vivo Kd values of signaling molecule complexes comprising the epidermal growth factor receptor (EGFR)-Ras-extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase pathway. With these parameters, we developed a kinetic simulation model of the EGFR-Ras-ERK MAP kinase pathway and uncovered a potential role played by stoichiometry in Shc binding to EGFR during the peak activations of Ras, MEK, and ERK. Intriguingly, most of the in vivo Kd values determined in this study were higher than the in vitro Kd values reported previously, suggesting the significance of competitive bindings inside cells. These in vivo Kd values will provide a sound basis for the quantitative understanding of signal transduction.
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21
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Jeoung M, Abdelmoti L, Jang ER, Vander Kooi CW, Galperin E. Functional Integration of the Conserved Domains of Shoc2 Scaffold. PLoS One 2013; 8:e66067. [PMID: 23805200 PMCID: PMC3689688 DOI: 10.1371/journal.pone.0066067] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 05/05/2013] [Indexed: 01/25/2023] Open
Abstract
Shoc2 is a positive regulator of signaling to extracellular signal-regulated protein kinases 1 and 2 (ERK1/2). Shoc2 is also proposed to interact with RAS and Raf-1 in order to accelerate ERK1/2 activity. To understand the mechanisms by which Shoc2 regulates ERK1/2 activation by the epidermal growth factor receptor (EGFR), we dissected the role of Shoc2 structural domains in binding to its signaling partners and its role in regulating ERK1/2 activity. Shoc2 is comprised of two main domains: the 21 leucine rich repeats (LRRs) core and the N-terminal non-LRR domain. We demonstrated that the N-terminal domain mediates Shoc2 binding to both M-Ras and Raf-1, while the C-terminal part of Shoc2 contains a late endosomal targeting motif. We found that M-Ras binding to Shoc2 is independent of its GTPase activity. While overexpression of Shoc2 did not change kinetics of ERK1/2 activity, both the N-terminal and the LRR-core domain were able to rescue ERK1/2 activity in cells depleted of Shoc2, suggesting that these Shoc2 domains are involved in modulating ERK1/2 activity.
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Affiliation(s)
- Myoungkun Jeoung
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Lina Abdelmoti
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Eun Ryoung Jang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Craig W. Vander Kooi
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Emilia Galperin
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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22
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Harmon RM, Simpson CL, Johnson JL, Koetsier JL, Dubash AD, Najor NA, Sarig O, Sprecher E, Green KJ. Desmoglein-1/Erbin interaction suppresses ERK activation to support epidermal differentiation. J Clin Invest 2013; 123:1556-70. [PMID: 23524970 DOI: 10.1172/jci65220] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 01/17/2013] [Indexed: 01/27/2023] Open
Abstract
Genetic disorders of the Ras/MAPK pathway, termed RASopathies, produce numerous abnormalities, including cutaneous keratodermas. The desmosomal cadherin, desmoglein-1 (DSG1), promotes keratinocyte differentiation by attenuating MAPK/ERK signaling and is linked to striate palmoplantar keratoderma (SPPK). This raises the possibility that cutaneous defects associated with SPPK and RASopathies share certain molecular faults. To identify intermediates responsible for executing the inhibition of ERK by DSG1, we conducted a yeast 2-hybrid screen. The screen revealed that Erbin (also known as ERBB2IP), a known ERK regulator, binds DSG1. Erbin silencing disrupted keratinocyte differentiation in culture, mimicking aspects of DSG1 deficiency. Furthermore, ERK inhibition and the induction of differentiation markers by DSG1 required both Erbin and DSG1 domains that participate in binding Erbin. Erbin blocks ERK signaling by interacting with and disrupting Ras-Raf scaffolds mediated by SHOC2, a protein genetically linked to the RASopathy, Noonan-like syndrome with loose anagen hair (NS/LAH). DSG1 overexpression enhanced this inhibitory function, increasing Erbin-SHOC2 interactions and decreasing Ras-SHOC2 interactions. Conversely, analysis of epidermis from DSG1-deficient patients with SPPK demonstrated increased Ras-SHOC2 colocalization and decreased Erbin-SHOC2 colocalization, offering a possible explanation for the observed epidermal defects. These findings suggest a mechanism by which DSG1 and Erbin cooperate to repress MAPK signaling and promote keratinocyte differentiation.
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Affiliation(s)
- Robert M Harmon
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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23
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Delprato A. Topological and functional properties of the small GTPases protein interaction network. PLoS One 2012; 7:e44882. [PMID: 23028658 PMCID: PMC3441499 DOI: 10.1371/journal.pone.0044882] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 08/15/2012] [Indexed: 12/31/2022] Open
Abstract
Small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) regulate key cellular processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. A great deal of experimental evidence supports the existence of signaling cascades and feedback loops within and among the small GTPase subfamilies suggesting that these proteins function in a coordinated and cooperative manner. The interplay occurs largely through association with bi-partite regulatory and effector proteins but can also occur through the active form of the small GTPases themselves. In order to understand the connectivity of the small GTPases signaling routes, a systems-level approach that analyzes data describing direct and indirect interactions was used to construct the small GTPases protein interaction network. The data were curated from the Search Tool for the Retrieval of Interacting Genes (STRING) database and include only experimentally validated interactions. The network method enables the conceptualization of the overall structure as well as the underlying organization of the protein-protein interactions. The interaction network described here is comprised of 778 nodes and 1943 edges and has a scale-free topology. Rac1, Cdc42, RhoA, and HRas are identified as the hubs. Ten sub-network motifs are also identified in this study with themes in apoptosis, cell growth/proliferation, vesicle traffic, cell adhesion/junction dynamics, the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase response, transcription regulation, receptor-mediated endocytosis, gene silencing, and growth factor signaling. Bottleneck proteins that bridge signaling paths and proteins that overlap in multiple small GTPase networks are described along with the functional annotation of all proteins in the network.
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Affiliation(s)
- Anna Delprato
- BioScience Project, Wakefield, Massachusetts, United States of America.
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24
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Galperin E, Abdelmoti L, Sorkin A. Shoc2 is targeted to late endosomes and required for Erk1/2 activation in EGF-stimulated cells. PLoS One 2012; 7:e36469. [PMID: 22606262 PMCID: PMC3351432 DOI: 10.1371/journal.pone.0036469] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Accepted: 04/05/2012] [Indexed: 12/21/2022] Open
Abstract
Shoc2 is the putative scaffold protein that interacts with RAS and RAF, and positively regulates signaling to extracellular signal-regulated protein kinases 1 and 2 (ERK1/2). To elucidate the mechanism by which Shoc2 regulates ERK1/2 activation by the epidermal growth factor (EGF) receptor (EGFR), we studied subcellular localization of Shoc2. Upon EGFR activation, endogenous Shoc2 and red fluorescent protein tagged Shoc2 were translocated from the cytosol to a subset of late endosomes containing Rab7. The endosomal recruitment of Shoc2 was blocked by overexpression of a GDP-bound H-RAS (N17S) mutant and RNAi knockdown of clathrin, suggesting the requirement of RAS activity and clathrin-dependent endocytosis. RNAi depletion of Shoc2 strongly inhibited activation of ERK1/2 by low, physiological EGF concentrations, which was rescued by expression of wild-type recombinant Shoc2. In contrast, the Shoc2 (S2G) mutant, that is myristoylated and found in patients with the Noonan-like syndrome, did not rescue ERK1/2 activation in Shoc2-depleted cells. Shoc2 (S2G) was not located in late endosomes but was present on the plasma membrane and early endosomes. These data suggest that targeting of Shoc2 to late endosomes may facilitate EGFR-induced ERK activation under physiological conditions of cell stimulation by EGF, and therefore, may be involved in the spatiotemporal regulation of signaling through the RAS-RAF module.
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Affiliation(s)
- Emilia Galperin
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, United States of America.
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25
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Abascal F, Zardoya R. LRRC8 proteins share a common ancestor with pannexins, and may form hexameric channels involved in cell-cell communication. Bioessays 2012; 34:551-60. [DOI: 10.1002/bies.201100173] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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26
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Yagi S, Matsuda M, Kiyokawa E. Suppression of Rac1 activity at the apical membrane of MDCK cells is essential for cyst structure maintenance. EMBO Rep 2012; 13:237-43. [PMID: 22261715 DOI: 10.1038/embor.2011.249] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 11/30/2011] [Accepted: 12/01/2011] [Indexed: 12/21/2022] Open
Abstract
Using MDCK cells that constitutively express a Förster resonance energy transfer biosensor, we found that Rac1 activity is homogenous at the entire plasma membrane in early stages of cystogenesis, whereas in later stages Rac1 activity is higher at the lateral membrane than at the apical plasma membrane. If Rac1 is activated at the apical membrane in later stages, however, the monolayer cells move into the luminal space. In these cells, tight junctions are disrupted, accompanied by mislocalization of polarization markers and disorientation of cell division. These observations indicate that Rac1 suppression at the apical membrane is essential for the maintenance of cyst structure.
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Affiliation(s)
- Shunsuke Yagi
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Yoshida Konoe-cho, Kyoto 606-8501, Japan
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Hirata E, Yukinaga H, Kamioka Y, Arakawa Y, Miyamoto S, Okada T, Sahai E, Matsuda M. In vivo fluorescence resonance energy transfer imaging reveals differential activation of Rho-family GTPases in glioblastoma cell invasion. J Cell Sci 2012; 125:858-68. [PMID: 22399802 DOI: 10.1242/jcs.089995] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024] Open
Abstract
Two-photon excitation microscopy was used to visualized two different modes of invasion at perivascular and intraparenchymal regions of rat C6 glioblastoma cells that were orthotopically implanted into rat brains. Probes based on the principle of Förster resonance energy transfer (FRET) further revealed that glioblastoma cells penetrating the brain parenchyma showed higher Rac1 and Cdc42 activities and lower RhoA activity than those advancing in the perivascular regions. This spatial regulation of Rho-family GTPase activities was recapitulated in three-dimensional spheroid invasion assays with rat and human glioblastoma cells, in which multipod glioblastoma cells that invaded the gels and led the other glioblastoma cells exhibited higher Rac1 and Cdc42 activities than the trailing glioblastoma cells. We also studied the Cdc42-specific guanine nucleotide exchange factor Zizimin1 (also known as DOCK9) as a possible contributor to this spatially controlled activation of Rho-family GTPases, because it is known to play an essential role in the extension of neurites. We found that shRNA-mediated knockdown of Zizimin1 inhibited formation of pseudopodia and concomitant invasion of glioblastoma cells both under a 3D culture condition and in vivo. Our results suggest that the difference in the activity balance of Rac1 and Cdc42 versus RhoA determines the mode of glioblastoma invasion and that Zizimin1 contributes to the invasiveness of glioblastoma cells with high Rac1 and Cdc42 activities.
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Affiliation(s)
- Eishu Hirata
- Department of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
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28
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Aoki K, Komatsu N, Hirata E, Kamioka Y, Matsuda M. Stable expression of FRET biosensors: a new light in cancer research. Cancer Sci 2012; 103:614-9. [PMID: 22188216 DOI: 10.1111/j.1349-7006.2011.02196.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 12/14/2011] [Accepted: 12/15/2011] [Indexed: 01/22/2023] Open
Abstract
The constituents of the oncogene signal transduction pathway are promising targets for anticancer drugs. Despite the wealth of available knowledge regarding their molecular properties, the spatiotemporal regulation of the signaling molecules remains elusive. Biosensors based on the principle of FRET have been developed to visualize the activities of the signaling molecules in living cells. However, difficulties in the development of sensitive FRET biosensors have prevented their widespread use in cancer research. The lack of cell lines constitutively expressing a FRET biosensor has also limited their use. In this review, we will introduce the principle of FRET-based biosensors, describe an optimized backbone of the FRET biosensors, techniques to express FRET biosensors stably in the cells, and discuss the future perspectives of FRET biosensors in cancer research.
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Affiliation(s)
- Kazuhiro Aoki
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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29
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Kamioka Y, Sumiyama K, Mizuno R, Sakai Y, Hirata E, Kiyokawa E, Matsuda M. Live imaging of protein kinase activities in transgenic mice expressing FRET biosensors. Cell Struct Funct 2012; 37:65-73. [PMID: 22277578 DOI: 10.1247/csf.11045] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Genetically-encoded biosensors based on the principle of Förster resonance energy transfer (FRET) have been widely used in biology to visualize the spatiotemporal dynamics of signaling molecules. Despite the increasing multitude of these biosensors, their application has been mostly limited to cultured cells with transient biosensor expression, due to particular difficulties in the development of transgenic mice that express FRET biosensors. In this study, we report the efficient generation of transgenic mouse lines expressing heritable and functional biosensors for ERK and PKA. These transgenic mice were created by the cytoplasmic co-injection of Tol2 transposase mRNA and a circular plasmid harbouring Tol2 recombination sites. High expression of the biosensors in a wide range of cell types allowed us to screen newborn mice simply by inspection. Observation of these transgenic mice by two-photon excitation microscopy yielded real-time activity maps of ERK and PKA in various tissues, with greatly improved signal-to-background ratios. Our transgenic mice may be bred into diverse genetic backgrounds; moreover, the protocol we have developed paves the way for the generation of transgenic mice that express other FRET biosensors, with important applications in the characterization of physiological and pathological signal transduction events in addition to drug development and screening.
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Affiliation(s)
- Yuji Kamioka
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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30
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A genetically encoded Förster resonance energy transfer biosensor for two-photon excitation microscopy. Anal Biochem 2011; 413:192-9. [DOI: 10.1016/j.ab.2011.02.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 02/14/2011] [Accepted: 02/16/2011] [Indexed: 12/16/2022]
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31
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Kiyokawa E, Aoki K, Nakamura T, Matsuda M. Spatiotemporal regulation of small GTPases as revealed by probes based on the principle of Förster Resonance Energy Transfer (FRET): Implications for signaling and pharmacology. Annu Rev Pharmacol Toxicol 2011; 51:337-58. [PMID: 20936947 DOI: 10.1146/annurev-pharmtox-010510-100234] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Low molecular weight ("small") GTPases are key regulators of a number of signaling cascades. Each GTPase is regulated by numerous guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs), and each GTPase binds to numerous effector proteins in a GTP-dependent manner. In many instances, individual regulators activate more than one GTPase, and each effector binds to one or more GTPases belonging to the same family. To untangle these complex networks, probes based on the principle of Förster resonance energy transfer (FRET) are widely used. Here, we provide an overview of the probes based on FRET and examples of discoveries achieved with them. In the process, we attempt to delineate the merits, current limitations, and future applications of this technique to pharmacological studies.
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Affiliation(s)
- Etsuko Kiyokawa
- Department of Pathology and Biology of Diseases, Kyoto University, Japan
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32
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Udell CM, Rajakulendran T, Sicheri F, Therrien M. Mechanistic principles of RAF kinase signaling. Cell Mol Life Sci 2011; 68:553-65. [PMID: 20820846 PMCID: PMC11114552 DOI: 10.1007/s00018-010-0520-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 08/24/2010] [Accepted: 08/25/2010] [Indexed: 12/19/2022]
Abstract
The RAF family of kinases are key components acting downstream of receptor tyrosine kinases and cells employ several distinct mechanisms to strictly control their activity. RAF transitions from an inactive state, where the N-terminal regulatory region binds intramolecularly to the C-terminal kinase domain, to an open state capable of executing the phosphoryl transfer reaction. This transition involves changes both within and between the protein domains in RAF. Many different proteins regulate the transition between inactive and active states of RAF, including RAS and KSR, which are arguably the two most prominent regulators of RAF function. Recent developments have added several new twists to our understanding of RAF regulation. Among others, dimerization of the RAF kinase domain is emerging as a crucial step in the RAF activation process. The multitude of regulatory protein-protein interactions involving RAF remains a largely untapped area for therapeutic applications.
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Affiliation(s)
- Christian M. Udell
- Laboratory of Intracellular Signaling, Département de pathologie et de biologie cellulaire, Institute for Research in Immunology and Cancer, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC H3C 3J7 Canada
| | - Thanashan Rajakulendran
- Centre for Systems Biology, Samuel Lunenfeld Research Institute, Toronto, ON M5G 1X5 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8 Canada
| | - Frank Sicheri
- Centre for Systems Biology, Samuel Lunenfeld Research Institute, Toronto, ON M5G 1X5 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8 Canada
| | - Marc Therrien
- Laboratory of Intracellular Signaling, Département de pathologie et de biologie cellulaire, Institute for Research in Immunology and Cancer, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC H3C 3J7 Canada
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