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Meraz IM, Majidi M, Fang B, Meng F, Gao L, Shao R, Song R, Li F, Lissanu Y, Chen H, Ha MJ, Wang Q, Wang J, Shpall E, Jung SY, Haderk F, Gui P, Riess JW, Olivas V, Bivona TG, Roth JA. 3-Phosphoinositide-dependent kinase 1 drives acquired resistance to osimertinib. Commun Biol 2023; 6:509. [PMID: 37169941 PMCID: PMC10175489 DOI: 10.1038/s42003-023-04889-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 05/01/2023] [Indexed: 05/13/2023] Open
Abstract
Osimertinib sensitive and resistant NSCLC NCI-H1975 clones are used to model osimertinib acquired resistance in humanized and non-humanized mice and delineate potential resistance mechanisms. No new EGFR mutations or loss of the EGFR T790M mutation are found in resistant clones. Resistant tumors grown under continuous osimertinib pressure both in humanized and non-humanized mice show aggressive tumor regrowth which is significantly less sensitive to osimertinib as compared with parental tumors. 3-phosphoinositide-dependent kinase 1 (PDK1) is identified as a potential driver of osimertinib acquired resistance, and its selective inhibition by BX795 and CRISPR gene knock out, sensitizes resistant clones. In-vivo inhibition of PDK1 enhances the osimertinib sensitivity against osimertinib resistant xenograft and a patient derived xenograft (PDX) tumors. PDK1 knock-out dysregulates PI3K/Akt/mTOR signaling, promotes cell cycle arrest at the G1 phase. Yes-associated protein (YAP) and active-YAP are upregulated in resistant tumors, and PDK1 knock-out inhibits nuclear translocation of YAP. Higher expression of PDK1 and an association between PDK1 and YAP are found in patients with progressive disease following osimertinib treatment. PDK1 is a central upstream regulator of two critical drug resistance pathways: PI3K/AKT/mTOR and YAP.
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Affiliation(s)
- Ismail M Meraz
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
| | - Mourad Majidi
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Bingliang Fang
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Feng Meng
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Lihui Gao
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - RuPing Shao
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Renduo Song
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Feng Li
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yonathan Lissanu
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Huiqin Chen
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Min Jin Ha
- Department of Biostatistics, Graduate School of Public Health, Yonsei University, Seoul, Korea
| | - Qi Wang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jing Wang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Elizabeth Shpall
- Department of Stem Cell Transplantation, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Sung Yun Jung
- Department of Biochemistry, Baylor College of Medicine, Houston, TX, USA
| | - Franziska Haderk
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | - Philippe Gui
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | | | - Victor Olivas
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
| | - Trever G Bivona
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | - Jack A Roth
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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2
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Koutsougianni F, Alexopoulou D, Uvez A, Lamprianidou A, Sereti E, Tsimplouli C, Ilkay Armutak E, Dimas K. P90 ribosomal S6 kinases: A bona fide target for novel targeted anticancer therapies? Biochem Pharmacol 2023; 210:115488. [PMID: 36889445 DOI: 10.1016/j.bcp.2023.115488] [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: 09/19/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023]
Abstract
The 90 kDa ribosomal S6 kinase (RSK) family of proteins is a group of highly conserved Ser/Thr kinases. They are downstream effectors of the Ras/ERK/MAPK signaling cascade. ERK1/2 activation directly results in the phosphorylation of RSKs, which further, through interaction with a variety of different downstream substrates, activate various signaling events. In this context, they have been shown to mediate diverse cellular processes like cell survival, growth, proliferation, EMT, invasion, and metastasis. Interestingly, increased expression of RSKs has also been demonstrated in various cancers, such as breast, prostate, and lung cancer. This review aims to present the most recent advances in the field of RSK signaling that have occurred, such as biological insights, function, and mechanisms associated with carcinogenesis. We additionally present and discuss the recent advances but also the limitations in the development of pharmacological inhibitors of RSKs, in the context of the use of these kinases as putative, more efficient targets for novel anticancer therapeutic approaches.
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Affiliation(s)
- Fani Koutsougianni
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Dimitra Alexopoulou
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Ayca Uvez
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, 34500 Istanbul, Turkey
| | - Andromachi Lamprianidou
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Evangelia Sereti
- Dept of Translational Medicine, Medical Faculty, Lund University and Center for Molecular Pathology, Skäne University Hospital, Jan Waldenströms gata 59, SE 205 02 Malmö, Sweden
| | - Chrisiida Tsimplouli
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Elif Ilkay Armutak
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, 34500 Istanbul, Turkey
| | - Konstantinos Dimas
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece.
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3
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Gupta S, Sharma P, Chaudhary M, Premraj S, Kaur S, Vijayan V, Arun MG, Prasad NG, Ramachandran R. Pten associates with important gene regulatory network to fine-tune Müller glia-mediated zebrafish retina regeneration. Glia 2023; 71:259-283. [PMID: 36128720 DOI: 10.1002/glia.24270] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 11/11/2022]
Abstract
Unlike mammals, zebrafish possess a remarkable ability to regenerate damaged retina after an acute injury. Retina regeneration in zebrafish involves the induction of Müller glia-derived progenitor cells (MGPCs) exhibiting stem cell-like characteristics, which are capable of restoring all retinal cell-types. The induction of MGPC through Müller glia-reprograming involves several cellular, genetic and biochemical events soon after a retinal injury. Despite the knowledge on the importance of Phosphatase and tensin homolog (Pten), which is a dual-specificity phosphatase and tumor suppressor in the maintaining of cellular homeostasis, its importance during retina regeneration remains unknown. Here, we explored the importance of Pten during zebrafish retina regeneration. The Pten gets downregulated upon retinal injury and is absent from the MGPCs, which is essential to trigger Akt-mediated cellular proliferation essential for retina regeneration. We found that the downregulation of Pten in the post-injury retina accelerates MGPCs formation, while its overexpression restricts the regenerative response. We observed that Pten regulates the proliferation of MGPCs not only through Akt pathway but also by Mmp9/Notch signaling. Mmp9-activity is essential to induce the proliferation of MGPCs in the absence of Pten. Lastly, we show that expression of Pten is fine-tuned through Mycb/histone deacetylase1 and Tgf-β signaling. The present study emphasizes on the stringent regulation of Pten and its crucial involvement during the zebrafish retina regeneration.
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Affiliation(s)
- Shivangi Gupta
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Poonam Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Mansi Chaudhary
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Sharanya Premraj
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Simran Kaur
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Vijithkumar Vijayan
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Manas Geeta Arun
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Nagaraj Guru Prasad
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Rajesh Ramachandran
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, Punjab, India
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4
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Gupta S, Kumar M, Chaudhuri S, Kumar A. The non-canonical nuclear functions of key players of the PI3K-AKT-MTOR pathway. J Cell Physiol 2022; 237:3181-3204. [PMID: 35616326 DOI: 10.1002/jcp.30782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/05/2022] [Accepted: 05/02/2022] [Indexed: 12/29/2022]
Abstract
The PI3K-AKT-MTOR signal transduction pathway is one of the essential signalling cascades within the cell due to its involvement in many vital functions. The pathway initiates with the recruitment of phosphatidylinositol-3 kinases (PI3Ks) onto the plasma membrane, generating phosphatidylinositol-3,4,5-triphosphate [PtdIns(3,4,5)P3 ] and subsequently activating AKT. Being the central node of the PI3K network, AKT activates the mechanistic target of rapamycin kinase complex 1 (MTORC1) via Tuberous sclerosis complex 2 inhibition in the cytoplasm. Although the cytoplasmic role of the pathway has been widely explored for decades, we now know that most of the effector molecules of the PI3K axis diverge from the canonical route and translocate to other cell organelles including the nucleus. The presence of phosphoinositides (PtdIns) inside the nucleus itself indicates the existence of a nuclear PI3K signalling. The nuclear localization of these signaling components is evident in regulating many nuclear processes like DNA replication, transcription, DNA repair, maintenance of genomic integrity, chromatin architecture, and cell cycle control. Here, our review intends to present a comprehensive overview of the nuclear functions of the PI3K-AKT-MTOR signaling biomolecules.
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Affiliation(s)
- Sakshi Gupta
- Department of Molecular Reproduction, Development & Genetics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Mukund Kumar
- Department of Molecular Reproduction, Development & Genetics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Soumi Chaudhuri
- Department of Molecular Reproduction, Development & Genetics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Arun Kumar
- Department of Molecular Reproduction, Development & Genetics, Indian Institute of Science, Bangalore, Karnataka, India
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5
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Levina A, Fleming KD, Burke JE, Leonard TA. Activation of the essential kinase PDK1 by phosphoinositide-driven trans-autophosphorylation. Nat Commun 2022; 13:1874. [PMID: 35387990 PMCID: PMC8986801 DOI: 10.1038/s41467-022-29368-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/08/2022] [Indexed: 12/18/2022] Open
Abstract
3-phosphoinositide-dependent kinase 1 (PDK1) is an essential serine/threonine protein kinase, which plays a crucial role in cell growth and proliferation. It is often referred to as a 'master' kinase due to its ability to activate at least 23 downstream protein kinases implicated in various signaling pathways. In this study, we have elucidated the mechanism of phosphoinositide-driven PDK1 auto-activation. We show that PDK1 trans-autophosphorylation is mediated by a PIP3-mediated face-to-face dimer. We report regulatory motifs in the kinase-PH interdomain linker that allosterically activate PDK1 autophosphorylation via a linker-swapped dimer mechanism. Finally, we show that PDK1 is autoinhibited by its PH domain and that positive cooperativity of PIP3 binding drives switch-like activation of PDK1. These results imply that the PDK1-mediated activation of effector kinases, including Akt, PKC, Sgk, S6K and RSK, many of whom are not directly regulated by phosphoinositides, is also likely to be dependent on PIP3 or PI(3,4)P2.
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Affiliation(s)
- Aleksandra Levina
- Department of Structural and Computational Biology, Max Perutz Labs, Campus Vienna Biocenter 5, 1030, Vienna, Austria
- Department of Medical Biochemistry, Medical University of Vienna, 1090, Vienna, Austria
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Thomas A Leonard
- Department of Structural and Computational Biology, Max Perutz Labs, Campus Vienna Biocenter 5, 1030, Vienna, Austria.
- Department of Medical Biochemistry, Medical University of Vienna, 1090, Vienna, Austria.
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6
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The Landscape of PDK1 in Breast Cancer. Cancers (Basel) 2022; 14:cancers14030811. [PMID: 35159078 PMCID: PMC8834120 DOI: 10.3390/cancers14030811] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 12/31/2021] [Indexed: 02/04/2023] Open
Abstract
Given that 3-phosphoinositide-dependent kinase 1 (PDK1) plays a crucial role in the malignant biological behaviors of a wide range of cancers, we review the influence of PDK1 in breast cancer (BC). First, we describe the power of PDK1 in cellular behaviors and characterize the interaction networks of PDK1. Then, we establish the roles of PDK1 in carcinogenesis, growth and survival, metastasis, and chemoresistance in BC cells. More importantly, we sort the current preclinical or clinical trials of PDK1-targeted therapy in BC and find that, even though no selective PDK1 inhibitor is currently available for BC therapy, the combination trials of PDK1-targeted therapy and other agents have provided some benefit. Thus, there is increasing anticipation that PDK1-targeted therapy will have its space in future therapeutic approaches related to BC, and we hope the novel approaches of targeted therapy will be conducive to ameliorating the dismal prognosis of BC patients.
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7
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Mazloumi Gavgani F, Karlsson T, Tangen IL, Morovicz AP, Arnesen VS, Turcu DC, Ninzima S, Spang K, Krakstad C, Guillermet-Guibert J, Lewis AE. Nuclear upregulation of class I phosphoinositide 3-kinase p110β correlates with high 47S rRNA levels in cancer cells. J Cell Sci 2021; 134:jcs.246090. [PMID: 33536247 DOI: 10.1242/jcs.246090] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 12/24/2020] [Indexed: 12/12/2022] Open
Abstract
The class I phosphoinositide 3-kinase (PI3K) catalytic subunits p110α and p110β are ubiquitously expressed but differently targeted in tumours. In cancer, PIK3CB (encoding p110β) is seldom mutated compared with PIK3CA (encoding p110α) but can contribute to tumorigenesis in certain PTEN-deficient tumours. The underlying molecular mechanisms are, however, unclear. We have previously reported that p110β is highly expressed in endometrial cancer (EC) cell lines and at the mRNA level in primary patient tumours. Here, we show that p110β protein levels are high in both the cytoplasmic and nuclear compartments in EC cells. Moreover, high nuclear:cytoplasmic staining ratios were detected in high-grade primary tumours. High levels of phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P 3] were measured in the nucleus of EC cells, and pharmacological and genetic approaches showed that its production was partly dependent upon p110β activity. Using immunofluorescence staining, p110β and PtdIns(3,4,5)P 3 were localised in the nucleolus, which correlated with high levels of 47S pre-rRNA. p110β inhibition led to a decrease in both 47S rRNA levels and cell proliferation. In conclusion, these results present a nucleolar role for p110β that may contribute to tumorigenesis in EC.This article has an associated First Person interview with Fatemeh Mazloumi Gavgani, joint first author of the paper.
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Affiliation(s)
| | - Thomas Karlsson
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Ingvild L Tangen
- Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen, Bergen 5021, Norway.,Department of Gynaecology and Obstetrics, Haukeland University Hospital, Bergen 5021, Norway
| | | | | | - Diana C Turcu
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Sandra Ninzima
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Katharina Spang
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
| | - Camilla Krakstad
- Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen, Bergen 5021, Norway.,Department of Gynaecology and Obstetrics, Haukeland University Hospital, Bergen 5021, Norway
| | - Julie Guillermet-Guibert
- Inserm U1037, Centre de Recherches en Cancérologie de Toulouse (CRCT), Institut National de la Santé et de la Recherche Médicale (INSERM), Université Toulouse III Paul Sabatier, 31037 Toulouse, France
| | - Aurélia E Lewis
- Department of Biological Sciences, University of Bergen, Bergen 5008, Norway
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8
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Guarnaccia AD, Rose KL, Wang J, Zhao B, Popay TM, Wang CE, Guerrazzi K, Hill S, Woodley CM, Hansen TJ, Lorey SL, Shaw JG, Payne WG, Weissmiller AM, Olejniczak ET, Fesik SW, Liu Q, Tansey WP. Impact of WIN site inhibitor on the WDR5 interactome. Cell Rep 2021; 34:108636. [PMID: 33472061 PMCID: PMC7871196 DOI: 10.1016/j.celrep.2020.108636] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/17/2020] [Accepted: 12/21/2020] [Indexed: 01/08/2023] Open
Abstract
The chromatin-associated protein WDR5 is a promising pharmacological target in cancer, with most drug discovery efforts directed against an arginine-binding cavity in WDR5 called the WIN site. Despite a clear expectation that WIN site inhibitors will alter the repertoire of WDR5 interaction partners, their impact on the WDR5 interactome remains unknown. Here, we use quantitative proteomics to delineate how the WDR5 interactome is changed by WIN site inhibition. We show that the WIN site inhibitor alters the interaction of WDR5 with dozens of proteins, including those linked to phosphatidylinositol 3-kinase (PI3K) signaling. As proof of concept, we demonstrate that the master kinase PDPK1 is a bona fide high-affinity WIN site binding protein that engages WDR5 to modulate transcription of genes expressed in the G2 phase of the cell cycle. This dataset expands our understanding of WDR5 and serves as a resource for deciphering the action of WIN site inhibitors.
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Affiliation(s)
- Alissa D Guarnaccia
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Kristie L Rose
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jing Wang
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Bin Zhao
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Tessa M Popay
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Christina E Wang
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Kiana Guerrazzi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Salisha Hill
- Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Chase M Woodley
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Tyler J Hansen
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Shelly L Lorey
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - J Grace Shaw
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - William G Payne
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - April M Weissmiller
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Edward T Olejniczak
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Stephen W Fesik
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - Qi Liu
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - William P Tansey
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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9
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Wong H, Levenga J, LaPlante L, Keller B, Cooper-Sansone A, Borski C, Milstead R, Ehringer M, Hoeffer C. Isoform-specific roles for AKT in affective behavior, spatial memory, and extinction related to psychiatric disorders. eLife 2020; 9:e56630. [PMID: 33325370 PMCID: PMC7787664 DOI: 10.7554/elife.56630] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 12/15/2020] [Indexed: 12/12/2022] Open
Abstract
AKT is implicated in neurological disorders. AKT has three isoforms, AKT1/AKT2/AKT3, with brain cell type-specific expression that may differentially influence behavior. Therefore, we examined single Akt isoform, conditional brain-specific Akt1, and double Akt1/3 mutant mice in behaviors relevant to neuropsychiatric disorders. Because sex is a determinant of these disorders but poorly understood, sex was an experimental variable in our design. Our studies revealed AKT isoform- and sex-specific effects on anxiety, spatial and contextual memory, and fear extinction. In Akt1 mutant males, viral-mediated AKT1 restoration in the prefrontal cortex rescued extinction phenotypes. We identified a novel role for AKT2 and overlapping roles for AKT1 and AKT3 in long-term memory. Finally, we found that sex-specific behavior effects were not mediated by AKT expression or activation differences between sexes. These results highlight sex as a biological variable and isoform- or cell type-specific AKT signaling as potential targets for improving treatment of neuropsychiatric disorders.
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Affiliation(s)
- Helen Wong
- Institute for Behavioral Genetics, University of Colorado, Boulder, United States
| | - Josien Levenga
- Institute for Behavioral Genetics, University of Colorado, Boulder, United States
- Linda Crnic Institute, Anschutz Medical Center, Aurora, United States
| | - Lauren LaPlante
- Institute for Behavioral Genetics, University of Colorado, Boulder, United States
| | - Bailey Keller
- Institute for Behavioral Genetics, University of Colorado, Boulder, United States
| | | | - Curtis Borski
- Institute for Behavioral Genetics, University of Colorado, Boulder, United States
| | - Ryan Milstead
- Department of Integrative Physiology, University of Colorado, Boulder, United States
| | - Marissa Ehringer
- Institute for Behavioral Genetics, University of Colorado, Boulder, United States
- Department of Integrative Physiology, University of Colorado, Boulder, United States
| | - Charles Hoeffer
- Institute for Behavioral Genetics, University of Colorado, Boulder, United States
- Linda Crnic Institute, Anschutz Medical Center, Aurora, United States
- Department of Integrative Physiology, University of Colorado, Boulder, United States
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10
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Lysosome Positioning Influences mTORC2 and AKT Signaling. Mol Cell 2019; 75:26-38.e3. [PMID: 31130364 DOI: 10.1016/j.molcel.2019.05.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/18/2019] [Accepted: 04/16/2019] [Indexed: 12/20/2022]
Abstract
Growth factor signaling is initiated at the plasma membrane and propagated through the cytoplasm for eventual relay to intracellular organelles such as lysosomes. The serine/threonine kinase mTOR participates in growth factor signaling as a component of two multi-subunit complexes, mTORC1 and mTORC2. mTORC1 associates with lysosomes, and its activity depends on the positioning of lysosomes within the cytoplasm, although there is no consensus regarding the exact effect of perinuclear versus peripheral distribution. mTORC2 and its substrate kinase AKT have a widespread distribution, but they are thought to act mainly at the plasma membrane. Using cell lines with knockout of components of the lysosome-positioning machinery, we show that perinuclear clustering of lysosomes delays reactivation of not only mTORC1, but also mTORC2 and AKT upon serum replenishment. These experiments demonstrate the existence of pools of mTORC2 and AKT that are sensitive to lysosome positioning.
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11
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Sher AA, Glover KKM, Coombs KM. Zika Virus Infection Disrupts Astrocytic Proteins Involved in Synapse Control and Axon Guidance. Front Microbiol 2019; 10:596. [PMID: 30984137 PMCID: PMC6448030 DOI: 10.3389/fmicb.2019.00596] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/08/2019] [Indexed: 12/24/2022] Open
Abstract
The first human Zika virus (ZIKV) outbreak was reported in Micronesia in 2007, followed by one in Brazil in 2015. Recent studies have reported cases in Europe, Oceania and Latin America. In 2016, ZIKV transmission was also reported in the US and the World Health Organization declared it a Public Health Emergency of International Concern. Because various neurological conditions are associated with ZIKV, such as microcephaly, Guillain-Barré syndrome, and other disorders of both the central and peripheral nervous systems, including encephalopathy, (meningo)encephalitis and myelitis, and because of the lack of reliable patient diagnosis, numerous ongoing studies seek to understand molecular mechanisms underlying ZIKV pathogenesis. Astrocytes are one of the most abundant cells in the CNS. They control axonal guidance, synaptic signaling, neurotransmitter trafficking and maintenance of neurons, and are targeted by ZIKV. In this study, we used a newly developed multiplexed aptamer-based technique (SOMAScan) to examine > 1300 human astrocyte cell proteins. We identified almost 300 astrocyte proteins significantly dysregulated by ZIKV infection that span diverse functions and signaling pathways, including protein translation, synaptic control, cell migration and differentiation.
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Affiliation(s)
- Affan A Sher
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,Manitoba Centre for Proteomics and Systems Biology, Winnipeg, MB, Canada
| | - Kathleen K M Glover
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,Manitoba Centre for Proteomics and Systems Biology, Winnipeg, MB, Canada
| | - Kevin M Coombs
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,Manitoba Centre for Proteomics and Systems Biology, Winnipeg, MB, Canada.,Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
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12
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Hurtado E, Cilleros V, Just L, Simó A, Nadal L, Tomàs M, Garcia N, Lanuza MA, Tomàs J. Synaptic Activity and Muscle Contraction Increases PDK1 and PKCβI Phosphorylation in the Presynaptic Membrane of the Neuromuscular Junction. Front Mol Neurosci 2017; 10:270. [PMID: 28890686 PMCID: PMC5574929 DOI: 10.3389/fnmol.2017.00270] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/11/2017] [Indexed: 12/20/2022] Open
Abstract
Conventional protein kinase C βI (cPKCβI) is a conventional protein kinase C (PKC) isoform directly involved in the regulation of neurotransmitter release in the neuromuscular junction (NMJ). It is located exclusively at the nerve terminal and both synaptic activity and muscle contraction modulate its protein levels and phosphorylation. cPKCβI molecular maturation includes a series of phosphorylation steps, the first of which is mediated by phosphoinositide-dependent kinase 1 (PDK1). Here, we sought to localize PDK1 in the NMJ and investigate the hypothesis that synaptic activity and muscle contraction regulate in parallel PDK1 and cPKCβI phosphorylation in the membrane fraction. To differentiate the presynaptic and postsynaptic activities, we abolished muscle contraction with μ-conotoxin GIIIB (μ-CgTx-GIIIB) in some experiments before stimulation of the phrenic nerve (1 Hz, 30 min). Then, we analyzed total and membrane/cytosol fractions of skeletal muscle by Western blotting. Results showed that PDK1 is located exclusively in the nerve terminal of the NMJ. After nerve stimulation with and without coincident muscle contraction, total PDK1 and phosphorylated PDK1 (pPDK1) protein levels remained unaltered. However, synaptic activity specifically enhanced phosphorylation of PDK1 in the membrane, an important subcellular location for PDK1 function. This increase in pPDK1 coincides with a significant increase in the phosphorylation of its substrate cPKCβI also in the membrane fraction. Moreover, muscle contraction maintains PDK1 and pPDK1 but increases cPKCβI protein levels and its phosphorylation. Thus, even though PDK1 activity is maintained, pcPKCβI levels increase in concordance with total cPKCβI. Together, these results indicate that neuromuscular activity could induce the membrane targeting of pPDK1 in the nerve terminal of the NMJ to promote the phosphorylation of the cPKCβI, which is involved in ACh release.
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Affiliation(s)
- Erica Hurtado
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Víctor Cilleros
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Laia Just
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Anna Simó
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Laura Nadal
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Marta Tomàs
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Neus Garcia
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Maria A Lanuza
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
| | - Josep Tomàs
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i VirgiliReus, Spain
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13
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Bonavia A, Miller L, Kellum JA, Singbartl K. Hemoadsorption corrects hyperresistinemia and restores anti-bacterial neutrophil function. Intensive Care Med Exp 2017; 5:36. [PMID: 28779451 PMCID: PMC5544662 DOI: 10.1186/s40635-017-0150-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/24/2017] [Indexed: 12/16/2022] Open
Abstract
Background Mounting evidence suggests that sepsis-induced morbidity and mortality are due to both immune activation and immunosuppression. Resistin is an inflammatory cytokine and uremic toxin. Septic hyperresistinemia (plasma resistin >20 ng/ml) has been associated with greater disease severity and worse outcomes, and it is further exacerbated by concomitant acute kidney injury (AKI). Septic hyperresistinemia disturbs actin polymerization in neutrophils leading to impaired neutrophil migration, a crucial first-line mechanism in host defense to bacterial infection. Our experimental objective was to study the effects of hyperresistinemia on other F-actin-dependent neutrophil defense mechanisms, in particular intracellular bacterial clearance and generation of reactive oxygen species (ROS). We also sought to examine the effects of hemoadsorption on hyperresistinemia and neutrophil dysfunction. Methods Thirteen patients with septic shock and six control patients were analyzed for serum resistin levels and their effects on neutrophil migration. In vitro, following incubation with resistin-spiked serum samples, Pseudomonasaeruginosa clearance and ROS generation in neutrophils were measured. Phosphorylation of 3-phosphoinositide-dependent protein kinase-1 (PDPK1) was assessed using flow cytometry. In vitro hemoadsorption with both Amberchrome™ columns (AC) and CytoSorb® cartridges (CC) were used to test correction of hyperresistinemia. We further tested AC for their effect on cell migration and ROS generation and CC for their effect on bacterial clearance. Results Patients with septic shock had higher serum resistin levels than control ICU patients and showed a strong, negative correlation between hyperresistinemia and neutrophil transwell migration (ρ= − 0.915, p < 0.001). In vitro, neutrophils exposed to hyperresistinemia exhibited twofold lower intracellular bacterial clearance rates compared to controls. Resistin impaired intracellular signaling and ROS production in a dose-dependent manner. Hemoadsorption with AC reduced serum concentrations of resistin and restored neutrophil migration and generation of ROS to normal levels. Hemoadsorption with CC also corrected hyperresistinemia and reconstituted normal intracellular bacterial clearance. Conclusions Septic hyperresistinemia strongly correlates with inhibition of neutrophil migration in vitro. Hyperresistinemia itself reversibly impairs neutrophil intracellular bacterial clearance and ROS generation. Hemoadsorption therapy with a clinically approved device corrects hyperresistinemia and neutrophil dysfunction. It may therefore provide a therapeutic option to improve neutrophil function during septic hyperresistinemia and ultimately alleviate immunosuppression in this disease state.
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Affiliation(s)
- Anthony Bonavia
- Department of Anesthesiology and Perioperative Medicine, Penn State Health, Hershey, PA, USA
| | - Lauren Miller
- Department of Anesthesiology and Perioperative Medicine, Penn State Health, Hershey, PA, USA
| | - John A Kellum
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kai Singbartl
- Department of Anesthesiology and Perioperative Medicine, Penn State Health, Hershey, PA, USA. .,Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh, PA, USA. .,Department of Critical Care Medicine, Mayo Clinic, 5777 East Mayo Boulevard, Phoenix, AZ, 85054, USA.
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14
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Boratyn E, Nowak I, Durbas M, Horwacik I, Sawicka A, Rokita H. MCPIP1 Exogenous Overexpression Inhibits Pathways Regulating MYCN Oncoprotein Stability in Neuroblastoma. J Cell Biochem 2017; 118:1741-1755. [DOI: 10.1002/jcb.25832] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 12/07/2016] [Indexed: 12/27/2022]
Affiliation(s)
- Elżbieta Boratyn
- Faculty of Biochemistry, Biophysics and Biotechnology; Laboratory of Molecular Genetics and Virology, Jagiellonian University; Gronostajowa 7 30-387 Kraków Poland
| | - Iwona Nowak
- Faculty of Biochemistry, Biophysics and Biotechnology; Laboratory of Molecular Genetics and Virology, Jagiellonian University; Gronostajowa 7 30-387 Kraków Poland
| | - Małgorzata Durbas
- Faculty of Biochemistry, Biophysics and Biotechnology; Laboratory of Molecular Genetics and Virology, Jagiellonian University; Gronostajowa 7 30-387 Kraków Poland
| | - Irena Horwacik
- Faculty of Biochemistry, Biophysics and Biotechnology; Laboratory of Molecular Genetics and Virology, Jagiellonian University; Gronostajowa 7 30-387 Kraków Poland
| | - Anna Sawicka
- Faculty of Biochemistry, Biophysics and Biotechnology; Laboratory of Molecular Genetics and Virology, Jagiellonian University; Gronostajowa 7 30-387 Kraków Poland
| | - Hanna Rokita
- Faculty of Biochemistry, Biophysics and Biotechnology; Laboratory of Molecular Genetics and Virology, Jagiellonian University; Gronostajowa 7 30-387 Kraków Poland
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15
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Kang JA, Choi H, Yang T, Cho SK, Park ZY, Park SG. PKCθ-Mediated PDK1 Phosphorylation Enhances T Cell Activation by Increasing PDK1 Stability. Mol Cells 2017; 40:37-44. [PMID: 28152304 PMCID: PMC5303887 DOI: 10.14348/molcells.2017.2236] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 12/08/2016] [Accepted: 12/12/2016] [Indexed: 11/27/2022] Open
Abstract
PDK1 is essential for T cell receptor (TCR)-mediated activation of NF-κB, and PDK1-induced phosphorylation of PKCθ is important for TCR-induced NF-κB activation. However, inverse regulation of PDK1 by PKCθ during T cell activation has not been investigated. In this study, we found that PKCθ is involved in human PDK1 phosphorylation and that its kinase activity is crucial for human PDK1 phosphorylation. Mass spectrometry analysis of wild-type PKCθ or of kinase-inactive form of PKCθ revealed that PKCθ induced phosphorylation of human PDK1 at Ser-64. This PKCθ-induced PDK1 phosphorylation positively regulated T cell activation and TCR-induced NF-κB activation. Moreover, phosphorylation of human PDK1 at Ser-64 increased the stability of human PDK1 protein. These results suggest that Ser-64 is an important phosphorylation site that is part of a positive feedback loop for human PDK1-PKCθ-mediated T cell activation.
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Affiliation(s)
- Jung-Ah Kang
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
| | - Hyunwoo Choi
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
| | - Taewoo Yang
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
| | - Steve K. Cho
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
| | - Zee-Yong Park
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
| | - Sung-Gyoo Park
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005,
Korea
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16
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Dokala A, Thakur SS. Extracellular region of epidermal growth factor receptor: a potential target for anti-EGFR drug discovery. Oncogene 2016; 36:2337-2344. [PMID: 27775071 DOI: 10.1038/onc.2016.393] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 09/15/2016] [Indexed: 02/07/2023]
Abstract
The epidermal growth factor receptor (EGFR) is a transmembrane receptor with tyrosine kinase activity involved in regulation of cellular multiplication, survival, differentiation and metastasis. Our knowledge about function and complex management of these receptors has driving the development of specific and targeted treatment modalities for human cancers in the last 20 years. EGFR is the first receptor target against which monoclonal antibodies (mAb) have been evolved for cancer treatment. Here we review the biology of ErbB receptors, including their architecture, signaling, regulation and therapeutic strategies and the mechanisms of resistances offered by the receptors against small-molecule tyrosine kinases and resistance overcome implications of mAbs. The efficacy of EGFR-specific mAb in cancer depends on site specific extracellular region of EGFR, which has crucial role in process of dimerization and activation. This review highlights evolution of various resistance mechanisms due to consequences of current small-molecule anti-EGFR therapies.
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Affiliation(s)
- A Dokala
- Proteomics and Cell Signaling, CSIR- Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, India
| | - S S Thakur
- Proteomics and Cell Signaling, CSIR- Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, India
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17
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Insulin-related signaling pathways elicited by light in photoreceptor nuclei from bovine retina. Exp Eye Res 2016; 145:36-47. [DOI: 10.1016/j.exer.2015.10.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 11/22/2022]
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18
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Claudin-18 inhibits cell proliferation and motility mediated by inhibition of phosphorylation of PDK1 and Akt in human lung adenocarcinoma A549 cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1170-8. [PMID: 26919807 DOI: 10.1016/j.bbamcr.2016.02.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Revised: 02/01/2016] [Accepted: 02/22/2016] [Indexed: 11/20/2022]
Abstract
Abnormal expression of claudin subtypes has been reported in various cancers. However, the pathological role of each claudin has not been clarified in detail. Claudin-18 was absent in human non-small cell and small cell lung cancers, although it is expressed in normal lung tissues. Here, we examined the effect of claudin-18 expression on the expression of junctional proteins, cell proliferation, and cell motility using human lung adenocarcinoma A549 cells. Real-time PCR and western blotting showed that exogenous expression of claudin-18 had no effect on the expression of junctional proteins including claudin-1, zonula occludens-1 (ZO-1), occludin, and E-cadherin. Claudin-18 was mainly distributed in cell-cell contact areas concomitant with ZO-1. Cell proliferation was significantly decreased at 48 and 72h after seeding of claudin 18-expressing cells. Claudin-18 suppressed cell motility, whereas it increased cell death in anoikis. Claudin-18 decreased phosphorylated (p)-3-phosphoinositide-dependent protein kinase-1 (PDK1) and p-Akt levels without affecting p-epidermal growth factor receptor and p-phosphatidylinositol-3 kinase (PI3K) levels. Furthermore, claudin-18 was bound with PDK1 and suppressed the nuclear localization of PDK1. We suggest that claudin-18 suppresses the abnormal proliferation and motility of lung epithelial cells mediated by inhibition of the PI3K/PDK1/Akt signaling pathway.
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19
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Asati V, Mahapatra DK, Bharti SK. PI3K/Akt/mTOR and Ras/Raf/MEK/ERK signaling pathways inhibitors as anticancer agents: Structural and pharmacological perspectives. Eur J Med Chem 2016; 109:314-41. [PMID: 26807863 DOI: 10.1016/j.ejmech.2016.01.012] [Citation(s) in RCA: 398] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 12/17/2022]
Abstract
The protein kinases regulate cellular functions such as transcription, translation, proliferation, growth and survival by the process of phosphorylation. Over activation of signaling pathways play a major role in oncogenesis. The PI3K signaling pathway is dysregulated almost in all cancers due to the amplification, genetic mutation of PI3K gene and the components of the PI3K pathway themselves. Stimulation of the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK pathways enhances growth, survival, and metabolism of cancer cells. Recently, the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK signaling pathways have been identified as promising therapeutic targets for cancer therapy. The kinase inhibitors with enhanced specificity and improved pharmacokinetics have been considered for design and development of anticancer agents. This review focuses primarily on the Ras/Raf/MEK/ERK and PI3K/Akt/mTOR signaling pathways as therapeutic targets of anticancer drugs, their specific and dual inhibitors, structure activity relationships (SARs) and inhibitors under clinical trials.
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Affiliation(s)
- Vivek Asati
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur 495009, Chhattisgarh, India
| | - Debarshi Kar Mahapatra
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur 495009, Chhattisgarh, India
| | - Sanjay Kumar Bharti
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur 495009, Chhattisgarh, India.
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20
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Ho N, Morrison J, Silva A, Coomber BL. The effect of 3-bromopyruvate on human colorectal cancer cells is dependent on glucose concentration but not hexokinase II expression. Biosci Rep 2016; 36:e00299. [PMID: 26740252 PMCID: PMC4759612 DOI: 10.1042/bsr20150267] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 12/16/2015] [Accepted: 01/06/2016] [Indexed: 12/21/2022] Open
Abstract
Cancer cells heavily rely on the glycolytic pathway regardless of oxygen tension. Hexokinase II (HKII) catalyses the first irreversible step of glycolysis and is often overexpressed in cancer cells. 3-Bromopyruvate (3BP) has been shown to primarily target HKII, and is a promising anti-cancer compound capable of altering critical metabolic pathways in cancer cells. Abnormal vasculature within tumours leads to heterogeneous microenvironments, including glucose availability, which may affect drug sensitivity. The aim of the present study was to elucidate the mechanisms by which 3BP acts on colorectal cancer (CRC) cells with focus on the HKII/Akt signalling axis. High HKII-expressing cell lines were more sensitive to 3BP than low HKII-expressing cells. 3BP-induced rapid Akt phosphorylation at site Thr-308 and cell death via both apoptotic and necrotic mechanisms. Cells grown under lower glucose concentrations showed greater resistance towards 3BP. Cells with HKII knockdown showed no changes in 3BP sensitivity, suggesting the effects of 3BP are independent of HKII expression. These results emphasize the importance of the tumour microenvironment and glucose availability when considering therapeutic approaches involving metabolic modulation.
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Affiliation(s)
- Nelson Ho
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Jodi Morrison
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Andreza Silva
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Brenda L Coomber
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
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21
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PDK1: A signaling hub for cell migration and tumor invasion. Biochim Biophys Acta Rev Cancer 2015; 1856:178-88. [DOI: 10.1016/j.bbcan.2015.07.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 07/28/2015] [Indexed: 01/22/2023]
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22
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Unacylated ghrelin restores insulin and autophagic signaling in skeletal muscle of diabetic mice. Pflugers Arch 2015; 467:2555-69. [PMID: 26228926 DOI: 10.1007/s00424-015-1721-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/21/2015] [Accepted: 07/13/2015] [Indexed: 01/04/2023]
Abstract
Impairment of insulin signaling in skeletal muscle detrimentally affects insulin-stimulated disposal of glucose. Restoration of insulin signaling in skeletal muscle is important as muscle is one of the major sites for disposal of blood glucose. Recently, unacylated ghrelin (UnAG) has received attention in diabetic research due to its favorable actions on improving glucose tolerance, glycemic control, and insulin sensitivity. The investigation of UnAG has entered phase Ib clinical trial in type 2 diabetes and phase II clinical trial in hyperphagia in Prader-Willi syndrome. Nonetheless, the precise mechanisms responsible for the anti-diabetic actions of UnAG remain incompletely understood. In this study, we examined the effects of UnAG on restoring the impaired insulin signaling in skeletal muscle of db/db diabetic mice. Our results demonstrated that UnAG effectively restored the impaired insulin signaling in diabetic muscle. UnAG decreased insulin receptor substrate (IRS) phosphorylation, increased protein kinase B (Akt) phosphorylation, and, hence, suppressed mTOR signaling. Consequently, UnAG enhanced Glut4 localization and increased PDH activity in the diabetic skeletal muscle. Intriguingly, our data indicated that UnAG normalized the suppressed autophagic signaling in diabetic muscle. In conclusion, our findings illustrated that UnAG restored the impaired insulin and autophagic signaling in skeletal muscle of diabetic mice, which are valuable to understand the underlying mechanisms of the anti-diabetic action of UnAG at peripheral skeletal muscle level.
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23
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Sturm EM, Parzmair GP, Radnai B, Frei RB, Sturm GJ, Hammer A, Schuligoi R, Lippe IT, Heinemann A. Phosphoinositide-dependent protein kinase 1 (PDK1) mediates potent inhibitory effects on eosinophils. Eur J Immunol 2015; 45:1548-59. [DOI: 10.1002/eji.201445196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/11/2014] [Accepted: 01/27/2015] [Indexed: 01/07/2023]
Affiliation(s)
- Eva M. Sturm
- Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - Gerald P. Parzmair
- Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - Balázs Radnai
- Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - Robert B. Frei
- Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - Gunter J. Sturm
- Department of Dermatology and Venereology; Division of Environmental Dermatology and Venereology; Medical University of Graz; Graz Austria
| | - Astrid Hammer
- Institute of Cell Biology; Histology and Embryology; Medical University of Graz; Graz Austria
| | - Rufina Schuligoi
- Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - Irmgard Th. Lippe
- Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - Akos Heinemann
- Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
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Hossen MJ, Kim SC, Yang S, Kim HG, Jeong D, Yi YS, Sung NY, Lee JO, Kim JH, Cho JY. PDK1 disruptors and modulators: a patent review. Expert Opin Ther Pat 2015; 25:513-37. [PMID: 25684022 DOI: 10.1517/13543776.2015.1014801] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
INTRODUCTION 3-Phosphoinositide-dependent kinase 1 (PDK1) is a master regulator of the AGC protein kinase family and is a critical activator of multiple pro-survival and oncogenic protein kinases, for which it has garnered considerable interest as an oncology drug target. AREAS COVERED This manuscript reviews small molecule patent literature disclosures between October 2011 and September 2014 for both PDK1 activators and inhibitors and restates the selective patents published before September 2011. PDK1 modulators are organized according to pharmaceutical company and chemical structural class. EXPERT OPINION Many academic institutions and pharmaceutical companies continue to research into the development of small molecules that can function as PDK1 inhibitors or modulators. To date, >50 patent publications on PDK1 disruptors and modulators have been published since the protein was first discovered in 1998. Most of these molecules act as ATP mimetics, forming similar hydrogen bonding patterns to PDK1 as ATP and functioning as hydrophobic pharmacophores. To achieve selectivity in PDK1 inhibition, the discovery of binding pockets structurally distinctive from the ATP site is a challenging but promising strategy.
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Affiliation(s)
- Muhammad Jahangir Hossen
- Sungkyunkwan University, Department of Genetic Engineering , 300 Chuncheon-Dong, Suwon 440-746 , Korea +82 31 290 7868 ; +82 31 290 7870 ;
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25
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Calleja V, Laguerre M, de Las Heras-Martinez G, Parker PJ, Requejo-Isidro J, Larijani B. Acute regulation of PDK1 by a complex interplay of molecular switches. Biochem Soc Trans 2014; 42:1435-40. [PMID: 25233428 DOI: 10.1042/bst20140222] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Phosphoinositide-dependent kinase 1 (PDK1) is the master regulator of at least 23 other AGC kinases whose downstream signalling has often been implicated in various diseases and in particular in cancer. Therefore there has been great interest in determining how PDK1 is controlled and how it regulates its substrates spatially and temporally. The understanding of these mechanisms could offer new possibilities for therapeutic intervention. Over the years, a more comprehensive view of the mechanisms involved in the regulation of PDK1 has emerged and these comprise serine/threonine as well as tyrosine phosphorylation, subcellular localization, regulator binding and conformation status. In the present review, we discuss how various molecular mechanisms are together responsible for the conformational regulation behind the activation of PDK1 in cells.
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Affiliation(s)
| | - Michel Laguerre
- ‡Institut Européen de Chimie et Biologie, Université de Bordeaux, UMR 5248, 2 rue Robert Escarpit, F-33607 Pessac, France
| | | | | | - Jose Requejo-Isidro
- §Biophotonics Lab, Unidad de Biofísica CSIC-UPV/EHU, Barrio de Sarriena s/n, 48940 Leioa, Spain
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Eräsalo H, Laavola M, Hämäläinen M, Leppänen T, Nieminen R, Moilanen E. PI3K Inhibitors LY294002 and IC87114 Reduce Inflammation in Carrageenan-Induced Paw Oedema and Down-Regulate Inflammatory Gene Expression in Activated Macrophages. Basic Clin Pharmacol Toxicol 2014; 116:53-61. [DOI: 10.1111/bcpt.12284] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 05/28/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Heikki Eräsalo
- The Immunopharmacology Research Group; University of Tampere School of Medicine and Tampere University Hospital; Tampere Finland
| | - Mirka Laavola
- The Immunopharmacology Research Group; University of Tampere School of Medicine and Tampere University Hospital; Tampere Finland
| | - Mari Hämäläinen
- The Immunopharmacology Research Group; University of Tampere School of Medicine and Tampere University Hospital; Tampere Finland
| | - Tiina Leppänen
- The Immunopharmacology Research Group; University of Tampere School of Medicine and Tampere University Hospital; Tampere Finland
| | - Riina Nieminen
- The Immunopharmacology Research Group; University of Tampere School of Medicine and Tampere University Hospital; Tampere Finland
| | - Eeva Moilanen
- The Immunopharmacology Research Group; University of Tampere School of Medicine and Tampere University Hospital; Tampere Finland
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Signaling specificity in the Akt pathway in biology and disease. Adv Biol Regul 2014; 55:28-38. [PMID: 24794538 DOI: 10.1016/j.jbior.2014.04.001] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 03/31/2014] [Accepted: 04/09/2014] [Indexed: 12/13/2022]
Abstract
Akt/PKB is a key master regulator of a wide range of physiological functions including metabolism, proliferation, survival, growth, angiogenesis and migration and invasion. The Akt protein kinase family comprises three highly related isoforms encoded by different genes. The initial observation that the Akt isoforms share upstream activators as well as several downstream effectors, together with the high sequence homology suggested that their functions were mostly redundant. By contrast, an increasing body of evidence has recently uncovered the concept of Akt isoform signaling specificity, supported by distinct phenotypes displayed by animal strains genetically modified for each of the three genes, as well as by the identification of isoform-specific substrates and association with discrete subcellular locations. Given that Akt is regarded as a promising therapeutic target in a number of pathologies, it is essential to dissect the relative contributions of each isoform, as well as the degree of compensation in pathophysiological function. Here we summarize our view of how Akt selectivity is achieved in the context of subcellular localization, isoform-specific substrate phosphorylation and context-dependent functions in normal and pathophysiological settings.
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Lin G, Brownsey RW, MacLeod KM. Complex regulation of PKCβ2 and PDK-1/AKT by ROCK2 in diabetic heart. PLoS One 2014; 9:e86520. [PMID: 24466133 PMCID: PMC3896488 DOI: 10.1371/journal.pone.0086520] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 12/15/2013] [Indexed: 01/13/2023] Open
Abstract
Objectives The RhoA/ROCK pathway contributes to diabetic cardiomyopathy in part by promoting the sustained activation of PKCβ2 but the details of their interaction are unclear. The purpose of this study was to investigate if over-activation of ROCK in the diabetic heart leads to direct phosphorylation and activation of PKCβ2, and to determine if their interaction affects PDK-1/Akt signaling. Methods Regulation by ROCK of PKCβ2 and related kinases was investigated by Western blotting and co-immunoprecipitation in whole hearts and isolated cardiomyocytes from 12 to 14-week diabetic rats. Direct ROCK2 phosphorylation of PKCβ2 was examined in vitro. siRNA silencing was used to confirm role of ROCK2 in PKCβ2 phosphorylation in vascular smooth muscle cells cultured in high glucose. Furthermore, the effect of ROCK inhibition on GLUT4 translocation was determined in isolated cardiomyocytes by confocal microscopy. Results Expression of ROCK2 and expression and phosphorylation of PKCβ2 were increased in diabetic hearts. A physical interaction between the two kinases was demonstrated by reciprocal immunoprecipitation, while ROCK2 directly phosphorylated PKCβ2 at T641 in vitro. ROCK2 siRNA in vascular smooth muscle cells or inhibition of ROCK in diabetic hearts reduced PKCβ2 T641 phosphorylation, and this was associated with attenuation of PKCβ2 activity. PKCβ2 also formed a complex with PDK-1 and its target AKT, and ROCK inhibition resulted in upregulation of the phosphorylation of PDK-1 and AKT, and increased translocation of glucose transporter 4 (GLUT4) to the plasma membrane in diabetic hearts. Conclusion This study demonstrates that over-activation of ROCK2 contributes to diabetic cardiomyopathy by multiple mechanisms, including direct phosphorylation and activation of PKCβ2 and interference with the PDK-1-mediated phosphorylation and activation of AKT and translocation of GLUT4. This suggests that ROCK2 is a critical node in the development of diabetic cardiomyopathy and may be an effective target to improve cardiac function in diabetes.
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Affiliation(s)
- Guorong Lin
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Roger W. Brownsey
- Dept. of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Kathleen M. MacLeod
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
- * E-mail:
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Kim HR, Gallant C, Morgan KG. Regulation of PKC autophosphorylation by calponin in contractile vascular smooth muscle tissue. BIOMED RESEARCH INTERNATIONAL 2013; 2013:358643. [PMID: 24350264 PMCID: PMC3852320 DOI: 10.1155/2013/358643] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/10/2013] [Accepted: 10/24/2013] [Indexed: 01/31/2023]
Abstract
Protein kinase C (PKC) is a key enzyme involved in agonist-induced smooth muscle contraction. In some cases, regulatory phosphorylation of PKC is required for full activation of the enzyme. However, this issue has largely been ignored with respect to PKC-dependent regulation of contractile vascular smooth muscle (VSM) contractility. The first event in PKC regulation is a transphosphorylation by PDK at a conserved threonine in the activation loop of PKC, followed by the subsequent autophosphorylation at the turn motif and hydrophobic motif sites. In the present study, we determined whether phosphorylation of PKC is a regulated process in VSM and also investigated a potential role of calponin in the regulation of PKC. We found that calponin increases the level of in vitro PKCα phosphorylation at the PDK and hydrophobic sites, but not the turn motif site. In vascular tissues, phosphorylation of the PKC hydrophobic site, but not turn motif site, as well as phosphorylation of PDK at S241 increased in response to phenylephrine. Calponin knockdown inhibits autophosphorylation of cellular PKC in response to phenylephrine, confirming results with recombinant PKC. Thus these results show that autophosphorylation of PKC is regulated in dVSM and calponin is necessary for autophosphorylation of PKC in VSM.
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Affiliation(s)
- Hak Rim Kim
- Department of Health Sciences, Boston University, 635 Commonwealth Avenue, Boston, MA 02215, USA
- Department of Pharmacology, College of Medicine, Dankook University, 119 Dandaero, Chungnam, Cheonan-si 330-714, Republic of Korea
| | - Cynthia Gallant
- Department of Health Sciences, Boston University, 635 Commonwealth Avenue, Boston, MA 02215, USA
| | - Kathleen G. Morgan
- Department of Health Sciences, Boston University, 635 Commonwealth Avenue, Boston, MA 02215, USA
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Ling LS, Voskas D, Woodgett JR. Activation of PDK-1 maintains mouse embryonic stem cell self-renewal in a PKB-dependent manner. Oncogene 2013; 32:5397-408. [PMID: 23455320 PMCID: PMC3898101 DOI: 10.1038/onc.2013.44] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 12/04/2012] [Accepted: 01/11/2013] [Indexed: 12/20/2022]
Abstract
The phosphatidylinositol 3′ kinase (PI3K) pathway is involved in many cellular processes including cell proliferation, survival and glucose transport, and is implicated in various disease states, such as cancer and diabetes. Although there have been numerous studies dissecting the role of PI3K signaling in different cell types and disease models, the mechanism by which PI3K signaling regulates embryonic stem (ES) cell fate remains unclear. It is believed that in addition to proliferation and tumorigenesis, PI3K activity may also be important for ES cell self-renewal. Paling et al. reported that the inhibition of PI3K led to a reduction in the ability of leukemia inhibitory factor to maintain self-renewal, causing cells to differentiate. Studies in our lab have revealed that ES cells completely lacking glycogen synthase kinase-3 (GSK-3) remain undifferentiated compared with wild-type ES cells. GSK-3 is negatively regulated by PI3K, suggesting that PI3K may have a vital role in maintaining pluripotency in ES cells through GSK-3. By using a modified Flp recombinase system, we expressed activated alleles of 3-phosphoinositide-dependent protein kinase-1 and protein kinase B to create stable, isogenic ES cell lines to further study the role of the PI3K signaling pathway in stem cell fate determination. In vitro characterization of the transgenic cell lines revealed a strong tendency toward the maintenance of pluripotency, and this phenotype was found to be independent of canonical Wnt signal transduction. In summary, PI3K signaling is sufficient to maintain the self-renewal and survival of stem cells. As this pathway is frequently mutationally activated in cancers, its effect on suppressing differentiation may contribute to its oncogenicity.
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Affiliation(s)
- L S Ling
- 1] Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada [2] Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
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Martelli AM, Tabellini G, Bressanin D, Ognibene A, Goto K, Cocco L, Evangelisti C. The emerging multiple roles of nuclear Akt. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:2168-78. [PMID: 22960641 DOI: 10.1016/j.bbamcr.2012.08.017] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 08/20/2012] [Accepted: 08/23/2012] [Indexed: 12/26/2022]
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Kikani CK, Verona EV, Ryu J, Shen Y, Ye Q, Zheng L, Qian Z, Sakaue H, Nakamura K, Du J, Ji Q, Ogawa W, Sun LZ, Dong LQ, Liu F. Proliferative and antiapoptotic signaling stimulated by nuclear-localized PDK1 results in oncogenesis. Sci Signal 2012; 5:ra80. [PMID: 23131847 DOI: 10.1126/scisignal.2003065] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Enhanced activation of phosphoinositide 3-kinase (PI3K) is a hallmark of many human tumors because it promotes cell proliferation and survival through several mechanisms. One of these mechanisms is the phosphorylation of the serine and threonine kinase Akt at the cytosolic side of the plasma membrane by phosphoinositide-dependent protein kinase 1 (PDK1), which is recruited and activated by binding to the phosphoinositides produced by PI3K. We previously demonstrated increased nuclear accumulation of PDK1 in cells with enhanced PI3K activity. We report that nuclear PDK1 promoted cell proliferation by suppressing FOXO3A-dependent transcription of the gene encoding p27Kip1 (an inhibitor of cell cycle progression), whereas it enhanced cell survival by inhibiting the activation of c-Jun amino-terminal kinase. Cells with nuclear-localized PDK1 showed anchorage-independent growth, and when injected into mice, these cells induced the formation of solid tumors. In human prostate tumors, cytoplasmic localization of PDK1 correlated only with early-stage, low-risk tumors, whereas nuclear PDK1 localization correlated with high-risk tumors. Together, our findings suggest a role for nuclear-translocated PDK1 in oncogenic cellular transformation and tumor progression in mice and humans.
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Affiliation(s)
- Chintan K Kikani
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229, USA
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He X, Saji M, Radhakrishnan D, Romigh T, Ngeow J, Yu Q, Wang Y, Ringel MD, Eng C. PTEN lipid phosphatase activity and proper subcellular localization are necessary and sufficient for down-regulating AKT phosphorylation in the nucleus in Cowden syndrome. J Clin Endocrinol Metab 2012; 97:E2179-87. [PMID: 22962422 PMCID: PMC3485596 DOI: 10.1210/jc.2012-1991] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Germline mutations in PTEN are associated with phosphatase and tensin homolog deleted on chromosome 10 (PTEN) hamartoma tumor syndrome including Cowden syndrome (CS) and Cowden-like syndrome (CSL) that predisposes to high risks of benign and malignant tumors of thyroid and breast. OBJECTIVE The objective of the study was to analyze the subcellular pattern of phosphorylated (P)-AKT expression in nonmedullary thyroid cancers from PTEN hamartoma tumor syndrome patients and to investigate whether the lack of PTEN in the nucleus and/or lack of proper PTEN function in the nucleus affect(s) nuclear AKT activity in CS patients. DESIGN In all, 664 patients with CS/CSL were screened for PTEN germline mutations and nonmedullary thyroid cancers. Twenty-two patients who have both pathogenic PTEN germline mutations and nonmedullary thyroid cancers were selected. Thyroid samples from these patients were stained for PTEN and P-AKT. In our in vitro study, PTEN was knocked down or overexpressed in both thyroid cancer cells and breast cancer cells, and nuclear P-AKT was compared with the control. RESULTS Loss of PTEN protein was found in thyroid adenomas and carcinomas from all 22 (100%) PTEN(Mut+) CS/CSL patients. AKT activation was identified in 17 of 22 (77.3%) thyroid adenoma/carcinoma specimens, and most patients (63.7%) have activated nuclear AKT. Knockdown of PTEN in cells containing wild-type PTEN enhanced nuclear P-AKT, whereas expression of wild-type PTEN, but not phosphatase-dead mutants (C124S or G129E), markedly reduced nuclear P-AKT in PTEN null cells. We also showed that in breast cancer but not thyroid cancer cells, PTEN suppresses nuclear P-AKT mainly through decreasing P-AKT nuclear translocation by reducing the PIP3/P-AKT reservoir in the cytoplasm. In thyroid cancer cells, PTEN suppresses phosphorylation of AKT already resident in the nucleus. CONCLUSIONS PTEN is necessary and sufficient for inhibiting AKT activation in the nucleus through its intact lipid phosphatase activity and proper subcellular localization.
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Affiliation(s)
- Xin He
- Cleveland Clinic, 9500 Euclid Avenue, NE50, Cleveland, Ohio 44195, USA
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Avila J, Gregory OG, Su D, Deeter TA, Chen S, Silva-Sanchez C, Xu S, Martin GB, Devarenne TP. The β-subunit of the SnRK1 complex is phosphorylated by the plant cell death suppressor Adi3. PLANT PHYSIOLOGY 2012; 159:1277-90. [PMID: 22573803 PMCID: PMC3387709 DOI: 10.1104/pp.112.198432] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 05/08/2012] [Indexed: 05/17/2023]
Abstract
The protein kinase AvrPto-dependent Pto-interacting protein3 (Adi3) is a known suppressor of cell death, and loss of its function has been correlated with cell death induction during the tomato (Solanum lycopersicum) resistance response to its pathogen Pseudomonas syringae pv tomato. However, Adi3 downstream interactors that may play a role in cell death regulation have not been identified. We used a yeast two-hybrid screen to identify the plant SnRK1 (for Sucrose non-Fermenting-1-Related Protein Kinase1) protein as an Adi3-interacting protein. SnRK1 functions as a regulator of carbon metabolism and responses to biotic and abiotic stresses. SnRK1 exists in a heterotrimeric complex with a catalytic α-subunit (SnRK1), a substrate-interacting β-subunit, and a regulatory γ-subunit. Here, we show that Adi3 interacts with, but does not phosphorylate, the SnRK1 α-subunit. The ability of Adi3 to phosphorylate the four identified tomato β-subunits was also examined, and it was found that only the Galactose Metabolism83 (Gal83) β-subunit was phosphorylated by Adi3. This phosphorylation site on Gal83 was identified as serine-26 using a mutational approach and mass spectrometry. In vivo expression of Gal83 indicates that it contains multiple phosphorylation sites, one of which is serine-26. An active SnRK1 complex containing Gal83 as the β-subunit and sucrose nonfermenting4 as the γ-subunit was constructed to examine functional aspects of the Adi3 interaction with SnRK1 and Gal83. These assays revealed that Adi3 is capable of suppressing the kinase activity of the SnRK1 complex through Gal83 phosphorylation plus the interaction with SnRK1 and suggested that this function may be related to the cell death suppression activity of Adi3.
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Affiliation(s)
- Julian Avila
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Oliver G. Gregory
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Dongyin Su
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Taunya A. Deeter
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Sixue Chen
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Cecilia Silva-Sanchez
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Shouling Xu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Gregory B. Martin
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Timothy P. Devarenne
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
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Seong HA, Jung H, Manoharan R, Ha H. PDK1 protein phosphorylation at Thr354 by murine protein serine-threonine kinase 38 contributes to negative regulation of PDK1 protein activity. J Biol Chem 2012; 287:20811-22. [PMID: 22544756 DOI: 10.1074/jbc.m111.331827] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Murine protein serine-threonine kinase 38 (MPK38) is a member of the AMP-activated protein kinase-related serine/threonine kinase family, which acts as cellular energy sensors. In this study, MPK38-induced PDK1 phosphorylation was examined to elucidate the biochemical mechanisms underlying phosphorylation-dependent regulation of 3-phosphoinositide-dependent protein kinase-1 (PDK1) activity. The results showed that MPK38 interacted with and inhibited PDK1 activity via Thr(354) phosphorylation. MPK38-PDK1 complex formation was mediated by the amino-terminal catalytic kinase domain of MPK38 and the pleckstrin homology domain of PDK1. This activity was dependent on insulin, a PI3K/PDK1 stimulator, as well as various apoptotic stimuli, including TNF-α, H(2)O(2), thapsigargin, and ionomycin. MPK38 inhibited PDK1 activity in a kinase-dependent manner and alleviated PDK1-mediated suppression of TGF-β (or ASK1) signaling, probably via the phosphorylation of PDK1 at Thr(354). In addition, MPK38-mediated inhibition of PDK1 activity was accompanied by the modulation of PDK1 binding to its positive and negative regulators, serine/threonine kinase receptor-associated protein and 14-3-3, respectively. Together, these findings suggest an important role for MPK38-mediated phosphorylation of PDK1 in the negative regulation of PDK1 activity.
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Affiliation(s)
- Hyun-A Seong
- Department of Biochemistry, School of Life Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea.
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Ubiquitin-specific protease 4 inhibits mono-ubiquitination of the master growth factor signaling kinase PDK1. PLoS One 2012; 7:e31003. [PMID: 22347420 PMCID: PMC3274522 DOI: 10.1371/journal.pone.0031003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 12/29/2011] [Indexed: 11/19/2022] Open
Abstract
Background Phosphorylation by the phospho-inositide-dependent kinase 1 (PDK1) is essential for many growth factor-activated kinases and thus plays a critical role in various processes such as cell proliferation and metabolism. However, the mechanisms that control PDK1 have not been fully explored and this is of great importance as interfering with PDK1 signaling may be useful to treat diseases, including cancer and diabetes. Methodology/Principal Findings In human cells, few mono-ubiquitinated proteins have been described but in all cases this post-translational modification has a key regulatory function. Unexpectedly, we find that PDK1 is mono-ubiquitinated in a variety of human cell lines, indicating that PDK1 ubiquitination is a common and regulated process. Ubiquitination occurs in the kinase domain of PDK1 yet is independent of its kinase activity. By screening a library of ubiquitin proteases, we further identify the Ubiquitin-Specific Protease 4 (USP4) as an enzyme that removes ubiquitin from PDK1 in vivo and in vitro and co-localizes with PDK1 at the plasma membrane when the two proteins are overexpressed, indicating direct deubiquitination. Conclusions The regulated mono-ubiquitination of PDK1 provides an unanticipated layer of complexity in this central signaling network and offers potential novel avenues for drug discovery.
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Loehberg CR, Strissel PL, Dittrich R, Strick R, Dittmer J, Dittmer A, Fabry B, Kalender WA, Koch T, Wachter DL, Groh N, Polier A, Brandt I, Lotz L, Hoffmann I, Koppitz F, Oeser S, Mueller A, Fasching PA, Lux MP, Beckmann MW, Schrauder MG. Akt and p53 are potential mediators of reduced mammary tumor growth by cloroquine and the mTOR inhibitor RAD001. Biochem Pharmacol 2011; 83:480-8. [PMID: 22142888 DOI: 10.1016/j.bcp.2011.11.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 11/20/2011] [Accepted: 11/21/2011] [Indexed: 01/02/2023]
Abstract
PI3K/Akt/mTOR and p53 signaling pathways are frequently deregulated in tumors. The anticancer drug RAD001 (everolimus) is a known mTOR-inhibitor, but mTOR-inhibition leads to phosphorylation of Akt inducing resistance against RAD001 treatment. There is growing evidence that conflicting signals transduced by the oncogene Akt and the tumorsuppressor p53 are integrated via negative feedback between the two pathways. We previously showed that the anti-malarial Chloroquine, a 4-alkylamino substituted quinoline, is a p53 activator and reduced the incidence of breast tumors in animal models. Additionally, Chloroquine is an effective chemosensitizer when used in combination with PI3K/Akt inhibitors but the mechanism is unknown. Therefore, our aim was to test, if Chloroquine could inhibit tumor growth and prevent RAD001-induced Akt activation. Chloroquine and RAD001 caused G1 cell cycle arrest in luminal MCF7 but not in mesenchymal MDA-MB-231 breast cancer cells, they significantly reduced MCF7 cell proliferation on a collagen matrix and mammospheroid formation. In a murine MCF7 xenograft model, combined treatment of Chloroquine and RAD001 significantly reduced mammary tumor growth by 4.6-fold (p = 0.0002) compared to controls. Chloroquine and RAD001 inhibited phosphorylation of mTOR and its downstream target, S6K1. Furthermore, Chloroquine was able to block the RAD001-induced phosphorylation of Akt serine 473. The Chloroquine effect of overcoming the RAD001-induced activation of the oncogene Akt, as well as the promising antitumor activity in our mammary tumor animal model present Chloroquine as an interesting combination partner for the mTOR-inhibitor RAD001.
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Affiliation(s)
- Christian R Loehberg
- Department of Obstetrics and Gynecology, University Hospital Erlangen, Universitaetsstr. 21-23, 91054 Erlangen, Germany.
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Hofler A, Nichols T, Grant S, Lingardo L, Esposito EA, Gridley S, Murphy ST, Kath JC, Cronin CN, Kraus M, Alton G, Xie Z, Sutton S, Gehring M, Ermolieff J. Study of the PDK1/AKT signaling pathway using selective PDK1 inhibitors, HCS, and enhanced biochemical assays. Anal Biochem 2011; 414:179-86. [PMID: 21402045 DOI: 10.1016/j.ab.2011.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Revised: 02/21/2011] [Accepted: 03/08/2011] [Indexed: 10/18/2022]
Abstract
The PI3K/AKT signaling pathway has an important regulatory role in cancer cell growth and tumorigenesis. Signal transduction through this pathway requires the assembly and activation of PDK1 and AKT at the plasma membrane. On activation of the pathway, PDK1 and AKT1/2 translocate to the membrane and bind to phosphatidylinositol-(3,4,5)-trisphosphate (PIP(3)) through interaction with their pleckstrin-homology domains. A biochemical method was developed to measure the kinase activity of PDK1 and AKT1/2, utilizing nickel-chelating coated lipid vesicles as a way to mimic the membrane environment. The presence of these vesicles in the reaction buffer enhanced the specific activity of the His-tagged PDK1 (full-length, and the truncated kinase domain) and the activity of the full-length His-tagged AKT1 and AKT2 when assayed in a cascade-type reaction. This enhanced biochemical assay is also suitable for measuring the inhibition of PDK1 by several selective compounds from the carbonyl-4-amino-pyrrolopyrimidine (CAP) series. One of these inhibitors, PF-5168899, was further evaluated using a high content cell-based assay in the presence of CHO cells engineered with GFP-PDK1.
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Affiliation(s)
- Alexandra Hofler
- Department of Oncology, Pfizer, 10578 Science Center Drive, San Diego, CA 92121, USA
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Dunn EF, Connor JH. Dominant inhibition of Akt/protein kinase B signaling by the matrix protein of a negative-strand RNA virus. J Virol 2011; 85:422-31. [PMID: 20980511 PMCID: PMC3014155 DOI: 10.1128/jvi.01671-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 10/14/2010] [Indexed: 12/24/2022] Open
Abstract
Vesicular stomatitis virus (VSV) is a rhabdovirus that alters host nuclear and cytoplasmic function upon infection. We have investigated the effect of VSV infection on cellular signaling through the phosphatidylinositol-3 kinase (PI3k)/Akt signaling pathway. Akt phosphorylation at both threonine 308 (Thr308) and serine 473 (Ser473) was inhibited in cells infected with VSV. This inhibition was rapid (beginning within the first 2 to 3 h postinfection) and correlated with the dephosphorylation of downstream effectors of Akt, such as glycogen synthase kinase 3β (GSK3β) and mammalian target of rapamycin (mTOR). The dephosphorylation of Akt occurred in the presence of growth factor stimulation and was not overcome through constitutive membrane targeting of Akt or high levels of phosphatidylinositol-3,4,5-triphosphate (PIP3) accumulation in the membrane. Akt dephosphorylation was not a result of alterations in PDK1 phosphorylation or activity, changes in phosphatase and tensin homologue deleted on chromosome 10 (PTEN) levels, or the downregulation of PI3k signaling. Inactivation of Akt was caused by the expression of the viral M protein in the absence of other viral components, and an M protein mutant that does not inhibit RNA polymerase II (Pol II) transcription and nuclear/cytoplasmic transport was also defective in inhibiting Akt phosphorylation. These data illustrate that VSV utilizes a novel mechanism to alter this central player in cell signaling and oncogenesis. It also suggests an inside-out model of signal transduction where VSV interruption of nuclear events has a rapid and significant effect on membrane signaling events.
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Affiliation(s)
- Ewan F Dunn
- Department of Microbiology, Boston University School of Medicine, 72 East Concord Street, Boston MA 02118, USA
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Li Y, Yang KJ, Park J. Multiple implications of 3-phosphoinositide-dependent protein kinase 1 in human cancer. World J Biol Chem 2010; 1:239-47. [PMID: 21537480 PMCID: PMC3083972 DOI: 10.4331/wjbc.v1.i8.239] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/13/2010] [Accepted: 07/20/2010] [Indexed: 02/05/2023] Open
Abstract
3-phosphoinositide-dependent protein kinase-1 (PDK1) is a central mediator of cellular signaling between phosphoinositide-3 kinase and various intracellular serine/threonine kinases, including protein kinase B, p70 ribosomal S6 kinase, serum and glucocorticoid-inducible kinase, and protein kinase C. PDK1 activates members of the AGC family of protein kinases by phosphorylating serine/threonine residues in the activation loop. Here, we review the regulatory mechanisms of PDK1 and its roles in cancer. PDK1 is activated by autophosphorylation in the activation loop and other serine residues, as well as by phosphorylation of Tyr-9 and Tyr-373/376. Src appears to recognize PDK1 following tyrosine phosphorylation. The role of heat shock protein 90 in regulating PDK1 stability and PDK1-Src complex formation are also discussed. Furthermore, we summarize the subcellular distribution of PDK1. Finally, an important role for PDK1 in cancer chemotherapy is proposed. In conclusion, a better understanding of its molecular regulatory mechanisms in various signaling pathways will help to explain how PDK1 acts as an oncogenic kinase in various cancers, and will contribute to the development of novel cancer chemotherapies.
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Affiliation(s)
- Yuwen Li
- Yuwen Li, Keum-Jin Yang, Jongsun Park, Department of Pharmacology, Metabolic Diseases and Cell Signaling Laboratory, Cancer Research Institute, Research Institute for Medical Sciences, College of Medicine, Chungnam National University, Daejeon 301-131, South Korea
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Ek-Ramos MJ, Avila J, Cheng C, Martin GB, Devarenne TP. The T-loop extension of the tomato protein kinase AvrPto-dependent Pto-interacting protein 3 (Adi3) directs nuclear localization for suppression of plant cell death. J Biol Chem 2010; 285:17584-94. [PMID: 20371603 PMCID: PMC2878523 DOI: 10.1074/jbc.m110.117416] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 04/05/2010] [Indexed: 02/02/2023] Open
Abstract
In tomato (Solanum lycopersicum), resistance to Pseudomonas syringae pv. tomato is elicited by the interaction of the host Pto kinase with the pathogen effector protein AvrPto, which leads to various immune responses including localized cell death termed the hypersensitive response. The AGC kinase Adi3 functions to suppress host cell death and interacts with Pto only in the presence of AvrPto. The cell death suppression (CDS) activity of Adi3 requires phosphorylation by 3-phosphoinositide-dependent protein kinase 1 (Pdk1) and loss of Adi3 function is associated with the hypersensitive response cell death initiated by the Pto/AvrPto interaction. Here we studied the relationship between Adi3 cellular localization and its CDS activity. Adi3 is a nuclear-localized protein, and this localization is dictated by a nuclear localization signal found in the Adi3 T-loop extension, an approximately 80 amino acid insertion into the T-loop, or activation loop, which is phosphorylated for kinase activation. Nuclear localization of Adi3 is required for its CDS activity and loss of nuclear localization causes elimination of Adi3 CDS activity and induction of cell death. This nuclear localization of Adi3 is dependent on Ser-539 phosphorylation by Pdk1 and non-nuclear Adi3 is found in punctate structures throughout the cell. Our data support a model in which Pdk1 phosphorylation of Adi3 directs nuclear localization for CDS and that disruption of Adi3 nuclear localization may be a mechanism for induction of cell death such as that during the Pto/AvrPto interaction.
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Affiliation(s)
- María J. Ek-Ramos
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Julian Avila
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Cheng Cheng
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Gregory B. Martin
- the Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, and
- the Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853
| | - Timothy P. Devarenne
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
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Ding Z, Liang J, Li J, Lu Y, Ariyaratna V, Lu Z, Davies MA, Westwick JK, Mills GB. Physical association of PDK1 with AKT1 is sufficient for pathway activation independent of membrane localization and phosphatidylinositol 3 kinase. PLoS One 2010; 5:e9910. [PMID: 20361045 PMCID: PMC2845649 DOI: 10.1371/journal.pone.0009910] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 03/04/2010] [Indexed: 02/03/2023] Open
Abstract
Frequent activation of the AKT serine-threonine kinase in cancer confers resistance to therapy. AKT is activated by a multi-step process involving phosphatidylinositide (PtdIns) phosphate-mediated recruitment of AKT and its upstream kinases, including 3-Phosphoinositide-dependent kinase 1 (PDK1), to the inner surface of the cell membrane. PDK1 in the appropriate context phosphorylates AKT at threonine 308 (T308) to activate AKT. Whether PtdIns(3,4,5)Ps (PtdInsP3) binding and AKT membrane translocation mediate functions other than formation of a functional PDK1::AKT complex have not been fully elucidated. We fused complementary fragments of intensely fluorescent protein (IFP) to AKT1 and PDK1 to induce a stable complex to study the prerequisites of AKT1 phosphorylation and function. In the stabilized PDK1-IFPC::IFPN-AKT1 complex, AKT1 T308 phosphorylation was independent of PtdIns, as demonstrated by treatment with Phosphatidylinositol 3 Kinase (PI3K) inhibitors. Further when interaction with PtdIns and the cell membrane was prevented by creating PH-domain mutants of AKT1 (R25A) and PDK1 (R474A), AKT1 phosphorylation on T308 was maintained in the PDK1-IFPC::IFPN-AKT1 complex. The PDK1-IFPC::IFPN-AKT1 complex was sufficient for phosphorylation of known AKT substrates, and conferred resistance to inhibitors of PI3K (LY294002, PI103, GDC0941 and TGX286) but not inhibitors of the downstream TORC1 complex (rapamycin). Thus the locus of action of targeted therapeutics can be elucidated by the constitutively active AKT1 complex. Our data indicate that PtdIns and membrane localization are not required for AKT phosphorylation and activation, but rather serve to induce a functional physical interaction between PDK1 and AKT. The PDK1-IFPC::IFPN-AKT1 complex provides a cell-based platform to examine specificity of drugs targeting PI3K pathway components.
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Affiliation(s)
- Zhiyong Ding
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
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Sephton CF, Zhang D, Lehmann TM, Pennington PR, Scheid MP, Mousseau DD. The nuclear localization of 3'-phosphoinositide-dependent kinase-1 is dependent on its association with the protein tyrosine phosphatase SHP-1. Cell Signal 2009; 21:1634-44. [PMID: 19591923 DOI: 10.1016/j.cellsig.2009.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 06/15/2009] [Accepted: 06/26/2009] [Indexed: 10/20/2022]
Abstract
3'-Phosphoinositide-dependent protein kinase-1 (PDK1), the direct upstream kinase of Akt, can localize to the nucleus during specific signalling events. The mechanism used for its import into the nucleus, however, remains unresolved as it lacks a canonical nuclear localization signal (NLS). Expression of activated Src kinase in C6 glioblastoma cells promotes the association of tyrosylphosphorylated PDK1 with the NLS-containing tyrosine phosphatase SHP-1 as well as the nuclear localization of both proteins. A constitutive nucleo-cytoplasmic SHP-1:PDK1 shuttling complex is supported by several lines of evidence including (i) the distribution of both proteins to similar subcellular compartments following manipulation of the nuclear pore complex, (ii) the nuclear retention of SHP-1 upon overexpression of a PDK1 protein bearing a disrupted nuclear export signal (NES), and (iii) the exclusion of PDK1 from the nucleus upon overexpression of SHP-1 lacking the NLS or following siRNA-mediated knock-down of SHP-1. The latter case results in a perinuclear distribution of PDK1 that corresponds with the distribution of PIP3 (phosphatidylinositol 3,4,5-triphosphate), while a PDK1 protein bearing a mutated PH domain that abrogates PIP3-binding is excluded from the nucleus. Our data suggest that the SHP-1:PDK1 complex is recruited to the nuclear membrane by binding to perinuclear PIP3, whereupon SHP-1 (and its NLS) facilitates active import. Export from the nucleus relies on PDK1 (and its NES). The intact complex contributes to Src kinase-induced, Akt-sensitive podial formation in C6 cells.
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Affiliation(s)
- C F Sephton
- Cell Signalling Laboratory, Department of Psychiatry, University of Saskatchewan, B45 HSB, 107 Wiggins Road, Saskatoon, SK, Canada
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Abstract
3'-phosphoinositide-dependent protein kinase-1 (PDK-1) is a crucial serine/threonine kinase in the insulin-like growth factor-I (IGF-I)/AKT signaling pathway, but its function and localization in the nervous system has not been fully characterized. In this study, we compared the localization of PDK-1 in adult neurons and non-neuronal PC-3 cells. We showed that PC-3 cells expressed phosphorylated and nonphosphorylated PDK-1 in the cytoplasm and nucleoplasm. In contrast, neuronal PDK-1 was located in the nucleoplasm and the phosphorylated form was located along the perinuclear region. Furthermore, we found that IGF-I transiently increased phosphorylation of neuronal PDK-1, resulting in its translocation to other cellular compartments. Our findings suggest that IGF-I may regulate neuronal PDK-1 differently than in non-neuronal cells, which may indicate a novel role for PDK-1 in IGF-I-mediated neuroprotective signaling.
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Liu Y, Wang J, Wu M, Wan W, Sun R, Yang D, Sun X, Ma D, Ying G, Zhang N. Down-regulation of 3-phosphoinositide-dependent protein kinase-1 levels inhibits migration and experimental metastasis of human breast cancer cells. Mol Cancer Res 2009; 7:944-54. [PMID: 19531564 DOI: 10.1158/1541-7786.mcr-08-0368] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High expression of 3-phosphoinositide-dependent protein kinase-1 (PDK1) has been detected in various invasive cancers. In the current study, we investigated its role in cancer cell migration and experimental metastasis. Down-regulation of PDK1 expression by small interference RNA markedly inhibited spontaneous migration and epidermal growth factor (EGF)-induced chemotaxis of human breast cancer cells. The defects were rescued by expressing wild-type PDK1. PDK1-depleted cells showed impaired EGF-induced actin polymerization and adhesion, probably due to a decrease in phosphorylation of LIM kinase/cofilin and integrin beta1. Confocal microscopy revealed that EGF induced cotranslocation of PDK1 with Akt and protein kinase Czeta (PKCzeta), regulators of LIM kinase, and integrin beta1. Furthermore, PDK1 depletion dampened EGF-induced phosphorylation and translocation of Akt and PKCzeta, suggesting that Akt and PKCzeta functioned downstream of PDK1 in the chemotactic signaling pathway. In severe combined immunodeficiency mice, PDK1-depleted human breast cancer cells formed more slowly growing tumors and were defective in extravasation to mouse lungs after i.v. injection. Our results indicate that PDK1 plays an important role in regulating the malignant behavior of breast cancer cells, including their motility, through activation of Akt and PKCzeta. Thus, PDK1, which increases its expression in cancer cells, can be used as a target for the development of novel therapies.
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Affiliation(s)
- Ying Liu
- Department of Chemical Biology, Peking University, Beijing, China
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47
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Abstract
Biological actions resulting from phosphoinositide synthesis trigger multiple downstream signalling cascades by recruiting proteins with pleckstrin homology domains, including phosphoinositide-dependent kinase-1 and protein kinase B (also known as Akt). Retrospectively, more attention has been focused on the plasma membrane-associated interactions of these molecules and resulting cytoplasmic target activation. The complex biological activities exerted by Akt activation suggest, however, that more subtle and complex subcellular control mechanisms are involved. This review examines the regulation of Akt activity from the perspective of subcellular compartmentalization and focuses specifically upon the actions of Akt activation downstream from phosphoinositide synthesis that influence cell biology by altering nuclear signalling leading to Pim-1 kinase induction as well as hexokinase phosphorylation that, together with Akt, serves to preserve mitochondrial integrity.
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Affiliation(s)
- Shigeki Miyamoto
- Department of Pharmacology, University of California, La Jolla, San Diego, CA 92093-0636, USA
| | - Marta Rubio
- Department of Biology, SDSU Heart Institute, San Diego State University, NLS 426, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Mark A. Sussman
- Department of Biology, SDSU Heart Institute, San Diego State University, NLS 426, 5500 Campanile Drive, San Diego, CA 92182, USA
- Corresponding author. Tel: +1 619 594 2983; +1 619 594 2610. E-mail address:
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Rubio M, Avitabile D, Fischer K, Emmanuel G, Gude N, Miyamoto S, Mishra S, Schaefer EM, Brown JH, Sussman MA. Cardioprotective stimuli mediate phosphoinositide 3-kinase and phosphoinositide dependent kinase 1 nuclear accumulation in cardiomyocytes. J Mol Cell Cardiol 2009; 47:96-103. [PMID: 19269295 DOI: 10.1016/j.yjmcc.2009.02.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 02/04/2009] [Accepted: 02/20/2009] [Indexed: 12/20/2022]
Abstract
The phosphoinositide 3-kinase (PI3K)/phosphoinositide dependent kinase 1 (PDK1) signaling pathway exerts cardioprotective effects in the myocardium through activation of key proteins including Akt. Activated Akt accumulates in nuclei of cardiomyocytes suggesting that biologically relevant targets are located in that subcellular compartment. Nuclear Akt activity could be potentiated in both intensity and duration by the presence of a nuclear-associated PI3K/PDK1 signaling cascade as has been described in other non-myocyte cell types. PI3K/PDK1 distribution was determined in vitro and in vivo by immunostaining and nuclear extraction of cultured rat neonatal cardiomyocytes or transgenic mouse hearts. Results show that PI3K and PDK1 are present at a basal level in cardiomyocytes nuclei and that cardioprotective stimulation with atrial natriuretic peptide (ANP) increases their nuclear localization. In comparison, overexpression of nuclear-targeted Akt does not mediate increased translocation of either PI3K or PDK1 indicating that accumulation of Akt does not drive PI3K or PDK1 into the nuclear compartment. Furthermore, PI3K and phospho-Akt(473) show parallel temporal accumulation in the nucleus following (MI) infarction challenge. These findings demonstrate the presence of a dynamically regulated nuclear-associated signaling cascade involving PI3K and PDK that presumably influences nuclear Akt activation.
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Affiliation(s)
- Marta Rubio
- SDSU Heart Institute, Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA.
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The kinase PDK1 integrates T cell antigen receptor and CD28 coreceptor signaling to induce NF-kappaB and activate T cells. Nat Immunol 2009; 10:158-66. [PMID: 19122654 PMCID: PMC2768497 DOI: 10.1038/ni.1687] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 10/31/2008] [Indexed: 11/08/2022]
Abstract
In addition to T cell receptor (TCR) ligation, activation of CD28 coreceptor by costimulatory molecule B7 is required for transcription factor NF-κB induction and robust T cell activation, though exactly how CD28 contributes to this remains incompletely understood. We demonstrated here that phosphoinositide-dependent kinase 1 (PDK1) plays an essential role in integrating TCR and CD28 signals. Upon deletion of PDK1 in T cells, TCR-CD28 signals failed to induce NF-κB activation or protein kinase C θ (PKC-θ) phosphorylation, although T cell survival and pathways dependent on p38 and Jnk kinases or transcription factor NF-AT were unaffected. CD28 facilitated NF-κB activation by regulating PDK1 recruitment and phosphorylation, which are necessary for efficient binding of PDK1 to PKC-θ and CARMA1, and thus for NF-κB induction.
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Abstract
The activation of PI3K (phosphoinositide 3-kinase) family members is a universal event in response to virtually all cytokines, growth factors and hormones. As a result of formation of PtdIns with an added phosphate at the 3 position of the inositol ring, activation of the protein kinases PDK1 (phosphoinositide-dependent kinase 1) and PKB (protein kinase B)/Akt occurs. The PI3K/PKB pathway impinges upon a remarkable array of intracellular events that influence either directly or indirectly whether or not a cell will undergo apoptosis. In this review, the many ways in which PI3K/PKB can control these processes are summarized. Not all of the events described will necessarily play a role in any one cell type, but a subset of these events is probably essential for the survival of every cell.
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