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Bai B, Wang T, Zhang X, Ba X, Zhang N, Zhao Y, Wang X, Yu Y, Wang B. PTPN22 activates the PI3K pathway via 14-3-3τ in T cells. FEBS J 2023; 290:4562-4576. [PMID: 37255287 DOI: 10.1111/febs.16878] [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: 11/08/2022] [Revised: 03/06/2023] [Accepted: 05/26/2023] [Indexed: 06/01/2023]
Abstract
The protein tyrosine phosphatase PTPN22 inhibits T cell activation by dephosphorylating some essential proteins in the T cell receptor-mediated signalling pathway, and its negative regulatory function protects organisms from autoimmune disease. 14-3-3τ is an adaptor protein that regulates target protein function through its intracellular localization. In the present study, we determined that PTPN22 binds to 14-3-3τ via the PTPN22-Ser640 phosphorylation side. PTPN22 binding to 14-3-3τ resulted in 14-3-3τ-Tyr179 dephosphorylation, and reduced the association between 14-3-3τ and Shc, which competitively increased 14-3-3ζ binding to Shc and activated phosphoinositide 3-kinase (PI3K) by bringing it to the membrane. In addition, PTPN22 decreased the tyrosine phosphorylation of p110 to activate PI3K. These two pathways cooperatively affect PI3K activity and the expression of PI3K downstream proteins, such as phosphorylated Akt, mammalian target of rapamycin and forkhead box O1, which inhibited the expression of some proinflammatory factors such as interleukin-1β, interleukin-2, interleukin-6, interferon-γ and tumour necrosis factor-α. Our research provides a preliminary theory for PTPN22 regulating T cell activation, development and immune response via the PI3K/Akt/mammalian target of rapamycin pathway and brings new information for clarifying the functions of PTPN22 in autoimmune diseases.
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Affiliation(s)
- Bin Bai
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Tao Wang
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Xiaonan Zhang
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Xinlei Ba
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Na Zhang
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yanjiao Zhao
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Xipeng Wang
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yang Yu
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Bing Wang
- Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang, China
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2
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Pathways to Parkinson's disease: a spotlight on 14-3-3 proteins. NPJ Parkinsons Dis 2021; 7:85. [PMID: 34548498 PMCID: PMC8455551 DOI: 10.1038/s41531-021-00230-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/23/2021] [Indexed: 02/08/2023] Open
Abstract
14-3-3s represent a family of highly conserved 30 kDa acidic proteins. 14-3-3s recognize and bind specific phospho-sequences on client partners and operate as molecular hubs to regulate their activity, localization, folding, degradation, and protein-protein interactions. 14-3-3s are also associated with the pathogenesis of several diseases, among which Parkinson's disease (PD). 14-3-3s are found within Lewy bodies (LBs) in PD patients, and their neuroprotective effects have been demonstrated in several animal models of PD. Notably, 14-3-3s interact with some of the major proteins known to be involved in the pathogenesis of PD. Here we first provide a detailed overview of the molecular composition and structural features of 14-3-3s, laying significant emphasis on their peculiar target-binding mechanisms. We then briefly describe the implication of 14-3-3s in the central nervous system and focus on their interaction with LRRK2, α-Synuclein, and Parkin, three of the major players in PD onset and progression. We finally discuss how different types of small molecules may interfere with 14-3-3s interactome, thus representing a valid strategy in the future of drug discovery.
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3
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Shabbir M, Mukhtar H, Syed D, Razak S, Afsar T, Almajwal A, Badshah Y, Aldisi D. Tissue microarray profiling and integrative proteomics indicate the modulatory potential of Maytenus royleanus in inhibition of overexpressed TPD52 in prostate cancers. Sci Rep 2021; 11:11935. [PMID: 34099820 PMCID: PMC8184821 DOI: 10.1038/s41598-021-91408-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 05/26/2021] [Indexed: 12/24/2022] Open
Abstract
Maytenus roylanus (MEM) is a plant with anti-proliferative effects against prostate cancer. We aimed to explore the mechanism of action of MEM in prostate cancer (PCa) by employing an in vitro global proteome approach to get useful information of various signaling pathways and effected genes to define the mechanism of MEM action in prostate cancer. We conducted a global proteome analysis of CWR22Rv1after treatment with methanolic extract of MEM. The result of the proteomic profiling of in vitro PCa cells demonstrated the reduction in tumor protein D52 (TPD52) expression after treatment with methanolic extract of MEM. Down-regulation of TPD52 expression at mRNA level was observed by MEM treatment in CWR22Rν1 and C4-2 cells in a dose-dependent fashion probably by cleavage of Caspase 3 and PARP, or by modulation of cyclin-dependent kinases in CWR22Rν1 and C4-2 cells. The progressive character of the TRAMP model demonstrates a chance to evaluate the potential of chemo-preventive agents for both initial and late stages of prostate cancer development, and induction in TPD52 protein expression with development as well as the progression of prostate cancer was observed in the TRAMP model. Analyses of the tissue microarray collection of 25 specimens confirmed the clinical significance of our findings identifying TPD52 as a potential marker for PCa progression. We determined that knockdown of TPD52 (CWR22Rν1 cells), a considerable downregulation was seen at the protein level. Downregulation of TPD52 inhibited the migration and invasive behavior of prostate cancer cells as observed. Moreover, we observed that the siRNA-TPD52 transfection of CWR22Rν1 cells resulted in tumor growth inhibition with a marked reduction in the secretion of prostate-specific antigen (PSA) in the serum. Intraperitoneal injection of MEM considerably slowed tumor growth in athymic mice, inhibited TPD52 expression, and caused a marked reduction in PSA levels of serum as demonstrated by immunoblot screening and immune-histochemical staining. This report illustrates a molecular overview of pathological processes in PCa, indicating possible new disease biomarkers and therapeutic targets.
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Affiliation(s)
- Maria Shabbir
- Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
| | - Hasan Mukhtar
- Department of Dermatology, University of Wisconsin, Madison, USA
| | - Deeba Syed
- Department of Dermatology, University of Wisconsin, Madison, USA
| | - Suhail Razak
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, KSA, Riyadh, Saudi Arabia.
| | - Tayyaba Afsar
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, KSA, Riyadh, Saudi Arabia
| | - Ali Almajwal
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, KSA, Riyadh, Saudi Arabia
| | - Yasmin Badshah
- Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Dara Aldisi
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, KSA, Riyadh, Saudi Arabia
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4
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Liu J, Cao S, Ding G, Wang B, Li Y, Zhao Y, Shao Q, Feng J, Liu S, Qin L, Xiao Y. The role of 14-3-3 proteins in cell signalling pathways and virus infection. J Cell Mol Med 2021; 25:4173-4182. [PMID: 33793048 PMCID: PMC8093981 DOI: 10.1111/jcmm.16490] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/06/2021] [Accepted: 03/13/2021] [Indexed: 12/14/2022] Open
Abstract
14-3-3 proteins are highly conserved in species ranging from yeast to mammals and regulate numerous signalling pathways via direct interactions with proteins carrying phosphorylated 14-3-3-binding motifs. Recent studies have shown that 14-3-3 proteins can also play a role in viral infections. This review summarizes the biological functions of 14-3-3 proteins in protein trafficking, cell-cycle control, apoptosis, autophagy and other cell signal transduction pathways, as well as the associated mechanisms. Recent findings regarding the role of 14-3-3 proteins in viral infection and innate immunity are also reviewed.
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Affiliation(s)
- Jiaqi Liu
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Shengliang Cao
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Guofei Ding
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Bin Wang
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Yingchao Li
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Yuzhong Zhao
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Qingyuan Shao
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Jian Feng
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Sidang Liu
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
| | - Liting Qin
- Shandong New Hope Liuhe Group Co., Ltd.QingdaoChina
- Qingdao Jiazhi Biotechnology Co., Ltd.QingdaoChina
| | - Yihong Xiao
- Department of Fundamental Veterinary MedicineCollege of Animal Science and Veterinary MedicineShandong Agricultural UniversityTai'anChina
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and PreventionShandong Agricultural UniversityTai’anChina
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5
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Aljabal G, Yap BK. 14-3-3σ and Its Modulators in Cancer. Pharmaceuticals (Basel) 2020; 13:ph13120441. [PMID: 33287252 PMCID: PMC7761676 DOI: 10.3390/ph13120441] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 01/19/2023] Open
Abstract
14-3-3σ is an acidic homodimer protein with more than one hundred different protein partners associated with oncogenic signaling and cell cycle regulation. This review aims to highlight the crucial role of 14-3-3σ in controlling tumor growth and apoptosis and provide a detailed discussion on the structure-activity relationship and binding interactions of the most recent 14-3-3σ protein-protein interaction (PPI) modulators reported to date, which has not been reviewed previously. This includes the new fusicoccanes stabilizers (FC-NAc, DP-005), fragment stabilizers (TCF521-123, TCF521-129, AZ-003, AZ-008), phosphate-based inhibitors (IMP, PLP), peptide inhibitors (2a-d), as well as inhibitors from natural sources (85531185, 95911592). Additionally, this review will also include the discussions of the recent efforts by a different group of researchers for understanding the binding mechanisms of existing 14-3-3σ PPI modulators. The strategies and state-of-the-art techniques applied by various group of researchers in the discovery of a different chemical class of 14-3-3σ modulators for cancer are also briefly discussed in this review, which can be used as a guide in the development of new 14-3-3σ modulators in the near future.
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6
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Endo H, Inoue I, Masunaka K, Tanaka M, Yano M. Curcumin induces apoptosis in lung cancer cells by 14-3-3 protein-mediated activation of Bad. Biosci Biotechnol Biochem 2020; 84:2440-2447. [PMID: 32841581 DOI: 10.1080/09168451.2020.1808443] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The anticancer effects of curcumin are based on the induction of apoptosis, but the specific mechanisms have not yet been fully elucidated. To address this issue, we investigated the effects of curcumin on the intrinsic apoptosis pathway using mitochondria from A549 cells. Curcumin decreased the levels of 14-3-3 proteins, key molecules that inhibit the activation of proapoptotic factors known as BH3-only proteins (e.g. Bad). Curcumin-induced suppression of 14-3-3 protein levels was associated with reduced cytosolic Bad and elevation of mitochondrial Bad, leading to a drop in the mitochondrial membrane potential. 14-3-3 proteins generally interact with Bad phosphorylated by AKT, thus preventing its translocation to the mitochondria where it can promote cell death. Curcumin not only decreased the expression of 14-3-3 proteins but also promoted Bad dephosphorylation in an AKT-dependent fashion. Our results provide novel evidence for the induction of apoptosis by curcumin at multiple stages of the mitochondrial cascade.
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Affiliation(s)
- Hiroshi Endo
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture , Hikone, Shiga 522-8533,Japan
| | - Izumi Inoue
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture , Hikone, Shiga 522-8533,Japan
| | - Kimiko Masunaka
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture , Hikone, Shiga 522-8533,Japan
| | - Masaya Tanaka
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture , Hikone, Shiga 522-8533,Japan
| | - Mihiro Yano
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture , Hikone, Shiga 522-8533,Japan
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7
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Hansen T, Thant C, White JA, Banerjee R, Thuamsang B, Gunawardena S. Excess active P13K rescues huntingtin-mediated neuronal cell death but has no effect on axonal transport defects. Apoptosis 2020; 24:341-358. [PMID: 30725352 DOI: 10.1007/s10495-019-01520-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High levels of oxidative stress is detected in neurons affected by many neurodegenerative diseases, including huntington's disease. Many of these diseases also show neuronal cell death and axonal transport defects. While nuclear inclusions/accumulations likely cause cell death, we previously showed that cytoplasmic axonal accumulations can also contribute to neuronal death. However, the cellular mechanisms responsible for activating cell death is unclear. One possibility is that perturbations in normal axonal transport alter the function of the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-pathway, a signal transduction pathway that promotes survival/growth in response to extracellular signals. To test this proposal in vivo, we expressed active PI3K in the context of pathogenic huntingtin (HTT-138Q) in Drosophila larval nerves, which show axonal transport defects and neuronal cell death. We found that excess expression of active P13K significantly suppressed HTT-138Q-mediated neuronal cell death, but had no effect on HTT-138Q-mediated axonal transport defects. Expression of active PI3K also rescued Paraquat-mediated cell death. Further, increased levels of pSer9 (inactive) glycogen synthase kinase 3β was seen in HTT-138Q-mediated larval brains, and in dynein loss of function mutants, indicating the modulation of the pro-survival pathway. Intriguingly, proteins in the PI3K/AKT-pathway showed functional interactions with motor proteins. Taken together our observations suggest that proper axonal transport is likely essential for the normal function of the pro-survival PI3K/AKT-signaling pathway and for neuronal survival in vivo. These results have important implications for targeting therapeutics to early insults during neurodegeneration and death.
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Affiliation(s)
- Timothy Hansen
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY, 14260, US
| | - Claire Thant
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY, 14260, US
| | - Joseph A White
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY, 14260, US
| | - Rupkatha Banerjee
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY, 14260, US
| | - Bhasirie Thuamsang
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY, 14260, US
| | - Shermali Gunawardena
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, NY, 14260, US. .,The State University of New York at Buffalo, 109 Cooke Hall, North/Amherst Campus, Buffalo, NY, 14260, US.
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8
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Froehlich J, Versapuech M, Megrelis L, Largeteau Q, Meunier S, Tanchot C, Bismuth G, Delon J, Mangeney M. FAM65B controls the proliferation of transformed and primary T cells. Oncotarget 2018; 7:63215-63225. [PMID: 27556504 PMCID: PMC5325358 DOI: 10.18632/oncotarget.11438] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/10/2016] [Indexed: 01/08/2023] Open
Abstract
Cell quiescence is controlled by regulated genome-encoded programs that actively express genes which are often down-regulated or inactivated in transformed cells. Among them is FoxO1, a transcription factor that imposes quiescence in several cell types, including T lymphocytes. In these cells, the FAM65B encoding gene is a major target of FOXO1. Here, we show that forced expression of FAM65B in transformed cells blocks their mitosis because of a defect of the mitotic spindle, leading to G2 cell cycle arrest and apoptosis. Upon cell proliferation arrest, FAM65B is engaged in a complex containing two proteins well known to be involved in cell proliferation i.e. the HDAC6 deacetylase and the 14.3.3 scaffolding protein. In primary T cells, FAM65B is down-regulated upon T cell receptor engagement, and maintaining its expression blocks their proliferation, establishing that the decrease of FAM65B expression is required for proliferation. Conversely, inhibiting FAM65B expression in naive T lymphocytes decreases their activation threshold. These results identify FAM65B as a potential new target for controlling proliferation of both transformed and normal cells.
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Affiliation(s)
- Jeanne Froehlich
- Inserm, Institut Cochin, Paris, France.,Cnrs, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Margaux Versapuech
- Inserm, Institut Cochin, Paris, France.,Cnrs, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Laura Megrelis
- Inserm, Institut Cochin, Paris, France.,Cnrs, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Quitterie Largeteau
- Inserm, Institut Cochin, Paris, France.,Cnrs, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Sylvain Meunier
- Inserm, PARCC, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Corinne Tanchot
- Inserm, PARCC, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Georges Bismuth
- Inserm, Institut Cochin, Paris, France.,Cnrs, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jérôme Delon
- Inserm, Institut Cochin, Paris, France.,Cnrs, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Marianne Mangeney
- Inserm, Institut Cochin, Paris, France.,Cnrs, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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9
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Kwon M, Jung J, Yu H, Lee D. HIDEEP: a systems approach to predict hormone impacts on drug efficacy based on effect paths. Sci Rep 2017; 7:16600. [PMID: 29192270 PMCID: PMC5709390 DOI: 10.1038/s41598-017-16855-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 11/19/2017] [Indexed: 01/09/2023] Open
Abstract
Experimental evidence has shown that some of the human endogenous hormones significantly affect drug efficacy. Since hormone status varies with individual physiological states, it is essential to understand the interplay of hormones and drugs for precision medicine. Here, we developed an in silico method to predict interactions between 283 human endogenous hormones and 590 drugs for 20 diseases including cancers and non-cancer diseases. We extracted hormone effect paths and drug effect paths from a large-scale molecular network that contains protein interactions, transcriptional regulations, and signaling interactions. If two kinds of effect paths for a hormone-drug pair intersect closely, we expect that the influence of the hormone on the drug efficacy is significant. It has been shown that the proposed method correctly distinguishes hormone-drug pairs with known interactions from random pairs in blind experiments. In addition, the method can suggest underlying interaction mechanisms at the molecular level so that it helps us to better understand the interplay of hormones and drugs.
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Affiliation(s)
- Mijin Kwon
- Department of Bio and Brain Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Jinmyung Jung
- Bio-Synergy Research Center, 291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea.,Department of Applied Statistics, College of Economics and Business, The University of Suwon, Bongdam-eup, Hwaseong, Republic of Korea
| | - Hasun Yu
- Bio-Synergy Research Center, 291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Doheon Lee
- Department of Bio and Brain Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea. .,Bio-Synergy Research Center, 291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea.
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10
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Sluchanko NN, Gusev NB. Moonlighting chaperone‐like activity of the universal regulatory 14‐3‐3 proteins. FEBS J 2017; 284:1279-1295. [DOI: 10.1111/febs.13986] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 11/20/2016] [Accepted: 12/06/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Nikolai N. Sluchanko
- Laboratory of Structural Biochemistry of Proteins A. N. Bach Institute of Biochemistry Federal Research Center of Biotechnology of the Russian Academy of Sciences Moscow Russia
| | - Nikolai B. Gusev
- Department of Biochemistry School of Biology Moscow State University Russia
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11
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Azoulay-Alfaguter I, Strazza M, Mor A. Chaperone-mediated specificity in Ras and Rap signaling. Crit Rev Biochem Mol Biol 2014; 50:194-202. [PMID: 25488471 DOI: 10.3109/10409238.2014.989308] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ras and Rap proteins are closely related small guanosine triphosphatase (GTPases) that share similar effector-binding domains but operate in a very different signaling networks; Ras has a dominant role in cell proliferation, while Rap mediates cell adhesion. Ras and Rap proteins are regulated by several shared processes such as post-translational modification, phosphorylation, activation by guanine exchange factors and inhibition by GTPase-activating proteins. Sub-cellular localization and trafficking of these proteins to and from the plasma membrane are additional important regulatory features that impact small GTPases function. Despite its importance, the trafficking mechanisms of Ras and Rap proteins are not completely understood. Chaperone proteins play a critical role in trafficking of GTPases and will be the focus of the discussion in this work. We will review several aspects of chaperone biology focusing on specificity toward particular members of the small GTPase family. Understanding this specificity should provide key insights into drug development targeting individual small GTPases.
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12
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Nussinov R, Jang H. Dynamic multiprotein assemblies shape the spatial structure of cell signaling. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 116:158-64. [PMID: 25046855 PMCID: PMC4250281 DOI: 10.1016/j.pbiomolbio.2014.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 07/07/2014] [Indexed: 11/25/2022]
Abstract
Cell signaling underlies critical cellular decisions. Coordination, efficiency as well as fail-safe mechanisms are key elements. How the cell ensures that these hallmarks are at play are important questions. Cell signaling is often viewed as taking place through discrete and cross-talking pathways; oftentimes these are modularized to emphasize distinct functions. While simple, convenient and clear, such models largely neglect the spatial structure of cell signaling; they also convey inter-modular (or inter-protein) spatial separation that may not exist. Here our thesis is that cell signaling is shaped by a network of multiprotein assemblies. While pre-organized, the assemblies and network are loose and dynamic. They contain transiently-associated multiprotein complexes which are often mediated by scaffolding proteins. They are also typically anchored in the membrane, and their continuum may span the cell. IQGAP1 scaffolding protein which binds proteins including Raf, calmodulin, Mek, Erk, actin, and tens more, with actin shaping B-cell (and likely other) membrane-anchored nanoclusters and allosterically polymerizing in dynamic cytoskeleton formation, and Raf anchoring in the membrane along with Ras, provides a striking example. The multivalent network of dynamic proteins and lipids, with specific interactions forming and breaking, can be viewed as endowing gel-like properties. Collectively, this reasons that efficient, productive and reliable cell signaling takes place primarily through transient, preorganized and cooperative protein-protein interactions spanning the cell rather than stochastic, diffusion-controlled processes.
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Affiliation(s)
- Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA; Sackler Inst. of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
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13
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Okayama A, Miyagi Y, Oshita F, Nishi M, Nakamura Y, Nagashima Y, Akimoto K, Ryo A, Hirano H. Proteomic Analysis of Proteins Related to Prognosis of Lung Adenocarcinoma. J Proteome Res 2014; 13:4686-94. [DOI: 10.1021/pr4012969] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Akiko Okayama
- Graduate
School of Medical Life Science and Advanced Medical Research Center, Yokohama City University, 3-9 Fukuura, Kanazawa-ku,
Yokohama, Kanagawa 236-0004, Japan
| | - Yohei Miyagi
- Kanagawa Cancer Center, 2-3-2
Nakao, Asahi-ku, Yokohama, Kanagawa 241-8515, Japan
| | - Fumihiro Oshita
- Kanagawa Cancer Center, 2-3-2
Nakao, Asahi-ku, Yokohama, Kanagawa 241-8515, Japan
| | | | - Yoshiyasu Nakamura
- Kanagawa Cancer Center, 2-3-2
Nakao, Asahi-ku, Yokohama, Kanagawa 241-8515, Japan
| | | | - Kazunori Akimoto
- Department
of Molecular Medical Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | | | - Hisashi Hirano
- Graduate
School of Medical Life Science and Advanced Medical Research Center, Yokohama City University, 3-9 Fukuura, Kanazawa-ku,
Yokohama, Kanagawa 236-0004, Japan
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14
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Riou P, Kjær S, Garg R, Purkiss A, George R, Cain R, Bineva G, Reymond N, McColl B, Thompson A, O’Reilly N, McDonald N, Parker P, Ridley A. 14-3-3 proteins interact with a hybrid prenyl-phosphorylation motif to inhibit G proteins. Cell 2013; 153:640-53. [PMID: 23622247 PMCID: PMC3690454 DOI: 10.1016/j.cell.2013.03.044] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 01/22/2013] [Accepted: 03/29/2013] [Indexed: 12/13/2022]
Abstract
Signaling through G proteins normally involves conformational switching between GTP- and GDP-bound states. Several Rho GTPases are also regulated by RhoGDI binding and sequestering in the cytosol. Rnd proteins are atypical constitutively GTP-bound Rho proteins, whose regulation remains elusive. Here, we report a high-affinity 14-3-3-binding site at the C terminus of Rnd3 consisting of both the Cys241-farnesyl moiety and a Rho-associated coiled coil containing protein kinase (ROCK)-dependent Ser240 phosphorylation site. 14-3-3 binding to Rnd3 also involves phosphorylation of Ser218 by ROCK and/or Ser210 by protein kinase C (PKC). The crystal structure of a phosphorylated, farnesylated Rnd3 peptide with 14-3-3 reveals a hydrophobic groove in 14-3-3 proteins accommodating the farnesyl moiety. Functionally, 14-3-3 inhibits Rnd3-induced cell rounding by translocating it from the plasma membrane to the cytosol. Rnd1, Rnd2, and geranylgeranylated Rap1A interact similarly with 14-3-3. In contrast to the canonical GTP/GDP switch that regulates most Ras superfamily members, our results reveal an unprecedented mechanism for G protein inhibition by 14-3-3 proteins.
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Affiliation(s)
- Philippe Riou
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
- Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Svend Kjær
- Protein Purification Facility, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Ritu Garg
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Andrew Purkiss
- Structural Biology Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Roger George
- Protein Purification Facility, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Robert J. Cain
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Ganka Bineva
- Peptide Synthesis Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Nicolas Reymond
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Brad McColl
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Andrew J. Thompson
- MRC Centre for Neurodegeneration Research, De Crespigny Park, King's College London, London SE5 8AF, UK
- The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
| | - Nicola O’Reilly
- Peptide Synthesis Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Neil Q. McDonald
- Structural Biology Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Malet Street, Birkbeck College, University of London, London WC1E 7HX, UK
| | - Peter J. Parker
- Division of Cancer Studies, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
- Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Anne J. Ridley
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London SE1 1UL, UK
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15
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Bolger JC, Young LS. ADAM22 as a Prognostic and Therapeutic Drug Target in the Treatment of Endocrine-Resistant Breast Cancer. VITAMINS & HORMONES 2013; 93:307-21. [DOI: 10.1016/b978-0-12-416673-8.00014-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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16
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Park SG, Jung S, Ryu HH, Jung TY, Moon KS, Kim IY, Jeong YI, Pei J, Park SJ, Kang SS. Role of 14-3-3-beta in the migration and invasion in human malignant glioma cell line U87MG. Neurol Res 2012; 34:893-900. [PMID: 22925547 DOI: 10.1179/1743132812y.0000000087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
PURPOSE To assess the influence of 14-3-3-beta in modulating the migration and invasion of human glioma cells. METHODS To profile the genes associated with malignant glioma cell motility, differential display-polymerase chain reaction was performed and the findings were validated by Northern blotting in the U343MG-A, U87MG, and U87MG-10' human glioma cell lines. Antisense 14-3-3-beta cDNA plasmid was transfected into U87MG ('U87-YA-3'). To follow motility changes after transfection, simple scratch test and matrigel assay were performed. Morphological and cytoskeletal changes were documented by light and confocal microscopy. In addition, doubling times of the transfectant and endogenous 14-3-3-beta levels were determined in various glioma cell lines with different motilities. RESULTS 14-3-3-beta was highly expressed in U87MG cells. U87-YA-3 cells became small and flat, and actin was depolarized. Furthermore, U87-YA-3 cell motility was inhibited markedly versus parental U87MG cells. The doubling times of transfected and parent cells were 32 and 37 hours, respectively. Endogenous 14-3-3-beta expression in the human glioma cell lines was proportional to their migratory and invasive abilities. CONCLUSION 14-3-3-beta modulates the migration and invasion in U87MG cells, which may be useful in developing therapeutic approaches for the treatment of glioma.
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Affiliation(s)
- Sung-Geun Park
- Department of Neurosurgery, Chonnam National University Hwasun Hospital and Medical School, Gwangju, Korea
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17
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Wang H, Huang H, Li W, Jin X, Zeng J, Liu Y, Gu Y, Sun X, Wen G, Ding Y, Zhao L. Nuclear localization of 14-3-3epsilon inversely correlates with poor long-term survival of patients with colorectal cancer. J Surg Oncol 2011; 106:224-31. [PMID: 22105787 DOI: 10.1002/jso.22152] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 10/31/2011] [Indexed: 01/21/2023]
Abstract
BACKGROUND 14-3-3ε regulates diverse biological processes and plays a significant role in the formation of malignant tumors. However, the localization and clinical significance of 14-3-3ε in colorectal cancer (CRC) have not been elucidated. METHODS We investigated 14-3-3ε expression and its prognostic significance in CRC. CRC surgical samples were taken from 137 clinicopathologically characterized CRC cases. 14-3-3ε expression was tested by immunohistochemical assay. Separate Western blot of nuclear and cytosol preparations confirmed nuclear localization of 14-3-3ε protein. RESULTS Nuclear expression of 14-3-3ε was observed in 76.9% of normal colorectal tissue and 78.8% of all CRC samples. Statistical analysis showed that there was significant difference of nuclear 14-3-3ε expression in patients categorized according to lymph node metastasis. A trend was identified between decreasing nuclear 14-3-3ε expression in CRC and worsening clinical prognosis. Multivariate analysis showed that loss of nuclear 14-3-3ε expression was an independent prognostic indicator for patient's survival. CONCLUSIONS The current data provide evidence that 14-3-3ε is not exclusively a cytosolic protein, but is also detectable within the nucleus. Our results suggest that nuclear 14-3-3ε as a suppressor may serve as important biomarker of tumor metastasis. Loss of nuclear 14-3-3ε is closely associated with poor overall survival in CRC patients.
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Affiliation(s)
- Hui Wang
- Department of Medical Oncology, Affiliated Tumor Hospital of Guangzhou Medical College, Guangzhou, China
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18
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Schuster TB, Costina V, Findeisen P, Neumaier M, Ahmad-Nejad P. Identification and functional characterization of 14-3-3 in TLR2 signaling. J Proteome Res 2011; 10:4661-70. [PMID: 21827211 DOI: 10.1021/pr200461p] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The Interleukin-1/Toll-like receptor signaling pathway is a crucial signaling pathway within the innate immune system and the use of mass spectrometric techniques became valuable to investigate signal transduction pathways. To date only a few reports exist that focus on the mass spectrometric identification of novel signaling intermediates within the TLR signal transduction pathway. Here we used this approach systematically to identify new interaction partners of the TLR signaling pathway and subsequently characterized them functionally. We identified 14-3-3 theta as a new member of the TLR signaling complex. With genetic complementation assays, we demonstrate that 14-3-3 negatively regulates TLR2-dependent NF-κB activity and amplifies the TLR4-dependent activation of the transcription factor. While 14-3-3 has no effect on TLR-induced apoptosis in innate immune cells, it controls the release of the inflammatory, IRF3-dependent cytokines like RANTES and IP-10 after stimulation with LPS. Most strikingly, 14-3-3 controls the production of proinflammatory cytokines like IL-6, IL-8, and TNFα in a different manner. Our results identify 14-3-3 theta as a new and important regulatory protein in the TLR signaling suppressing the MyD88-dependent pathway.
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Affiliation(s)
- Tobias B Schuster
- Institute for Clinical Chemistry, Medical Faculty Mannheim, University of Heidelberg , Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
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19
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Aitken A. Post-translational modification of 14-3-3 isoforms and regulation of cellular function. Semin Cell Dev Biol 2011; 22:673-80. [PMID: 21864699 DOI: 10.1016/j.semcdb.2011.08.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 08/06/2011] [Indexed: 12/18/2022]
Abstract
14-3-3 is now well established as a family of dimeric proteins that can modulate interaction between proteins involved in a wide range of functions. In many cases, these proteins show a distinct preference for a particular isoform(s) of 14-3-3 and in many cases a specific repertoire of dimer formation influences the particular proteins that 14-3-3 interact. Well over 200 proteins have been shown to interact with 14-3-3. The purpose of this review is to give an overview of the recently identified post-translational modifications of 14-3-3 isoforms and how this regulates function, interaction, specificity of dimerisation between isoforms and cellular location of target proteins. The association between 14-3-3 and its targets usually involves phosphorylation of the interacting protein which has been the subject of many reviews and discussion of this is included in other reviews in this series. However, it is now realised that in some cases the phosphorylation and a number of other, novel covalent modifications of 14-3-3 isoforms may modulate interaction and dimerisation of 14-3-3. Since this aspect is now emerging to be of major importance in the mechanism of regulation by 14-3-3 isoforms and has not been the focus of previous reviews, this will be detailed here.
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Affiliation(s)
- Alastair Aitken
- University of Edinburgh, School of Biological Sciences, Darwin Building, Kings Buildings, Edinburgh EH9 3JR, Scotland, UK.
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20
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Neal CL, Xu J, Li P, Mori S, Yang J, Neal NN, Zhou X, Wyszomierski SL, Yu D. Overexpression of 14-3-3ζ in cancer cells activates PI3K via binding the p85 regulatory subunit. Oncogene 2011; 31:897-906. [PMID: 21743495 PMCID: PMC3193867 DOI: 10.1038/onc.2011.284] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The ubiquitously expressed 14-3-3 proteins regulate many pathways involved in transformation. Previously, we found that 14-3-3ζ overexpression increased Akt phosphorylation in human mammary epithelial cells. Here, we investigated the clinical relevance and molecular mechanism of 14-3-3ζ overexpression-mediated Akt phosphorylation and the potential impact on breast cancer progression. We found that 14-3-3ζ overexpression was significantly (P = 0.005) associated with increased Akt phosphorylation in human breast tumors. Additionally, 14-3-3ζ overexpression combined with strong Akt phosphorylation was significantly (P=0.01) associated with increased cancer recurrence in patients. In contrast, knockdown of 14-3-3ζ expression by siRNA in cancer cell lines and tumor xenografts reduced Akt phosphorylation. Furthermore, 14-3-3ζ enhanced Akt phosphorylation through activation of PI3K. Mechanistically, 14-3-3ζ bound to the p85 regulatory subunit of PI3K and increased PI3K translocation to the cell membrane. A single 14-3-3 binding motif encompassing serine 83 on p85 is largely responsible for 14-3-3ζ-mediated p85 binding and PI3K/Akt activation. Mutation of serine 83 to alanine on p85 inhibited 14-3-3ζ binding to the p85 subunit of PI3K, reduced PI3K membrane localization and activation, impeded anchorage independent growth and enhanced stress induced apoptosis. These findings revealed a novel mechanism by which 14-3-3ζ overexpression activates PI3K, a key node in the mitogenic signaling network known to promote malignancies in many cell types.
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Affiliation(s)
- C L Neal
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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21
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Verma NK, Dempsey E, Freeley M, Botting CH, Long A, Kelleher D, Volkov Y. Analysis of dynamic tyrosine phosphoproteome in LFA-1 triggered migrating T-cells. J Cell Physiol 2011; 226:1489-98. [PMID: 20945386 DOI: 10.1002/jcp.22478] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The ordered, directional migration of T-lymphocytes is a key process during immune surveillance and response. This requires cell adhesion to the high endothelial venules or to the extracellular matrix by a series of surface receptor/ligand interactions involving adhesion molecules of the integrin family including lymphocyte function associated molecule-1 (LFA-1) and intercellular adhesion molecules (ICAMs). Reversible protein phosphorylation is emerging as a key player in the regulation of biological functions with tyrosine phosphorylation playing a crucial role in signal transduction. Thus, the study of this type of post-translational modification at the proteomic level has great biological significance. In this work, phospho-enriched cell lysates from LFA-1-triggered migrating human T-cells were subjected to immunoaffinity purification of tyrosine phosphorylated proteins, mass spectrometric, and bioinformatic analysis. In addition to the identification of several well-documented proteins, the analysis suggested involvement of a number of new and novel proteins in LFA-1 induced T-cell migration. This dataset expands the list of the signaling components of the LFA-1 induced phosphotyrosine protein complexes in migrating T-cells that will be extremely useful in the study of their specific roles within LFA-1 associated signaling pathways. Identification of proteins previously not reported in the context of LFA-1 stimulated signal transduction might provide new insights into understanding the LFA-1 signaling networks and aid in the search for new potential therapeutic targets.
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Affiliation(s)
- Navin K Verma
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College Dublin, Ireland.
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22
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Russell D, Ross H, Lane EB. ERK Involvement in Resistance to Apoptosis in Keratinocytes with Mutant Keratin. J Invest Dermatol 2010; 130:671-81. [DOI: 10.1038/jid.2009.327] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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Qi JY, Xu M, Lu ZZ, Zhang YY. 14-3-3 inhibits insulin-like growth factor-I-induced proliferation of cardiac fibroblasts via a phosphatidylinositol 3-kinase-dependent pathway. Clin Exp Pharmacol Physiol 2009; 37:296-302. [PMID: 19719751 DOI: 10.1111/j.1440-1681.2009.05282.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. Insulin-like growth factor (IGF)-I plays an important role in the pathogenesis of heart disease and has been shown to strongly induce the proliferation of cardiac fibroblasts (CFs). It remains unknown whether 14-3-3 proteins, which are associated the regulation of signal transduction, affect IGF-I-induced CF proliferation. 2. In the present study, we investigated the effects of 14-3-3 proteins on CF proliferation in response to IGF-I. Proliferation of CFs was determined by cell counting and a bromodeoxyuridine incorporation assay. Phosphorylation of signalling molecules was evaluated by western blottling. Activity of nuclear factor of activated T cells (NFAT) was examined using a dual luciferase reporter gene assay and immunofluorescence. 3. It was found that adenovirus-mediated transfection of YFP-R18 peptide (AdR18), a known inhibitor of 14-3-3, significantly enhanced IGF-I-induced CF proliferation. This potentiation arose from an increase in phosphorylation of phosphatidylinositol 3-kinase (PI3-K) and AKT (protein kinase B), inactivation of glycogen synthesis kinase (GSK) 3beta and increased NFAT activity. 4. Collectively, the results of the present study suggest that 14-3-3 proteins inhibit IGF-I-induced CF proliferation via a PI3-K-dependent NFAT signalling pathway. This finding may contribute to our understanding of the function of 14-3-3 proteins in the heart.
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Affiliation(s)
- Jian-Yong Qi
- Institute of Vascular Medicine, Peking University Third Hospital and Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
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24
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Abstract
The pemphigus family of autoimmune blistering diseases is characterized by an autoantibody response to desmosomal cadherins in epithelia. Autoantibodies against desmogleins, desmosome cell adhesion molecules, induce loss of cell-cell adhesion that is characterized clinically by blister formation. The mechanism by which these autoantibodies induce loss of cell-cell adhesion is under active investigation, but appears to involve a coordinated intracellular response including activation of intracellular signaling and phosphorylation of a number of proteins in the target keratinocyte. Activation of p38 mitogen activated protein kinase may have a critical role in the acantholytic mechanism as inhibitors of p38MAPK block the ability of pemphigus IgG to induce blistering in pemphigus animal models.
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Affiliation(s)
- David S Rubenstein
- Department of Dermatology, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599-7287, USA.
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25
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Kuzelová K, Grebenová D, Pluskalová M, Kavan D, Halada P, Hrkal Z. Isoform-specific cleavage of 14-3-3 proteins in apoptotic JURL-MK1 cells. J Cell Biochem 2009; 106:673-81. [PMID: 19173300 DOI: 10.1002/jcb.22061] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The proteins of 14-3-3 family are substantially involved in the regulation of many biological processes including the apoptosis. We studied the changes in the expression of five 14-3-3 isoforms (beta, gamma, epsilon, tau, and zeta) during the apoptosis of JURL-MK1 and K562 cells. The expression level of all these proteins markedly decreased in relation with the apoptosis progression and all isoforms underwent truncation, which probably corresponds to the removal of several C-terminal amino acids. The observed 14-3-3 modifications were partially blocked by caspase-3 inhibition. In addition to caspases, a non-caspase protease is likely to contribute to 14-3-3's cleavage in an isoform-specific manner. While 14-3-3 gamma seems to be cleaved mainly by caspase-3, the alternative mechanism is essentially involved in the case of 14-3-3 tau, and a combined effect was observed for the isoforms epsilon, beta, and zeta. We suggest that the processing of 14-3-3 proteins could form an integral part of the programmed cell death or at least of some apoptotic pathways.
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Affiliation(s)
- Katerina Kuzelová
- Department of Cellular Biochemistry, Institute of Hematology and Blood Transfusion, Prague 2, Czech Republic.
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26
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Kakinuma N, Roy BC, Zhu Y, Wang Y, Kiyama R. Kank regulates RhoA-dependent formation of actin stress fibers and cell migration via 14-3-3 in PI3K-Akt signaling. ACTA ACUST UNITED AC 2008; 181:537-49. [PMID: 18458160 PMCID: PMC2364698 DOI: 10.1083/jcb.200707022] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Phosphoinositide-3 kinase (PI3K)/Akt signaling is activated by growth factors such as insulin and epidermal growth factor (EGF) and regulates several functions such as cell cycling, apoptosis, cell growth, and cell migration. Here, we find that Kank is an Akt substrate located downstream of PI3K and a 14-3-3–binding protein. The interaction between Kank and 14-3-3 is regulated by insulin and EGF and is mediated through phosphorylation of Kank by Akt. In NIH3T3 cells expressing Kank, the amount of actin stress fibers is reduced, and the coexpression of 14-3-3 disrupted this effect. Kank also inhibits insulin-induced cell migration via 14-3-3 binding. Furthermore, Kank inhibits insulin and active Akt-dependent activation of RhoA through binding to 14-3-3. Based on these findings, we hypothesize that Kank negatively regulates the formation of actin stress fibers and cell migration through the inhibition of RhoA activity, which is controlled by binding of Kank to 14-3-3 in PI3K–Akt signaling.
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Affiliation(s)
- Naoto Kakinuma
- Signaling Molecules Research Laboratory, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan
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27
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Tak H, Jang E, Kim SB, Park J, Suk J, Yoon YS, Ahn JK, Lee JH, Joe CO. 14-3-3epsilon inhibits MK5-mediated cell migration by disrupting F-actin polymerization. Cell Signal 2007; 19:2379-87. [PMID: 17728103 DOI: 10.1016/j.cellsig.2007.07.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Accepted: 07/23/2007] [Indexed: 11/26/2022]
Abstract
The signal pathway by which 14-3-3epsilon inhibits cell migration induced by MAPK-activated protein kinase 5 (MK5) was investigated in cultured HeLa cells. Both in vivo and in vitro analyses have revealed that 14-3-3epsilon interacts with MK5. 14-3-3epsilon bound to MK5 inhibits the phosphorylation of HSP27, a known substrate of MK5. Disturbance of actin cytoskeleton organization by 14-3-3epsilon was shown in transfected cells transiently expressing 14-3-3epsilon as well as established cells stably expressing 14-3-3epsilon. Moreover, overexpression of 14-3-3epsilon resulted in the inhibition of cell migration induced by MK5 overexpression or TNFalpha treatment. Our results suggest that 14-3-3epsilon bound to MK5 inhibits cell migration by inhibiting the phosphorylation of HSP27 whose phosphorylation regulates F-actin polymerization, actin cytoskeleton organization and subsequent actinfilament dynamics.
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Affiliation(s)
- Heejae Tak
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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28
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Medina A, Ghaffari A, Kilani RT, Ghahary A. The role of stratifin in fibroblast-keratinocyte interaction. Mol Cell Biochem 2007; 305:255-64. [PMID: 17646930 DOI: 10.1007/s11010-007-9538-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 06/21/2007] [Indexed: 10/23/2022]
Abstract
Stratifin is a member of 14-3-3 protein family, a highly conserved group of proteins constituted by seven isoforms. They are involved in numerous crucial intracellular functions such as cell cycle and apoptosis, regulation of signal transduction pathways, cellular trafficking, cell proliferation and differentiation, cell survival, and protein folding and processing, among others. At epidermal level, stratifin (also called 14-3-3 sigma) has been described as molecule with relevant functions. For instance, this isoform is a marker associated with keratinocyte differentiation. In this maturation process, the presence of dominant negative molecules of p53 induces a "stemness condition" of keratinocyte precursor cells and suppression of stratifin expression. In addition, the recently described keratinocyte-releasable form of stratifin is involved in dermal fibroblast MMP-1 over-expression through c-Fos and c-Jun activity. This effect is mediated, at least in part, by p38 mitogen-activated protein kinase (MAPK). Other MMP family members such as stromelysin-1 (MMP-3), stromelysin-2 (MMP-10), neutrophil collagenase (MMP-8), and membrane-type MMP-24 (MT5-MMP) are also up-regulated by stratifin. Within fibroproliferative disorder of skin, hypertrophic scar and keloids exhibit a high content of collagen, proteoglycans, and fibronectin. Thus, the MMP profile induced by stratifin is an interesting starting point to establish new therapeutic tools to control the process of wound healing. In this review, we will focus on site of synthesis and mode of action of stratifin in skin and wound healing.
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Affiliation(s)
- Abelardo Medina
- BC Professional Fire Fighters' Burn and Wound Healing Laboratory, Division of Plastic Surgery, University of British Columbia, Vancouver, BC, Canada
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29
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Alvarez M, Altafaj X, Aranda S, de la Luna S. DYRK1A autophosphorylation on serine residue 520 modulates its kinase activity via 14-3-3 binding. Mol Biol Cell 2007; 18:1167-78. [PMID: 17229891 PMCID: PMC1838983 DOI: 10.1091/mbc.e06-08-0668] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 12/05/2006] [Accepted: 01/05/2007] [Indexed: 02/06/2023] Open
Abstract
Dual-specificity tyrosine-phosphorylated and regulated kinase (DYRK) proteins are an evolutionarily conserved family of protein kinases, with members identified from yeast to humans, that participate in a variety of cellular processes. DYRKs are serine/threonine protein kinases that are activated by autophosphorylation on a tyrosine residue in the activation loop. The family member DYRK1A has been shown to phosphorylate several cytosolic proteins and a number of splicing and transcription factors, including members of the nuclear factor of activated T cells family. In the present study, we show that DYRK1A autophosphorylates, via an intramolecular mechanism, on Ser-520, in the PEST domain of the protein. We also show that phosphorylation of this residue, which we show is subjected to dynamic changes in vivo, mediates the interaction of DYRK1A with 14-3-3beta. A second 14-3-3 binding site is present within the N-terminal of the protein. In the context of the DYRK1A molecule, neither site can act independently of the other. Bacterially produced DYRK1A and the mutant DYRK1A/S520A have similar kinase activities, suggesting that Ser-520 phosphorylation does not affect the intrinsic kinase activity on its own. Instead, we demonstrate that this phosphorylation allows the binding of 14-3-3beta, which in turn stimulates the catalytic activity of DYRK1A. These findings provide evidence for a novel mechanism for the regulation of DYRK1A kinase activity.
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Affiliation(s)
- Mónica Alvarez
- *Genes and Disease Program, Centre de Regulació Genómica, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain; and
| | - Xavier Altafaj
- *Genes and Disease Program, Centre de Regulació Genómica, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain; and
| | - Sergi Aranda
- *Genes and Disease Program, Centre de Regulació Genómica, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain; and
| | - Susana de la Luna
- *Genes and Disease Program, Centre de Regulació Genómica, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain; and
- Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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30
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Di Bartolo V, Montagne B, Salek M, Jungwirth B, Carrette F, Fourtane J, Sol-Foulon N, Michel F, Schwartz O, Lehmann WD, Acuto O. A novel pathway down-modulating T cell activation involves HPK-1-dependent recruitment of 14-3-3 proteins on SLP-76. ACTA ACUST UNITED AC 2007; 204:681-91. [PMID: 17353368 PMCID: PMC2137917 DOI: 10.1084/jem.20062066] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The SH2 domain-containing leukocyte protein of 76 kD (SLP-76) is a pivotal element of the signaling machinery controlling T cell receptor (TCR)-mediated activation. Here, we identify 14-3-3epsilon and zeta proteins as SLP-76 binding partners. This interaction was induced by TCR ligation and required phosphorylation of SLP-76 at serine 376. Ribonucleic acid interference and in vitro phosphorylation experiments showed that serine 376 is the target of the hematopoietic progenitor kinase 1 (HPK-1). Interestingly, either S376A mutation or HPK-1 knockdown resulted in increased TCR-induced tyrosine phosphorylation of SLP-76 and phospholipase C-gamma1. Moreover, an SLP-76-S376A mutant induced higher interleukin 2 gene transcription than wild-type SLP-76. These data reveal a novel negative feedback loop involving HPK-1-dependent serine phosphorylation of SLP-76 and 14-3-3 protein recruitment, which tunes T cell activation.
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Affiliation(s)
- Vincenzo Di Bartolo
- Molecular Immunology Unit, Centre National de la Recherche Scientifique (CNRS) URA 1961, Institut Pasteur, 75724 Paris, Cedex 15, France.
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31
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Shui JW, Boomer JS, Han J, Xu J, Dement GA, Zhou G, Tan TH. Hematopoietic progenitor kinase 1 negatively regulates T cell receptor signaling and T cell-mediated immune responses. Nat Immunol 2006; 8:84-91. [PMID: 17115060 DOI: 10.1038/ni1416] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 10/26/2006] [Indexed: 11/09/2022]
Abstract
HPK1 is a Ste20-related serine-threonine kinase that inducibly associates with the adaptors SLP-76 and Gads after T cell receptor (TCR) signaling. Here, HPK1 deficiency resulted in enhanced TCR-induced phosphorylation of SLP-76, phospholipase C-gamma1 and the kinase Erk, more-persistent calcium flux, and increased production of cytokines and antigen-specific antibodies. Furthermore, HPK1-deficient mice were more susceptible to experimental autoimmune encephalomyelitis. Although the interaction between SLP-76 and Gads was unaffected, the inducible association of SLP-76 with 14-3-3tau (a phosphorylated serine-binding protein and negative regulator of TCR signaling) was reduced in HPK1-deficient T cells after TCR stimulation. HPK1 phosphorylated SLP-76 and induced the interaction of SLP-76 with 14-3-3tau. Our results indicate that HPK1 negatively regulates TCR signaling and T cell-mediated immune responses.
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Affiliation(s)
- Jr-Wen Shui
- Department of Immunology, Baylor College of Medicine, Houston, Texas 77030, USA
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32
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Yano M, Nakamuta S, Wu X, Okumura Y, Kido H. A novel function of 14-3-3 protein: 14-3-3zeta is a heat-shock-related molecular chaperone that dissolves thermal-aggregated proteins. Mol Biol Cell 2006; 17:4769-79. [PMID: 16943323 PMCID: PMC1635386 DOI: 10.1091/mbc.e06-03-0229] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The 14-3-3 proteins are highly conserved molecules that function as intracellular adaptors in a variety of biological processes, such as signal transduction, cell cycle control, and apoptosis. Here, we show that a 14-3-3 protein is a heat-shock protein (Hsp) that protects cells against physiological stress as its new cellular function. We have observed that, in Drosophila cells, the 14-3-3zeta is up-regulated under heat stress conditions, a process mediated by a heat shock transcription factor. As the biological action linked to heat stress, 14-3-3zeta interacted with apocytochrome c, a mitochondrial precursor protein of cytochrome c, in heat-treated cells, and the suppression of 14-3-3zeta expression by RNA interference resulted in the formation of significant amounts of aggregated apocytochrome c in the cytosol. The aggregated apocytochrome c was converted to a soluble form by the addition of 14-3-3zeta protein and ATP in vitro. 14-3-3zeta also resolubilized heat-aggregated citrate synthase and facilitated its reactivation in cooperation with Hsp70/Hsp40 in vitro. Our observations provide the first direct evidence that a 14-3-3 protein functions as a stress-induced molecular chaperone that dissolves and renaturalizes thermal-aggregated proteins.
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Affiliation(s)
- Mihiro Yano
- Division of Enzyme Chemistry, Institute for Enzyme Research, The University of Tokushima, Tokushima 770-8503, Japan
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33
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Abramow-Newerly M, Ming H, Chidiac P. Modulation of subfamily B/R4 RGS protein function by 14-3-3 proteins. Cell Signal 2006; 18:2209-22. [PMID: 16839744 DOI: 10.1016/j.cellsig.2006.05.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 05/09/2006] [Indexed: 12/01/2022]
Abstract
Regulator of G protein signalling (RGS) proteins are primarily known for their ability to act as GTPase activating proteins (GAPs) and thus attenuate G protein function within G protein-coupled receptor (GPCR) signalling pathways. However, RGS proteins have been found to interact with additional binding partners, and this has introduced more complexity to our understanding of their potential role in vivo. Here, we identify a novel interaction between RGS proteins (RGS4, RGS5, RGS16) and the multifunctional protein 14-3-3. Two isoforms, 14-3-3beta and 14-3-3epsilon, directly interact with all three purified RGS proteins and data from in vitro steady state GTP hydrolysis assays show that 14-3-3 inhibits the GTPase activity of RGS4 and RGS16, but has limited effects on RGS5 under comparable conditions. Moreover in a competitive pull-down experiment, 14-3-3epsilon competes with Galphao for RGS4, but not for RGS5. This mechanism is further reinforced in living cells, where 14-3-3epsilon sequesters RGS4 in the cytoplasm and impedes its recruitment to the plasma membrane by Galpha protein. Thus, 14-3-3 might act as a molecular chelator, preventing RGS proteins from interacting with Galpha, and ultimately prolonging the signal transduction pathway. In conclusion, our findings suggest that 14-3-3 proteins may indirectly promote GPCR signalling via their inhibitory effects on RGS GAP function.
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Affiliation(s)
- Maria Abramow-Newerly
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada N6A 5C1
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34
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Simmons A, Gangadharan B, Hodges A, Sharrocks K, Prabhakar S, García A, Dwek R, Zitzmann N, McMichael A. Nef-mediated lipid raft exclusion of UbcH7 inhibits Cbl activity in T cells to positively regulate signaling. Immunity 2006; 23:621-34. [PMID: 16356860 DOI: 10.1016/j.immuni.2005.11.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Revised: 09/09/2005] [Accepted: 11/09/2005] [Indexed: 12/23/2022]
Abstract
Lentiviral Nef increases T cell signaling activity, but the molecular nature of the stimulus involved is incompletely described. We explored CD4 T cell lipid raft composition in the presence and absence of Nef. Here, the E2 ubiquitin-conjugating enzyme UbcH7, which acts in conjunction with c-Cbl, is absent from lipid rafts. This Nef-mediated exclusion is associated with failure of ubiquitination of activated Vav. In the presence of Nef, lipid raft Cdc42 is activated and forms a ternary complex between the c-Cbl-interacting protein p85Cool-1/betaPix and c-Cbl, displacing UbcH7 from rafts. Suppression of p85Cool-1/betaPix expression restores UbcH7 raft localization and Vav ubiquitination and diminishes Cdc42 activity. Moreover, p85Cool-1/betaPix knockdown attenuates HIV replication. Thresholds for activation of signaling involve the intricate balance of positive and negative regulators. Here we provide evidence for Nef disruption of a negative regulator of T cell signaling in promoting HIV replication.
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Affiliation(s)
- Alison Simmons
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, United Kingdom.
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35
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Abstract
This chapter includes a historic overview of 14-3-3 proteins with an emphasis on the differences between potentially cancer-relevant isoforms on the genomic, protein and functional level. The focus will therefore be on mammalian 14-3-3s although many important developments in the field have involved Drosophila 14-3-3 proteins for example and the cross-fertilisation from parallel studies on plant 14-3-3 should not be underestimated. In the major part of this review I will attempt to focus on some novel data and aspects of 14-3-3 structure and function, in particular regulation of 14-3-3 isoforms by oncogene-related protein kinase phosphorylation and aspects of 14-3-3 research with which newcomers to the field may be less familiar.
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Affiliation(s)
- Alastair Aitken
- University of Edinburgh, School of Biological Sciences, Kings Buildings, Scotland, UK.
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36
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Abstract
14-3-3 proteins are a family of highly conserved cellular proteins that play key roles in the regulation of central physiological pathways. More than 200 14-3-3 target proteins have been identified, including proteins involved in mitogenic and cell survival signaling, cell cycle control and apoptotic cell death. Importantly, the involvement of 14-3-3 proteins in the regulation of various oncogenes and tumor suppressor genes points to a potential role in human cancer. The present review summarizes current findings implicating a 14-3-3 role in cancer while discussing potential mechanisms and points of action of 14-3-3 during cancer development and progression.
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Affiliation(s)
- Guri Tzivion
- Karmanos Cancer Institute and Department of Pathology, Wayne State University, Detroit, MI 48201, USA.
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37
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Alexander RD, Morris PC. A proteomic analysis of 14-3-3 binding proteins from developing barley grains. Proteomics 2006; 6:1886-96. [PMID: 16470656 DOI: 10.1002/pmic.200500548] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
14-3-3 proteins are important eukaryotic regulatory proteins. Barley (Hordeum vulgare L.) 14-3-3A was over-expressed, immobilised and used to affinity purify 14-3-3 binding proteins from developing barley grains. Binding was shown to be phosphorylation-dependent. These proteins were fractionated by PAGE and identified by MALDI-TOF MS. In total, 54 14-3-3 binding proteins were identified, 49 of these interactions are novel to plants. These proteins fell into a number of functional categories. The largest category was for carbohydrate metabolism, including plastidic enzymes for starch synthesis and modification. 14-3-3 was shown to be present in isolated plastids. Four of five enzymes involved in sucrose biosynthesis from triose phosphates were identified, suggesting co-ordinated regulation of this pathway. Invertase and sucrose synthase, which break down sucrose to hexoses, were found. Sucrose synthase activity was shown to be inhibited by exogenous 14-3-3 in a dosage-dependent manner. The second-largest functional group was for proteins involved in stress and defence responses; for example, RGH2A, closely related to the MLA powdery mildew resistance protein, was found. This work illustrates the broad range of processes in which 14-3-3 may be involved, and augments previous data demonstrating key roles in carbohydrate metabolism and plant defence.
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38
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Cao WD, Zhang X, Zhang JN, Yang ZJ, Zhen HN, Cheng G, Li B, Gao D. Immunocytochemical detection of 14-3-3 in primary nervous system tumors. J Neurooncol 2005; 77:125-30. [PMID: 16292484 DOI: 10.1007/s11060-005-9027-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Accepted: 07/25/2005] [Indexed: 10/25/2022]
Abstract
14-3-3 proteins have attracted much recent interest in the etiopathogenesis of human cancers owing to their involvement in the prevention of apoptosis. However, the expression of 14-3-3 in primary nervous system tumors has not been previously characterized. In this paper, Immunohistochemistry using a specific anti-14-3-3 antibody was performed on formalin-fixed, paraffin embedded archival tissue from 124 primary human nervous system tumors and 10 normal brain tissues. In the normal control brains, 14-3-3 immunoreactivity was localized mainly in the neuronal somata and processes, and some glial cells showed only weak immunoreactivity. However, 14-3-3 immunoreactivity was seen in the majority of astrocytomas [grade I (9/11), II (16/21), III (13/17), IV (17/21)]. There was no difference between the positive expression rates of 14-3-3 in different grades of astrocytomas (P = 0.968). But the intensity and degree of 14-3-3 immunoreactivity in diffuse astrocytomas, anaplastic astrocytoma, and glioblastoma multiformes showed trends with tumor grade, with glioblastomas having the highest positivity (P = 0.048). The 14-3-3 immunoreactivity was also seen in the majority of other gliomas [oligodendroglioma (2/3), anaplastic oligodendroglioma (4/4), ependymoma (1/2), anaplastic ependymoma (2/2), choroid plexus papilloma (3/3), pineocytoma (2/2), medulloblastoma (5/8)]. All meningiomas [syncytical (3), fibrous/fibroblastic (4), angiomatous (4), transitional/mixed (3)] were intensely and diffusely positive. All schwannomas (4), neurofibromas (2), pituitary adenomas (6) and craniopharyngiomas(4) also showed intense positive staining. These results showed that 14-3-3 is expressed in the majority of the primary human nervous system tumors. The up-regulated expression of 14-3-3 may be a common mechanism for evading apoptosis in most primary human nervous system tumors, and targeting 14-3-3 may be a novel promising strategy for the treatment of these tumors, especially for malignant tumors.
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Affiliation(s)
- Wei-Dong Cao
- Institute of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Shaanxi Province, Xi'an, People's Republic of China
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39
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Abstract
Although the signaling pathways related to GPIb-IX-V have not been fully elucidated, an accumulating body of evidence suggests that phospholipase C (PLC)gamma2 activation, subsequent Ca++ release and oscillations constitute an essential signal transduction pathway related to GPIb-IX-V. Src family kinases are required for PLCgamma2 activation, while FcR gamma-chain/Fc gammaRIIA may be dispensable for PLCgamma2 activation. Although PI-3K serves to potentiate various signaling events culminating in alpha(IIb)beta3 activation, PI-3K activity may be dispensable for Src-PLCgamma2 activation in GPIb-IX-V-mediated signaling. Glycosphingolipid-enriched microdomains (GEMs) appear to provide platforms for the signal transduction pathway related to GIb-IX-V, as the interaction between GPIb-IX-V and Src or PLCgamma2 tyrosine phosphorylation occurs exclusively in GEMs.
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Affiliation(s)
- Y Ozaki
- Department of Laboratory Medicine, University of Yamanashi, Nakakoma, Yamanashi, Japan.
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40
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Clokie SJ, Cheung KY, Mackie S, Marquez R, Peden AH, Aitken A. BCR kinase phosphorylates 14-3-3 Tau on residue 233. FEBS J 2005; 272:3767-76. [PMID: 16045749 DOI: 10.1111/j.1742-4658.2005.04765.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The breakpoint cluster region protein, BCR, has protein kinase activity that can auto- and trans-phosphorylate serine, threonine and tyrosine residues. BCR has been implicated in chronic myelogenous leukaemia as well as important signalling pathways, and as such its interaction with 14-3-3 is of major interest. 14-3-3tau and zeta isoforms have been shown previously to be phosphorylated in vitro and in vivo by BCR kinase on serine and threonine residue(s) but site(s) were not determined. Phosphorylation of 14-3-3 isoforms at distinct sites is an important mode of regulation that negatively affects interaction with Raf kinase and Bax, and potentially influences the dimerization of 14-3-3. In this study we have further characterized the BCR-14-3-3 interaction and have identified the site phosphorylated by BCR. We show here that BCR interacts with at least five isoforms of 14-3-3 in vivo and phosphorylates 14-3-3tau on Ser233 and to a lesser extent 14-3-3zeta on Thr233. We have previously shown that these two isoforms are also phosphorylated at this site by casein kinase 1, which, in contrast to BCR, preferentially phosphorylates 14-3-3zeta.
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Affiliation(s)
- Samuel J Clokie
- School of Biomedical and Clinical Laboratory Sciences, University of Edinburgh, UK
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41
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Zhu P, Sang Y, Xu H, Zhao J, Xu R, Sun Y, Xu T, Wang X, Chen L, Feng H, Li C, Zhao S. ADAM22 plays an important role in cell adhesion and spreading with the assistance of 14-3-3. Biochem Biophys Res Commun 2005; 331:938-46. [PMID: 15882968 DOI: 10.1016/j.bbrc.2005.03.229] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2005] [Indexed: 10/25/2022]
Abstract
Cellular adhesion plays important roles in a variety of biological processes. The ADAM family contains disintegrin-like and metalloproteinase-like domains which potentially have cell adhesion and protease activities. Recent studies suggest that the interaction between 14-3-3zeta and ADAM22cyt can regulate cell adhesion and spreading, therefore it has a potential role in neural development and function. 14-3-3 family has seven highly conserved members that regulate various cellular functions. Using yeast two-hybrid method, we identified that ADAM22cyt bound some other 14-3-3 family members. The interaction was further confirmed by in vitro protein pull-down assay and co-immunoprecipitation. We also found that the overexpression of exogenous ADAM22 in HEK293 cells could significantly enhance cell adhesion and spreading, compared with the truncated ADAM22 lack of 14-3-3 binding motifs. These results strongly demonstrated a functional role for ADAM22/14-3-3 in cell adhesion and spreading.
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Affiliation(s)
- Pengcheng Zhu
- The State Key Laboratory of Genetic Engineering, Institute of Genetics, Fudan University, Shanghai 200433, China.
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42
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Efendiev R, Chen Z, Krmar RT, Uhles S, Katz AI, Pedemonte CH, Bertorello AM. The 14-3-3 protein translates the NA+,K+-ATPase {alpha}1-subunit phosphorylation signal into binding and activation of phosphoinositide 3-kinase during endocytosis. J Biol Chem 2005; 280:16272-7. [PMID: 15722354 DOI: 10.1074/jbc.m500486200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clathrin-dependent endocytosis of Na(+),K(+)-ATPase molecules in response to G protein-coupled receptor signals is triggered by phosphorylation of the alpha-subunit and the binding of phosphoinositide 3-kinase. In this study, we describe a molecular mechanism linking phosphorylation of Na(+),K(+)-ATPase alpha-subunit to binding and activation of phosphoinositide 3-kinase. Co-immunoprecipitation studies, as well as experiments using confocal microscopy, revealed that dopamine favored the association of 14-3-3 protein with the basolateral plasma membrane and its co-localization with the Na(+),K(+)-ATPase alpha-subunit. The functional relevance of this interaction was established in opossum kidney cells expressing a 14-3-3 dominant negative mutant, where dopamine failed to decrease Na(+),K(+)-ATPase activity and to promote its endocytosis. The phosphorylated Ser-18 residue within the alpha-subunit N terminus is critical for 14-3-3 binding. Activation of phosphoinositide 3-kinase by dopamine during Na(+),K(+)-ATPase endocytosis requires the binding of the kinase to a proline-rich domain within the alpha-subunit, and this effect was blocked by the presence of a 14-3-3 dominant negative mutant. Thus, the 14-3-3 protein represents a critical linking mechanism for recruiting phosphoinositide 3-kinase to the site of Na(+),K(+)-ATPase endocytosis.
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Affiliation(s)
- Riad Efendiev
- Department of Medicine, Atherosclerosis Research Unit, Membrane Signaling Networks, Karolinska Institutet, Karolinska University Hospital-Solna, S-171 76 Stockholm, Sweden
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43
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Rodriguez LG, Guan JL. 14-3-3 regulation of cell spreading and migration requires a functional amphipathic groove. J Cell Physiol 2005; 202:285-94. [PMID: 15389601 DOI: 10.1002/jcp.20122] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The 14-3-3 proteins associate with many cellular proteins that participate in the regulation of various cellular events including apoptosis, the cell cycle, spreading, and migration. We have previously described that 14-3-3beta binds the beta1-integrin and overexpression of 14-3-3beta promoted increased cell spreading and migration (Han et al. [2001] Oncogene 20: 346-357). In this study, we find that mutation of Ser 60 of 14-3-3beta, outside of the amphipathic groove which is involved in 14-3-3 protein interactions with other ligands, abolished its interaction with integrin. Surprisingly, this mutant retained its ability to promote cell spreading, suggesting that 14-3-3beta interaction with the beta1-integrin is not required for its regulation of cell adhesion. We next showed that mutations of several critical residues in the amphipathic groove did not affect 14-3-3beta interaction with the beta1-integrin. As expected, these mutants disrupted their association with the phosphoserine dependent ligands Raf and Cas. Analysis of the groove mutant LF (mutation of Arg129Tyr130 to Leu and Phe) indicated that, unlike wild type 14-3-3beta, it could not stimulate cell spreading or migration, suggesting that a functional amphipathic groove is required for 14-3-3 regulation of cell adhesion and migration. Consistent with this, cells expressing the LF mutant exhibited a delay in F-actin organization compared to cells expressing wild type or the S60A mutant (Ser 60 to Ala mutation) upon cell adhesion to fibronectin (FN). Taken together, these studies identified a novel binding site on 14-3-3 for integrin beta1 and showed that a functional amphipathic groove, rather than its interaction with integrin beta1, is required for 14-3-3 regulation of cell spreading and migration.
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Affiliation(s)
- Luis G Rodriguez
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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44
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Davare MA, Saneyoshi T, Guire ES, Nygaard SC, Soderling TR. Inhibition of Calcium/Calmodulin-dependent Protein Kinase Kinase by Protein 14-3-3. J Biol Chem 2004; 279:52191-9. [PMID: 15469938 DOI: 10.1074/jbc.m409873200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intracellular calcium concentrations regulate diverse cellular events including cytoskeletal dynamics, gene transcription, and synaptic plasticity. The calcium signal is transduced in part by the calcium/calmodulin-dependent protein kinase (CaMK) cascade that is comprised of CaMK kinase (CaMKK) and its primary downstream substrates, CaMKI and CaMKIV. The CaMK cascade also participates in cross-talk with other signaling pathways: CaMKK/CaMKI can activate the mitogen-activated protein kinase pathway and cAMP-dependent protein kinase (PKA) can directly phosphorylate two inhibitory sites (Thr108 and Ser458) in CaMKK. Here we report an additional PKA-dependent regulation of CaMKK through its interaction with protein 14-3-3. CaMKK and 14-3-3 co-immunoprecipitated from co-transfected heterologous cells as well as from rat brain homogenate, and site-directed mutagenesis studies identified phospho-Ser74 in CaMKK as the primary 14-3-3 binding site. In cultured rat hippocampal neurons and acute hippocampal slices this interaction was robustly stimulated by activation of PKA through forskolin treatment and was blocked by inhibition of PKA. Interaction of 14-3-3 with CaMKK had two regulatory consequences in vitro. It directly inhibited CaMKK activity, and it also blocked dephosphorylation of Thr108, an inhibitory PKA phosphorylation site. In human embryonic kidney 293 cells transfected with CaMKK and stimulated with forskolin, co-transfection with 14-3-3 prevented dephosphorylation of Thr108 to the same extent as did inhibition of protein phosphatases with okadaic acid. We conclude that binding of 14-3-3 to CaMKK stabilizes its inhibition by PKA-mediated phosphorylation, which may have important consequences in the regulation of CaMKI, CaMKIV, protein kinase B, and ERK signaling pathways.
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Affiliation(s)
- Monika A Davare
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239, USA
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45
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Canobbio I, Balduini C, Torti M. Signalling through the platelet glycoprotein Ib-V–IX complex. Cell Signal 2004; 16:1329-44. [PMID: 15381249 DOI: 10.1016/j.cellsig.2004.05.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Accepted: 05/12/2004] [Indexed: 11/16/2022]
Abstract
The glycoprotein Ib-V-IX is one of the major adhesive receptors expressed on the surface of circulating platelets. It is composed of four different polypeptides-GPIbalpha, GPIbbeta, GPIX, and GPV-and represents a multifunctional receptor able to interact with a number of ligands, including the adhesive protein von Willebrand factor, the coagulation factors thrombin, factors XI and XII, and the membrane glycoproteins P-selectin and Mac-1. Interaction of GPIb-V-IX with the subendothelial von Willebrand factor is essential for primary haemostasis, as it initiates platelet adhesion to the subendothelial matrix at the sites of vascular injury even under high flow conditions. Upon interaction with von Willebrand factor, GPIb-V-IX initiates transmembrane signalling events for platelet activation, which eventually result in integrin alpha(IIb)beta(3) stimulation and platelet aggregation. The investigation of the biochemical mechanisms for platelet activation by GPIb-V-IX has attracted increasing attention during the last years. This review will describe and discuss recent findings that have provided new insights into the events underlying GPIb-V-IX transmembrane signalling. In particular, it will summarise basic concepts on the structure of this receptor, extracellular ligands, and intracellular interactors potentially involved in transmembrane signalling. The recently suggested role of membrane Fc receptors in GPIb-V-IX-initiated platelet activation will also be discussed, along with the involvement of lipid metabolising enzymes, tyrosine kinases, and the cytoskeleton in the crosstalk between GPIb-V-IX and integrin alpha(IIb)beta(3).
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Affiliation(s)
- Ilaria Canobbio
- Center of Excellence for Applied Biology, Department of Biochemistry, University of Pavia, via Bassi 21, Pavia 27100, Italy
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46
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Li L, Ren CH, Tahir SA, Ren C, Thompson TC. Caveolin-1 maintains activated Akt in prostate cancer cells through scaffolding domain binding site interactions with and inhibition of serine/threonine protein phosphatases PP1 and PP2A. Mol Cell Biol 2003; 23:9389-404. [PMID: 14645548 PMCID: PMC309640 DOI: 10.1128/mcb.23.24.9389-9404.2003] [Citation(s) in RCA: 235] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2003] [Revised: 06/04/2003] [Accepted: 09/09/2003] [Indexed: 12/28/2022] Open
Abstract
Previously it has been reported that caveolin-1 (cav-1) has antiapoptotic activities in prostate cancer cells and functions downstream of androgenic stimulation. In this study, we demonstrate that cav-1 overexpression significantly reduced thapsigargin (Tg)-stimulated apoptosis. Examination of the phosphatidylinositol 3-kinase (PI3-K)/Akt signaling cascade revealed higher activities of PDK1 and Akt but not PI3-K in cav-1-stimulated cells compared to control cells. We subsequently found that cav-1 interacts with and inhibits serine/threonine protein phosphatases PP1 and PP2A through scaffolding domain binding site interactions. Deletion of the cav-1 scaffolding domain significantly reduces phosphorylated Akt and cell viability compared with wild-type cav-1. Analysis of potential substrates for PP1 and PP2A revealed that cav-1-mediated inhibition of PP1 and PP2A leads to increased PDK1, Akt, and ERK1/2 activities. We demonstrate that increased Akt activities are largely responsible for cav-1-mediated cell survival using dominant-negative Akt mutants and specific inhibitors to MEK1/MEK and show that cav-1 increases the half-life of phosphorylated PDK1 and Akt after inhibition of PI3-K by LY294002. We further demonstrate that cav-1-stimulated Akt activities lead to increased phosphorylation of multiple Akt substrates, including GSK3, FKHR, and MDM2. In addition, overexpression of cav-1 significantly increases translocation of phosphorylated androgen receptor to nucleus. Our studies therefore reveal a novel mechanism of Akt activation in prostate cancer and potentially other malignancies.
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Affiliation(s)
- Likun Li
- Scott Department of Urology, Baylor College of Medicine, 6560 Fannin, Suite 2100, Houston, TX 77030, USA
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47
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Bialkowska K, Zaffran Y, Meyer SC, Fox JEB. 14-3-3 zeta mediates integrin-induced activation of Cdc42 and Rac. Platelet glycoprotein Ib-IX regulates integrin-induced signaling by sequestering 14-3-3 zeta. J Biol Chem 2003; 278:33342-50. [PMID: 12810725 DOI: 10.1074/jbc.m301217200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integrin-induced cytoskeletal reorganizations are initiated by Cdc42 and Rac1 but little is known about mechanisms by which integrins activate these Rho GTPases. 14-3-3 proteins are adaptors implicated in binding and regulating the function and subcellular location of numerous signaling molecules. In platelets, the 14-3-3 zeta isoform interacts with the glycoprotein (GP) Ibalpha subunit of the adhesion receptor GP Ib-IX. In this study, we show that integrin-induced activation of Cdc42, activation of Rac, cytoskeletal reorganizations, and cell spreading were inhibited in Chinese hamster ovary cells expressing full-length GP Ibalpha compared with GP Ibalpha lacking the 14-3-3 zeta binding site. Activation of Rho GTPases and cytoskeletal reorganizations were restored by expression of 14-3-3 zeta. Spreading in cells expressing truncated GP Ibalpha was inhibited by co-expressing a chimeric receptor containing interleukin 2 receptor alpha and GP Ibalpha cytoplasmic domain. These results identify a previously unrecognized function of 14-3-3 zeta, that of mediating integrin-induced signaling. They show that 14-3-3 zeta mediates Cdc42 and Rac activation. They also reveal a novel function of platelet GP Ib-IX, that of regulating integrin-induced cytoskeletal reorganizations by sequestering 14-3-3 zeta. Signaling across integrins initiates changes in cell behavior such as spreading, migration, differentiation, apoptosis, or cell division. Thus, introduction of the 14-3-3 zeta binding domain of GP Ibalpha into target cells might provide a method for regulating integrin-induced pathways in a variety of pathological conditions.
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Affiliation(s)
- Katarzyna Bialkowska
- Joseph J. Jacobs Center for Thrombosis and Vascular Biology, Department of Molecular Cardiology, the Lerner Research Institute, the Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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48
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Zhang J, Popken GJ, Ye P, D'Ercole AJ. Down-regulation of 14-3-3 eta gene expression by IGF-I in mouse cerebellum during postnatal development. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2003; 143:199-206. [PMID: 12855191 DOI: 10.1016/s0165-3806(03)00132-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Insulin-like growth factor I (IGF-I) overexpression in the postnatal cerebellum of transgenic (Tg) mice results in remarkable cerebellar overgrowth characterized by a near doubling of granule cell number that is predominantly due to inhibition of apoptosis. Using this Tg model we set out to investigate IGF-I anti-apoptotic mechanisms by defining the influence of IGF-I on gene expression. Using a cDNA array technique, we screened a total of 243 mouse apoptosis-related genes, and found that 14-3-3 eta gene expression was significantly reduced in the cerebella of Tg mice compared with their wild-type (Wt) littermates. Using Northern blot analysis to corroborate our microarray finding, we showed that 14-3-3 eta mRNA abundance was decreased from postnatal day P5 through P17. Nonetheless, the expression pattern of 14-3-3 eta in Tg mice followed the same pattern observed in Wt mice, and was indistinguishable from that in Wt mice at P20 and P23. 14-3-3 eta protein abundance, as determined by Western immunoblot analyses, showed similar decreases in the cerebella of Tg mice. In situ hybridization demonstrated that 14-3-3 eta was predominantly, if not exclusively, expressed and regulated in Purkinje cells. 14-3-3 proteins have multiple functions, including participation in pathways that favor cell survival. Our finding of IGF-I-induced down-regulation of 14-3-3 eta expression in Purkinje cell at a time when IGF-I promotes granule cell survival leads us to speculate that down-regulation of 14-3-3 eta may: (a) serve a negative feedback role to modulate Purkinje cell survival, i.e. limit Purkinje cell number, and/or (b) function as part of a distinct signaling mechanism, perhaps one that augments the capacity of Purkinje cells to promote granule cell survival.
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Affiliation(s)
- Jihui Zhang
- Department of Pediatrics, Division of Endocrinology, CB# 7039, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7039, USA
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49
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Cavet ME, Lehoux S, Berk BC. 14-3-3beta is a p90 ribosomal S6 kinase (RSK) isoform 1-binding protein that negatively regulates RSK kinase activity. J Biol Chem 2003; 278:18376-83. [PMID: 12618428 DOI: 10.1074/jbc.m208475200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
p90 ribosomal S6 kinase 1 (RSK1) is a serine/threonine kinase that is activated by extracellular signal-related kinases 1/2 and phosphoinositide-dependent protein kinase 1 upon mitogen stimulation. Under basal conditions, RSK1 is located in the cytosol and upon stimulation, RSK1 translocates to the plasma membrane where it is fully activated. The ability of RSK1 to bind the adapter protein 14-3-3beta was investigated because RSK1 contains several putative 14-3-3-binding motifs. We demonstrate that RSK1 specifically and directly binds 14-3-3beta. This interaction was dependent on phosphorylation of serine 154 within the motif RLSKEV of RSK1. Binding of RSK1 to 14-3-3beta was maximal under basal conditions and decreased significantly upon mitogen stimulation. After 5 min of serum stimulation, a portion of 14-3-3beta and RSK1 translocated to the membrane fraction, and immunofluorescence studies demonstrated colocalization of RSK1 and 14-3-3beta at the plasma membrane in vivo. Incubation of recombinant RSK1 with 14-3-3beta decreased RSK1 kinase activity by approximately 50%. Mutation of RSK1 serine 154 increased both basal and serum-stimulated RSK activity. In addition, the epidermal growth factor response of RSK1S154A was enhanced compared with wild type RSK. The amount of RSK1S154A was significantly increased in the membrane fraction under basal conditions. Increased phosphorylation of two sites essential for RSK1 kinase activity (Ser(380) and Ser(363)) in RSK1S154A compared with RSK1 wild type, demonstrated that 14-3-3 interferes with RSK1 phosphorylation. These data suggest that 14-3-3beta binding negatively regulates RSK1 activity to maintain signal specificity and that association/dissociation of the 14-3-3beta-RSK1 complex is likely to be important for mitogen-mediated RSK1 activation.
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MESH Headings
- 14-3-3 Proteins
- 3T3 Cells
- Amino Acid Sequence
- Animals
- Binding Sites
- COS Cells
- Cell Line
- Cell Membrane/metabolism
- Cells, Cultured
- Cricetinae
- DNA/metabolism
- Dose-Response Relationship, Drug
- Genes, Reporter
- Glutathione Transferase/metabolism
- Humans
- Immunohistochemistry
- Mice
- Microscopy, Confocal
- Microscopy, Fluorescence
- Models, Biological
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation
- Phosphorylation
- Point Mutation
- Precipitin Tests
- Promoter Regions, Genetic
- Protein Binding
- Protein Biosynthesis
- Protein Isoforms
- Protein Kinases/metabolism
- Protein Transport
- Rats
- Recombinant Proteins/chemistry
- Ribosomal Protein S6 Kinases
- Ribosomal Protein S6 Kinases, 90-kDa/chemistry
- Ribosomal Protein S6 Kinases, 90-kDa/metabolism
- Serine/chemistry
- Time Factors
- Transfection
- Tyrosine 3-Monooxygenase/metabolism
- Tyrosine 3-Monooxygenase/physiology
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Affiliation(s)
- Megan E Cavet
- Center for Cardiovascular Research and Department of Medicine, University of Rochester, Rochester, New York 14642, USA
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Agarwal-Mawal A, Qureshi HY, Cafferty PW, Yuan Z, Han D, Lin R, Paudel HK. 14-3-3 connects glycogen synthase kinase-3 beta to tau within a brain microtubule-associated tau phosphorylation complex. J Biol Chem 2003; 278:12722-8. [PMID: 12551948 DOI: 10.1074/jbc.m211491200] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In a recent study, we reported that in bovine brain extract, glycogen synthase kinase-3beta and tau are parts of an approximately 400-500 kDa microtubule-associated tau phosphorylation complex (Sun, W., Qureshi, H. Y., Cafferty, P. W., Sobue, K., Agarwal-Mawal, A., Neufield, K. D., and Paudel, H. K. (2002) J. Biol. Chem. 277, 11933-11940). In this study, we find that when purified brain microtubules are subjected to Superose 12 gel filtration column chromatography, the dimeric scaffold protein 14-3-3 zeta co-elutes with the tau phosphorylation complex components tau and GSK3 beta. From gel filtration fractions containing the tau phosphorylation complex, 14-3-3 zeta, GSK3 beta, and tau co-immunoprecipitate with each other. From extracts of bovine brain, COS-7 cells, and HEK-293 cells transfected with GSK3 beta, 14-3-3 zeta co-precipitates with GSK3 beta, indicating that GSK3 beta binds to 14-3-3 zeta. From HEK-293 cells transfected with tau, GSK3 beta, and 14-3-3 zeta in different combinations, tau co-immunoprecipitates with GSK3 beta only in the presence of 14-3-3 zeta. In vitro, approximately 10-fold more tau binds to GSK3 beta in the presence of than in the absence of 14-3-3 zeta. In transfected HEK-293 cells, 14-3-3 zeta stimulates GSK3 beta-catalyzed tau phosphorylation in a dose-dependent manner. These data indicate that in brain, the 14-3-3 zeta dimer simultaneously binds and bridges tau and GSK3 beta and stimulates GSK3 beta-catalyzed tau phosphorylation.
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Affiliation(s)
- Alka Agarwal-Mawal
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
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