1
|
Markitantova Y, Fokin A, Boguslavsky D, Simirskii V, Kulikov A. Molecular Signatures Integral to Natural Reprogramming in the Pigment Epithelium Cells after Retinal Detachment in Pleurodeles waltl. Int J Mol Sci 2023; 24:16940. [PMID: 38069262 PMCID: PMC10707686 DOI: 10.3390/ijms242316940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
The reprogramming of retinal pigment epithelium (RPE) cells into retinal cells (transdifferentiation) lies in the bases of retinal regeneration in several Urodela. The identification of the key genes involved in this process helps with looking for approaches to the prevention and treatment of RPE-related degenerative diseases of the human retina. The purpose of our study was to examine the transcriptome changes at initial stages of RPE cell reprogramming in adult newt Pleurodeles waltl. RPE was isolated from the eye samples of day 0, 4, and 7 after experimental surgical detachment of the neural retina and was used for a de novo transcriptome assembly through the RNA-Seq method. A total of 1019 transcripts corresponding to the differently expressed genes have been revealed in silico: the 83 increased the expression at an early stage, and 168 increased the expression at a late stage of RPE reprogramming. We have identified up-regulation of classical early response genes, chaperones and co-chaperones, genes involved in the regulation of protein biosynthesis, suppressors of oncogenes, and EMT-related genes. We revealed the growth in the proportion of down-regulated ribosomal and translation-associated genes. Our findings contribute to revealing the molecular mechanism of RPE reprogramming in Urodela.
Collapse
Affiliation(s)
| | | | | | - Vladimir Simirskii
- Koltsov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (Y.M.); (A.K.)
| | | |
Collapse
|
2
|
Li Y, Zhu J, Yu Z, Zhai F, Li H, Jin X. Regulation of apoptosis by ubiquitination in liver cancer. Am J Cancer Res 2023; 13:4832-4871. [PMID: 37970337 PMCID: PMC10636691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/04/2023] [Indexed: 11/17/2023] Open
Abstract
Apoptosis is a programmed cell death process critical to cell development and tissue homeostasis in multicellular organisms. Defective apoptosis is a crucial step in the malignant transformation of cells, including hepatocellular carcinoma (HCC), where the apoptosis rate is higher than in normal liver tissues. Ubiquitination, a post-translational modification process, plays a precise role in regulating the formation and function of different death-signaling complexes, including those involved in apoptosis. Aberrant expression of E3 ubiquitin ligases (E3s) in liver cancer (LC), such as cellular inhibitors of apoptosis proteins (cIAPs), X chromosome-linked IAP (XIAP), and linear ubiquitin chain assembly complex (LUBAC), can contribute to HCC development by promoting cell survival and inhibiting apoptosis. Therefore, the review introduces the main apoptosis pathways and the regulation of proteins in these pathways by E3s and deubiquitinating enzymes (DUBs). It summarizes the abnormal expression of these regulators in HCC and their effects on cancer inhibition or promotion. Understanding the role of ubiquitination in apoptosis and LC can provide insights into potential targets for therapeutic intervention.
Collapse
Affiliation(s)
- Yuxuan Li
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo UniversityNingbo 315040, Zhejiang, P. R. China
- Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo UniversityNingbo 315211, Zhejiang, P. R. China
| | - Jie Zhu
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo UniversityNingbo 315040, Zhejiang, P. R. China
- Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo UniversityNingbo 315211, Zhejiang, P. R. China
| | - Zongdong Yu
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo UniversityNingbo 315040, Zhejiang, P. R. China
- Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo UniversityNingbo 315211, Zhejiang, P. R. China
| | - Fengguang Zhai
- Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo UniversityNingbo 315211, Zhejiang, P. R. China
| | - Hong Li
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo UniversityNingbo 315040, Zhejiang, P. R. China
- Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo UniversityNingbo 315211, Zhejiang, P. R. China
| | - Xiaofeng Jin
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo UniversityNingbo 315040, Zhejiang, P. R. China
- Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo UniversityNingbo 315211, Zhejiang, P. R. China
| |
Collapse
|
3
|
Roberts JZ, Crawford N, Longley DB. The role of Ubiquitination in Apoptosis and Necroptosis. Cell Death Differ 2021; 29:272-284. [PMID: 34912054 PMCID: PMC8817035 DOI: 10.1038/s41418-021-00922-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 12/29/2022] Open
Abstract
Cell death pathways have evolved to maintain tissue homoeostasis and eliminate potentially harmful cells from within an organism, such as cells with damaged DNA that could lead to cancer. Apoptosis, known to eliminate cells in a predominantly non-inflammatory manner, is controlled by two main branches, the intrinsic and extrinsic apoptotic pathways. While the intrinsic pathway is regulated by the Bcl-2 family members, the extrinsic pathway is controlled by the Death receptors, members of the tumour necrosis factor (TNF) receptor superfamily. Death receptors can also activate a pro-inflammatory type of cell death, necroptosis, when Caspase-8 is inhibited. Apoptotic pathways are known to be tightly regulated by post-translational modifications, especially by ubiquitination. This review discusses research on ubiquitination-mediated regulation of apoptotic signalling. Additionally, the emerging importance of ubiquitination in regulating necroptosis is discussed.
Collapse
Affiliation(s)
- Jamie Z Roberts
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
| | - Nyree Crawford
- Almac Discovery Laboratories, Health Sciences Building, Queen's University Belfast, Belfast, UK
| | - Daniel B Longley
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
| |
Collapse
|
4
|
Roles of RACK1 in centrosome regulation and carcinogenesis. Cell Signal 2021; 90:110207. [PMID: 34843916 DOI: 10.1016/j.cellsig.2021.110207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/22/2022]
Abstract
Receptor for activated C kinase 1 (RACK1) regulates various cellular functions and signaling pathways by interacting with different proteins. Recently, we showed that RACK1 interacts with breast cancer gene 1 (BRCA1), which regulates centrosome duplication. RACK1 localizes to centrosomes and spindle poles and is involved in the proper centrosomal localization of BRCA1. The interaction between RACK1 and BRCA1 is critical for the regulation of centrosome number. In addition, RACK1 contributes to centriole duplication by regulating polo-like kinase 1 (PLK1) activity in S phase. RACK1 binds directly to PLK1 and Aurora A, promoting the phosphorylation of PLK1 and activating the Aurora A/PLK1 signaling axis. Overexpression of RACK1 causes centrosome amplification, especially in mammary gland epithelial cells, inducing overactivation of PLK1 followed by premature centriole disengagement and centriole re-duplication. Other proteins, including hypoxia-inducible factor α, von Hippel-Lindau protein, heat-shock protein 90, β-catenin, and glycogen synthase kinase-3β, interact with RACK1 and play roles in centrosome regulation. In this review, we focus on the roles and underlying molecular mechanisms of RACK1 in centrosome regulation mediated by its interaction with different proteins and the modulation of their functions.
Collapse
|
5
|
Buoso E, Masi M, Racchi M, Corsini E. Endocrine-Disrupting Chemicals' (EDCs) Effects on Tumour Microenvironment and Cancer Progression: Emerging Contribution of RACK1. Int J Mol Sci 2020; 21:ijms21239229. [PMID: 33287384 PMCID: PMC7729595 DOI: 10.3390/ijms21239229] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 02/06/2023] Open
Abstract
Endocrine disruptors (EDCs) can display estrogenic and androgenic effects, and their exposure has been linked to increased cancer risk. EDCs have been shown to directly affect cancer cell regulation and progression, but their influence on tumour microenvironment is still not completely elucidated. In this context, the signalling hub protein RACK1 (Receptor for Activated C Kinase 1) could represent a nexus between cancer and the immune system due to its roles in cancer progression and innate immune activation. Since RACK1 is a relevant EDCs target that responds to steroid-active compounds, it could be considered a molecular bridge between the endocrine-regulated tumour microenvironment and the innate immune system. We provide an analysis of immunomodulatory and cancer-promoting effects of different EDCs in shaping tumour microenvironment, with a final focus on the scaffold protein RACK1 as a pivotal molecular player due to its dual role in immune and cancer contexts.
Collapse
Affiliation(s)
- Erica Buoso
- Dipartimento di Scienze del Farmaco, Università Degli Studi di Pavia, Viale Taramelli 12/14, 27100 Pavia, Italy; (M.M.); (M.R.)
- Correspondence:
| | - Mirco Masi
- Dipartimento di Scienze del Farmaco, Università Degli Studi di Pavia, Viale Taramelli 12/14, 27100 Pavia, Italy; (M.M.); (M.R.)
- Classe di Scienze Umane e della Vita (SUV), Scuola Universitaria Superiore IUSS, Piazza della Vittoria 15, 27100 Pavia, Italy
| | - Marco Racchi
- Dipartimento di Scienze del Farmaco, Università Degli Studi di Pavia, Viale Taramelli 12/14, 27100 Pavia, Italy; (M.M.); (M.R.)
| | - Emanuela Corsini
- Laboratory of Toxicology, Dipartimento di Scienze Politiche ed Ambientali, Università Degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy;
| |
Collapse
|
6
|
Buoso E, Masi M, Long A, Chiappini C, Travelli C, Govoni S, Racchi M. Ribosomes as a nexus between translation and cancer progression: Focus on ribosomal Receptor for Activated C Kinase 1 (RACK1) in breast cancer. Br J Pharmacol 2020; 179:2813-2828. [PMID: 32726469 DOI: 10.1111/bph.15218] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/30/2020] [Accepted: 07/16/2020] [Indexed: 12/19/2022] Open
Abstract
Ribosomes coordinate spatiotemporal control of gene expression, contributing to the acquisition and maintenance of cancer phenotype. The link between ribosomes and cancer is found in the roles of individual ribosomal proteins in tumorigenesis and cancer progression, including the ribosomal protein, receptor for activated C kinase 1 (RACK1). RACK1 regulates cancer cell invasion and is localized in spreading initiation centres, structural adhesion complexes containing RNA binding proteins and poly-adenylated mRNAs that suggest a local translation process. As RACK1 is a ribosomal protein directly involved in translation and in breast cancer progression, we propose a new molecular mechanism for breast cancer cell migration and invasion, which considers the molecular differences between epithelial and mesenchymal cell profiles in order to characterize and provide novel targets for therapeutic strategies. Hence, we provide an analysis on how ribosomes translate cancer progression with a final focus on the ribosomal protein RACK1 in breast cancer.
Collapse
Affiliation(s)
- Erica Buoso
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Mirco Masi
- Department of Drug Sciences, University of Pavia, Pavia, Italy.,Scuola Universitaria Superiore IUSS Pavia, Pavia, Italy
| | - Aideen Long
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College, Dublin, Ireland
| | | | | | - Stefano Govoni
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Marco Racchi
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| |
Collapse
|
7
|
Fan Y, Si W, Ji W, Wang Z, Gao Z, Tian R, Song W, Zhang H, Niu R, Zhang F. Rack1 mediates Src binding to drug transporter P-glycoprotein and modulates its activity through regulating Caveolin-1 phosphorylation in breast cancer cells. Cell Death Dis 2019; 10:394. [PMID: 31113938 PMCID: PMC6529477 DOI: 10.1038/s41419-019-1633-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/24/2022]
Abstract
The failure of chemotherapy and the emergence of multidrug resistance (MDR) are the major obstacles for effective therapy in locally advanced and metastatic breast cancer. Overexpression of the drug transporter P-glycoprotein (P-gp) in cancer cells is one of the main causes of MDR due to its ability to efflux anticancer drugs out of cells. Although the signaling node that regulates the expression of P-gp has been intensively investigated; the regulatory mechanism underlying P-gp transport activity remains obscure. Herein, we reported that Rack1 and tyrosine kinase Src confer drug resistance through modulating the transport function of P-gp without altering its protein level. We provide evidences that Rack1 and Src regulate P-gp activity by modulating caveolin-1 (Cav1) phosphorylation. Importantly, Rack1 acts as a signaling hub and mediates Src binding to P-gp, thereby facilitating the phosphorylation of Cav1 by Src and abolishing the inhibitory effect of Cav1 on P-gp. Taken together, our results demonstrate the pivotal roles of Rack1 and Src in modulating P-gp activity in drug-resistant cells. Our findings also provide novel insights into the mechanism regulating P-gp transport activity. Rack1 may represent a new target for the development of effective therapies for reversing drug resistance.
Collapse
Affiliation(s)
- Yanling Fan
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - Weiyao Si
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - Wei Ji
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - Zhiyong Wang
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - Zicong Gao
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - Ran Tian
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - Weijie Song
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - He Zhang
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China
| | - Ruifang Niu
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China. .,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China. .,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China. .,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China.
| | - Fei Zhang
- Public Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, 300060, China. .,Key Laboratory of Cancer Prevention and Therapy, Tianjin, 300060, China. .,Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China. .,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, 300060, China.
| |
Collapse
|
8
|
Resistance to anti-microtubule drug-induced cell death is determined by regulation of BimEL expression. Oncogene 2019; 38:4352-4365. [PMID: 30770899 DOI: 10.1038/s41388-019-0727-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 12/22/2018] [Accepted: 01/21/2019] [Indexed: 11/09/2022]
Abstract
Anti-microtubule agents are frequently used as anticancer therapeutics. Cell death induced by these agents is considered to be due to sustained mitotic arrest caused by the activation of spindle assembly checkpoint (SAC). However, some cell types are resistant to mitotic cell death. Cells' ability to escape mitotic arrest (mitotic slippage) is thought to be a major mechanism contributing to this resistance. Here, we show that resistance to cell death induced by anti-mitotic agents is not linked to cells' capacity to undergo mitotic slippage as generally believed but is dependent on the state of BimEL regulation during mitosis. While transcriptional repression of BimEL in the mitotic death-resistant cells involves polycomb repressive complex 2 (PRC2)-mediated histone trimethylation, the BimEL protein is destabilized by cullin 1/4A-βTrCP-dependent degradation involving activation of cullin 1/4A by neddylation. These results imply that pharmacological augmentation of BimEL activity in anti-microtubule drug-resistant tumors may have important therapeutic implications.
Collapse
|
9
|
Day JP, Whiteley E, Freeley M, Long A, Malacrida B, Kiely P, Baillie GS. RAB40C regulates RACK1 stability via the ubiquitin-proteasome system. Future Sci OA 2018; 4:FSO317. [PMID: 30112187 PMCID: PMC6088270 DOI: 10.4155/fsoa-2018-0022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 05/15/2018] [Indexed: 11/17/2022] Open
Abstract
AIM RACK1 is a multifunctional scaffolding protein that is expressed in many cellular compartments, orchestrating a number of signaling processes. RACK1 acts as a signaling hub to localize active enzymes to discrete locations; therefore tight control of RACK1 is vital to cellular homeostasis. Our aim was to identify the mechanisms responsible for RACK1 turnover and show that degradation is directed by the ubiquitin proteasome system. RESULTS Using siRNA screening, we identified RAB40C as the ubiquitin E3 ligase responsible for ubiquitination of RACK1, and that the action of RAB40C in controlling RACK1 levels is crucial to both cancer cell growth and migration of T cells. CONCLUSION Our data suggest that manipulation of RACK1 levels in this way may provide a novel strategy to explore RACK1 function.
Collapse
Affiliation(s)
- Jon P Day
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Ellanor Whiteley
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Michael Freeley
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College, Dublin, D08 W9RT, Ireland
| | - Aideen Long
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College, Dublin, D08 W9RT, Ireland
| | - Beatrice Malacrida
- Materials & Surface Science Institute & Health Research Institute, University of Limerick, Limerick, Ireland
| | - Patrick Kiely
- Materials & Surface Science Institute & Health Research Institute, University of Limerick, Limerick, Ireland
| | - George S Baillie
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| |
Collapse
|
10
|
Queval CJ, Song OR, Carralot JP, Saliou JM, Bongiovanni A, Deloison G, Deboosère N, Jouny S, Iantomasi R, Delorme V, Debrie AS, Park SJ, Gouveia JC, Tomavo S, Brosch R, Yoshimura A, Yeramian E, Brodin P. Mycobacterium tuberculosis Controls Phagosomal Acidification by Targeting CISH-Mediated Signaling. Cell Rep 2018; 20:3188-3198. [PMID: 28954234 PMCID: PMC5637157 DOI: 10.1016/j.celrep.2017.08.101] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/29/2017] [Accepted: 08/30/2017] [Indexed: 11/29/2022] Open
Abstract
Pathogens have evolved a range of mechanisms to counteract host defenses, notably to survive harsh acidic conditions in phagosomes. In the case of Mycobacterium tuberculosis, it has been shown that regulation of phagosome acidification could be achieved by interfering with the retention of the V-ATPase complexes at the vacuole. Here, we present evidence that M. tuberculosis resorts to yet another strategy to control phagosomal acidification, interfering with host suppressor of cytokine signaling (SOCS) protein functions. More precisely, we show that infection of macrophages with M. tuberculosis leads to granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion, inducing STAT5-mediated expression of cytokine-inducible SH2-containing protein (CISH), which selectively targets the V-ATPase catalytic subunit A for ubiquitination and degradation by the proteasome. Consistently, we show that inhibition of CISH expression leads to reduced replication of M. tuberculosis in macrophages. Our findings further broaden the molecular understanding of mechanisms deployed by bacteria to survive. M. tuberculosis interferes with host pathways to control vacuolar acidification Infection induces the expression of host CISH and recruitment to the phagosome CISH triggers the degradation of H+-V-ATPase via SOCS box-mediated ubiquitination This defense mechanism complements previous schemes relying on virulence factors
Collapse
Affiliation(s)
- Christophe J Queval
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France; Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
| | - Ok-Ryul Song
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France; Institut Pasteur Korea, 16 Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-400, South Korea
| | - Jean-Philippe Carralot
- Institut Pasteur Korea, 16 Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-400, South Korea
| | - Jean-Michel Saliou
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France; Plateforme de Protéomique et Peptides Modifiés (P3M), CNRS, Institut Pasteur de Lille, University Lille, 59000 Lille, France
| | - Antonino Bongiovanni
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Gaspard Deloison
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Nathalie Deboosère
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Samuel Jouny
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Raffaella Iantomasi
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Vincent Delorme
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France; Institut Pasteur Korea, 16 Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-400, South Korea
| | - Anne-Sophie Debrie
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Sei-Jin Park
- Institut Pasteur Korea, 16 Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-400, South Korea
| | - Joana Costa Gouveia
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Stanislas Tomavo
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France; Plateforme de Protéomique et Peptides Modifiés (P3M), CNRS, Institut Pasteur de Lille, University Lille, 59000 Lille, France
| | - Roland Brosch
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
| | - Akihiko Yoshimura
- Department of Microbiology and Immunology, Keio University School of Medicine, 35 Shinanomachi, Shinjyuku-ku, Tokyo 160-8582, Japan
| | - Edouard Yeramian
- Unité de Microbiologie Structurale, CNRS UMR3528 Institut Pasteur, 75015 Paris, France.
| | - Priscille Brodin
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204, CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France; Institut Pasteur Korea, 16 Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-400, South Korea.
| |
Collapse
|
11
|
Gupta I, Singh K, Varshney NK, Khan S. Delineating Crosstalk Mechanisms of the Ubiquitin Proteasome System That Regulate Apoptosis. Front Cell Dev Biol 2018; 6:11. [PMID: 29479529 PMCID: PMC5811474 DOI: 10.3389/fcell.2018.00011] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/26/2018] [Indexed: 01/10/2023] Open
Abstract
Regulatory functions of the ubiquitin-proteasome system (UPS) are exercised mainly by the ubiquitin ligases and deubiquitinating enzymes. Degradation of apoptotic proteins by UPS is central to the maintenance of cell health, and deregulation of this process is associated with several diseases including tumors, neurodegenerative disorders, diabetes, and inflammation. Therefore, it is the view that interrogating protein turnover in cells can offer a strategy for delineating disease-causing mechanistic perturbations and facilitate identification of drug targets. In this review, we are summarizing an overview to elucidate the updated knowledge on the molecular interplay between the apoptosis and UPS pathways. We have condensed around 100 enzymes of UPS machinery from the literature that ubiquitinates or deubiquitinates the apoptotic proteins and regulates the cell fate. We have also provided a detailed insight into how the UPS proteins are able to fine-tune the intrinsic, extrinsic, and p53-mediated apoptotic pathways to regulate cell survival or cell death. This review provides a comprehensive overview of the potential of UPS players as a drug target for cancer and other human disorders.
Collapse
Affiliation(s)
- Ishita Gupta
- Structural Immunology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.,Drug Discovery Research Centre, Translational Health Science and Technology Institute, Faridabad, India
| | - Kanika Singh
- Drug Discovery Research Centre, Translational Health Science and Technology Institute, Faridabad, India
| | - Nishant K Varshney
- Drug Discovery Research Centre, Translational Health Science and Technology Institute, Faridabad, India
| | - Sameena Khan
- Drug Discovery Research Centre, Translational Health Science and Technology Institute, Faridabad, India
| |
Collapse
|
12
|
Liu B, Wang C, Chen P, Cheng B, Cheng Y. RACKI induces chemotherapy resistance in esophageal carcinoma by upregulating the PI3K/AKT pathway and Bcl-2 expression. Onco Targets Ther 2018; 11:211-220. [PMID: 29379302 PMCID: PMC5757499 DOI: 10.2147/ott.s152818] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Introduction Accumulating evidence indicates that RACK1 is involved in the progression of tumors. We aimed to evaluate the function of RACK1 in esophageal squamous cell carcinoma (ESCC) and its role in the mechanism of chemotherapy resistance. Materials and methods Transfected ESCC cell lines with plasmids expressed shRACK1 or open reading frame (ORF) targeting RACK1 and established stable cell lines. We then examined the effects of RACK1 on cell proliferation and chemotherapy resistance in ESCC cell lines, and the expression of AKT, pAKT, ERK1/2, Bcl-2, and Bim was introduced to further detect the association between RACK1 and chemotherapy resistance. Results The proliferation ability of ESCC cells was improved in the overexpression RACK1 groups (P<0.001) and decreased in the transfected shRACK1 groups (P<0.001) compared with the control ones. Meanwhile, upregulation of RACK1 significantly suppressed cisplatin-induced apoptosis in Eca109 and EC9706 cells, while downregulation of RACK1 promoted the sensitivity compared to the control group (Eca109: P<0.001 for shRACK1, P<0.01 for shNC, and P<0.001 for overexpression group; EC9706: P<0.001 for shRACK1, P<0.001 for shNC, and P<0.05 for overexpression group). Furthermore, we found that RACK1 could activate the PI3K/AKT pathway and increase the expression level of Bcl-2 in ESCC, which leads to the enhancement of chemoresistance in ESCC. Conclusion RACK1 promotes proliferation and chemotherapy resistance in ESCC by activating the PI3K/AKT pathway and upregulating the Bcl-2 expression.
Collapse
Affiliation(s)
- Bowen Liu
- Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China
| | - Cong Wang
- Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China
| | - Pengxiang Chen
- Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China
| | - Bo Cheng
- Department of Radiation Oncology, Shandong Provincial Cancer Hospital, Jinan, Shandong, People's Republic of China
| | - Yufeng Cheng
- Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China
| |
Collapse
|
13
|
Knockdown of miR-155 protects microglia against LPS-induced inflammatory injury via targeting RACK1: a novel research for intracranial infection. JOURNAL OF INFLAMMATION-LONDON 2017; 14:17. [PMID: 28804270 PMCID: PMC5549339 DOI: 10.1186/s12950-017-0162-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 07/05/2017] [Indexed: 11/17/2022]
Abstract
Background Intracranial infection, one of the complications of traumatic brain injury, is usually associated with inflammation. Several microRNAs (miRNAs), including miR-155, have been reported to be critical modulators in peripheral and central nervous system inflammation. In this study, we investigated the role of miR-155 in lipopolysaccharide (LPS)-induced inflammatory injury in mouse microglia BV2 cells. Results The expression level of miR-155 was significantly up-regulated after LPS stimulation in BV2 cells. LPS administration decreased BV2 cell viability, promoted apoptosis and increased the release of pro-inflammatory cytokines; while miR-155 knockdown rescued BV2 cell from LPS-induced injury. RACK1 was a directly target of miR-155. Interestingly, miR-155 knockdown did not attenuate LPS-induced inflammatory injury when RACK1 was knocked down. The mechanistic study indicated that miR-155 knockdown deactivated MAPK/NF-κB and mTOR signaling pathways under LPS-treated conditions. Conclusions Knockdown of miR-155 protected mouse microglia BV2 cells from LPS-induced inflammatory injury via targeting RACK1 and deactivating MAPK/NF-κB and mTOR signaling pathways.
Collapse
|
14
|
Zhang X, Liu N, Ma D, Liu L, Jiang L, Zhou Y, Zeng X, Li J, Chen Q. Receptor for activated C kinase 1 (RACK1) promotes the progression of OSCC via the AKT/mTOR pathway. Int J Oncol 2016; 49:539-48. [DOI: 10.3892/ijo.2016.3562] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 04/04/2016] [Indexed: 11/05/2022] Open
|
15
|
Sionov RV, Vlahopoulos SA, Granot Z. Regulation of Bim in Health and Disease. Oncotarget 2015; 6:23058-134. [PMID: 26405162 PMCID: PMC4695108 DOI: 10.18632/oncotarget.5492] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 08/08/2015] [Indexed: 11/25/2022] Open
Abstract
The BH3-only Bim protein is a major determinant for initiating the intrinsic apoptotic pathway under both physiological and pathophysiological conditions. Tight regulation of its expression and activity at the transcriptional, translational and post-translational levels together with the induction of alternatively spliced isoforms with different pro-apoptotic potential, ensure timely activation of Bim. Under physiological conditions, Bim is essential for shaping immune responses where its absence promotes autoimmunity, while too early Bim induction eliminates cytotoxic T cells prematurely, resulting in chronic inflammation and tumor progression. Enhanced Bim induction in neurons causes neurodegenerative disorders including Alzheimer's, Parkinson's and Huntington's diseases. Moreover, type I diabetes is promoted by genetically predisposed elevation of Bim in β-cells. On the contrary, cancer cells have developed mechanisms that suppress Bim expression necessary for tumor progression and metastasis. This review focuses on the intricate network regulating Bim activity and its involvement in physiological and pathophysiological processes.
Collapse
Affiliation(s)
- Ronit Vogt Sionov
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel Canada, Hebrew University, Hadassah Medical School, Jerusalem, Israel
| | - Spiros A. Vlahopoulos
- First Department of Pediatrics, University of Athens, Horemeio Research Laboratory, Thivon and Levadias, Goudi, Athens, Greece
| | - Zvi Granot
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel Canada, Hebrew University, Hadassah Medical School, Jerusalem, Israel
| |
Collapse
|
16
|
Targeting Cdc20 as a novel cancer therapeutic strategy. Pharmacol Ther 2015; 151:141-51. [PMID: 25850036 DOI: 10.1016/j.pharmthera.2015.04.002] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 03/31/2015] [Indexed: 12/25/2022]
Abstract
The Anaphase Promoting Complex (APC, also called APC/C) regulates cell cycle progression by forming two closely related, but functionally distinct E3 ubiquitin ligase sub-complexes, APC(Cdc20) and APC(Cdh1), respectively. Emerging evidence has begun to reveal that Cdc20 and Cdh1 have opposing functions in tumorigenesis. Specifically, Cdh1 functions largely as a tumor suppressor, whereas Cdc20 exhibits an oncogenic function, suggesting that Cdc20 could be a promising therapeutic target for combating human cancer. However, the exact underlying molecular mechanisms accounting for their differences in tumorigenesis remain largely unknown. Therefore, in this review, we summarize the downstream substrates of Cdc20 and the critical functions of Cdc20 in cell cycle progression, apoptosis, ciliary disassembly and brain development. Moreover, we briefly describe the upstream regulators of Cdc20 and the oncogenic role of Cdc20 in a variety of human malignancies. Furthermore, we summarize multiple pharmacological Cdc20 inhibitors including TAME and Apcin, and their potential clinical benefits. Taken together, development of specific Cdc20 inhibitors could be a novel strategy for the treatment of human cancers with elevated Cdc20 expression.
Collapse
|
17
|
Jensik PJ, Arbogast LA. Regulation of cytokine-inducible SH2-containing protein (CIS) by ubiquitination and Elongin B/C interaction. Mol Cell Endocrinol 2015; 401:130-41. [PMID: 25448846 PMCID: PMC4373541 DOI: 10.1016/j.mce.2014.10.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/22/2014] [Accepted: 10/22/2014] [Indexed: 10/24/2022]
Abstract
Cytokine-inducible SH2-containing protein (CIS) inhibits prolactin receptor (PRLR) signaling and acts as part of an E3 ubiquitin ligase complex through interactions with Elongin B/C proteins. This study aimed to identify CIS lysine ubiquitination sites and determine roles of ubiquitination and Elongin B/C interactions on CIS protein stability and PRLR signaling inhibition. Site-directed mutations revealed that CIS can be ubiquitinated on all six lysine residues. Elongin B/C interaction box mutation had no influence on CIS ubiquitination. CIS stability was increased by mutation of lysine residues and further enhanced by co-mutation of Elongin B/C interaction domain. CIS inhibition of STAT5B phosphorylation and casein promoter activation was dependent on CIS interactions with Elongin B/C, but not on CIS ubiquitination. These data indicate CIS protein stability is regulated through multiple mechanisms, including ubiquitination and interaction with Elongin B/C proteins, whereas CIS functional inhibition of PRLR signaling is dependent on the Elongin B/C interaction.
Collapse
|
18
|
Silva KT, Oliveira-Castro RA, Rodrigues VC, de Lima WG, Rodrigues CV, Castro-Borges W, Andrade MHG. DBT- and DBTO2-Induced Dysplasia and Their Associated Proteomic Alterations in the Small Intestines of Wistar Rats. J Proteome Res 2014; 14:385-96. [DOI: 10.1021/pr5009459] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karina Taciana Silva
- Núcleo
de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, Minas Gerais, Brasil
| | - Renata Alves Oliveira-Castro
- Núcleo
de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, Minas Gerais, Brasil
| | | | - Wanderson Geraldo de Lima
- Departamento
de Ciências Biológicas, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, Minas Gerais, Brasil
| | - Cibele Velloso Rodrigues
- Departamento
de Biologia, Universidade Federal de Juiz de Fora, Campus Avançado, Governador Valadares, Minas Gerais, Brasil
| | - William Castro-Borges
- Departamento
de Ciências Biológicas, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, Minas Gerais, Brasil
| | - Milton Hércules Guerra Andrade
- Departamento
de Ciências Biológicas, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, Minas Gerais, Brasil
| |
Collapse
|
19
|
APC(Cdc20) suppresses apoptosis through targeting Bim for ubiquitination and destruction. Dev Cell 2014; 29:377-91. [PMID: 24871945 DOI: 10.1016/j.devcel.2014.04.022] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 02/08/2014] [Accepted: 04/18/2014] [Indexed: 01/01/2023]
Abstract
Anaphase-promoting complex Cdc20 (APC(Cdc20)) plays pivotal roles in governing mitotic progression. By suppressing APC(Cdc20), antimitotic agents activate the spindle-assembly checkpoint and induce apoptosis after prolonged treatment, whereas depleting endogenous Cdc20 suppresses tumorigenesis in part by triggering mitotic arrest and subsequent apoptosis. However, the molecular mechanism(s) underlying apoptosis induced by Cdc20 abrogation remains poorly understood. Here, we report the BH3-only proapoptotic protein Bim as an APC(Cdc20) target, such that depletion of Cdc20 sensitizes cells to apoptotic stimuli. Strikingly, Cdc20 and multiple APC-core components were identified in a small interfering RNA screen that, upon knockdown, sensitizes otherwise resistant cancer cells to chemoradiation in a Bim-dependent manner. Consistently, human adult T cell leukemia cells that acquire elevated APC(Cdc20) activity via expressing the Tax viral oncoprotein exhibit reduced Bim levels and resistance to anticancer agents. These results reveal an important role for APC(Cdc20) in governing apoptosis, strengthening the rationale for developing specific Cdc20 inhibitors as effective anticancer agents.
Collapse
|
20
|
Gandin V, Senft D, Topisirovic I, Ronai ZA. RACK1 Function in Cell Motility and Protein Synthesis. Genes Cancer 2014; 4:369-77. [PMID: 24349634 DOI: 10.1177/1947601913486348] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The receptor for activated C kinase 1 (RACK1) serves as an adaptor for a number of proteins along the MAPK, protein kinase C, and Src signaling pathways. The abundance and near ubiquitous expression of RACK1 reflect its role in coordinating signaling molecules for many critical biological processes, from mRNA translation to cell motility to cell survival and death. Complete deficiency of Rack1 is embryonic lethal, but the recent development of genetic Rack1 hypomorphic mice has highlighted the central role that RACK1 plays in cell movement and protein synthesis. This review focuses on the importance of RACK1 in these processes and places the recent work in the larger context of understanding RACK1 function.
Collapse
Affiliation(s)
- Valentina Gandin
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, QC, Canada ; Department of Oncology, McGill University, Montréal, QC, Canada
| | - Daniela Senft
- Signal Transduction Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Ivan Topisirovic
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, QC, Canada ; Department of Oncology, McGill University, Montréal, QC, Canada
| | - Ze'ev A Ronai
- Signal Transduction Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| |
Collapse
|
21
|
RACK1, a versatile hub in cancer. Oncogene 2014; 34:1890-8. [PMID: 24882575 DOI: 10.1038/onc.2014.127] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/07/2014] [Accepted: 04/10/2014] [Indexed: 01/15/2023]
Abstract
RACK1 is a highly conserved intracellular adaptor protein with significant homology to Gβ and was originally identified as the anchoring protein for activated protein kinase C. In the past 20 years, the number of binding partners and validated cellular functions for RACK1 has increased, which facilitates clarification of its involvement in different biological events. In this review, we will focus on its role in cancer, summarizing its aberrant expression, pro- or anti-oncogenic effects and the underlying mechanisms in various cancers.
Collapse
|
22
|
Sato T, Takahashi H, Hatakeyama S, Iguchi A, Ariga T. The TRIM-FLMN protein TRIM45 directly interacts with RACK1 and negatively regulates PKC-mediated signaling pathway. Oncogene 2014; 34:1280-91. [PMID: 24681954 DOI: 10.1038/onc.2014.68] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 01/08/2014] [Accepted: 01/12/2014] [Indexed: 12/19/2022]
Abstract
The receptor for activated C-kinase (RACK1), a scaffolding protein that participates in the protein kinase C (PKC) signaling pathway, has an important role in shuttling active PKCs to its substrate. Indeed, recent studies have revealed that RACK1 has an important role in tumorigenesis and that enhancement of the feed-forward mechanism of the c-Jun N-terminal kinase (JNK)-Jun pathway via RACK1 is associated with constitutive activation of MEK (MAPK-ERK kinase)-ERK (extracellular signal-regulated kinase) signaling in human melanoma cells. Taken together, RACK1 additionally has a very important role in the mitogen-activated protein kinase (MAPK) signaling pathway. Here, we show that one of the tripartite motif-containing (TRIM) family ubiquitin ligases, TRIM45, is a novel RACK1-interacting protein and downregulates MAPK signal transduction. Importantly, the expression of TRIM45 is induced when growth-promoting extracellular stimuli activate the MAPK signaling pathway, resulting in attenuation of activation of the MAPK pathway. These findings suggest that TRIM45 functions as a member of the negative feedback loop of the MAPK pathway.
Collapse
Affiliation(s)
- T Sato
- 1] Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan [2] Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - H Takahashi
- Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - S Hatakeyama
- Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - A Iguchi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - T Ariga
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| |
Collapse
|
23
|
RACK1 modulates NF-κB activation by interfering with the interaction between TRAF2 and the IKK complex. Cell Res 2013; 24:359-71. [PMID: 24323043 DOI: 10.1038/cr.2013.162] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 09/28/2013] [Accepted: 10/22/2013] [Indexed: 01/10/2023] Open
Abstract
The transcription factor NF-κB plays a pivotal role in innate immunity in response to a variety of stimuli, and the coordinated regulation of this pathway determines the proper host responses to extracellular signals. In this study, we identified RACK1 as a novel negative regulator of NF-κB signaling, NF-κB-mediated cytokine induction and inflammatory reactions. RACK1 physically associates with the IKK complex in a TNF-triggered manner. This interaction interferes with the recruitment of the IKK complex to TRAF2, which is a critical step for IKK phosphorylation and subsequent activation triggered by TNF. By modulating the interaction between TRAF2 and IKK, RACK1 regulates the levels of NF-κB activation in response to different intensities of stimuli. Our findings suggest that RACK1 plays an important role in controlling the sensitivity of TNF-triggered NF-κB signaling by regulating IKK activation and provide new insight into the negative regulation of inflammatory reactions.
Collapse
|
24
|
Fernald K, Kurokawa M. Evading apoptosis in cancer. Trends Cell Biol 2013; 23:620-33. [PMID: 23958396 DOI: 10.1016/j.tcb.2013.07.006] [Citation(s) in RCA: 382] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 12/12/2022]
Abstract
Carcinogenesis is a mechanistically complex and variable process with a plethora of underlying genetic causes. Cancer development comprises a multitude of steps that occur progressively starting with initial driver mutations leading to tumorigenesis and, ultimately, metastasis. During these transitions, cancer cells accumulate a series of genetic alterations that confer on the cells an unwarranted survival and proliferative advantage. During the course of development, however, cancer cells also encounter a physiologically ubiquitous cellular program that aims to eliminate damaged or abnormal cells: apoptosis. Thus, it is essential that cancer cells acquire instruments to circumvent programmed cell death. Here we discuss emerging evidence indicating how cancer cells adopt various strategies to override apoptosis, including amplifying the antiapoptotic machinery, downregulating the proapoptotic program, or both.
Collapse
Affiliation(s)
- Kaleigh Fernald
- Department of Pharmacology and Toxicology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | | |
Collapse
|
25
|
Lei D, Li F, Su H, Liu J, Wei N, Wang X. Hepatic deficiency of COP9 signalosome subunit 8 induces ubiquitin-proteasome system impairment and Bim-mediated apoptosis in murine livers. PLoS One 2013; 8:e67793. [PMID: 23840878 PMCID: PMC3698095 DOI: 10.1371/journal.pone.0067793] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 05/27/2013] [Indexed: 11/19/2022] Open
Abstract
The COP9 signalosome (CSN), an evolutionally highly conserved protein complex composed of 8 unique subunits (CSN1 through CSN8) in higher eukaryotes, is purported to modulate protein degradation mediated by the ubiquitin-proteasome system (UPS) but this has not been demonstrated in a critical mitotic parenchymal organ of vertebrates. Hepatocyte-specific knockout of the Cops8 gene (HS-Csn8KO) was shown to cause massive hepatocyte apoptosis and liver malfunction but the underlying mechanism remains unclear. Here, we report that Csn8/CSN exerts profound impacts on hepatic UPS function and is critical to the stability of the pro-apoptotic protein Bim. Significant decreases in CIS (cytokine-inducible Src homology 2 domain-containing protein), a Bim receptor of a cullin2-based ubiquitin ligase, were found to co-exist with a marked increase of Bim proteins. Csn8 deficiency also significantly decreased 19S proteasome subunit Rpt5 and markedly increased high molecular weight neddylated and ubiquitinated proteins. The use of a surrogate UPS substrate further reveals severe impairment of UPS-mediated proteolysis in HS-Csn8KO livers. Inclusion body-like materials were accumulated in Csn8 deficient hepatocytes. In addition to Bim, massive hepatocyte apoptosis in HS-Csn8KO livers is also associated with elevated expression of other members of the Bcl2 family, including pro-apoptotic Bax as well as anti-apoptotic Bcl2 and Bcl-XL. Increased interaction between Bcl2 and Bim, but not between Bcl2 and Bax, was detected. Hence, it is concluded that hepatic CSN8 deficiency impairs the UPS in the liver and the resultant Bim upregulation likely plays an important role in triggering hepatocyte apoptosis via sequestering Bcl2 away from Bax.
Collapse
Affiliation(s)
- Daoxiong Lei
- Division of Basic Biomedical Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, United States of America
- Department of Hepatobiliary Surgery, Tianjin 4th Central Hospital and The 4th Central Clinical College of Tianjin Medical University, Tianjin, China
| | - Faqian Li
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Huabo Su
- Division of Basic Biomedical Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, United States of America
- Vascular Biology Center and Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Jinbao Liu
- Division of Basic Biomedical Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, United States of America
- Department of Pathophysiology, Guangzhou Medical College, Guangzhou, Guangdong, China
| | - Ning Wei
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Xuejun Wang
- Division of Basic Biomedical Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, United States of America
| |
Collapse
|
26
|
Abstract
BIM represents a BH3-only proapoptotic member of the BCL-2 family of apoptotic regulatory proteins. Recent evidence suggests that in addition to its involvement in normal homeostasis, BIM plays a critical role in tumor cell biology, including the regulation of tumorigenesis through activities as a tumor suppressor, tumor metastasis, and tumor cell survival. Consequently, BIM has become the focus of intense interest as a potential target for cancer chemotherapy. The control of BIM expression is complex, and involves multiple factors, including epigenetic events (i.e., promoter acetylation or methylation, miRNA), transcription factors, posttranscriptional regulation, and posttranslational modifications, most notably phosphorylation. Significantly, the expression of BIM by tumor cells has been shown to play an important role in determining the response of transformed cells to not only conventional cytotoxic agents, but also to a broad array of targeted agents that interrupt cell signaling and survival pathways. Furthermore, modifications in BIM expression may be exploited to improve the therapeutic activity and potentially the selectivity of such agents. It is likely that evolving insights into the factors that regulate BIM expression will ultimately lead to novel BIM-based therapeutic strategies in the future.
Collapse
Affiliation(s)
- Hisashi Harada
- Department of Oral and Craniofacial Molecular Biology, Massey Cancer Center, Virginia Commonwealth University Health Sciences System, Richmond VA, 23298, USA
| | | |
Collapse
|
27
|
Rachfall N, Schmitt K, Bandau S, Smolinski N, Ehrenreich A, Valerius O, Braus GH. RACK1/Asc1p, a ribosomal node in cellular signaling. Mol Cell Proteomics 2012; 12:87-105. [PMID: 23071099 DOI: 10.1074/mcp.m112.017277] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
RACK1/Asc1p and its essential orthologues in higher eukaryotes, such as RACK1 in metazoa, are involved in several distinct cellular signaling processes. The implications of a total deletion have never been assessed in a comprehensive manner. This study reveals the major cellular processes affected in a Saccharomyces cerevisiae Δasc1 deletion background via de novo proteome and transcriptome analysis, as well as subsequent phenotypical characterizations. The deletion of ASC1 reduces iron uptake and causes nitrosative stress, both known indicators for hypoxia, which manifests in a shift of energy metabolism from respiration to fermentation in the Δasc1 strain. Asc1p further impacts cellular metabolism through its regulative role in the MAP kinase signal transduction pathways of invasive/filamentous growth and cell wall integrity. In the Δasc1 mutant strain, aberrations from the expected cellular response, mediated by these pathways, can be observed and are linked to changes in protein abundances of pathway-targeted transcription factors. Evidence of the translational regulation of such transcription factors suggests that ribosomal Asc1p is involved in signal transduction pathways and controls the biosynthesis of the respective final transcriptional regulators.
Collapse
Affiliation(s)
- Nicole Rachfall
- Institute of Microbiology and Genetics, Georg-August Universität, D-37077 Göttingen, Germany
| | | | | | | | | | | | | |
Collapse
|
28
|
Campagne C, Julé S, Bernex F, Estrada M, Aubin-Houzelstein G, Panthier JJ, Egidy G. RACK1, a clue to the diagnosis of cutaneous melanomas in horses. BMC Vet Res 2012; 8:95. [PMID: 22747534 PMCID: PMC3543212 DOI: 10.1186/1746-6148-8-95] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 06/15/2012] [Indexed: 01/20/2023] Open
Abstract
Background Melanocytic proliferations are common in horses but the diagnosis of malignancy is not always straightforward. To improve diagnosis and prognosis, markers of malignancy are needed. Receptor for activated C kinase 1 (RACK1) protein may be such a marker. RACK1 was originally found to characterize malignant melanocytic lesions in the Melanoblastoma-bearing Libechov minipig (MeLiM) and, later, in human patients. Our purpose was to investigate the value of RACK1 in the classification of cutaneous melanocytic proliferations in horses. Results Using immunofluorescence, we report here that both MITF (Microphthalmia-associated transcription factor) and PAX3 (Paired box 3) allow the identification of melanocytic cells in horse skin samples. Importantly, RACK1 was detected in melanocytic lesions but not in healthy skin melanocytes. Finally, we found that RACK1 labeling can be used in horses to distinguish benign melanocytic tumors from melanomas. Indeed, RACK1 labeling appeared more informative to assess malignancy than individual histomorphological features. Conclusions This study confirms that horses provide an interesting model for melanoma genesis studies. It establishes MITF and PAX3 as markers of horse melanocytic cells. RACK1 emerges as an important marker of malignancy which may contribute to progress in the diagnosis of melanomas in both human and veterinary medicine.
Collapse
Affiliation(s)
- Cécile Campagne
- INRA, UMR955 de Génétique fonctionnelle et médicale, Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, Maisons-Alfort, F-94704, France
| | | | | | | | | | | | | |
Collapse
|
29
|
Ruan Y, Sun L, Hao Y, Wang L, Xu J, Zhang W, Xie J, Guo L, Zhou L, Yun X, Zhu H, Shen A, Gu J. Ribosomal RACK1 promotes chemoresistance and growth in human hepatocellular carcinoma. J Clin Invest 2012; 122:2554-66. [PMID: 22653060 DOI: 10.1172/jci58488] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 04/24/2012] [Indexed: 01/14/2023] Open
Abstract
Coordinated translation initiation is coupled with cell cycle progression and cell growth, whereas excessive ribosome biogenesis and translation initiation often lead to tumor transformation and survival. Hepatocellular carcinoma (HCC) is among the most common and aggressive cancers worldwide and generally displays inherently high resistance to chemotherapeutic drugs. We found that RACK1, the receptor for activated C-kinase 1, was highly expressed in normal liver and frequently upregulated in HCC. Aberrant expression of RACK1 contributed to in vitro chemoresistance as well as in vivo tumor growth of HCC. These effects depended on ribosome localization of RACK1. Ribosomal RACK1 coupled with PKCβII to promote the phosphorylation of eukaryotic initiation factor 4E (eIF4E), which led to preferential translation of the potent factors involved in growth and survival. Inhibition of PKCβII or depletion of eIF4E abolished RACK1-mediated chemotherapy resistance of HCC in vitro. Our results imply that RACK1 may function as an internal factor involved in the growth and survival of HCC and suggest that targeting RACK1 may be an efficacious strategy for HCC treatment.
Collapse
Affiliation(s)
- Yuanyuan Ruan
- Key Laboratory of Glycoconjugate Research, Ministry of Public Health, Shanghai Medical College of Fudan University, Shanghai, People’s Republic of China
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Myklebust LM, Akslen LA, Varhaug JE, Lillehaug JR. Receptor for activated protein C kinase 1 (RACK1) is overexpressed in papillary thyroid carcinoma. Thyroid 2011; 21:1217-25. [PMID: 22007921 DOI: 10.1089/thy.2010.0186] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND The receptor for activated C kinase 1 (RACK1) has been shown to be overexpressed in several types of cancers such as breast, colon, melanomas, and lung. RACK1 is linked to Ras-Raf-mediated signal transduction and transformed foci formation of 3T3 cells in vitro, and since this pathway is central in papillary thyroid carcinoma (PTC) oncogenesis, we hypothesized that RACK1 could play a role in the development or maintenance of PTC. No report on RACK1 expression in thyroid tissue is available; the present study was therefore aimed at identifying possible correlation of RACK1 expression at the mRNA or protein level in normal thyroid tissue compared to PTC. METHODS We used TaqMan quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry to study the RACK1 gene and protein expression in matched tumor and nontumor samples from 59 PTC patients. The tumor samples were divided into two main categories, low-risk (group 1-3) and high-risk (group 4-6), in accordance with both histological classification and clinical appearance. RESULTS RACK1 mRNA and protein levels were found highly overexpressed in tumor samples, whereas Ki-Ras mRNA was found to be relatively unchanged. B-Raf mRNA expression was low and detected only in tumor samples. Sequencing analysis detected no mutations in RACK1 or Ki-Ras, but 62.7% of the patients harbored the B-Raf single-nucleotide substitution T1799A (codon V600E). Phosphorylated extracellular signal-regulated kinase (pERK) immunohistochemistry analysis demonstrated activation of the mitogen-activated protein kinase (MAPK) pathway in tumor cells. Poorly differentiated and undifferentiated PTCs expressed significantly higher RACK1 mRNA levels than well-differentiated PTCs (p<0.017). CONCLUSIONS Taken together, our findings point to an important role of RACK1 protein in PTC development and progression. Our data also emphasize the importance of assessing protein expression and not only mRNA levels.
Collapse
Affiliation(s)
- Line M Myklebust
- Department of Molecular Biology, University of Bergen, Bergen, Norway
| | | | | | | |
Collapse
|
31
|
Adams DR, Ron D, Kiely PA. RACK1, A multifaceted scaffolding protein: Structure and function. Cell Commun Signal 2011; 9:22. [PMID: 21978545 PMCID: PMC3195729 DOI: 10.1186/1478-811x-9-22] [Citation(s) in RCA: 324] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Accepted: 10/06/2011] [Indexed: 12/17/2022] Open
Abstract
The Receptor for Activated C Kinase 1 (RACK1) is a member of the tryptophan-aspartate repeat (WD-repeat) family of proteins and shares significant homology to the β subunit of G-proteins (Gβ). RACK1 adopts a seven-bladed β-propeller structure which facilitates protein binding. RACK1 has a significant role to play in shuttling proteins around the cell, anchoring proteins at particular locations and in stabilising protein activity. It interacts with the ribosomal machinery, with several cell surface receptors and with proteins in the nucleus. As a result, RACK1 is a key mediator of various pathways and contributes to numerous aspects of cellular function. Here, we discuss RACK1 gene and structure and its role in specific signaling pathways, and address how posttranslational modifications facilitate subcellular location and translocation of RACK1. This review condenses several recent studies suggesting a role for RACK1 in physiological processes such as development, cell migration, central nervous system (CN) function and circadian rhythm as well as reviewing the role of RACK1 in disease.
Collapse
Affiliation(s)
- David R Adams
- Department of Life Sciences, and Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.
| | | | | |
Collapse
|
32
|
|
33
|
Rapali P, Szenes Á, Radnai L, Bakos A, Pál G, Nyitray L. DYNLL/LC8: a light chain subunit of the dynein motor complex and beyond. FEBS J 2011; 278:2980-96. [PMID: 21777386 DOI: 10.1111/j.1742-4658.2011.08254.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The LC8 family members of dynein light chains (DYNLL1 and DYNLL2 in vertebrates) are highly conserved ubiquitous eukaryotic homodimer proteins that interact, besides dynein and myosin 5a motor proteins, with a large (and still incomplete) number of proteins involved in diverse biological functions. Despite an earlier suggestion that LC8 light chains function as cargo adapters of the above molecular motors, they are now recognized as regulatory hub proteins that interact with short linear motifs located in intrinsically disordered protein segments. The most prominent LC8 function is to promote dimerization of their binding partners that are often scaffold proteins of various complexes, including the intermediate chains of the dynein motor complex. Structural and functional aspects of this intriguing hub protein will be highlighted in this minireview.
Collapse
Affiliation(s)
- Péter Rapali
- Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | | | | | | | | | | |
Collapse
|
34
|
Akiyama T, Tanaka S. Bim: guardian of tissue homeostasis and critical regulator of the immune system, tumorigenesis and bone biology. Arch Immunol Ther Exp (Warsz) 2011; 59:277-87. [PMID: 21633919 DOI: 10.1007/s00005-011-0126-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 01/11/2011] [Indexed: 12/16/2022]
Abstract
One of the most important roles of apoptosis is the maintenance of tissue homeostasis. Impairment of apoptosis leads to a number of pathological conditions. In response to apoptotic signals, various proteins are activated in a pathway and signal-specific manner. Recently, the pro-apoptotic molecule Bim has attracted increasing attention as a pivotal regulator of tissue homeostasis. The Bim expression level is strictly controlled in both transcriptional and post-transcriptional levels. This control is dependent on cell, tissue and apoptotic stimuli. The phenotype of Bim-deficient mice is a systemic lupus erythematosus-like autoimmune disease with an abnormal accumulation of hematopoietic cells. Bim is thus a critical regulator of hematopoietic cells and immune system. Further studies have revealed the critical roles of Bim in various normal and pathological conditions, including bone homeostasis and tumorigenesis. The current understanding of Bim signaling and roles in the maintenance of tissue homeostasis is reviewed in this paper, focusing on the immune system, bone biology and tumorigenesis to illustrate the diversified role of Bim.
Collapse
Affiliation(s)
- Toru Akiyama
- Department of Orthopaedic Surgery, Saitama Medical Center, Jichi Medical University, Omiya-ku, Saitama, Japan
| | | |
Collapse
|
35
|
Thompson S, Pearson AN, Ashley MD, Jessick V, Murphy BM, Gafken P, Henshall DC, Morris KT, Simon RP, Meller R. Identification of a novel Bcl-2-interacting mediator of cell death (Bim) E3 ligase, tripartite motif-containing protein 2 (TRIM2), and its role in rapid ischemic tolerance-induced neuroprotection. J Biol Chem 2011; 286:19331-9. [PMID: 21478148 DOI: 10.1074/jbc.m110.197707] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously shown that the cell death-promoting protein Bcl-2-interacting mediator of cell death (Bim) is ubiquitinated and degraded following a neuroprotection-conferring episode of brief ischemia (preconditioning). Here, we identify the E3 ligase that ubiquitinates Bim in this model, using a proteomics approach. Using phosphorylated GST-Bim as bait, we precipitated and identified by mass spectrometry tripartite motif protein 2 (TRIM2), a RING (really interesting new gene) domain-containing protein. The reaction between TRIM2 and Bim was confirmed using co-immunoprecipitation followed by immunoblotting. We show that TRIM2 binds to Bim when it is phosphorylated by p42/p44 MAPK but does not interact with a nonphosphorylatable Bim mutant (3ABim). 12-O-tetradecanoylphorbol-13-acetate activation of p42/p44 MAPK drives Bim ubiquitination in mouse embryonic fibroblast cells and is associated with an increased interaction between TRIM2 and Bim. One hour following preconditioning ischemia, the binding of Bim to TRIM2 increased, consistent with the time window of enhanced Bim degradation. Blocking p42/p44 MAPK activation following preconditioning ischemia with U0126 or using the nonphosphorylatable 3ABim reduced the binding between Bim and TRIM2. Immunodepletion of TRIM2 from cell lysates prepared from preconditioned cells reduced Bim ubiquitination. Finally, suppression of TRIM2 expression, using lentivirus transduction of shRNAmir, stabilized Bim protein levels and blocked neuroprotection observed in rapid ischemic tolerance. Taken together, these data support a role for TRIM2 in mediating the p42/p44 MAPK-dependent ubiquitination of Bim in rapid ischemic tolerance.
Collapse
Affiliation(s)
- Simon Thompson
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, Georgia 30310-1495, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Wiggins CM, Tsvetkov P, Johnson M, Joyce CL, Lamb CA, Bryant NJ, Komander D, Shaul Y, Cook SJ. BIMEL, an intrinsically disordered protein, is degraded by 20S proteasomes in the absence of poly-ubiquitylation. J Cell Sci 2011; 124:969-77. [DOI: 10.1242/jcs.058438] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BIM-extra long (BIMEL), a pro-apoptotic BH3-only protein and part of the BCL-2 family, is degraded by the proteasome following activation of the ERK1/2 signalling pathway. Although studies have demonstrated poly-ubiquitylation of BIMEL in cells, the nature of the ubiquitin chain linkage has not been defined. Using ubiquitin-binding domains (UBDs) specific for defined ubiquitin chain linkages, we show that BIMEL undergoes K48-linked poly-ubiquitylation at either of two lysine residues. Surprisingly, BIMELΔKK, which lacks both lysine residues, was not poly-ubiquitylated but still underwent ERK1/2-driven, proteasome-dependent turnover. BIM has been proposed to be an intrinsically disordered protein (IDP) and some IDPs can be degraded by uncapped 20S proteasomes in the absence of poly-ubiquitylation. We show that BIMEL is degraded by isolated 20S proteasomes but that this is prevented when BIMEL is bound to its pro-survival target protein MCL-1. Furthermore, knockdown of the proteasome cap component Rpn2 does not prevent BIMEL turnover in cells, and inhibition of the E3 ubiquitin ligase β-TrCP, which catalyses poly-Ub of BIMEL, causes Cdc25A accumulation but does not inhibit BIMEL turnover. These results provide new insights into the regulation of BIMEL by defining a novel ubiquitin-independent pathway for the proteasome-dependent destruction of this highly toxic protein.
Collapse
Affiliation(s)
- Ceri M. Wiggins
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Peter Tsvetkov
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Mark Johnson
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Claire L. Joyce
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Christopher A. Lamb
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Nia J. Bryant
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - David Komander
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
| | - Yosef Shaul
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Simon J. Cook
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| |
Collapse
|
37
|
Ikebuchi Y, Ito K, Takada T, Anzai N, Kanai Y, Suzuki H. Receptor for activated C-kinase 1 regulates the cell surface expression and function of ATP binding cassette G2. Drug Metab Dispos 2010; 38:2320-8. [PMID: 20858845 DOI: 10.1124/dmd.110.034603] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In a previous report, we identified the receptor for activated C-kinase 1 (RACK1) as a positive regulator of the cellular localization and expression of ATP-binding cassette B4, a phosphatidylcholine translocator expressed on the bile canalicular membrane. In the present study, we focused on the role of RACK1 on ATP-binding cassette G2 (ABCG2), which is responsible for the cellular extrusion of compounds including antitumor drugs. Protein expression of ABCG2 was up-regulated by RACK1 overexpression, although mRNA expression of ABCG2 was not dependent on RACK1. The effect of RACK1 on the expression of ABCG2 on the cell surface was confirmed by the uptake of [(3)H]estrone sulfate, an ABCG2 substrate, into isolated membrane vesicles. The expression of RACK1 affected cellular resistance to mitoxantrone, an anticancer drug excreted by ABCG2, and this effect of RACK1 was abolished in the presence of fumitremorgin C, a selective ABCG2 inhibitor. These results suggest that RACK1 has functional significance as a regulatory cofactor of ABCG2 and is indispensable for the cell surface expression and excretion function of ABCG2. The precise mechanism for RACK1-dependent expression of ABCG2 remains to be clarified, because the results of N-benzoyloxycarbonyl (Z)-Leu-Leu-leucinal (MG132) and chloroquine treatment and those of metabolic labeling experiments did not give us clear evidence whether the reduction of ABCG2 expression in RACK1-knocked down cells may be caused by the suppression of ABCG2 protein synthesis or by acceleration of its degradation.
Collapse
Affiliation(s)
- Yuki Ikebuchi
- Department of Pharmacy, The University of Tokyo Hospital, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
38
|
Bull VH, Fargestad EM, Strozynski M, Thiede B. Temporal proteome profiling of taxol-induced mitotic arrest and apoptosis. Electrophoresis 2010; 31:1873-85. [PMID: 20506421 DOI: 10.1002/elps.200900780] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Taxol (Paclitaxel) is a mitotic inhibitor widely used in cancer therapy. Temporal proteome profiling was performed to study changes of proteins during the different cellular states of HeLa cells caused by exposure to taxol. The changes of proteins over time could be associated with various cellular processes such as mitotic arrest, an intermediate between mitotic arrest and apoptosis, apoptosis, and late apoptosis. Calumenin, stress-induced phosphoprotein 1 (STIP1), and translationally controlled tumor protein (TCTP) were assigned to mitotic arrest and selected for further experiments using immunoblotting and subcellular fractionation. Calumenin translocated from membranes to the cytosol during mitotic arrest and late apoptosis, but was significantly reduced in the cytosol during apoptosis. Translocation of STIP1 to the nucleus was observed at apoptosis and to the cytoskeleton at late apoptosis. TCTP increased in the cytosol at mitotic arrest and in membranes at apoptosis. In addition, the quantitative time courses of Bim isoforms revealed differences between BimL and BimS in comparison with BimEL. In summary, temporal proteome profiling of HeLa cells incubated with taxol allowed the assignment of proteins to certain processes and additional experiments with complementary approaches enabled a more comprehensive understanding of spatial changes of selected proteins during mitotic arrest and apoptosis.
Collapse
Affiliation(s)
- Vibeke H Bull
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | | | | | | |
Collapse
|
39
|
Wiggins CM, Johnson M, Cook SJ. Refining the minimal sequence required for ERK1/2-dependent poly-ubiquitination and proteasome-dependent turnover of BIM. Cell Signal 2010; 22:801-8. [DOI: 10.1016/j.cellsig.2010.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 01/03/2010] [Accepted: 01/05/2010] [Indexed: 12/23/2022]
|
40
|
Akiyama T, Dass CR, Choong PFM. Bim-targeted cancer therapy: a link between drug action and underlying molecular changes. Mol Cancer Ther 2010; 8:3173-80. [PMID: 19934277 DOI: 10.1158/1535-7163.mct-09-0685] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In the past few years, the pro-apoptotic molecule Bim has attracted increasing attention as a plausible target for tumor therapy. A variety of normal and pathological systems regulated by Bim, dependent on cell type, apoptotic stimulation, and chemotherapeutic agents, have been documented. Bim promotes anoikis of many tumor cells, such as lung cancer, breast cancer, osteosarcoma, and melanoma. Various chemotherapeutic agents use Bim as a mediating executioner of cell death. Hence, Bim suppression supports metastasis and chemoresistance. Imatinib, gefitinib, bortezomib, and Bim protein itself are spotlighted as current and future Bim-targeting therapeutic agents. The potential benefits of Bim-targeted therapies are selectivity of treatment for tumor cells and reduction in tumor-associated phenomena such as chemoresistance and metastasis. Thus, Bim-targeting therapies may provide more effective and unique tumor management modalities in future. This review article discusses all these issues.
Collapse
Affiliation(s)
- Toru Akiyama
- Department of Orthopaedics, University of Melbourne, and St. Vincent's Hospital Melbourne, L3-Daly Wing, 35 Victoria Pde., Fitzroy, Melbourne, VIC 3065 Australia
| | | | | |
Collapse
|
41
|
RACK1 associates with CLEC-2 and promotes its ubiquitin–proteasome degradation. Biochem Biophys Res Commun 2009; 390:217-22. [DOI: 10.1016/j.bbrc.2009.09.087] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 09/22/2009] [Indexed: 11/18/2022]
|
42
|
Gillings AS, Balmanno K, Wiggins CM, Johnson M, Cook SJ. Apoptosis and autophagy: BIM as a mediator of tumour cell death in response to oncogene-targeted therapeutics. FEBS J 2009; 276:6050-62. [PMID: 19788418 DOI: 10.1111/j.1742-4658.2009.07329.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The BCL-2 homology domain 3 (BH3)-only protein, B-cell lymphoma 2 interacting mediator of cell death (BIM) is a potent pro-apoptotic protein belonging to the B-cell lymphoma 2 protein family. In recent years, advances in basic biology have provided a clearer picture of how BIM kills cells and how BIM expression and activity are repressed by growth factor signalling pathways, especially the extracellular signal-regulated kinase 1/2 and protein kinase B pathways. In tumour cells these oncogene-regulated pathways are used to counter the effects of BIM, thereby promoting tumour cell survival. In parallel, a new generation of targeted therapeutics has been developed, which show remarkable specificity and efficacy in tumour cells that are addicted to particular oncogenes. It is now apparent that the expression and activation of BIM is a common response to these new therapeutics. Indeed, BIM has emerged from this marriage of basic and applied biology as an important mediator of tumour cell death in response to such drugs. The induction of BIM alone may not be sufficient for significant tumour cell death, as BIM is more likely to act in concert with other BH3-only proteins, or other death pathways, when new targeted therapeutics are used in combination with traditional chemotherapy agents. Here we discuss recent advances in understanding BIM regulation and review the role of BIM as a mediator of tumour cell death in response to novel oncogene-targeted therapeutics.
Collapse
Affiliation(s)
- Annette S Gillings
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, UK
| | | | | | | | | |
Collapse
|
43
|
Ambrosini G, Seelman SL, Schwartz GK. Differentiation-related gene-1 decreases Bim stability by proteasome-mediated degradation. Cancer Res 2009; 69:6115-21. [PMID: 19622774 DOI: 10.1158/0008-5472.can-08-3024] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Drg1 was identified as a differentiation-related, putative metastatic suppressor gene in human colon and prostate cancer. Its expression is associated with resistance to irinotecan (CPT-11) therapy in preclinical colorectal cancer models both in vitro and in vivo. However, the functional significance of Drg1 in these processes is unknown. We have shown for the first time that Drg1 directly binds to the BH3-only proapoptotic protein Bim. Depletion of Drg1 by small interfering RNA induced up-regulation of Bim and its accumulation in the mitochondria, which correlated with loss of mitochondrial membrane potential and induction of apoptosis in cells exposed to SN-38. Further analyses revealed that Drg1 promotes degradation of Bim through the Cullin2/ElonginB-CIS ubiquitin-protein ligase complex. Conversely, in the absence of Drg1, Bim was stabilized and bound more abundantly to Hsp70. These results show that Drg1 renders cancer cells more resistant to chemotherapy through enhanced proteasome-mediated Bim degradation.
Collapse
Affiliation(s)
- Grazia Ambrosini
- Department of Medicine, Laboratory of New Drug Development, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
| | | | | |
Collapse
|
44
|
Guo Y, Schoell MC, Freeman RS. The von Hippel-Lindau protein sensitizes renal carcinoma cells to apoptotic stimuli through stabilization of BIM(EL). Oncogene 2009; 28:1864-74. [PMID: 19305426 PMCID: PMC2701369 DOI: 10.1038/onc.2009.35] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
von Hippel-Lindau (VHL) disease is caused by germ-line mutations in the VHL tumor suppressor gene and is the most common cause of inherited renal cell carcinoma (RCC). Mutations in the VHL gene also occur in a large majority of sporadic cases of clear-cell RCC, which have high intrinsic resistance to chemotherapy and radiotherapy. Here we show that VHL-deficient RCC cells express lower levels of the proapoptotic Bcl-2 family protein BIM(EL) and are more resistant to etoposide and UV radiation-induced death compared to the same cells stably expressing the wild-type VHL protein (pVHL). Reintroducing pVHL into VHL-null cells increased the half-life of BIM(EL) protein without affecting its mRNA expression, and overexpressing pVHL inhibited BIM(EL) polyubiquitination. Suppressing pVHL expression with RNA interference resulted in a decrease in BIM(EL) protein and a corresponding decrease in the sensitivity of RCC cells to apoptotic stimuli. Directly inhibiting BIM(EL) expression in pVHL-expressing RCC cells caused a similar decrease in cell death. These results demonstrate that pVHL acts to promote BIM(EL) protein stability in RCC cells, and that destabilization of BIM(EL) in the absence of pVHL contributes to the increased resistance of VHL-null RCC cells to certain apoptotic stimuli.
Collapse
Affiliation(s)
- Y Guo
- University of Rochester School of Medicine, NY 14642, USA
| | | | | |
Collapse
|
45
|
betaTrCP- and Rsk1/2-mediated degradation of BimEL inhibits apoptosis. Mol Cell 2009; 33:109-16. [PMID: 19150432 PMCID: PMC2655121 DOI: 10.1016/j.molcel.2008.12.020] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 12/02/2008] [Accepted: 12/17/2008] [Indexed: 11/23/2022]
Abstract
The BimEL tumor suppressor is a potent proapoptotic BH3-only protein. We found that, in response to survival signals, BimEL was rapidly phosphorylated on three serine residues in a conserved degron, facilitating binding and degradation via the F box protein betaTrCP. Phosphorylation of the BimEL degron was executed by Rsk1/2 and promoted by the Erk1/2-mediated phosphorylation of BimEL on Ser69. Compared to wild-type BimEL, a BimEL phosphorylation mutant unable to bind betaTrCP was stabilized and consequently potent at inducing apoptosis by the intrinsic mitochondrial pathway. Moreover, although non-small cell lung cancer (NSCLC) cells often become resistant to gefitinib (a clinically relevant tyrosine kinase inhibitor that induces apoptosis through BimEL), silencing of either betaTrCP or Rsk1/2 resulted in BimEL-mediated apoptosis of both gefitinib-sensitive and gefitinib-insensitive NSCLC cells. Our findings reveal that betaTrCP promotes cell survival in cooperation with the ERK-RSK pathway by targeting BimEL for degradation.
Collapse
|
46
|
Meller R. The role of the ubiquitin proteasome system in ischemia and ischemic tolerance. Neuroscientist 2009; 15:243-60. [PMID: 19181875 DOI: 10.1177/1073858408327809] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Ubiquitin modification targets a protein for rapid degradation by the proteasome. However, polyubiquitination of proteins can result in multiple functions depending on the topology of the ubiquitin chain. Therefore, ubiquitin signaling offers a more complex and versatile biology compared with many other posttranslational modifications. One area of potential for the application of this knowledge is the field of ischemia-induced brain damage, as occurs following a stroke. The ubiquitin proteasome system may exert a dual role on neuronal outcome following ischemia. Harmful ischemia results in an overload of the ubiquitin proteasome system, and blocking the proteasome reduces brain infarction following ischemia. However, the rapid and selective degradation of proteins following brief ischemia results in endogenous protection against ischemia. Therefore, further understanding of the molecular signaling mechanisms that regulate the ubiquitin proteasome system may reveal novel therapeutic targets to reduce brain damage when ischemia is predicted or reduce the activation of the cell death mechanisms and the inflammatory response following stroke. The aim of this review is to discuss some of the recent advances in the understanding of protein ubiquitination and its implications for novel stroke therapies.
Collapse
Affiliation(s)
- Robert Meller
- Legacy Clinical Research and Technology Center, Portland, Oregon, USA.
| |
Collapse
|
47
|
Ramesh S, Wildey GM, Howe PH. Transforming growth factor beta (TGFbeta)-induced apoptosis: the rise & fall of Bim. Cell Cycle 2009; 8:11-7. [PMID: 19106608 DOI: 10.4161/cc.8.1.7291] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Transforming growth factor beta (TGFbeta) regulates essential cellular functions such as cellular proliferation, differentiation and apoptosis. Multiple apoptotic mediators and signaling pathways have been implicated in TGFbeta-induced apoptosis. Bim, a BH3-only protein, is critical for apoptosis in a variety of cell types. In resting cells, BimEL expression levels, the major and most abundant isoform, are controlled by Erk1/2-mediated phosphorylation, which targets BimEL for ubiquitination and degradation. We previously reported that TGFbeta induces the expression of the pro-apoptotic protein Bim through a Smad3-dependent mechanism to induce cell death in B-lymphocytes. A number of studies have shown TGFbeta to cause transcriptional induction of Bim in many cell types. Recently, we demonstrated that, in addition to its transcriptional effects on Bim, TGFbeta induces a MAPK phosphatase (MKP), MKP2/DUSP4, to rapidly increase BimEL levels by inactivation of Erk1/2, resulting in dephosphorylation and escape of BimEL from ubiquitin-mediated degradation. Our findings are of importance not only in the context that we implicate TGFbeta to increase BimEL levels through both an immediate post-translational regulatory mechanism and a long-term effect through transcriptional induction, but also in the context of implicating MKPs as regulatory players in apoptosis. Here we summarize these recent findings and their significance to our understanding of how TGFbeta mediates apoptosis, and we explore the possible regulatory mechanisms controlling Bim expression levels.
Collapse
Affiliation(s)
- Sneha Ramesh
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | | | | |
Collapse
|
48
|
Ai E, Poole DS, Skop AR. RACK-1 directs dynactin-dependent RAB-11 endosomal recycling during mitosis in Caenorhabditis elegans. Mol Biol Cell 2009; 20:1629-38. [PMID: 19158384 DOI: 10.1091/mbc.e08-09-0917] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Membrane trafficking pathways are necessary for the addition and removal of membrane during cytokinesis. In animal cells, recycling endosomes act as a major source of the additional membranes during furrow progression and abscission. However, the mechanisms and factors that regulate recycling endosomes during the cell cycle remain poorly understood. Here, we show that the Caenorhabditis elegans Receptor of Activated C Kinase 1 (RACK-1) is required for cytokinesis, germline membrane organization, and the recruitment of RAB-11-labeled recycling endosomes to the pericentrosomal region and spindle. RACK-1 is also required for proper chromosome separation and astral microtubule length. RACK-1 localizes to the centrosomes, kinetochores, the midbody, and nuclear envelopes during the cell cycle. We found that RACK-1 directly binds to DNC-2, the C. elegans p50/dynamitin subunit of the dynactin complex. Last, RACK-1 may facilitate the sequestration of recycling endosomes by targeting DNC-2 to centrosomes and the spindle. Our findings suggest a mechanism by which RACK-1 directs the dynactin-dependent redistribution of recycling endosomes during the cell cycle, thus ensuring proper membrane trafficking events during cytokinesis.
Collapse
Affiliation(s)
- Erkang Ai
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | | |
Collapse
|