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Xiao Y, Xia L, Jiang W, Qin J, Zhao L, Li Z, Huang L, Li K, Yu P, Wei L, Jiang X, Chen Z, Yu X. Cardiopulmonary progenitors facilitate cardiac repair via exosomal transfer of miR-27b-3p targeting the SIK1-CREB1 axis. Cell Prolif 2024; 57:e13593. [PMID: 38185757 PMCID: PMC11056695 DOI: 10.1111/cpr.13593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/27/2023] [Accepted: 12/17/2023] [Indexed: 01/09/2024] Open
Abstract
Ischemic heart disease, especially myocardial infarction (MI), is one of the leading causes of death worldwide, and desperately needs effective treatments, such as cell therapy. Cardiopulmonary progenitors (CPPs) are stem cells for both heart and lung, but their repairing role in damaged heart is still unknown. Here, we obtained CPPs from E9.5 mouse embryos, maintained their stemness while expanding, and identified their characteristics by scRNA-seq, flow cytometry, quantitative reverse transcription-polymerase chain reaction, and differentiation assays. Moreover, we employed mouse MI model to investigate whether CPPs could repair the injured heart. Our data identified that CPPs exhibit hybrid fibroblastic, endothelial, and mesenchymal state, and they could differentiate into cell lineages within the cardiopulmonary system. Moreover, intramyocardial injection of CPPs improves cardiac function through CPPs exosomes (CPPs-Exo) by promotion of cardiomyocytic proliferation and vascularization. To uncover the underlying mechanism, we used miRNA-seq, bulk RNA-seq, and bioinformatic approaches, and found the highly expressed miR-27b-3p in CPPs-Exo and its target gene Sik1, which can influence the transcriptional activity of CREB1. Therefore, we postulate that CPPs facilitate cardiac repair partially through the SIK1-CREB1 axis via exosomal miR-27b-3p. Our study offers a novel insight into the role of CPPs-Exo in heart repair and highlights the potential of CPPs-Exo as a promising therapeutic strategy for MI.
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Affiliation(s)
- Ying‐Ying Xiao
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
- Department of Pharmacy, The First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Luo‐Xing Xia
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Wen‐Jing Jiang
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Jian‐Feng Qin
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Li‐Xin Zhao
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Zhan Li
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Li‐Juan Huang
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Ke‐Xin Li
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Peng‐Jiu Yu
- Department of Pharmacy, The First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Li Wei
- Department of Pharmacy, The First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Xue‐Yan Jiang
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
| | - Zhe‐Sheng Chen
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Institute for BiotechnologySt. John's UniversityQueensNew YorkUSA
| | - Xi‐Yong Yu
- Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, The Fifth Affiliated Hospital & the First Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdongChina
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2
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Lipid Polarization during Cytokinesis. Cells 2022; 11:cells11243977. [PMID: 36552741 PMCID: PMC9776629 DOI: 10.3390/cells11243977] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
The plasma membrane of eukaryotic cells is composed of a large number of lipid species that are laterally segregated into functional domains as well as asymmetrically distributed between the outer and inner leaflets. Additionally, the spatial distribution and organization of these lipids dramatically change in response to various cellular states, such as cell division, differentiation, and apoptosis. Division of one cell into two daughter cells is one of the most fundamental requirements for the sustenance of growth in all living organisms. The successful completion of cytokinesis, the final stage of cell division, is critically dependent on the spatial distribution and organization of specific lipids. In this review, we discuss the properties of various lipid species associated with cytokinesis and the mechanisms involved in their polarization, including forward trafficking, endocytic recycling, local synthesis, and cortical flow models. The differences in lipid species requirements and distribution in mitotic vs. male meiotic cells will be discussed. We will concentrate on sphingolipids and phosphatidylinositols because their transbilayer organization and movement may be linked via the cytoskeleton and thus critically regulate various steps of cytokinesis.
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3
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Fine-tuning cell organelle dynamics during mitosis by small GTPases. Front Med 2022; 16:339-357. [PMID: 35759087 DOI: 10.1007/s11684-022-0926-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/24/2022] [Indexed: 11/04/2022]
Abstract
During mitosis, the allocation of genetic material concurs with organelle transformation and distribution. The coordination of genetic material inheritance with organelle dynamics directs accurate mitotic progression, cell fate determination, and organismal homeostasis. Small GTPases belonging to the Ras superfamily regulate various cell organelles during division. Being the key regulators of membrane dynamics, the dysregulation of small GTPases is widely associated with cell organelle disruption in neoplastic and non-neoplastic diseases, such as cancer and Alzheimer's disease. Recent discoveries shed light on the molecular properties of small GTPases as sophisticated modulators of a remarkably complex and perfect adaptors for rapid structure reformation. This review collects current knowledge on small GTPases in the regulation of cell organelles during mitosis and highlights the mediator role of small GTPase in transducing cell cycle signaling to organelle dynamics during mitosis.
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4
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Richardson DS, Spehar JM, Han DT, Chakravarthy PA, Sizemore ST. The RAL Enigma: Distinct Roles of RALA and RALB in Cancer. Cells 2022; 11:cells11101645. [PMID: 35626682 PMCID: PMC9139244 DOI: 10.3390/cells11101645] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 11/16/2022] Open
Abstract
RALA and RALB are highly homologous small G proteins belonging to the RAS superfamily. Like other small GTPases, the RALs are molecular switches that can be toggled between inactive GDP-bound and active GTP-bound states to regulate diverse and critical cellular functions such as vesicle trafficking, filopodia formation, mitochondrial fission, and cytokinesis. The RAL paralogs are activated and inactivated by a shared set of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) and utilize similar sets of downstream effectors. In addition to their important roles in normal cell biology, the RALs are known to be critical mediators of cancer cell survival, invasion, migration, and metastasis. However, despite their substantial similarities, the RALs often display striking functional disparities in cancer. RALA and RALB can have redundant, unique, or even antagonistic functions depending on cancer type. The molecular basis for these discrepancies remains an important unanswered question in the field of cancer biology. In this review we examine the functions of the RAL paralogs in normal cellular physiology and cancer biology with special consideration provided to situations where the roles of RALA and RALB are non-redundant.
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5
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Li PH, He JY, Cai YJ, Wei YS, Zhu XL, Yang JDH, Yang SQ, Zhou S, Qin QW, Sun HY. Molecular cloning, inducible expression and function analysis of Epinephelus coioides Sec6 response to SGIV infection. FISH & SHELLFISH IMMUNOLOGY 2022; 124:462-471. [PMID: 35483595 DOI: 10.1016/j.fsi.2022.04.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 03/19/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
Exocyst complex component 3 Sec6 of mammals, one of the components of the exocyst complex, participates in numerous cellular functions, such as promoting cell migration and inhibiting apoptosis. In this study, the Sec6 was obtained from Epinephelus coioides, an economically important cultured fish. The full length of E. coioides Sec6 was 2655 bp including a 245 bp 5' UTR, a 154 bp 3' UTR, and a 2256 bp open reading frame (ORF) encoding 751 amino acids, with a molecular mass of 86.76 kDa and a theoretical pI of 5.57. Sec6 mRNA was detected in all the tissues examined, but the expression level is different in these tissues. Using fluorescence microscopy, Sec6 were distributed in both the nucleus and the cytoplasm. After SGIV infection, the expression of E. coioides Sec6 was significantly up-regulated in both trunk kidney and spleen response to Singapore grouper iridovirus (SGIV), an important pathogens of E. coioides. Sec6 could increase the SGIV-induced cytopathic effects (CPE), the expression of the SGIV genes VP19, LITAF, MCP, ICP18 and MCP, and the viral titers. Besides, E. coioides Sec6 significantly downregulated the promoter of NF-κB and AP-1, and inhibited the SGIV-induced apoptosis. The results demonstrated that E. coioides Sec6 might play important roles in SGIV infection.
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Affiliation(s)
- Pin-Hong Li
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, PR China
| | - Jia-Yang He
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Yi-Jie Cai
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Yu-Si Wei
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Xiang-Long Zhu
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Jia-Deng-Hui Yang
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Shi-Qi Yang
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Sheng Zhou
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, PR China
| | - Qi-Wei Qin
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, PR China.
| | - Hong-Yan Sun
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, PR China.
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6
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Wang LT, Proulx MÈ, Kim AD, Lelarge V, McCaffrey L. A proximity proteomics screen in three-dimensional spheroid cultures identifies novel regulators of lumen formation. Sci Rep 2021; 11:22807. [PMID: 34815476 PMCID: PMC8610992 DOI: 10.1038/s41598-021-02178-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/28/2021] [Indexed: 11/18/2022] Open
Abstract
Apical-basal cell polarity and lumen formation are essential features of many epithelial tissues, which are disrupted in diseases like cancer. Here, we describe a proteomics-based screen to identify proteins involved in lumen formation in three-dimensional spheroid cultures. We established a suspension-based culture method suitable for generating polarized cysts in sufficient quantities for proteomic analysis. Using this approach, we identified several known and unknown proteins proximally associated with PAR6B, an apical protein involved in lumen formation. Functional analyses of candidates identified PARD3B (a homolog of PARD3), RALB, and HRNR as regulators of lumen formation. We also identified PTPN14 as a component of the Par-complex that is required for fidelity of apical-basal polarity. Cells transformed with KRASG12V exhibit lumen collapse/filling concomitant with disruption of the Par-complex and down-regulation of PTPN14. Enforced expression of PTPN14 maintained the lumen and restricted the transformed phenotype in KRASG12V-expressing cells. This represents an applicable approach to explore protein–protein interactions in three-dimensional culture and to identify proteins important for lumen maintenance in normal and oncogene-expressing cells.
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Affiliation(s)
- Li-Ting Wang
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, H4A 3J1, Canada
| | - Marie-Ève Proulx
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada.,Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Anne D Kim
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, H4A 3J1, Canada
| | - Virginie Lelarge
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada
| | - Luke McCaffrey
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada. .,Division of Experimental Medicine, McGill University, Montreal, QC, H4A 3J1, Canada. .,Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada. .,Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, H4A 3T2, Canada.
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7
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Ohta S, Tago K, Kuchimaru T, Funakoshi-Tago M, Horie H, Aoki-Ohmura C, Matsugi J, Yanagisawa K. The role of MerTK in promoting cell migration is enhanced by the oncogenic Ras/IL-33 signaling axis. FEBS J 2021; 289:1950-1967. [PMID: 34743410 DOI: 10.1111/febs.16271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/15/2021] [Accepted: 11/05/2021] [Indexed: 11/29/2022]
Abstract
Ras genes are frequently mutated in many cancer types; however, there are currently no conclusively effective anticancer drugs against Ras-induced cancer. Therefore, the downstream effectors of Ras signaling need to be identified for the development of promising novel therapeutic approaches. We previously reported that oncogenic Ras induced the expression of NF-HEV/IL-33, a member of the interleukin-1 family, and showed that intracellular IL-33 was required for oncogenic Ras-induced cellular transformation. In the present study, we demonstrated that the c-Mer proto-oncogene tyrosine kinase (MerTK), a receptor tyrosine kinase, played essential roles in oncogenic Ras/IL-33 signaling. The expression of MerTK was enhanced in transformed NIH-3T3 cells by the expression of oncogenic Ras, H-Ras (G12V), in an IL-33-dependent manner. In human colorectal cancer tissues, MerTK expression also correlated with IL-33 expression. The knockdown of IL-33 or MerTK effectively attenuated the migration of NIH-3T3 cells transformed by H-Ras (G12V) and A549, LoVo, and HCT116 cells harboring an oncogenic K-Ras mutation. Furthermore, the suppression of Ras-induced cell migration by the knockdown of IL-33 was rescued by the enforced expression of MerTK. The present results also revealed that MerTK was effectively phosphorylated in NIH-3T3 cells transformed by Ras (G12V). Ras signaling was essential for the tyrosine phosphorylation of MerTK, and the kinase activity of MerTK was indispensable for accelerating cell migration. Collectively, the present results reveal a novel role for MerTK in cancer malignancy, which may be utilized to develop novel therapeutic strategies that target Ras-transformed cells.
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Affiliation(s)
- Satoshi Ohta
- Department of Biochemistry, Jichi Medical University, Tochigi, Japan
| | - Kenji Tago
- Department of Biochemistry, Jichi Medical University, Tochigi, Japan
| | | | | | - Hisanaga Horie
- Department of Surgery, Jichi Medical University, Tochigi, Japan
| | | | - Jitsuhiro Matsugi
- Department of Biochemistry, Jichi Medical University, Tochigi, Japan
| | - Ken Yanagisawa
- Department of Biochemistry, Jichi Medical University, Tochigi, Japan
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8
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Zaman A, Wu X, Lemoff A, Yadavalli S, Lee J, Wang C, Cooper J, McMillan EA, Yeaman C, Mirzaei H, White MA, Bivona TG. Exocyst protein subnetworks integrate Hippo and mTOR signaling to promote virus detection and cancer. Cell Rep 2021; 36:109491. [PMID: 34348154 DOI: 10.1016/j.celrep.2021.109491] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/20/2021] [Accepted: 07/14/2021] [Indexed: 11/25/2022] Open
Abstract
The exocyst is an evolutionarily conserved protein complex that regulates vesicular trafficking and scaffolds signal transduction. Key upstream components of the exocyst include monomeric RAL GTPases, which help mount cell-autonomous responses to trophic and immunogenic signals. Here, we present a quantitative proteomics-based characterization of dynamic and signal-dependent exocyst protein interactomes. Under viral infection, an Exo84 exocyst subcomplex assembles the immune kinase Protein Kinase R (PKR) together with the Hippo kinase Macrophage Stimulating 1 (MST1). PKR phosphorylates MST1 to activate Hippo signaling and inactivate Yes Associated Protein 1 (YAP1). By contrast, a Sec5 exocyst subcomplex recruits another immune kinase, TANK binding kinase 1 (TBK1), which interacted with and activated mammalian target of rapamycin (mTOR). RALB was necessary and sufficient for induction of Hippo and mTOR signaling through parallel exocyst subcomplex engagement, supporting the cellular response to virus infection and oncogenic signaling. This study highlights RALB-exocyst signaling subcomplexes as mechanisms for the integrated engagement of Hippo and mTOR signaling in cells challenged by viral pathogens or oncogenic signaling.
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Affiliation(s)
- Aubhishek Zaman
- Department of Medicine, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158, USA; UCSF Helen Diller Comprehensive Cancer Center, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA.
| | - Xiaofeng Wu
- Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Andrew Lemoff
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Sivaramakrishna Yadavalli
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Jeon Lee
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA; Bioinformatics Core Facility, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Chensu Wang
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Jonathan Cooper
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Elizabeth A McMillan
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Charles Yeaman
- Department of Anatomy and Cell Biology, University of Iowa, 51 Newton Road, Iowa City, IA 52242, USA
| | - Hamid Mirzaei
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Michael A White
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Trever G Bivona
- Department of Medicine, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158, USA; UCSF Helen Diller Comprehensive Cancer Center, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158, USA.
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9
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Apken LH, Oeckinghaus A. The RAL signaling network: Cancer and beyond. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 361:21-105. [PMID: 34074494 DOI: 10.1016/bs.ircmb.2020.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The RAL proteins RALA and RALB belong to the superfamily of small RAS-like GTPases (guanosine triphosphatases). RAL GTPases function as molecular switches in cells by cycling through GDP- and GTP-bound states, a process which is regulated by several guanine exchange factors (GEFs) and two heterodimeric GTPase activating proteins (GAPs). Since their discovery in the 1980s, RALA and RALB have been established to exert isoform-specific functions in central cellular processes such as exocytosis, endocytosis, actin organization and gene expression. Consequently, it is not surprising that an increasing number of physiological functions are discovered to be controlled by RAL, including neuronal plasticity, immune response, and glucose and lipid homeostasis. The critical importance of RAL GTPases for oncogenic RAS-driven cellular transformation and tumorigenesis still attracts most research interest. Here, RAL proteins are key drivers of cell migration, metastasis, anchorage-independent proliferation, and survival. This chapter provides an overview of normal and pathological functions of RAL GTPases and summarizes the current knowledge on the involvement of RAL in human disease as well as current therapeutic targeting strategies. In particular, molecular mechanisms that specifically control RAL activity and RAL effector usage in different scenarios are outlined, putting a spotlight on the complexity of the RAL GTPase signaling network and the emerging theme of RAS-independent regulation and relevance of RAL.
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Affiliation(s)
- Lisa H Apken
- Institute of Molecular Tumor Biology, Faculty of Medicine, University of Münster, Münster, Germany
| | - Andrea Oeckinghaus
- Institute of Molecular Tumor Biology, Faculty of Medicine, University of Münster, Münster, Germany.
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10
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Kelly MR, Kostyrko K, Han K, Mooney NA, Jeng EE, Spees K, Dinh PT, Abbott KL, Gwinn DM, Sweet-Cordero EA, Bassik MC, Jackson PK. Combined Proteomic and Genetic Interaction Mapping Reveals New RAS Effector Pathways and Susceptibilities. Cancer Discov 2020; 10:1950-1967. [PMID: 32727735 PMCID: PMC7710624 DOI: 10.1158/2159-8290.cd-19-1274] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 06/08/2020] [Accepted: 07/24/2020] [Indexed: 11/16/2022]
Abstract
Activating mutations in RAS GTPases drive many cancers, but limited understanding of less-studied RAS interactors, and of the specific roles of different RAS interactor paralogs, continues to limit target discovery. We developed a multistage discovery and screening process to systematically identify genes conferring RAS-related susceptibilities in lung adenocarcinoma. Using affinity purification mass spectrometry, we generated a protein-protein interaction map of RAS interactors and pathway components containing hundreds of interactions. From this network, we constructed a CRISPR dual knockout library targeting 119 RAS-related genes that we screened for KRAS-dependent genetic interactions (GI). This approach identified new RAS effectors, including the adhesion controller RADIL and the endocytosis regulator RIN1, and >250 synthetic lethal GIs, including a potent KRAS-dependent interaction between RAP1GDS1 and RHOA. Many GIs link specific paralogs within and between gene families. These findings illustrate the power of multiomic approaches to uncover synthetic lethal combinations specific for hitherto untreatable cancer genotypes. SIGNIFICANCE: We establish a deep network of protein-protein and genetic interactions in the RAS pathway. Many interactions validated here demonstrate important specificities and redundancies among paralogous RAS regulators and effectors. By comparing synthetic lethal interactions across KRAS-dependent and KRAS-independent cell lines, we identify several new combination therapy targets for RAS-driven cancers.This article is highlighted in the In This Issue feature, p. 1775.
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Affiliation(s)
- Marcus R Kelly
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California.,Program in Cancer Biology, Stanford University School of Medicine, Stanford, California
| | - Kaja Kostyrko
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - Kyuho Han
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Nancie A Mooney
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California
| | - Edwin E Jeng
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Kaitlyn Spees
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Phuong T Dinh
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - Keene L Abbott
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California
| | - Dana M Gwinn
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - E Alejandro Sweet-Cordero
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, San Francisco, California.
| | - Michael C Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, California. .,Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, Stanford, California
| | - Peter K Jackson
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California. .,Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, Stanford, California.,Department of Pathology, Stanford University School of Medicine, Stanford, California
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11
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Nishida‐Fukuda H. The Exocyst: Dynamic Machine or Static Tethering Complex? Bioessays 2019; 41:e1900056. [DOI: 10.1002/bies.201900056] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/14/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Hisayo Nishida‐Fukuda
- Department of Genome Editing, Institute of Biomedical ScienceKansai Medical University2‐5‐1 Shin‐machi, Hirakata Osaka 5731010 Japan
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12
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Singh MK, Martin APJ, Joffre C, Zago G, Camonis J, Coppey M, Parrini MC. Localization of RalB signaling at endomembrane compartments and its modulation by autophagy. Sci Rep 2019; 9:8910. [PMID: 31222145 PMCID: PMC6586930 DOI: 10.1038/s41598-019-45443-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/30/2019] [Indexed: 02/02/2023] Open
Abstract
The monomeric GTPase RalB controls crucial physiological processes, including autophagy and invasion, but it still remains unclear how this multi-functionality is achieved. Previously, we reported that the RalGEF (Guanine nucleotide Exchange Factor) RGL2 binds and activates RalB to promote invasion. Here we show that RGL2, a major activator of RalB, is also required for autophagy. Using a novel automated image analysis method, Endomapper, we quantified the endogenous localization of the RGL2 activator and its substrate RalB at different endomembrane compartments, in an isogenic normal and Ras-transformed cell model. In both normal and Ras-transformed cells, we observed that RGL2 and RalB substantially localize at early and recycling endosomes, and to lesser extent at autophagosomes, but not at trans-Golgi. Interestingly the use of a FRET-based RalB biosensor indicated that RalB signaling is active at these endomembrane compartments at basal level in rich medium. Furthermore, induction of autophagy by nutrient starvation led to a considerable reduction of early and recycling endosomes, in contrast to the expected increase of autophagosomes, in both normal and Ras-transformed cells. However, autophagy mildly affected relative abundances of both RGL2 and RalB at early and recycling endosomes, and at autophagosomes. Interestingly, RalB activity increased at autophagosomes upon starvation in normal cells. These results suggest that the contribution of endosome membranes (carrying RGL2 and RalB molecules) increases total pool of RGL2-RalB at autophagosome forming compartments and might contribute to amplify RalB signaling to support autophagy.
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Affiliation(s)
- Manish Kumar Singh
- Institut Curie, Centre de Recherche, Paris Sciences et Lettres Research University, 75005, Paris, France
- ART group, Inserm U830, 75005, Paris, France
| | - Alexandre P J Martin
- Institut Curie, Centre de Recherche, Paris Sciences et Lettres Research University, 75005, Paris, France
- ART group, Inserm U830, 75005, Paris, France
| | - Carine Joffre
- Centre de Recherches en Cancérologie de Toulouse (CRCT), Inserm UMR1037, Toulouse, France
| | - Giulia Zago
- Institut Curie, Centre de Recherche, Paris Sciences et Lettres Research University, 75005, Paris, France
- ART group, Inserm U830, 75005, Paris, France
| | - Jacques Camonis
- Institut Curie, Centre de Recherche, Paris Sciences et Lettres Research University, 75005, Paris, France
- ART group, Inserm U830, 75005, Paris, France
| | - Mathieu Coppey
- Institut Curie, Centre de Recherche, Paris Sciences et Lettres Research University, 75005, Paris, France
- LOCCO group, UMR168, 75005, Paris, France
| | - Maria Carla Parrini
- Institut Curie, Centre de Recherche, Paris Sciences et Lettres Research University, 75005, Paris, France.
- ART group, Inserm U830, 75005, Paris, France.
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13
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Ommer A, Figlia G, Pereira JA, Datwyler AL, Gerber J, DeGeer J, Lalli G, Suter U. Ral GTPases in Schwann cells promote radial axonal sorting in the peripheral nervous system. J Cell Biol 2019; 218:2350-2369. [PMID: 31201267 PMCID: PMC6605813 DOI: 10.1083/jcb.201811150] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 04/03/2019] [Accepted: 05/15/2019] [Indexed: 12/11/2022] Open
Abstract
Schwann cell–resident Ral GTPases foster radial sorting of axons in developing peripheral nerves and are involved in exocyst-dependent control of Schwann cell process extensions. Small GTPases of the Rho and Ras families are important regulators of Schwann cell biology. The Ras-like GTPases RalA and RalB act downstream of Ras in malignant peripheral nerve sheath tumors. However, the physiological role of Ral proteins in Schwann cell development is unknown. Using transgenic mice with ablation of one or both Ral genes, we report that Ral GTPases are crucial for axonal radial sorting. While lack of only one Ral GTPase was dispensable for early peripheral nerve development, ablation of both RalA and RalB resulted in persistent radial sorting defects, associated with hallmarks of deficits in Schwann cell process formation and maintenance. In agreement, ex vivo–cultured Ral-deficient Schwann cells were impaired in process extension and the formation of lamellipodia. Our data indicate further that RalA contributes to Schwann cell process extensions through the exocyst complex, a known effector of Ral GTPases, consistent with an exocyst-mediated function of Ral GTPases in Schwann cells.
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Affiliation(s)
- Andrea Ommer
- Institute of Molecular Health Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Gianluca Figlia
- Institute of Molecular Health Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Jorge A Pereira
- Institute of Molecular Health Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Anna Lena Datwyler
- Institute of Molecular Health Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Joanne Gerber
- Institute of Molecular Health Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Jonathan DeGeer
- Institute of Molecular Health Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Giovanna Lalli
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Ueli Suter
- Institute of Molecular Health Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
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14
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Galino J, Cervellini I, Zhu N, Stöberl N, Hütte M, Fricker FR, Lee G, McDermott L, Lalli G, Bennett DLH. RalGTPases contribute to Schwann cell repair after nerve injury via regulation of process formation. J Cell Biol 2019; 218:2370-2387. [PMID: 31201266 PMCID: PMC6605803 DOI: 10.1083/jcb.201811002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 04/10/2019] [Accepted: 05/15/2019] [Indexed: 12/02/2022] Open
Abstract
RalA and RalB are involved in cell migration and membrane dynamics. This study finds that ablation of RalGTPases impairs nerve regeneration and alters Schwann cell process formation; conversely, activation of RalGTPases enhancea Schwann cell process formation, migration, and axon myelination. RalA and RalB are small GTPases that are involved in cell migration and membrane dynamics. We used transgenic mice in which one or both GTPases were genetically ablated to investigate the role of RalGTPases in the Schwann cell (SC) response to nerve injury and repair. RalGTPases were dispensable for SC function in the naive uninjured state. Ablation of both RalA and RalB (but not individually) in SCs resulted in impaired axon remyelination and target reinnervation following nerve injury, which resulted in slowed recovery of motor function. Ral GTPases were localized to the leading lamellipodia in SCs and were required for the formation and extension of both axial and radial processes of SCs. These effects were dependent on interaction with the exocyst complex and impacted on the rate of SC migration and myelination. Our results show that RalGTPases are required for efficient nerve repair by regulating SC process formation, migration, and myelination, therefore uncovering a novel role for these GTPases.
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Affiliation(s)
- Jorge Galino
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Ilaria Cervellini
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Ning Zhu
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Nina Stöberl
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Meike Hütte
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Florence R Fricker
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Garrett Lee
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Lucy McDermott
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Giovanna Lalli
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London, UK
| | - David L H Bennett
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
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15
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Qiu L, Chang G, Bi Y, Liu X, Chen G. Circular RNA and mRNA profiling reveal competing endogenous RNA networks during avian leukosis virus, subgroup J-induced tumorigenesis in chickens. PLoS One 2018; 13:e0204931. [PMID: 30286182 PMCID: PMC6171863 DOI: 10.1371/journal.pone.0204931] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 09/17/2018] [Indexed: 01/30/2023] Open
Abstract
Avian leukosis virus subgroup J (ALV-J) can induce myeloid tumors and hemangiomas in chickens and causes severe economic losses with commercial layer chickens and meat-type chickens. Here, we generated ribominus RNA sequencing data from three normal chicken spleen tissues and three ALV-J-infected chicken spleen tissues. Structure analysis of transcripts showed that, compared to mRNAs and lncRNAs, chicken circRNAs shared relatively shorter transcripts and similar GC content. Differentially expression analysis showed 152 differentially expressed circRNAs with 106 circRNAs up regulated and 46 circRNAs down regulated. Through comparing differentially expressed circRNA host genes and mRNAs and performed ceRNA network analysis, we found several tumor or immune-related genes, in which, there were four genes existed in both differentially expressed mRNAs and circRNA host genes (Dock4, Fmr1, Zfhx3, Ralb) and two genes (Mll, Aoc3) involved in ceRNA network. We further characterized one exon-intron circRNA derived from HRH4 gene in the ceRNA network, termed circHRH4, which is an abundant and stable circRNA expressed in various tissues and cells in chicken and localizes in cytoplasm. Our results provide new insight into the pathology of ALV-J infection and circRNAs may also mediate tumorigenesis in chicken.
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Affiliation(s)
- Lingling Qiu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, PR, China
| | - Guobin Chang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, PR, China
| | - Yulin Bi
- College of Animal Science and Technology, Yangzhou University, Yangzhou, PR, China
| | - Xiangping Liu
- Poultry Institute, Chinese Academy of Agricultural Sciences, Yangzhou, PR, China
| | - Guohong Chen
- College of Animal Science and Technology, Yangzhou University, Yangzhou, PR, China
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16
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Sec6 enhances cell migration and suppresses apoptosis by elevating the phosphorylation of p38 MAPK, MK2, and HSP27. Cell Signal 2018; 49:1-16. [DOI: 10.1016/j.cellsig.2018.04.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 04/27/2018] [Accepted: 04/30/2018] [Indexed: 11/20/2022]
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17
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Tight junction-associated protein GEF-H1 in the neighbours of dividing epithelial cells is essential for adaptation of cell-cell membrane during cytokinesis. Exp Cell Res 2018; 371:72-82. [PMID: 30056063 DOI: 10.1016/j.yexcr.2018.07.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 11/22/2022]
Abstract
Animal cells divide by a process called cytokinesis which relies on the constriction of a contractile actomyosin ring leading to the production of two daughter cells. Cytokinesis is an intrinsic property of cells which occurs even for artificially isolated cells. During division, isolated cells undergo dramatic changes in shape such as rounding and membrane deformation as the division furrow ingresses. However, cells are often embedded in tissues and thus are surrounded by neighbouring cells. How these neighbours might influence, or might themselves be influenced by, the shape changes of cytokinesis is poorly understood in vertebrates. Here, we show that during cytokinesis of epithelial cells in the Xenopus embryo, lateral cell-cell contacts remain almost perpendicular to the epithelial plane. Depletion of the tight junction-associated protein GEF-H1 leads to a transient and stereotyped deformation of cell-cell contacts. Although, this deformation occurs only during cytokinesis, we show that it originates from immediate neighbours of the dividing cell. Moreover, we show that exocyst and recycling endosome regulation by GEF-H1 are involved in adaptation of cell-cell contacts to deformation. Our results highlight the crucial role of tight junctions and GEF-H1 in cell-cell contact adaptation when cells are exposed to a mechanical stress such as cytokinesis.
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18
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19
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Abstract
Cells depend on hugely diverse lipidomes for many functions. The actions and structural integrity of the plasma membrane and most organelles also critically depend on membranes and their lipid components. Despite the biological importance of lipids, our understanding of lipid engagement, especially the roles of lipid hydrophobic alkyl side chains, in key cellular processes is still developing. Emerging research has begun to dissect the importance of lipids in intricate events such as cell division. This review discusses how these structurally diverse biomolecules are spatially and temporally regulated during cell division, with a focus on cytokinesis. We analyze how lipids facilitate changes in cellular morphology during division and how they participate in key signaling events. We identify which cytokinesis proteins are associated with membranes, suggesting lipid interactions. More broadly, we highlight key unaddressed questions in lipid cell biology and techniques, including mass spectrometry, advanced imaging, and chemical biology, which will help us gain insights into the functional roles of lipids.
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Affiliation(s)
- Elisabeth M Storck
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London SE1 1UL, United Kingdom;
| | - Cagakan Özbalci
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London SE1 1UL, United Kingdom;
| | - Ulrike S Eggert
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London SE1 1UL, United Kingdom; .,Department of Chemistry, King's College London, London SE1 1DB, United Kingdom
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20
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Nakhaei-Rad S, Haghighi F, Nouri P, Rezaei Adariani S, Lissy J, Kazemein Jasemi NS, Dvorsky R, Ahmadian MR. Structural fingerprints, interactions, and signaling networks of RAS family proteins beyond RAS isoforms. Crit Rev Biochem Mol Biol 2018; 53:130-156. [PMID: 29457927 DOI: 10.1080/10409238.2018.1431605] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Saeideh Nakhaei-Rad
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Fereshteh Haghighi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Parivash Nouri
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Soheila Rezaei Adariani
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Jana Lissy
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Neda S Kazemein Jasemi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Radovan Dvorsky
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Mohammad Reza Ahmadian
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
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21
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D’Aloia A, Berruti G, Costa B, Schiller C, Ambrosini R, Pastori V, Martegani E, Ceriani M. RalGPS2 is involved in tunneling nanotubes formation in 5637 bladder cancer cells. Exp Cell Res 2018; 362:349-361. [DOI: 10.1016/j.yexcr.2017.11.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/27/2017] [Accepted: 11/29/2017] [Indexed: 11/25/2022]
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22
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Moghadam AR, Patrad E, Tafsiri E, Peng W, Fangman B, Pluard TJ, Accurso A, Salacz M, Shah K, Ricke B, Bi D, Kimura K, Graves L, Najad MK, Dolatkhah R, Sanaat Z, Yazdi M, Tavakolinia N, Mazani M, Amani M, Ghavami S, Gartell R, Reilly C, Naima Z, Esfandyari T, Farassati F. Ral signaling pathway in health and cancer. Cancer Med 2017; 6:2998-3013. [PMID: 29047224 PMCID: PMC5727330 DOI: 10.1002/cam4.1105] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 04/10/2017] [Accepted: 04/14/2017] [Indexed: 12/12/2022] Open
Abstract
The Ral (Ras-Like) signaling pathway plays an important role in the biology of cells. A plethora of effects is regulated by this signaling pathway and its prooncogenic effectors. Our team has demonstrated the overactivation of the RalA signaling pathway in a number of human malignancies including cancers of the liver, ovary, lung, brain, and malignant peripheral nerve sheath tumors. Additionally, we have shown that the activation of RalA in cancer stem cells is higher in comparison with differentiated cancer cells. In this article, we review the role of Ral signaling in health and disease with a focus on the role of this multifunctional protein in the generation of therapies for cancer. An improved understanding of this pathway can lead to development of a novel class of anticancer therapies that functions on the basis of intervention with RalA or its downstream effectors.
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Affiliation(s)
- Adel Rezaei Moghadam
- Department of Human Anatomy and Cell ScienceUniversity of ManitobaWinnipegCanada
| | - Elham Patrad
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Elham Tafsiri
- Department of Pediatrics, Columbia Presbyterian Medical CenterNew YorkNew York
| | - Warner Peng
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Benjamin Fangman
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Timothy J Pluard
- Saint Luke's HospitalUniversity of Missouri at Kansas CityKansas CityMissouri
| | - Anthony Accurso
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Michael Salacz
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Kushal Shah
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Brandon Ricke
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Danse Bi
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Kyle Kimura
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Leland Graves
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Marzieh Khajoie Najad
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Roya Dolatkhah
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Zohreh Sanaat
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Mina Yazdi
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Naeimeh Tavakolinia
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Mohammad Mazani
- Pasteur Institute of IranTehranIran
- Ardabil University of Medical Sciences, BiochemistryArdabilIran
| | - Mojtaba Amani
- Pasteur Institute of IranTehranIran
- Ardabil University of Medical Sciences, BiochemistryArdabilIran
| | - Saeid Ghavami
- Department of Human Anatomy and Cell ScienceUniversity of ManitobaWinnipegCanada
| | - Robyn Gartell
- Department of Pediatrics, Columbia Presbyterian Medical CenterNew YorkNew York
| | - Colleen Reilly
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Zaid Naima
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Tuba Esfandyari
- Department of Medicine, Molecular Medicine LaboratoryThe University of Kansas Medical SchoolKansas CityKansas
| | - Faris Farassati
- Research Service (151)Kansas City Veteran Affairs Medical Center & Midwest Biomedical Research Foundation4801 E Linwood BlvdKansas CityMissouri64128‐2226
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23
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Abstract
Polarized exocytosis is generally considered as the multistep vesicular trafficking process in which membrane-bounded carriers are transported from the Golgi or endosomal compartments to specific sites of the plasma membrane. Polarized exocytosis in cells is achieved through the coordinated actions of membrane trafficking machinery and cytoskeleton orchestrated by signaling molecules such as the Rho family of small GTPases. Elucidating the molecular mechanisms of polarized exocytosis is essential to our understanding of a wide range of pathophysiological processes from neuronal development to tumor invasion.
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Affiliation(s)
- Jingwen Zeng
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018
| | - Shanshan Feng
- Key Laboratory for Regenerative Medicine of Ministry of Education and Department of Developmental & Regenerative Biology, Jinan University, Guangzhou 510632, P.R. China
| | - Bin Wu
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018
| | - Wei Guo
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018
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24
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Integrin-Dependent Regulation of Small GTPases: Role in Cell Migration. J Indian Inst Sci 2017. [DOI: 10.1007/s41745-016-0010-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Cicenas J, Tamosaitis L, Kvederaviciute K, Tarvydas R, Staniute G, Kalyan K, Meskinyte-Kausiliene E, Stankevicius V, Valius M. KRAS, NRAS and BRAF mutations in colorectal cancer and melanoma. Med Oncol 2017; 34:26. [DOI: 10.1007/s12032-016-0879-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 12/29/2016] [Indexed: 01/13/2023]
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26
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Abstract
The midbody is a protein-dense assembly that forms during cytokinesis when the actomyosin ring constricts around bundling central spindle microtubules. After its initial description by Walther Flemming in the late nineteenth century and its rediscovery through electron microscopy in the 1960s and 1970s, its ultrastructural organization and the sequential recruitment of its molecular constituents has only been elucidated in the past decade. Recently, it has become clear that the midbody can serve as a polarity cue during asymmetric cell division, cell polarization, and spindle orientation by coordinating cytoskeletal organization, vesicular transport, and localized cortical cues. In this chapter, these newly emerging functions will be discussed as well as asymmetries during midbody formation and their consequences for cellular organization in tissues.
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Affiliation(s)
- Christian Pohl
- Buchmann Institute for Molecular Life Sciences, Institute of Biochemistry II, Goethe University Medical School, Max-von-Laue-Strasse 15, 60438, Frankfurt (Main), Germany.
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27
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Tanaka T, Goto K, Iino M. Diverse Functions and Signal Transduction of the Exocyst Complex in Tumor Cells. J Cell Physiol 2016; 232:939-957. [DOI: 10.1002/jcp.25619] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 09/23/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Toshiaki Tanaka
- Department of Anatomy and Cell Biology; School of Medicine; Yamagata University; Yamagata Japan
- Department of Dentistry, Oral and Maxillofacial Surgery; Plastic and Reconstructive Surgery; School of Medicine; Yamagata University; Yamagata Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology; School of Medicine; Yamagata University; Yamagata Japan
| | - Mitsuyoshi Iino
- Department of Dentistry, Oral and Maxillofacial Surgery; Plastic and Reconstructive Surgery; School of Medicine; Yamagata University; Yamagata Japan
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28
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Pawar A, Meier JA, Dasgupta A, Diwanji N, Deshpande N, Saxena K, Buwa N, Inchanalkar S, Schwartz MA, Balasubramanian N. Ral-Arf6 crosstalk regulates Ral dependent exocyst trafficking and anchorage independent growth signalling. Cell Signal 2016; 28:1225-1236. [PMID: 27269287 PMCID: PMC4973806 DOI: 10.1016/j.cellsig.2016.05.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/30/2016] [Accepted: 05/31/2016] [Indexed: 12/01/2022]
Abstract
Integrin dependent regulation of growth factor signalling confers anchorage dependence that is deregulated in cancers. Downstream of integrins and oncogenic Ras the small GTPase Ral is a vital mediator of adhesion dependent trafficking and signalling. This study identifies a novel regulatory crosstalk between Ral and Arf6 that controls Ral function in cells. In re-adherent mouse fibroblasts (MEFs) integrin dependent activation of RalA drives Arf6 activation. Independent of adhesion constitutively active RalA and RalB could both however activate Arf6. This is further conserved in oncogenic H-Ras containing bladder cancer T24 cells, which express anchorage independent active Ral that supports Arf6 activation. Arf6 mediates active Ral-exocyst dependent delivery of raft microdomains to the plasma membrane that supports anchorage independent growth signalling. Accordingly in T24 cells the RalB-Arf6 crosstalk is seen to preferentially regulate anchorage independent Erk signalling. Active Ral we further find uses a Ral-RalBP1-ARNO-Arf6 pathway to mediate Arf6 activation. This study hence identifies Arf6, through this regulatory crosstalk, to be a key downstream mediator of Ral isoform function along adhesion dependent pathways in normal and cancer cells. Ral mediates Arf6 activation downstream of integrins and oncogenic Ras. Arf6 mediates Ral-exocyst dependent delivery of raft microdomains. Active Ral supports anchorage independent Arf6 activation in bladder cancer T24 cells. Ral-Arf6 crosstalk in T24 cells regulates anchorage independent Erk signalling. A Ral-RalBP1-ARNO-Arf6 pathway mediates the Ral-Arf6 crosstalk.
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Affiliation(s)
- Archana Pawar
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India
| | - Jeremy A Meier
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, United States
| | - Anwesha Dasgupta
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India
| | - Neha Diwanji
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India
| | - Neha Deshpande
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India
| | - Kritika Saxena
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India
| | - Natasha Buwa
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India
| | - Siddhi Inchanalkar
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India
| | - Martin Alexander Schwartz
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, United States; Yale Cardiovascular Research Center, 300 George Street, 7th Floor, New Haven, CT 06511, United States
| | - Nagaraj Balasubramanian
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India.
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Inamdar SM, Hsu SC, Yeaman C. Probing Functional Changes in Exocyst Configuration with Monoclonal Antibodies. Front Cell Dev Biol 2016; 4:51. [PMID: 27376061 PMCID: PMC4891948 DOI: 10.3389/fcell.2016.00051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/10/2016] [Indexed: 01/19/2023] Open
Abstract
Spatial regulation of exocytosis relies on the exocyst, a hetero-octameric protein complex that tethers vesicles to fusion sites at the plasma membrane. Nevertheless, our understanding of mechanisms regulating exocyst assembly/disassembly, localization, and function are incomplete. Here, we have exploited a panel of anti-Sec6 monoclonal antibodies (mAbs) to probe possible configurational changes accompanying transitions in exocyst function in epithelial MDCK cells. Sec6 is quantitatively associated with Sec8 in high molecular weight complexes, as shown by gel filtration and co-immunoprecipitation studies. We mapped epitopes recognized by more than 20 distinct mAbs to one of six Sec6 segments. Surprisingly, mAbs that bound epitopes in each segment labeled distinct subcellular structures. In general, antibodies to epitopes in N-terminal domains labeled Sec6 in either cytosolic or nuclear pools, whereas those that bound epitopes in C-terminal domains labeled membrane-associated Sec6. In this latter group, we identified antibodies that labeled distinct Sec6 populations at the apical junctional complex, desmosomes, endoplasmic reticulum and vimentin-type intermediate filaments. That each antibody was specific was verified by both Sec6 RNAi and competition with fusion proteins containing each domain. Comparison of non-polarized and polarized cells revealed that many Sec6 epitopes either redistribute or become concealed during epithelial polarization. Transitions in exocyst configurations may be regulated in part by the actions of Ral GTPases, because the exposure of Sec6 C-terminal domain epitopes at the plasma membrane is significantly reduced upon RalA RNAi. To determine whether spatio-temporal changes in epitope accessibility was correlated with differential stability of interactions between Sec6 and other exocyst subunits, we quantified relative amounts of each subunit that co-immunoprecipitated with Sec6 when antibodies to N-terminal or C-terminal epitopes were used. Antibodies to Sec6NT co-precipitated substantially more Sec5, -10, -15, Exo70 and -84 than did those to Sec6CT. In contrast, antibodies to Sec6CT co-precipitated more Sec3 and Sec8 than did those to Sec6NT. These results are consistent with a model in which exocyst activation during periods of rapid membrane expansion is accompanied by molecular rearrangements within the holocomplex or association with accessory proteins, which expose the Sec6 C-terminal domain when the complex is membrane-bound and conceal it when the complex is cytoplasmic.
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Affiliation(s)
- Shivangi M Inamdar
- Molecular and Cellular Biology Program, University of IowaIowa City, IA, USA; Department of Anatomy and Cell Biology, University of IowaIowa City, IA, USA
| | - Shu-Chan Hsu
- Department of Cell Biology and Neuroscience, Rutgers University Piscataway, NJ, USA
| | - Charles Yeaman
- Molecular and Cellular Biology Program, University of IowaIowa City, IA, USA; Department of Anatomy and Cell Biology, University of IowaIowa City, IA, USA
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RalGPS2 Is Essential for Survival and Cell Cycle Progression of Lung Cancer Cells Independently of Its Established Substrates Ral GTPases. PLoS One 2016; 11:e0154840. [PMID: 27149377 PMCID: PMC4858283 DOI: 10.1371/journal.pone.0154840] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/20/2016] [Indexed: 11/19/2022] Open
Abstract
The human genome contains six genes coding for proteins validated in vitro as specific activators of the small GTPases “Ras-related protein Ral-A” and “Ras-related protein Ral-B”, generically named Ral-guanine nucleotide exchange factors (RalGEF). Ral proteins are important contributors to Ras oncogenic signaling, and RAS oncogenes are important in human Non-Small Cell Lung Carcinoma (NSCLC). Therefore in this work, RalGEF contribution to oncogenic and non-oncogenic features of human NSCLC cell lines, as anchorage-dependent and independent growth, cell survival, and proliferation, was investigated. Among all human RalGEF, silencing of RGL1 and RALGPS1 had no detectable effect. However, silencing of either RGL2, RGL3, RALGDS or, to a larger extent, RALGPS2 inhibited cell population growth in anchorage dependent and independent conditions (up to 90 and 80%, respectively). RALGPS2 silencing also caused an increase in the number of apoptotic cells, up to 45% of the cell population in transformed bronchial BZR cells. In H1299 and A549, two NSCLC cell lines, RALGPS2 silencing caused an arrest of cells in the G0/G1-phase of cell cycle. Furthermore, it was associated with the modulation of important cell cycle regulators: the E3 Ubiquitin Protein Ligase S-phase kinase-associated protein 2 (Skp2) was strongly down-regulated (both at mRNA and protein levels), and its targets, the cell cycle inhibitors p27 and p21, were up-regulated. These molecular effects were not mimicked by silencing RALA, RALB, or both. However, RALB silencing caused a modest inhibition of cell cycle progression, which in H1299 cells was associated with Cyclin D1 regulation. In conclusion, RALGPS2 is implicated in the control of cell cycle progression and survival in the in vitro growth of NSCLC cell lines. This function is largely independent of Ral GTPases and associated with modulation of Skp2, p27 and p21 cell cycle regulators.
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Intracellular NF-HEV/IL-33 harbors essential roles in Ras-induced cellular transformation by contributing to cyclin D1 protein synthesis. Cell Signal 2016; 28:1025-36. [PMID: 27155324 DOI: 10.1016/j.cellsig.2016.04.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/10/2016] [Accepted: 04/27/2016] [Indexed: 12/19/2022]
Abstract
A member of the interleukin-1 family, interleukin-33 (NF-HEV/IL-33), is a ligand for the receptor, ST2L and stimulates the production of Th2 cytokines. Although IL-33 localizes to the nucleus and may be involved in the regulation of transcription independent of ST2L, its functions in the nucleus currently remain unclear. We herein demonstrated that the expression of IL-33 was markedly enhanced in NIH-3T3 cells transformed by an oncogenic H-Ras mutant (H-Ras (G12V)), and the induced IL-33 was mainly located in the nuclei of these cells. The enforced expression of IL-33 accelerated H-Ras (G12V)-induced transformation in NIH-3T3 cells, and this transforming activity was markedly reduced by the knockdown of IL-33 with shRNA. We subsequently analyzed several signaling molecules regulated by Ras in order to elucidate the mechanism by which IL-33 contributes to Ras (G12V)-induced transformation. We found that the knockdown of IL-33 effectively attenuated the Ras (G12V)-induced expression of cyclin D1. However, the knockdown of IL-33 failed to affect cyclin D1 mRNA expression levels, and epoxomicin, a proteasome inhibitor, did not cancel the IL-33 knockdown-induced down-regulation of its protein levels. We showed that Ras (G12V)-induced cyclin D1 protein synthesis was markedly suppressed by the knockdown of IL-33. Taken together, the results of the present study strongly suggest a novel role for IL-33 in cellular transformation.
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Wang N, Lee IJ, Rask G, Wu JQ. Roles of the TRAPP-II Complex and the Exocyst in Membrane Deposition during Fission Yeast Cytokinesis. PLoS Biol 2016; 14:e1002437. [PMID: 27082518 PMCID: PMC4833314 DOI: 10.1371/journal.pbio.1002437] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 03/15/2016] [Indexed: 12/27/2022] Open
Abstract
The cleavage-furrow tip adjacent to the actomyosin contractile ring is believed to be the predominant site for plasma-membrane insertion through exocyst-tethered vesicles during cytokinesis. Here we found that most secretory vesicles are delivered by myosin-V on linear actin cables in fission yeast cytokinesis. Surprisingly, by tracking individual exocytic and endocytic events, we found that vesicles with new membrane are deposited to the cleavage furrow relatively evenly during contractile-ring constriction, but the rim of the cleavage furrow is the main site for endocytosis. Fusion of vesicles with the plasma membrane requires vesicle tethers. Our data suggest that the transport particle protein II (TRAPP-II) complex and Rab11 GTPase Ypt3 help to tether secretory vesicles or tubulovesicular structures along the cleavage furrow while the exocyst tethers vesicles at the rim of the division plane. We conclude that the exocyst and TRAPP-II complex have distinct localizations at the division site, but both are important for membrane expansion and exocytosis during cytokinesis. Two putative vesicle tethers—the exocyst and TRAPP-II complexes—localize differently at the division plane to ensure efficient plasma-membrane deposition along the whole cleavage furrow during cytokinesis in the fission yeast Schizosaccharomyces pombe. Cytokinesis partitions a mother cell into two daughter cells at the end of each cell-division cycle. A significant amount of new plasma membrane is needed at the cleavage furrow during cytokinesis in many cell types. Membrane expansion is achieved through the balance of exocytosis and endocytosis. It is poorly understood where and when the membrane is deposited and retrieved during cytokinesis. By tracking individual vesicles with high spatiotemporal resolution and using electron microscopy, we found that new membrane is deposited relatively evenly along the cleavage furrow in fission yeast, while the rim of the division plane is the predominant site for endocytosis. The secretory vesicles/compartments carrying new membrane are mainly delivered along formin-nucleated actin cables by myosin-V motors. Surprisingly, we find that both exocytosis and endocytosis at the division site are ramped up before contractile-ring constriction and last until daughter-cell separation. We discovered that two putative vesicle tethers, the exocyst and TRAPP-II complexes, localize to different sites at the cleavage furrow to promote tethering of different, yet overlapping, classes of secretory vesicles/compartments for exocytosis and new membrane deposition.
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Affiliation(s)
- Ning Wang
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - I-Ju Lee
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Galen Rask
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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Giansanti MG, Vanderleest TE, Jewett CE, Sechi S, Frappaolo A, Fabian L, Robinett CC, Brill JA, Loerke D, Fuller MT, Blankenship JT. Exocyst-Dependent Membrane Addition Is Required for Anaphase Cell Elongation and Cytokinesis in Drosophila. PLoS Genet 2015; 11:e1005632. [PMID: 26528720 PMCID: PMC4631508 DOI: 10.1371/journal.pgen.1005632] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 10/07/2015] [Indexed: 11/18/2022] Open
Abstract
Mitotic and cytokinetic processes harness cell machinery to drive chromosomal segregation and the physical separation of dividing cells. Here, we investigate the functional requirements for exocyst complex function during cell division in vivo, and demonstrate a common mechanism that directs anaphase cell elongation and cleavage furrow progression during cell division. We show that onion rings (onr) and funnel cakes (fun) encode the Drosophila homologs of the Exo84 and Sec8 exocyst subunits, respectively. In onr and fun mutant cells, contractile ring proteins are recruited to the equatorial region of dividing spermatocytes. However, cytokinesis is disrupted early in furrow ingression, leading to cytokinesis failure. We use high temporal and spatial resolution confocal imaging with automated computational analysis to quantitatively compare wild-type versus onr and fun mutant cells. These results demonstrate that anaphase cell elongation is grossly disrupted in cells that are compromised in exocyst complex function. Additionally, we observe that the increase in cell surface area in wild type peaks a few minutes into cytokinesis, and that onr and fun mutant cells have a greatly reduced rate of surface area growth specifically during cell division. Analysis by transmission electron microscopy reveals a massive build-up of cytoplasmic astral membrane and loss of normal Golgi architecture in onr and fun spermatocytes, suggesting that exocyst complex is required for proper vesicular trafficking through these compartments. Moreover, recruitment of the small GTPase Rab11 and the PITP Giotto to the cleavage site depends on wild-type function of the exocyst subunits Exo84 and Sec8. Finally, we show that the exocyst subunit Sec5 coimmunoprecipitates with Rab11. Our results are consistent with the exocyst complex mediating an essential, coordinated increase in cell surface area that potentiates anaphase cell elongation and cleavage furrow ingression. The cell shape changes that underlie cell division are some of the most fundamental changes in cell morphology. Here, we show that a common membrane trafficking pathway is required for both the cell lengthening that occurs during anaphase, and the physical separation of a cell into two equal daughter cells. We measure and define the periods of surface area increase during cell division in Drosophila male germline cells, and demonstrate that subunits of the exocyst tethering complex are required for this process. Invagination of the cleavage furrow fails at an early stage in exocyst mutant spermatocytes, suggesting that membrane addition is part of the initial ingression mechanism. In the absence of exocyst complex function, vesicular trafficking pathways are disrupted, leading to enlarged cytoplasmic membrane stores, and disruption of Golgi architecture. In addition, a vesicular Rab protein, Rab11, biochemically associates with the exocyst complex subunit Sec5. These results suggest that remodeling of the plasma membrane and targeted increases in surface area are an active part of the fundamental mechanisms that permit eukaryotic cell division to occur.
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Affiliation(s)
- Maria Grazia Giansanti
- Istituto di Biologia e Patologia Molecolari del CNR, Dipartimento di Biologia e Biotecnologie, Università Sapienza di Roma, Roma, Italy
- * E-mail: (MGG), (JTB)
| | | | - Cayla E. Jewett
- Department of Biological Sciences, University of Denver, Denver, Colorado, United States of America
| | - Stefano Sechi
- Istituto di Biologia e Patologia Molecolari del CNR, Dipartimento di Biologia e Biotecnologie, Università Sapienza di Roma, Roma, Italy
| | - Anna Frappaolo
- Istituto di Biologia e Patologia Molecolari del CNR, Dipartimento di Biologia e Biotecnologie, Università Sapienza di Roma, Roma, Italy
| | - Lacramioara Fabian
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Carmen C. Robinett
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Julie A. Brill
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Dinah Loerke
- Department of Physics, University of Denver, Denver, Colorado, United States of America
| | - Margaret T. Fuller
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - J. Todd Blankenship
- Department of Biological Sciences, University of Denver, Denver, Colorado, United States of America
- * E-mail: (MGG), (JTB)
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Joffre C, Dupont N, Hoa L, Gomez V, Pardo R, Gonçalves-Pimentel C, Achard P, Bettoun A, Meunier B, Bauvy C, Cascone I, Codogno P, Fanto M, Hergovich A, Camonis J. The Pro-apoptotic STK38 Kinase Is a New Beclin1 Partner Positively Regulating Autophagy. Curr Biol 2015; 25:2479-92. [PMID: 26387716 PMCID: PMC4598746 DOI: 10.1016/j.cub.2015.08.031] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 07/09/2015] [Accepted: 08/13/2015] [Indexed: 12/15/2022]
Abstract
Autophagy plays key roles in development, oncogenesis, cardiovascular, metabolic, and neurodegenerative diseases. Hence, understanding how autophagy is regulated can reveal opportunities to modify autophagy in a disease-relevant manner. Ideally, one would want to functionally define autophagy regulators whose enzymatic activity can potentially be modulated. Here, we describe the STK38 protein kinase (also termed NDR1) as a conserved regulator of autophagy. Using STK38 as bait in yeast-two-hybrid screens, we discovered STK38 as a novel binding partner of Beclin1, a key regulator of autophagy. By combining molecular, cell biological, and genetic approaches, we show that STK38 promotes autophagosome formation in human cells and in Drosophila. Upon autophagy induction, STK38-depleted cells display impaired LC3B-II conversion; reduced ATG14L, ATG12, and WIPI-1 puncta formation; and significantly decreased Vps34 activity, as judged by PI3P formation. Furthermore, we observed that STK38 supports the interaction of the exocyst component Exo84 with Beclin1 and RalB, which is required to initiate autophagosome formation. Upon studying the activation of STK38 during autophagy induction, we found that STK38 is stimulated in a MOB1- and exocyst-dependent manner. In contrast, RalB depletion triggers hyperactivation of STK38, resulting in STK38-dependent apoptosis under prolonged autophagy conditions. Together, our data establish STK38 as a conserved regulator of autophagy in human cells and flies. We also provide evidence demonstrating that STK38 and RalB assist the coordination between autophagic and apoptotic events upon autophagy induction, hence further proposing a role for STK38 in determining cellular fate in response to autophagic conditions.
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Affiliation(s)
- Carine Joffre
- INSERM U830, Institut Curie, Paris 75248, France; Cancer Research Center of Toulouse, UMR1037, Toulouse 31037, France
| | - Nicolas Dupont
- INSERM U1151-CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75993, France
| | - Lily Hoa
- University College London, Cancer Institute, London WC1E 6BT, UK
| | - Valenti Gomez
- University College London, Cancer Institute, London WC1E 6BT, UK
| | - Raul Pardo
- Department of Basic and Clinical Neuroscience, Kings College London, London SE5 9NU, UK
| | | | - Pauline Achard
- Cancer Research Center of Toulouse, UMR1037, Toulouse 31037, France
| | | | | | - Chantal Bauvy
- INSERM U1151-CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75993, France
| | | | - Patrice Codogno
- INSERM U1151-CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75993, France.
| | - Manolis Fanto
- Department of Basic and Clinical Neuroscience, Kings College London, London SE5 9NU, UK.
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Papini D, Langemeyer L, Abad MA, Kerr A, Samejima I, Eyers PA, Jeyaprakash AA, Higgins JMG, Barr FA, Earnshaw WC. TD-60 links RalA GTPase function to the CPC in mitosis. Nat Commun 2015; 6:7678. [PMID: 26158537 PMCID: PMC4510650 DOI: 10.1038/ncomms8678] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 05/29/2015] [Indexed: 12/26/2022] Open
Abstract
TD-60 (also known as RCC2) is a highly conserved protein that structurally resembles the Ran guanine exchange factor (GEF) RCC1, but has not previously been shown to have GEF activity. TD-60 has a typical chromosomal passenger complex (CPC) distribution in mitotic cells, but associates with integrin complexes and is involved in cell motility during interphase. Here we show that TD-60 exhibits GEF activity, in vitro and in cells, for the small GTPase RalA. TD-60 or RalA depletion causes spindle abnormalities in prometaphase associated with abnormal centromeric accumulation of CPC components. TD-60 and RalA apparently work together to contribute to the regulation of kinetochore-microtubule interactions in early mitosis. Importantly, several mitotic phenotypes caused by TD-60 depletion are reverted by the expression of a GTP-locked mutant, RalA (Q72L). The demonstration that a small GTPase participates in the regulation of the CPC reveals a level of mitotic regulation not suspected in previous studies.
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Affiliation(s)
- Diana Papini
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
- Institute for Cell and Molecular Biosciences (ICaMB), Newcastle University, Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Lars Langemeyer
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Maria A. Abad
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Alastair Kerr
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Itaru Samejima
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Patrick A. Eyers
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
| | - A. Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Jonathan M. G. Higgins
- Institute for Cell and Molecular Biosciences (ICaMB), Newcastle University, Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Francis A. Barr
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - William C. Earnshaw
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
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36
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Shirakawa R, Horiuchi H. Ral GTPases: crucial mediators of exocytosis and tumourigenesis. J Biochem 2015; 157:285-99. [DOI: 10.1093/jb/mvv029] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/07/2015] [Indexed: 11/12/2022] Open
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The RAS-RAL axis in cancer: evidence for mutation-specific selectivity in non-small cell lung cancer. Acta Pharmacol Sin 2015; 36:291-7. [PMID: 25557115 DOI: 10.1038/aps.2014.129] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 10/30/2014] [Indexed: 12/21/2022] Open
Abstract
Activating RAS mutations are common in human tumors. These mutations are often markers for resistance to therapy and subsequent poor prognosis. So far, targeting the RAF-MEK-ERK and PI3K-AKT signaling pathways downstream of RAS is the only promising approach in the treatment of cancer patients harboring RAS mutations. RAL GTPase, another downstream effector of RAS, is also considered as a therapeutic option for the treatment of RAS-mutant cancers. The RAL GTPase family comprises RALA and RALB, which can have either divergent or similar functions in different tumor models. Recent studies on non-small cell lung cancer (NSCLC) have showed that different RAS mutations selectively activate specific effector pathways. This observation requires broader validation in other tumor tissue types, but if true, will provide a new approach to the treatment of RAS-mutant cancer patients by targeting specific downstream RAS effectors according to the type of RAS mutation. It also suggests that RAL GTPase inhibition will be an important treatment strategy for tumors harboring RAS glycine to cysteine (G12C) or glycien to valine (G12V) mutations, which are commonly found in NSCLC and pancreatic cancer.
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38
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Campbell LJ, Peppa M, Crabtree MD, Shafiq A, McGough NF, Mott HR, Owen D. Thermodynamic mapping of effector protein interfaces with RalA and RalB. Biochemistry 2015; 54:1380-9. [PMID: 25621740 DOI: 10.1021/bi501530u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
RalA and RalB are members of the Ras family of small G proteins and are activated downstream of Ras via RalGEFs. The RalGEF-Ral axis represents one of the major effector pathways controlled by Ras and as such is an important pharmacological target. RalA and RalB are approximately 80% identical at the amino acid level; despite this, they have distinct roles both in normal cells and in the disease state. We have used our structure of RalB-RLIP76 to guide an analysis of Ral-effector interaction interfaces, creating panels of mutant proteins to probe the energetics of these interactions. The data provide a physical mechanism that underpins the effector selective mutations commonly employed to dissect Ral G protein function. Comparing the energetic landscape of the RalB-RLIP76 and RalB-Sec5 complexes reveals mutations in RalB that lead to differential binding of the two effector proteins. A panel of RLIP76 mutants was used to probe the interaction between RLIP76 and RalA and -B. Despite 100% sequence identity in the RalA and -B contact residues with RLIP76, differences still exist in the energetic profiles of the two complexes. Therefore, we have revealed properties that may account for some of the functional separation observed with RalA and RalB at the cellular level. Our mutations, in both the Ral isoforms and RLIP76, provide new tools that can be employed to parse the complex biology of Ral G protein signaling networks. The combination of these thermodynamic and structural data can also guide efforts to ablate RalA and -B activity with small molecules and peptides.
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Affiliation(s)
- Louise J Campbell
- Department of Biochemistry, University of Cambridge , 80 Tennis Court Road, Cambridge CB2 1GA, U.K
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Phosphoinositides: Lipids with informative heads and mastermind functions in cell division. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:832-43. [PMID: 25449648 DOI: 10.1016/j.bbalip.2014.10.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/21/2014] [Accepted: 10/28/2014] [Indexed: 01/22/2023]
Abstract
Phosphoinositides are low abundant but essential phospholipids in eukaryotic cells and refer to phosphatidylinositol and its seven polyphospho-derivatives. In this review, we summarize our current knowledge on phosphoinositides in multiple aspects of cell division in animal cells, including mitotic cell rounding, longitudinal cell elongation, cytokinesis furrow ingression, intercellular bridge abscission and post-cytokinesis events. PtdIns(4,5)P₂production plays critical roles in spindle orientation, mitotic cell shape and bridge stability after furrow ingression by recruiting force generator complexes and numerous cytoskeleton binding proteins. Later, PtdIns(4,5)P₂hydrolysis and PtdIns3P production are essential for normal cytokinesis abscission. Finally, emerging functions of PtdIns3P and likely PtdIns(4,5)P₂have recently been reported for midbody remnant clearance after abscission. We describe how the multiple functions of phosphoinositides in cell division reflect their distinct roles in local recruitment of protein complexes, membrane traffic and cytoskeleton remodeling. This article is part of a Special Issue entitled Phosphoinositides.
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40
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Gentry LR, Martin TD, Reiner DJ, Der CJ. Ral small GTPase signaling and oncogenesis: More than just 15minutes of fame. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2976-2988. [PMID: 25219551 DOI: 10.1016/j.bbamcr.2014.09.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/03/2014] [Accepted: 09/04/2014] [Indexed: 01/26/2023]
Abstract
Since their discovery in 1986, Ral (Ras-like) GTPases have emerged as critical regulators of diverse cellular functions. Ral-selective guanine nucleotide exchange factors (RalGEFs) function as downstream effectors of the Ras oncoprotein, and the RalGEF-Ral signaling network comprises the third best characterized effector of Ras-dependent human oncogenesis. Because of this, Ral GTPases as well as their effectors are being explored as possible therapeutic targets in the treatment of RAS mutant cancer. The two Ral isoforms, RalA and RalB, interact with a variety of downstream effectors and have been found to play key and distinct roles in both normal and neoplastic cell physiology including regulation of vesicular trafficking, migration and invasion, tumor formation, metastasis, and gene expression. In this review we provide an overview of Ral biochemistry and biology, and we highlight recent discoveries.
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Affiliation(s)
- Leanna R Gentry
- University of North Carolina at Chapel Hill, Department of Pharmacology, Chapel Hill, NC, USA
| | | | - David J Reiner
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Channing J Der
- University of North Carolina at Chapel Hill, Department of Pharmacology, Chapel Hill, NC, USA; University of North Carolina at Chapel Hill, Lineberger Comprehensive Cancer Center, Chapel Hill, NC, USA.
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41
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Personnic N, Lakisic G, Gouin E, Rousseau A, Gautreau A, Cossart P, Bierne H. A role for Ral GTPase-activating protein subunit β in mitotic regulation. FEBS J 2014; 281:2977-89. [PMID: 24814574 DOI: 10.1111/febs.12836] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 04/30/2014] [Accepted: 05/02/2014] [Indexed: 01/05/2023]
Abstract
Ral proteins are small GTPases that play critical roles in normal physiology and in oncogenesis. There is little information on the GTPase-activating proteins (GAPs) that downregulate their activity. Here, we provide evidence that the noncatalytic β subunit of RalGAPα1/2 β complexes is involved in mitotic control. RalGAPβ localizes to the Golgi and nucleus during interphase, and relocalizes to the mitotic spindle and cytokinetic intercellular bridge during mitosis. Depletion of RalGAPβ causes chromosome misalignment and decreases the amount of mitotic cyclin B1, disturbing the metaphase-to-anaphase transition. Overexpression of RalGAPβ interferes with cell division, leading to binucleation and multinucleation, and cell death. We propose that RalGAPβ plays an essential role in the sequential progression of mitosis by controlling the spatial and temporal activation of Ral GTPases in the spindle assembly checkpoint (SAC) and cytokinesis. Deregulation of RalGAPβ might cause genomic instability, leading to human carcinogenesis.
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Affiliation(s)
- Nicolas Personnic
- Institut Pasteur, Unité des interactions Bactéries cellules, Paris, France; Inserm, U604, Paris, France; INRA, USC2020, Paris, France
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42
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Sánchez-Molina S, Estarás C, Oliva JL, Akizu N, Asensio-Juan E, Rojas JM, Martínez-Balbás MA. Regulation of CBP and Tip60 coordinates histone acetylation at local and global levels during Ras-induced transformation. Carcinogenesis 2014; 35:2194-202. [DOI: 10.1093/carcin/bgu111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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43
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Ral and Rheb GTPase activating proteins integrate mTOR and GTPase signaling in aging, autophagy, and tumor cell invasion. Mol Cell 2014; 53:209-20. [PMID: 24389102 DOI: 10.1016/j.molcel.2013.12.004] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 11/11/2013] [Accepted: 11/27/2013] [Indexed: 01/01/2023]
Abstract
Diverse environmental cues converge on and are integrated by the mTOR signaling network to control cellular growth and homeostasis. The mammalian Tsc1-Tsc2 GTPase activating protein (GAP) heterodimer is a critical negative regulator of Rheb and mTOR activation. The RalGAPα-RalGAPβ heterodimer shares sequence and structural similarity with Tsc1-Tsc2. Unexpectedly, we observed that C. elegans expresses orthologs for the Rheb and RalA/B GTPases and for RalGAPα/β, but not Tsc1/2. This prompted our investigation to determine whether RalGAPs additionally modulate mTOR signaling. We determined that C. elegans RalGAP loss decreased lifespan, consistent with a Tsc-like function. Additionally, RalGAP suppression in mammalian cells caused RalB-selective activation and Sec5- and exocyst-dependent engagement of mTORC1 and suppression of autophagy. Unexpectedly, we also found that Tsc1-Tsc2 loss activated RalA/B independently of Rheb-mTOR signaling. Finally, RalGAP suppression caused mTORC1-dependent pancreatic tumor cell invasion. Our findings identify an unexpected crosstalk and integration of the Ral and mTOR signaling networks.
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44
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Lafaurie-Janvore J. [Temporal regulation of abscission, the last step of cell division]. Biol Aujourdhui 2013; 207:133-148. [PMID: 24103343 DOI: 10.1051/jbio/2013010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Indexed: 06/02/2023]
Abstract
Cell division is one of the most tightly controlled steps of the cell cycle. Indeed, the many steps of cell division have to be perfectly coordinated both in time and space in order to ensure an error-free division and an accurate transmission of the genome from the mother cell to the two daughter cells. Abscission, the last step of cytokinesis, consists in the severing of the intercellular bridge that connects the two daughter cells after the contraction of the acto-myosin ring. As is the case for any other step of cell division, abscission has to be precisely regulated in order to take place at the right time and the proper place. Whereas the spatial regulation of abscission is quite well understood, the study of temporal regulation is in its infancy. This review begins by describing the formation of the intercellular bridge, its organization, and its composition. Next the different models of abscission are discussed. Finally, the current understanding of the temporal regulation of abscission is detailed. In particular, I present my recent results on the role of forces exerted by the daughter cells on the intercellular bridge.
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45
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Telkoparan P, Erkek S, Yaman E, Alotaibi H, Bayık D, Tazebay UH. Coiled-coil domain containing protein 124 is a novel centrosome and midbody protein that interacts with the Ras-guanine nucleotide exchange factor 1B and is involved in cytokinesis. PLoS One 2013; 8:e69289. [PMID: 23894443 PMCID: PMC3716640 DOI: 10.1371/journal.pone.0069289] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 06/06/2013] [Indexed: 01/11/2023] Open
Abstract
Cytokinetic abscission is the cellular process leading to physical separation of two postmitotic sister cells by severing the intercellular bridge. The most noticeable structural component of the intercellular bridge is a transient organelle termed as midbody, localized at a central region marking the site of abscission. Despite its major role in completion of cytokinesis, our understanding of spatiotemporal regulation of midbody assembly is limited. Here, we report the first characterization of coiled-coil domain-containing protein-124 (Ccdc124), a eukaryotic protein conserved from fungi-to-man, which we identified as a novel centrosomal and midbody protein. Knockdown of Ccdc124 in human HeLa cells leads to accumulation of enlarged and multinucleated cells; however, centrosome maturation was not affected. We found that Ccdc124 interacts with the Ras-guanine nucleotide exchange factor 1B (RasGEF1B), establishing a functional link between cytokinesis and activation of localized Rap2 signaling at the midbody. Our data indicate that Ccdc124 is a novel factor operating both for proper progression of late cytokinetic stages in eukaryotes, and for establishment of Rap2 signaling dependent cellular functions proximal to the abscission site.
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Affiliation(s)
- Pelin Telkoparan
- Department of Molecular Biology and Genetics, Faculty of Science, Bilkent University, Ankara, Turkey
| | - Serap Erkek
- Department of Molecular Biology and Genetics, Faculty of Science, Bilkent University, Ankara, Turkey
| | - Elif Yaman
- Department of Molecular Biology and Genetics, Faculty of Science, Bilkent University, Ankara, Turkey
| | - Hani Alotaibi
- Department of Molecular Biology and Genetics, Faculty of Science, Bilkent University, Ankara, Turkey
| | - Defne Bayık
- Department of Molecular Biology and Genetics, Faculty of Science, Bilkent University, Ankara, Turkey
| | - Uygar H. Tazebay
- Department of Molecular Biology and Genetics, Faculty of Science, Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Gebze Institute of Technology, Kocaeli, Turkey
- * E-mail:
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46
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Ral GTPases in tumorigenesis: emerging from the shadows. Exp Cell Res 2013; 319:2337-42. [PMID: 23830877 DOI: 10.1016/j.yexcr.2013.06.020] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 06/18/2013] [Accepted: 06/26/2013] [Indexed: 01/03/2023]
Abstract
Oncogenic Ras proteins rely on a series of key effector pathways to drive the physiological changes that lead to tumorigenic growth. Of these effector pathways, the RalGEF pathway, which activates the two Ras-related GTPases RalA and RalB, remains the most poorly understood. This review will focus on key developments in our understanding of Ral biology, and will speculate on how aberrant activation of the multiple diverse Ral effector proteins might collectively contribute to oncogenic transformation and other aspects of tumor progression.
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47
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Affeldt S, Singh PP, Cascone I, Selimoglu R, Camonis J, Isambert H. [Evolution and cancer: expansion of dangerous gene repertoire by whole genome duplications]. Med Sci (Paris) 2013; 29:358-61. [PMID: 23621930 DOI: 10.1051/medsci/2013294008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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48
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Martin TD, Der CJ. Differential involvement of RalA and RalB in colorectal cancer. Small GTPases 2013; 3:126-30. [PMID: 22790202 PMCID: PMC3408977 DOI: 10.4161/sgtp.19571] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mutationally activated K-Ras can utilize a multitude of downstream effector proteins to promote oncogenesis. While the Raf and phosphoinositol 3-kinase effector pathways are the best-studied and validated, recent studies have established the critical importance of Ral guanine nucleotide exchange factor (RalGEF) activation of the RalA and RalB small GTPases in cancer biology. Due to recent evidence that the RalGEF-Ral pathway is necessary for the tumorigenic and metastatic potential of KRAS mutant pancreatic ductal adenocarcinoma (PDAC) tumor cells, we investigated whether or not Ral signaling was necessary for KRAS mutant colorectal cancer (CRC) tumor cell growth. As in PDAC, we found upregulated RalA and RalB activation in CRC tumor cell lines and tumors. Surprisingly we found antagonistic roles for RalA and RalB in the regulation of CRC tumor cell anchorage-independent growth. This observation contrasts with PDAC, where RalA but not RalB is necessary for PDAC tumor cell anchorage-independent growth. Our results emphasize cancer cell type differences in Ral function and hence the need for distinct Ral targeted therapeutic approaches in the treatment of CRC vs. PDAC.
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Affiliation(s)
- Timothy D Martin
- Deparment of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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49
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Deschamps C, Echard A, Niedergang F. Phagocytosis and cytokinesis: do cells use common tools to cut and to eat? Highlights on common themes and differences. Traffic 2013; 14:355-64. [PMID: 23331933 DOI: 10.1111/tra.12045] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 01/11/2013] [Accepted: 01/17/2012] [Indexed: 01/22/2023]
Abstract
Eukaryotic cells with specialized functions often use and adapt common molecular machineries. Recent findings have highlighted that actin polymerization, contractile activity and membrane remodelling with exocytosis of internal compartments are required both for successful phagocytosis, the internalization of particulate material and for cytokinesis, the last step of cell division. Phagocytosis is induced by the triggering of specific cell surface receptors, which leads to membrane deformation, pseudopod extension and contraction to engulf particles. Cytokinesis relies on intense contractile activity and eventually leads to the physical scission of sister cells. In this review, shared features of signalling, cytoskeletal reorganization and vesicular trafficking used in both phagocytosis and cytokinesis will be described, but non-common mechanisms and questions that remain open in these dynamic areas of research are also highlighted.
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50
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Leto D, Uhm M, Williams A, Chen XW, Saltiel AR. Negative regulation of the RalGAP complex by 14-3-3. J Biol Chem 2013; 288:9272-83. [PMID: 23386617 DOI: 10.1074/jbc.m112.426106] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RGC1 and RGC2 comprise a functional RalGAP complex (RGC) that suppresses RalA activity. The PI3-kinase/Akt signaling pathway activates RalA through phosphorylation-mediated inhibition of the RGC. Here we identify a novel phosphorylation-dependent interaction between 14-3-3 and the RGC. 14-3-3 binds to the complex through an Akt-phosphorylated residue, threonine 715, on RGC2. Interaction with 14-3-3 does not alter in vitro activity of the GTPase-activating protein complex. However, blocking the interaction between 14-3-3 and RGC2 in cells increases suppression of RalA activity by the RGC, suggesting that 14-3-3 inhibits the complex through a non-catalytic mechanism. Together, these data show that 14-3-3 negatively regulates the RGC downstream of the PI3-kinase/Akt signaling pathway.
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Affiliation(s)
- Dara Leto
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
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