1
|
Zhou M, Ren X, Yan X, Sun Y, Xu T. Rho-GDP-dissociation inhibitor-γ negatively regulates NF-κB signaling by promoting the degradation of TAK1 in miiuy croaker (Miichthys miiuy). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 135:104496. [PMID: 35870543 DOI: 10.1016/j.dci.2022.104496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 07/03/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
Transforming growth factor-beta activated kinase 1 (TAK1) is an adaptor molecular in TLR-mediated NF-κB signaling pathway and plays indispensable roles in innate immunity. As the most typical innate immune pathway, the strict regulation of NF-κB signaling pathway is particularly important. Rho-GDP-dissociation inhibitor-γ (Rho-GDIγ) is a member of the Rho protein family that regulates many important physiological processes. In this study, we demonstrated the mechanism of suppressing TAK1 expression in the teleost and found that Rho-GDIγ negatively regulated the NF-κB signaling pathway mediated by TAK1. We determined that TAK1 could directly interact with Rho-GDIγ. It is interesting that Rho-GDIγ promotes TAK1 degradation through the ubiquitin proteasome pathway. This study brings a new experimental basis to the teleost fish innate immune signaling pathway. Moreover, this discovery may provide new insights into innate immune regulation mechanism in mammals.
Collapse
Affiliation(s)
- Ming Zhou
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Xiaomeng Ren
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Xiaolong Yan
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Yuena Sun
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai, 201306, China.
| | - Tianjun Xu
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai, 201306, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai, 201306, China.
| |
Collapse
|
2
|
Ahmad Mokhtar AM, Ahmed SBM, Darling NJ, Harris M, Mott HR, Owen D. A Complete Survey of RhoGDI Targets Reveals Novel Interactions with Atypical Small GTPases. Biochemistry 2021; 60:1533-1551. [PMID: 33913706 PMCID: PMC8253491 DOI: 10.1021/acs.biochem.1c00120] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/16/2021] [Indexed: 01/07/2023]
Abstract
There are three RhoGDIs in mammalian cells, which were initially defined as negative regulators of Rho family small GTPases. However, it is now accepted that RhoGDIs not only maintain small GTPases in their inactive GDP-bound form but also act as chaperones for small GTPases, targeting them to specific intracellular membranes and protecting them from degradation. Studies to date with RhoGDIs have usually focused on the interactions between the "typical" or "classical" small GTPases, such as the Rho, Rac, and Cdc42 subfamily members, and either the widely expressed RhoGDI-1 or the hematopoietic-specific RhoGDI-2. Less is known about the third member of the family, RhoGDI-3 and its interacting partners. RhoGDI-3 has a unique N-terminal extension and is found to localize in both the cytoplasm and the Golgi. RhoGDI-3 has been shown to target RhoB and RhoG to endomembranes. In order to facilitate a more thorough understanding of RhoGDI function, we undertook a systematic study to determine all possible Rho family small GTPases that interact with the RhoGDIs. RhoGDI-1 and RhoGDI-2 were found to have relatively restricted activity, mainly binding members of the Rho and Rac subfamilies. RhoGDI-3 displayed wider specificity, interacting with the members of Rho, Rac, and Cdc42 subfamilies but also forming complexes with "atypical" small Rho GTPases such as Wrch2/RhoV, Rnd2, Miro2, and RhoH. Levels of RhoA, RhoB, RhoC, Rac1, RhoH, and Wrch2/RhoV bound to GTP were found to decrease following coexpression with RhoGDI-3, confirming its role as a negative regulator of these small Rho GTPases.
Collapse
Affiliation(s)
| | | | | | | | - Helen R. Mott
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, United Kingdom
| | - Darerca Owen
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, United Kingdom
| |
Collapse
|
3
|
Effect of the Rho GTPase inhibitor-1 on the entry of dengue serotype 2 virus into EAhy926 cells. Mol Biol Rep 2020; 47:9739-9747. [PMID: 33200314 DOI: 10.1007/s11033-020-05980-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023]
Abstract
Dengue virus (DV) is the most rapidly spreading arbovirus in the world. Our previous studies indicated that Rac1, a kind of Rho GTPase, was related with the increased vascular permeability in DV infection. However, the molecular mechanisms that regulate the activity of the Rac1 pathway during DV infection is not fully understood yet. Recently, Rho-specific guanine nucleotide dissociated inhibitors (Rho GDIs), as a pivotal upstream regulator of Rho GTPase, attract our attention. To identify the role of GDI-1 in DV2 infection, the expression of GDI in Eahy926 cells was detected. Moreover, a GDI-1 down-regulated cell line was constructed to explore the correlation between GDI-1 and Rac1 and to further evaluate the function of GDI in DV life cycle. Our results indicated that DV2 infection could up-regulate GDI-1 expression, and down-regulation of GDI enhanced the activity of Rac1. In addition, down-regulated GDI-1 significantly inhibited all steps of DV2 replication cycle. GDI-1 plays an important role in DV2 infection via negatively regulating the activation of the Rac1-actin pathway. These results not only contribute to our further understanding of the pathogenesis of severe dengue but also provide further insight into the development of antiviral drugs.
Collapse
|
4
|
Cho HJ, Ryu KJ, Baek KE, Lim J, Kim T, Song CY, Yoo J, Lee HG. Cullin 3/KCTD5 Promotes the Ubiqutination of Rho Guanine Nucleotide Dissociation Inhibitor 1 and Regulates Its Stability. J Microbiol Biotechnol 2020; 30:1488-1494. [PMID: 32876072 PMCID: PMC9728164 DOI: 10.4014/jmb.2007.07033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/15/2022]
Abstract
Rho guanine nucleotide dissociation inhibitor 1 (RhoGDI1) plays important roles in numerous cellular processes, including cell motility, adhesion, and proliferation, by regulating the activity of Rho GTPases. Its expression is altered in various human cancers and is associated with malignant progression. Here, we show that RhoGDI1 interacts with Cullin 3 (CUL3), a scaffold protein for E3 ubiquitin ligase complexes. Ectopic expression of CUL3 increases the ubiquitination of RhoGDI1. Furthermore, potassium channel tetramerization domain containing 5 (KCTD5) also binds to RhoGDI1 and increases its interaction with CUL3. Ectopic expression of KCTD5 increases the ubiquitination of RhoGDI1, whereas its knockdown by RNA interference has the opposite effect. Depletion of KCTD5 or expression of dominant-negative CUL3 (DN-CUL3) enhances the stability of RhoGDI1. Our findings reveal a previously unknown mechanism for controlling RhoGDI1 degradation that involves a CUL3/KCTD5 ubiquitin ligase complex.
Collapse
Affiliation(s)
- Hee Jun Cho
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Ki-Jun Ryu
- Division of Applied Life Science, Research Institute of Life Sciences, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Kyoung Eun Baek
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Jeewon Lim
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Taeyoung Kim
- Division of Applied Life Science, Research Institute of Life Sciences, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Chae Yeong Song
- Division of Applied Life Science, Research Institute of Life Sciences, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Jiyun Yoo
- Division of Applied Life Science, Research Institute of Life Sciences, Gyeongsang National University, Jinju 52828, Republic of Korea,J.Y. Phone: +82-55-772-1327 Fax: +82-55-772-2553 E-mail:
| | - Hee Gu Lee
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea,Corresponding authors H.G.L. Phone: +82-42-860-4182 Fax: +82-42-860-4593 E-mail:
| |
Collapse
|
5
|
Humphries BA, Wang Z, Yang C. MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis. Cancers (Basel) 2020; 12:E1092. [PMID: 32353968 PMCID: PMC7281527 DOI: 10.3390/cancers12051092] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/24/2020] [Accepted: 04/25/2020] [Indexed: 02/07/2023] Open
Abstract
The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.
Collapse
Affiliation(s)
- Brock A. Humphries
- Center for Molecular Imaging, Department of Radiology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Zhishan Wang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
| | - Chengfeng Yang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
| |
Collapse
|
6
|
Cho HJ, Kim JT, Baek KE, Kim BY, Lee HG. Regulation of Rho GTPases by RhoGDIs in Human Cancers. Cells 2019; 8:cells8091037. [PMID: 31492019 PMCID: PMC6769525 DOI: 10.3390/cells8091037] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 12/15/2022] Open
Abstract
Rho GDP dissociation inhibitors (RhoGDIs) play important roles in various cellular processes, including cell migration, adhesion, and proliferation, by regulating the functions of the Rho GTPase family. Dissociation of Rho GTPases from RhoGDIs is necessary for their spatiotemporal activation and is dynamically regulated by several mechanisms, such as phosphorylation, sumoylation, and protein interaction. The expression of RhoGDIs has changed in many human cancers and become associated with the malignant phenotype, including migration, invasion, metastasis, and resistance to anticancer agents. Here, we review how RhoGDIs control the function of Rho GTPases by regulating their spatiotemporal activity and describe the regulatory mechanisms of the dissociation of Rho GTPases from RhoGDIs. We also discuss the role of RhoGDIs in cancer progression and their potential uses for therapeutic intervention.
Collapse
Affiliation(s)
- Hee Jun Cho
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea.
| | - Jong-Tae Kim
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea.
| | - Kyoung Eun Baek
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea.
| | - Bo-Yeon Kim
- Anticancer Cancer Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea.
| | - Hee Gu Lee
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea.
- Department of Biomolecular Science, University of Science and Technology (UST), Daejeon 34141, Korea.
| |
Collapse
|
7
|
Møller LLV, Klip A, Sylow L. Rho GTPases-Emerging Regulators of Glucose Homeostasis and Metabolic Health. Cells 2019; 8:E434. [PMID: 31075957 PMCID: PMC6562660 DOI: 10.3390/cells8050434] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/11/2022] Open
Abstract
Rho guanosine triphosphatases (GTPases) are key regulators in a number of cellular functions, including actin cytoskeleton remodeling and vesicle traffic. Traditionally, Rho GTPases are studied because of their function in cell migration and cancer, while their roles in metabolism are less documented. However, emerging evidence implicates Rho GTPases as regulators of processes of crucial importance for maintaining metabolic homeostasis. Thus, the time is now ripe for reviewing Rho GTPases in the context of metabolic health. Rho GTPase-mediated key processes include the release of insulin from pancreatic β cells, glucose uptake into skeletal muscle and adipose tissue, and muscle mass regulation. Through the current review, we cast light on the important roles of Rho GTPases in skeletal muscle, adipose tissue, and the pancreas and discuss the proposed mechanisms by which Rho GTPases act to regulate glucose metabolism in health and disease. We also describe challenges and goals for future research.
Collapse
Affiliation(s)
- Lisbeth Liliendal Valbjørn Møller
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100 Copenhagen Oe, Denmark.
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100 Copenhagen Oe, Denmark.
| |
Collapse
|
8
|
Cho HJ, Kim JT, Lee SJ, Hwang YS, Park SY, Kim BY, Yoo J, Hong KS, Min JK, Lee CH, Lim JS, Yoon SR, Choi I, Choe YK, Lee HG. Protein phosphatase 1B dephosphorylates Rho guanine nucleotide dissociation inhibitor 1 and suppresses cancer cell migration and invasion. Cancer Lett 2018; 417:141-151. [DOI: 10.1016/j.canlet.2018.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 12/20/2017] [Accepted: 01/03/2018] [Indexed: 12/21/2022]
|
9
|
Cho HJ, Hwang YS, Yoon J, Lee M, Lee HG, Daar IO. EphrinB1 promotes cancer cell migration and invasion through the interaction with RhoGDI1. Oncogene 2017; 37:861-872. [PMID: 29059157 PMCID: PMC5814325 DOI: 10.1038/onc.2017.386] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 12/20/2022]
Abstract
Eph receptors and their corresponding ephrin ligands have been associated with regulating cell–cell adhesion and motility, and thus have a critical role in various biological processes including tissue morphogenesis and homeostasis, as well as pathogenesis of several diseases. Aberrant regulation of Eph/ephrin signaling pathways is implicated in tumor progression of various human cancers. Here, we show that a Rho family GTPase regulator, Rho guanine nucleotide dissociation inhibitor 1 (RhoGDI1), can interact with ephrinB1, and this interaction is enhanced upon binding the extracellular domain of the cognate EphB2 receptor. Deletion mutagenesis revealed that amino acids 327–334 of the ephrinB1 intracellular domain are critical for the interaction with RhoGDI1. Stimulation with an EphB2 extracellular domain-Fc fusion protein (EphB2-Fc) induces RhoA activation and enhances the motility as well as invasiveness of wild-type ephrinB1-expressing cells. These Eph-Fc-induced effects were markedly diminished in cells expressing the mutant ephrinB1 construct (Δ327–334) that is ineffective at interacting with RhoGDI1. Furthermore, ephrinB1 depletion by siRNA suppresses EphB2-Fc-induced RhoA activation, and reduces motility and invasiveness of the SW480 and Hs578T human cancer cell lines. Our study connects the interaction between RhoGDI1 and ephrinB1 to the promotion of cancer cell behavior associated with tumor progression. This interaction may represent a therapeutic target in cancers that express ephrinB1.
Collapse
Affiliation(s)
- H J Cho
- Immunotherapy Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong-gu, Daejeon, Korea.,Cancer & Developmental Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - Y-S Hwang
- Cancer & Developmental Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - J Yoon
- Cancer & Developmental Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - M Lee
- Cancer & Developmental Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - H G Lee
- Immunotherapy Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong-gu, Daejeon, Korea
| | - I O Daar
- Cancer & Developmental Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| |
Collapse
|
10
|
Activating Transcription Factor 4 (ATF4) modulates Rho GTPase levels and function via regulation of RhoGDIα. Sci Rep 2016; 6:36952. [PMID: 27841340 PMCID: PMC5107905 DOI: 10.1038/srep36952] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/21/2016] [Indexed: 01/21/2023] Open
Abstract
In earlier studies, we showed that ATF4 down-regulation affects post-synaptic development and dendritic spine morphology in neurons through increased turnover of the Rho GTPase Cell Division Cycle 42 (Cdc42) protein. Here, we find that ATF4 down-regulation in both hippocampal and cortical neuron cultures reduces protein and message levels of RhoGDIα, a stabilizer of the Rho GTPases including Cdc42. This effect is rescued by an shATF4-resistant active form of ATF4, but not by a mutant that lacks transcriptional activity. This is, at least in part, due to the fact that Arhgdia, the gene encoding RhoGDIα, is a direct transcriptional target of ATF4 as is shown in ChIP assays. This pathway is not restricted to neurons. This is seen in an impairment of cell migration on ATF4 reduction in non-neuronal cells. In conclusion, we have identified a new cellular pathway in which ATF4 regulates the expression of RhoGDIα that in turn affects Rho GTPase protein levels, and thereby, controls cellular functions as diverse as memory and cell motility.
Collapse
|
11
|
de León-Bautista MP, Cardenas-Aguayo MDC, Casique-Aguirre D, Almaraz-Salinas M, Parraguirre-Martinez S, Olivo-Diaz A, Thompson-Bonilla MDR, Vargas M. Immunological and Functional Characterization of RhoGDI3 and Its Molecular Targets RhoG and RhoB in Human Pancreatic Cancerous and Normal Cells. PLoS One 2016; 11:e0166370. [PMID: 27832197 PMCID: PMC5104321 DOI: 10.1371/journal.pone.0166370] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 10/27/2016] [Indexed: 11/19/2022] Open
Abstract
RhoGDI proteins have been implicated in several human cancers; changes in their expression levels have shown pro- or anti-tumorigenic effects. Pancreatic Ductal Adenocarcinoma (PDAC) is a complex pathology, with poor prognosis, and most patients die shortly after diagnosis. Efforts have been focused on understanding the role of RhoGDI's in PDAC, specially, RhoGDI1 and RhoGDI2. However, the role of RhoGDI3 has not been studied in relation to cancer or to PDAC. Here, we characterized the expression and functionality of RhoGDI3 and its target GTPases, RhoG and RhoB in pancreatic cell lines from both normal pancreatic tissue and tissue in late stages of PDAC, and compared them to human biopsies. Through immunofluorescences, pulldown assays and subcellular fractionation, we found a reduction in RhoGDI3 expression in the late stages of PDAC, and this reduction correlates with tumor progression and aggressiveness. Despite the reduction in the expression of RhoGDI3 in PDAC, we found that RhoB was underexpressed while RhoG was overexpressed, suggesting that cancerous cells preserve their capacity to activate this pathway, thus these cells may be more eager to response to the stimuli needed to proliferate and become invasive unlike normal cells. Surprisingly, we found nuclear localization of RhoGDI3 in non-cancerous pancreatic cell line and normal pancreatic tissue biopsies, which could open the possibility of novel nuclear functions for this protein, impacting gene expression regulation and cellular homeostasis.
Collapse
Affiliation(s)
- Mercedes Piedad de León-Bautista
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, col. San Pedro Zacatenco, C.P. 07360, Mexico City, Mexico
| | - Maria del Carmen Cardenas-Aguayo
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Col. Copilco Universidad, Delegación Coyoacán, C.P. 04510, Mexico City, Mexico
| | - Diana Casique-Aguirre
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, col. San Pedro Zacatenco, C.P. 07360, Mexico City, Mexico
| | - Manuel Almaraz-Salinas
- Facultad de Bioquímica, Instituto Tecnológico de Milpa Alta, Independencia Sur 36, San Salvador Cuauhtenco, Milpa Alta, 12300, Mexico City, Mexico
| | - Sara Parraguirre-Martinez
- Departamento de Anatomía Patológica, Hospital General Doctor Manuel Gea González, Av. Calzada de Tlalpan 4800, Tlalpan, Sección XVI, 14080, Mexico City, Mexico
| | - Angelica Olivo-Diaz
- Departamento de Biología Molecular e Histocompatibilidad, Hospital Doctor Manuel Gea González, Av. Calzada de Tlalpan 4800, Tlalpan, Sección XVI, 14080, Mexico City, Mexico
| | - María del Rocío Thompson-Bonilla
- Investigación Biomédica y Traslacional, Laboratorio de Medicina Genómica, Hospital 1° de Octubre, ISSSTE, Av. Instituto Politécnico Nacional No. 1669, Colonia: Magdalena de las Salinas, Delegación: Gustavo A Madero, 07760, Mexico City, Mexico
| | - Miguel Vargas
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, col. San Pedro Zacatenco, C.P. 07360, Mexico City, Mexico
- * E-mail:
| |
Collapse
|
12
|
Fujiwara M, Okamoto M, Hori M, Suga H, Jikihara H, Sugihara Y, Shimamoto F, Mori T, Nakaoji K, Hamada K, Ota T, Wiedemuth R, Temme A, Tatsuka M. Radiation-Induced RhoGDIβ Cleavage Leads to Perturbation of Cell Polarity: A Possible Link to Cancer Spreading. J Cell Physiol 2016; 231:2493-505. [DOI: 10.1002/jcp.25362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 02/23/2016] [Indexed: 01/17/2023]
Affiliation(s)
- Mamoru Fujiwara
- Faculty of Life and Environmental Sciences; Department of Life Sciences; Prefectural University of Hiroshima; Shoubara Hiroshima Japan
| | - Mayumi Okamoto
- Faculty of Life and Environmental Sciences; Department of Life Sciences; Prefectural University of Hiroshima; Shoubara Hiroshima Japan
| | - Masato Hori
- Faculty of Life and Environmental Sciences; Department of Life Sciences; Prefectural University of Hiroshima; Shoubara Hiroshima Japan
| | - Hiroshi Suga
- Faculty of Life and Environmental Sciences; Department of Life Sciences; Prefectural University of Hiroshima; Shoubara Hiroshima Japan
| | - Hiroshi Jikihara
- Department of Health Sciences; Faculty of Human Culture and Science; Prefectural University of Hiroshima; Minami-ku Hiroshima Japan
| | - Yuka Sugihara
- Department of Health Sciences; Faculty of Human Culture and Science; Prefectural University of Hiroshima; Minami-ku Hiroshima Japan
| | - Fumio Shimamoto
- Department of Health Sciences; Faculty of Human Culture and Science; Prefectural University of Hiroshima; Minami-ku Hiroshima Japan
| | - Toshio Mori
- Radioisotope Research Center; Nara Medical University School of Medicine; Kashihara Nara Japan
| | - Koichi Nakaoji
- Research & Development Division; Pias Corporation; Kobe Japan
| | - Kazuhiko Hamada
- Research & Development Division; Pias Corporation; Kobe Japan
| | - Takahide Ota
- Department of Life Science; Medical Research Institute; Kanazawa Medical University; Uchinada Ishikawa Japan
| | - Ralf Wiedemuth
- Department of Neurosurgery; University Hospital Carl Gustav Carus; Technical University Dresden; Dresden Germany
| | - Achim Temme
- Department of Neurosurgery; University Hospital Carl Gustav Carus; Technical University Dresden; Dresden Germany
| | - Masaaki Tatsuka
- Faculty of Life and Environmental Sciences; Department of Life Sciences; Prefectural University of Hiroshima; Shoubara Hiroshima Japan
| |
Collapse
|
13
|
Zamanian–Azodi M, Rezaei-Tavirani M, Rahmati-Rad S, Rezaei Tavirani M. Ethanol and Cancer Induce Similar Changes on Protein Expression Pattern of Human Fibroblast Cell. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2016; 15:175-184. [PMID: 28228815 PMCID: PMC5242363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ethanol has a vast consumption around the world. Many researches confirmed some adverse effect of this component on human health. In addition, recent studies showed significant alteration in both cellular population, and protein profile of human foreskin fibroblast cell line (HFFF2) in the specific dosage of ethanol. Here, the role and interaction of some proteins (characterized by significant alteration in expression due to ethanol effect) analyzed by proteomics and evaluated by considering cancerous case. 2D-electrophoresis findings of comparison of normal fibroblast cells and treated fibroblast with 270 mM dosage of ethanol analyzed by using SameSpots software, R software, and Cytoscape for protein-protein interaction (PPI) investigation. Six proteins with significantly altered expression associated with fundamental properties in a cell identified in ethanol-treated sample. These include AnnexinA5, Heterogeneous nuclear ribonucleoprotein A1, Rho-GDP dissociation inhibitor, Cathepsin L, Cu/Zn-SOD, Rho-GDP dissociation inhibitor, and Serpin peptidase inhibitor. Surprisingly, all these proteins were down-regulated and this pattern is similar to nasopharyngeal carcinoma-associated stromal fibroblast sample. Additionally, protein-protein interaction (PPI) indicates that HNRNPA1, SERPINE1 are hub proteins. Once their expression alters, it can impose vast changes on other molecular function. Based on this approach, ethanol may target same pathways that are related to cancer onset. In addition, some epidemiologic studies proved that ethanol consumption is related to increment of cancer risk. Therefore, more investigation is required in this regard to elicit the feasible relationship.
Collapse
Affiliation(s)
- Mona Zamanian–Azodi
- Proteomics Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | | | - Sara Rahmati-Rad
- Department of Cell and Molecular Biology, Faculty of Science, University of Tehran, Tehran, Iran.
| | | |
Collapse
|
14
|
TAT-RhoGDI2, a novel tumor metastasis suppressor fusion protein: expression, purification and functional evaluation. Appl Microbiol Biotechnol 2014; 98:9633-41. [DOI: 10.1007/s00253-014-6021-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 05/13/2014] [Accepted: 05/15/2014] [Indexed: 01/03/2023]
|
15
|
Li W, Wang H, Jin X, Zhao L. Loss of RhoGDI is a novel independent prognostic factor in hepatocellular carcinoma. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2013; 6:2535-2541. [PMID: 24228117 PMCID: PMC3816824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 10/12/2013] [Indexed: 06/02/2023]
Abstract
RhoGDI (Rho GDP-dissociation inhibitor alpha or RhoGDIα) has been identified as a regulator of Rho GTPases, which are essential for tumor progression, but its role in cancer remains controversial and little is known in hepatocellular carcinoma (HCC). Using immunohistochemistry, we analyzed RhoGDI expression in 147 clinicopathologically characterized HCC cases. RhoGDI expression was detected in cytoplasm of HCC tissues. Statistical analysis showed that there was no relationship between RhoGDI expression and clinicopathological features. Importantly, a significant trend was identified between loss of RhoGDI expression in HCC and worsening clinical prognosis. Multivariate survival analysis showed that negative RhoGDI expression was recognized as an independent prognostic factor of patient's survival. Our results suggest that RhoGDI protein is a valuable marker of prognosis for patients with HCC.
Collapse
Affiliation(s)
- Weidong Li
- Department of Medical Oncology, Affiliated Tumor Hospital of Guangzhou Medical UniversityGuangzhou, China
| | - Hui Wang
- Department of Medical Oncology, Affiliated Tumor Hospital of Guangzhou Medical UniversityGuangzhou, China
| | - Xuejun Jin
- Department of Medical Oncology, Affiliated Tumor Hospital of Guangzhou Medical UniversityGuangzhou, China
| | - Liang Zhao
- Department of Pathology, Nanfang Hospital, Southern Medical UniversityGuangzhou, China
- Department of Pathology, School of Basic Medical Sciences, Southern Medical UniversityGuangzhou, China
| |
Collapse
|
16
|
Pu J, Mao Y, Lei X, Yan Y, Lu X, Tian J, Yin X, Zhao G, Zhang B. FERM domain containing protein 7 interacts with the Rho GDP dissociation inhibitor and specifically activates Rac1 signaling. PLoS One 2013; 8:e73108. [PMID: 23967341 PMCID: PMC3742540 DOI: 10.1371/journal.pone.0073108] [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: 12/24/2012] [Accepted: 07/18/2013] [Indexed: 11/28/2022] Open
Abstract
The FERM domain containing protein 7 gene (FRMD7) associated with the X-linked disorder idiopathic congenital nystagmus (ICN) is involved in the regulation of neurite elongation during neuronal development. Members of the Rho family of small G-proteins (Rho GTPases) are key regulators of the actin cytoskeleton and are implicated in the control of neuronal morphology. The Rho GDP dissociation inhibitor alpha, RhoGDIα, the main regulator of Rho GTPases, can form a complex with the GDP-bound form of Rho GTPases and inhibit their activation. Here, we demonstrate that the full length of the mouse FRMD7, rather than the N-terminus or the C-terminus alone, directly interacts with RhoGDIα and specifically initiates Rac1 signaling in mouse neuroblastoma cell line (neuro-2a). Moreover, we show that wild-type human FRMD7 protein is able to activate Rac1 signaling by interacting with RhoGDIα and releasing Rac1 from Rac1-RhoGDIα complex. However, two missense mutations (c.781C>G and c.886G>C) of human FRMD7 proteins weaken the ability to interact with RhoGDIα and release less Rac1, that induce the activation of Rac1 to a lesser degree; while an additional mutant, c.1003C>T, which results in a C-terminal truncated protein, almost fails to interact with RhoGDIα and to activate Rac1 signaling. Collectively, these results suggest that FRMD7 interacts with one of the Rho GTPase regulators, RhoGDIα, and activates the Rho subfamily member Rac1, which regulates reorganization of actin filaments and controls neuronal outgrowth. We predict that human mutant FRMD7 thus influences Rac1 signaling activation, which can lead to abnormal neuronal outgrowth and cause the X-linked ICN.
Collapse
Affiliation(s)
- Jiali Pu
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yanfang Mao
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoguang Lei
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yaping Yan
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoxiong Lu
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jun Tian
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xinzhen Yin
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Guohua Zhao
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Baorong Zhang
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- * E-mail:
| |
Collapse
|
17
|
Abstract
RhoGDI2 is a guanine nucleotide dissociation inhibitor (GDI) specific for the Rho family of small GTPases that plays dual opposite roles in tumor progression, being both a promoter in tissues such as breast and a metastasis suppressor in tissues such as the bladder. Despite a clear role for this protein in modulating the invasive and metastatic process, the mechanisms through which RhoGDI2 executes these functions remain unclear. This review will highlight the current state of our knowledge regarding how RhoGDI2 functions in metastasis with a focus on bladder cancer and will also seek to highlight other potential underappreciated avenues through which this protein may affect cancer cell behavior.
Collapse
Affiliation(s)
- Erin M Griner
- Center for Cell Signaling and Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | | |
Collapse
|
18
|
Sabbatini ME, Williams JA. Cholecystokinin-mediated RhoGDI phosphorylation via PKCα promotes both RhoA and Rac1 signaling. PLoS One 2013; 8:e66029. [PMID: 23776598 PMCID: PMC3679036 DOI: 10.1371/journal.pone.0066029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Accepted: 05/07/2013] [Indexed: 01/18/2023] Open
Abstract
RhoA and Rac1 have been implicated in the mechanism of CCK-induced amylase secretion from pancreatic acini. In all cell types studied to date, inactive Rho GTPases are present in the cytosol bound to the guanine nucleotide dissociation inhibitor RhoGDI. Here, we identified the switch mechanism regulating RhoGDI1-Rho GTPase dissociation and RhoA translocation upon CCK stimulation in pancreatic acini. We found that both Gα13 and PKC, independently, regulate CCK-induced RhoA translocation and that the PKC isoform involved is PKCα. Both RhoGDI1 and RhoGDI3, but not RhoGDI2, are expressed in pancreatic acini. Cytosolic RhoA and Rac1 are associated with RhoGDI1, and CCK-stimulated PKCα activation releases the complex. Overexpression of RhoGDI1, by binding RhoA, inhibits its activation, and thereby, CCK-induced apical amylase secretion. RhoA translocation is also inhibited by RhoGDI1. Inactive Rac1 influences CCK-induced RhoA activation by preventing RhoGDI1 from binding RhoA. By mutational analysis we found that CCK-induced PKCα phosphorylation on RhoGDI1 at Ser96 releases RhoA and Rac1 from RhoGDI1 to facilitate Rho GTPases signaling.
Collapse
Affiliation(s)
- Maria Eugenia Sabbatini
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America.
| | | |
Collapse
|
19
|
Wang J, Hu F, Cheng H, Zhao XM, Wen T. A systems biology approach to identify the signalling network regulated by Rho-GDI-γ during neural stem cell differentiation. MOLECULAR BIOSYSTEMS 2013; 8:2916-23. [PMID: 22892720 DOI: 10.1039/c2mb25147g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Understanding the molecular mechanism that underlies the differentiation of neural stem cells (NSCs) is vital to develop regenerative medicines for neurological disorders. In our previous work, Rho-GDI-γ was found to be able to prompt neuronal differentiation when it was down regulated. However, it is unclear how Rho-GDI-γ regulates this differentiation process. Therefore, a novel systems biology approach is presented here to identify putative signalling pathways regulated by Rho-GDI-γ during NSC differentiation, and these pathways can provide insights into the NSC differentiation mechanisms. In particular, our proposed approach combines the predictive power of computational biology and molecular experiments. With different biological experiments, the genes in the computationally identified signalling network were validated to be indeed regulated by Rho-GDI-γ during the differentiation of NSCs. In particular, one randomly selected pathway involving Vcp, Mapk8, Ywhae and Ywhah was experimentally verified to be regulated by Rho-GDI-γ. These promising results demonstrate the effectiveness of our proposed systems biology approach, indicating the potential predictive power of integrating computational and experimental approaches.
Collapse
Affiliation(s)
- Jiao Wang
- Institute of Systems Biology, Shanghai University, Shanghai 200444, China
| | | | | | | | | |
Collapse
|
20
|
Jiang YS, Maeda M, Okamoto M, Fujii M, Fukutomi R, Hori M, Tatsuka M, Ota T. Centrosomal localization of RhoGDIβ and its relevance to mitotic processes in cancer cells. Int J Oncol 2012; 42:460-8. [PMID: 23232495 PMCID: PMC3583720 DOI: 10.3892/ijo.2012.1730] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 11/16/2012] [Indexed: 12/15/2022] Open
Abstract
Rho GDP-dissociation inhibitors (RhoGDIs) are regulators of Rho family GTPases. RhoGDIβ has been implicated in cancer progression, but its precise role remains unclear. We determined the subcellular localization of RhoGDIβ and examined the effects of its overexpression and RNAi knockdown in cancer cells. Immunofluorescence staining showed that RhoGDIβ localized to centrosomes in human cancer cells. In HeLa cells, exogenous GFP-tagged RhoGDIβ localized to centrosomes and its overexpression caused prolonged mitosis and aberrant cytokinesis in which the cell shape was distorted. RNAi knockdown of RhoGDIβ led to increased incidence of monopolar spindle mitosis resulting in polyploid cells. These results suggest that RhoGDIβ has mitotic functions, including regulation of cytokinesis and bipolar spindle formation. The dysregulated expression of RhoGDIβ may contribute to cancer progression by disrupting these processes.
Collapse
Affiliation(s)
- Yong-Sheng Jiang
- Division of Tumor Biology, Department of Life Science, Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Brymora A, Duggin IG, Berven LA, van Dam EM, Roufogalis BD, Robinson PJ. Identification and characterisation of the RalA-ERp57 interaction: evidence for GDI activity of ERp57. PLoS One 2012; 7:e50879. [PMID: 23226417 PMCID: PMC3511393 DOI: 10.1371/journal.pone.0050879] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 10/25/2012] [Indexed: 01/03/2023] Open
Abstract
RalA is a membrane-associated small GTPase that regulates vesicle trafficking. Here we identify a specific interaction between RalA and ERp57, an oxidoreductase and signalling protein. ERp57 bound specifically to the GDP-bound form of RalA, but not the GTP-bound form, and inhibited the dissociation of GDP from RalA in vitro. These activities were inhibited by reducing agents, but no disulphide bonds were detected between RalA and ERp57. Mutation of all four of ERp57’s active site cysteine residues blocked sensitivity to reducing agents, suggesting that redox-dependent conformational changes in ERp57 affect binding to RalA. Mutations in the switch II region of the GTPase domain of RalA specifically reduced or abolished binding to ERp57, but did not block GTP-specific binding to known RalA effectors, the exocyst and RalBP1. Oxidative treatment of A431 cells with H2O2 inhibited cellular RalA activity, and the effect was exacerbated by expression of recombinant ERp57. The oxidative treatment significantly increased the amount of RalA localised to the cytosol. These findings suggest that ERp57 regulates RalA signalling by acting as a redox-sensitive guanine-nucleotide dissociation inhibitor (RalGDI).
Collapse
Affiliation(s)
- Adam Brymora
- Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Iain G. Duggin
- Faculty of Pharmacy, The University of Sydney, Sydney, Australia
| | - Leise A. Berven
- Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Sydney, Australia
| | - Ellen M. van Dam
- Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Sydney, Australia
| | | | - Phillip J. Robinson
- Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Sydney, Australia
- * E-mail:
| |
Collapse
|
22
|
Regulation of neural stem cell differentiation by transcription factors HNF4-1 and MAZ-1. Mol Neurobiol 2012; 47:228-40. [PMID: 22944911 DOI: 10.1007/s12035-012-8335-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 08/16/2012] [Indexed: 10/27/2022]
Abstract
Neural stem cells (NSCs) are promising candidates for a variety of neurological diseases due to their ability to differentiate into neurons, astrocytes, and oligodentrocytes. During this process, Rho GTPases are heavily involved in neuritogenesis, axon formation and dendritic development, due to their effects on the cytoskeleton through downstream effectors. The activities of Rho GTPases are controlled by Rho-GDP dissociation inhibitors (Rho-GDIs). As shown in our previous study, these are also involved in the differentiation of NSCs; however, little is known about the underlying regulatory mechanism. Here, we describe how the transcription factors hepatic nuclear factor (HNF4-1) and myc-associated zinc finger protein (MAZ-1) regulate the expression of Rho-GDIγ in the stimulation of NSC differentiation. Using a transfection of cis-element double-stranded oligodeoxynucleotides (ODNs) strategy, referred to as "decoy" ODNs, we examined the effects of HNF4-1 and MAZ-1 on NSC differentiation in the NSC line C17.2. Our results show that HNF4-1 and MAZ-1 decoy ODNs significantly knock down Rho-GDIγ gene transcription, leading to NSC differentiation towards neurons. We observed that HNF4-1 and MAZ-1 decoy ODNs are able enter to the cell nucleolus and specifically bind to their target transcription factors. Furthermore, the expression of Rho-GDIγ-mediated genes was identified, suggesting that the regulatory mechanism for the differentiation of NSCs is triggered by the transcription factors MAZ-1 and HNF4-1. These findings indicate that HNF4-1 and MAZ-1 regulate the expression of Rho-GDIγ and contribute to the differentiation of NSCs. Our findings provide a new perspective within regulatory mechanism research during differentiation of NSCs, especially the clinical application of transcription factor decoys in vivo, suggesting potential therapeutic strategies for neurodegenerative disease.
Collapse
|
23
|
Gonzalez-Billault C, Muñoz-Llancao P, Henriquez DR, Wojnacki J, Conde C, Caceres A. The role of small GTPases in neuronal morphogenesis and polarity. Cytoskeleton (Hoboken) 2012; 69:464-85. [PMID: 22605667 DOI: 10.1002/cm.21034] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 04/12/2012] [Accepted: 04/16/2012] [Indexed: 12/21/2022]
Abstract
The highly dynamic remodeling and cross talk of the microtubule and actin cytoskeleton support neuronal morphogenesis. Small RhoGTPases family members have emerged as crucial regulators of cytoskeletal dynamics. In this review we will comprehensively analyze findings that support the participation of RhoA, Rac, Cdc42, and TC10 in different neuronal morphogenetic events ranging from migration to synaptic plasticity. We will specifically address the contribution of these GTPases to support neuronal polarity and axonal elongation.
Collapse
Affiliation(s)
- Christian Gonzalez-Billault
- Faculty of Sciences, Laboratory of Cell and Neuronal Dynamics, Department of Biology and Institute for Cell Dynamics and Biotechnology, Universidad de Chile, Santiago, Chile.
| | | | | | | | | | | |
Collapse
|
24
|
Liu J, Zhang D, Luo W, Yu J, Li J, Yu Y, Zhang X, Chen J, Wu XR, Huang C. E3 ligase activity of XIAP RING domain is required for XIAP-mediated cancer cell migration, but not for its RhoGDI binding activity. PLoS One 2012; 7:e35682. [PMID: 22532870 PMCID: PMC3330820 DOI: 10.1371/journal.pone.0035682] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Accepted: 03/20/2012] [Indexed: 12/16/2022] Open
Abstract
Although an increased expression level of XIAP is associated with cancer cell metastasis, the underlying molecular mechanisms remain largely unexplored. To verify the specific structural basis of XIAP for regulation of cancer cell migration, we introduced different XIAP domains into XIAP−/− HCT116 cells, and found that reconstitutive expression of full length HA-XIAP and HA-XIAP ΔBIR, both of which have intact RING domain, restored β-Actin expression, actin polymerization and cancer cell motility. Whereas introduction of HA-XIAP ΔRING or H467A mutant, which abolished its E3 ligase function, did not show obvious restoration, demonstrating that E3 ligase activity of XIAP RING domain played a crucial role of XIAP in regulation of cancer cell motility. Moreover, RING domain rather than BIR domain was required for interaction with RhoGDI independent on its E3 ligase activity. To sum up, our present studies found that role of XIAP in regulating cellular motility was uncoupled from its caspase-inhibitory properties, but related to physical interaction between RhoGDI and its RING domain. Although E3 ligase activity of RING domain contributed to cell migration, it was not involved in RhoGDI binding nor its ubiquitinational modification.
Collapse
Affiliation(s)
- Jinyi Liu
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States of America
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Cho HJ, Baek KE, Kim IK, Park SM, Choi YL, Nam IK, Park SH, Im MJ, Yoo JM, Ryu KJ, Oh YT, Hong SC, Kwon OH, Kim JW, Lee CW, Yoo J. Proteomics-based strategy to delineate the molecular mechanisms of RhoGDI2-induced metastasis and drug resistance in gastric cancer. J Proteome Res 2012; 11:2355-64. [PMID: 22364609 DOI: 10.1021/pr2011186] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Rho GDP dissociation inhibitor 2 (RhoGDI2) was initially identified as a regulator of the Rho family of GTPases. Our recent works suggest that RhoGDI2 promotes tumor growth and malignant progression, as well as enhances chemoresistance in gastric cancer. Here, we delineate the mechanism by which RhoGDI2 promotes gastric cancer cell invasion and chemoresistance using two-dimensional gel electrophoresis (2-DE) on proteins derived from a RhoGDI2-overexpressing SNU-484 human gastric cancer cell line and control cells. Differentially expressed proteins were identified using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). In total, 47 differential protein spots were identified; 33 were upregulated, and 14 were downregulated by RhoGDI2 overexpression. Upregulation of SAE1, Cathepsin D, Cofilin1, CIAPIN1, and PAK2 proteins was validated by Western blot analysis. Loss-of-function analysis using small interference RNA (siRNA) directed against candidate genes reveals the need for CIAPIN1 and PAK2 in RhoGDI2-induced cancer cell invasion and Cathepsin D and PAK2 in RhoGDI2-mediated chemoresistance in gastric cancer cells. These data extend our understanding of the genes that act downstream of RhoGDI2 during the progression of gastric cancer and the acquisition of chemoresistance.
Collapse
Affiliation(s)
- Hee Jun Cho
- Department of Microbiology/Research Institute of Life Science, College of Natural Sciences, Gyeongsang National University, Jinju, Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Cdc42: An important regulator of neuronal morphology. Int J Biochem Cell Biol 2012; 44:447-51. [DOI: 10.1016/j.biocel.2011.11.022] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 11/28/2011] [Accepted: 11/30/2011] [Indexed: 12/21/2022]
|
27
|
Long H, Zhu X, Yang P, Gao Q, Chen Y, Ma L. Myo9b and RICS modulate dendritic morphology of cortical neurons. ACTA ACUST UNITED AC 2012; 23:71-9. [PMID: 22250289 DOI: 10.1093/cercor/bhr378] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Regulated growth and branching of dendritic processes is critical for the establishment of neuronal circuitry and normal brain functions. Rho family GTPases, including RhoA, Rac1, and Cdc42, play a prominent role in dendritic development. RhoA inhibits dendritic branching and growth, whereas Rac1/Cdc42 does the opposite. It has been suggested that the activity of RhoA must be kept low to allow dendritic growth. However, how neurons restrict the activation of RhoA for proper dendritic development is not clear. In the present study, we undertook a comprehensive loss-of-function analysis of putative RhoA GTPase-activating proteins (RhoA GAPs) in the cortical neurons. The expression of 16 RhoA GAPs was detected in the developing rat brain, and RNA interference experiments suggest that 2 of them, Myo9b and RICS, are critical regulators of dendritic morphogenesis. Knockdown of either Myo9b or RICS in cultured cortical neurons or developing cortex resulted in decreased dendrite length and number. Inhibition of RhoA/ROCK signaling restores the defects of dendritic morphology induced by knockdown of Myo9b or RICS. These data demonstrate that Myo9b and RICS repress RhoA/Rock signaling and modulate dendritic morphogenesis in cortical neurons, providing evidence for critical physiological function of RhoA GAPs in regulation of dendritic development.
Collapse
Affiliation(s)
- Hui Long
- The State Key Laboratory of Medical Neurobiology and Pharmacology Research Center, Shanghai Medical College and Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | | | | | | | | | | |
Collapse
|
28
|
Boulter E, Garcia-Mata R. Analysis of the role of RhoGDI1 and isoprenylation in the degradation of RhoGTPases. Methods Mol Biol 2012; 827:97-105. [PMID: 22144270 DOI: 10.1007/978-1-61779-442-1_7] [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] [Indexed: 05/31/2023]
Abstract
RhoGDI1 is one of the three major regulators of the Rho switch along with RhoGEFs and RhoGAPs. RhoGDI1 extracts prenylated Rho proteins from lipid membranes, sequesters them in the cytosol, and prevents nucleotide exchange or hydrolysis. In addition, RhoGDI1 protects prenylated Rho proteins from degradation. Here, we describe techniques to monitor Rho proteins degradation upon depletion of RhoGDI1 and their dependence upon prenylation for degradation.
Collapse
Affiliation(s)
- Etienne Boulter
- Institut National de la Santé et de la Recherche Mé dicale Avenir Team, U634, Sophia-Antipolis University, Nice, France
| | | |
Collapse
|
29
|
Garcia-Mata R, Boulter E, Burridge K. The 'invisible hand': regulation of RHO GTPases by RHOGDIs. Nat Rev Mol Cell Biol 2011; 12:493-504. [PMID: 21779026 DOI: 10.1038/nrm3153] [Citation(s) in RCA: 406] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The 'invisible hand' is a term originally coined by Adam Smith in The Theory of Moral Sentiments to describe the forces of self-interest, competition and supply and demand that regulate the resources in society. This metaphor continues to be used by economists to describe the self-regulating nature of a market economy. The same metaphor can be used to describe the RHO-specific guanine nucleotide dissociation inhibitor (RHOGDI) family, which operates in the background, as an invisible hand, using similar forces to regulate the RHO GTPase cycle.
Collapse
Affiliation(s)
- Rafael Garcia-Mata
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA.
| | | | | |
Collapse
|
30
|
Cho HJ, Baek KE, Park SM, Kim IK, Nam IK, Choi YL, Park SH, Im MJ, Choi J, Ryu J, Kim JW, Lee CW, Kang SS, Yoo J. RhoGDI2 confers gastric cancer cells resistance against cisplatin-induced apoptosis by upregulation of Bcl-2 expression. Cancer Lett 2011; 311:48-56. [PMID: 21752536 DOI: 10.1016/j.canlet.2011.06.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 06/07/2011] [Accepted: 06/16/2011] [Indexed: 12/12/2022]
Abstract
Rho GDP dissociation inhibitor (RhoGDI)2 has been identified as a regulator of Rho family GTPase. Recently, we suggested that RhoGDI2 could promote tumor growth and malignant progression in gastric cancer. In this study, we demonstrate that RhoGDI2 contributes to another important feature of aggressive cancers, i.e., resistance to chemotherapeutic agents such as cisplatin. Forced expression of RhoGDI2 attenuated cisplatin-induced apoptosis, whereas RhoGDI2 depletion showed opposite effects in vitro. Moreover, the increased anti-apoptotic effect of RhoGDI2 on cisplatin was further validated in RhoGDI2-overexpressing SNU-484 xenograft model in nude mice. Furthermore, we identified Bcl-2 as a major determinant of RhoGDI2-mediated cisplatin resistance in gastric cancer cells. Depletion of Bcl-2 expression significantly increased cisplatin-induced apoptosis in RhoGDI2-overexpressing gastric cancer cells, whereas overexpression of Bcl-2 blocked cisplatin-induced apoptosis in RhoGDI2-depleted gastric cancer cells. Overall, these findings establish RhoGDI2 as an important therapeutic target for simultaneously enhancing chemotherapy efficacy and reducing metastasis risk in gastric cancer.
Collapse
Affiliation(s)
- Hee Jun Cho
- Department of Microbiology/Research Institute of Life Science, College of Natural Sciences, Gyeongsang National University, Jinju, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Zazueta-Novoa V, Martínez-Cadena G, Wessel GM, Zazueta-Sandoval R, Castellano L, García-Soto J. Concordance and interaction of guanine nucleotide dissociation inhibitor (RhoGDI) with RhoA in oogenesis and early development of the sea urchin. Dev Growth Differ 2011; 53:427-39. [PMID: 21492154 DOI: 10.1111/j.1440-169x.2011.01261.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rho GTPases are Ras-related GTPases that regulate a variety of cellular processes. In the sea urchin Strongylocentrotus purpuratus, RhoA in the oocyte associates with the membrane of the cortical granules and directs their movement from the cytoplasm to the cell cortex during maturation to an egg. RhoA also plays an important role regulating the Na(+) -H(+) exchanger activity, which determines the internal pH of the cell during the first minutes of embryogenesis. We investigated how this activity may be regulated by a guanine-nucleotide dissociation inhibitor (RhoGDI). The sequence of this RhoA regulatory protein was identified in the genome on the basis of its similarity to other RhoGDI species, especially for key segments in the formation of the isoprenyl-binding pocket and in interactions with the Rho GTPase. We examined the expression and the subcellular localization of RhoGDI during oogenesis and in different developmental stages. We found that RhoGDI mRNA levels were high in eggs and during cleavage divisions until blastula, when it disappeared, only to reappear in gastrula stage. RhoGDI localization overlaps the presence of RhoA during oogenesis and in embryonic development, reinforcing the regulatory premise of the interaction. By use of recombinant protein interactions in vitro, we also find that these two proteins selectively interact. These results support the hypothesis of a functional relationship in vivo and now enable mechanistic insight for the cellular and organelle rearrangements that occur during oogenesis and embryonic development.
Collapse
Affiliation(s)
- Vanesa Zazueta-Novoa
- Department of Biology, Natural and Exact Sciences Division, Guanajuato Campus, University of Guanajuato, Box 187, Guanajuato, Gto. 36000, Mèxico
| | | | | | | | | | | |
Collapse
|
32
|
Park YJ, Ahn HJ, Kim YS, Cho Y, Joo DJ, Ju MK. Illumina-microarray analysis of mycophenolic acid-induced cell death in an insulin-producing cell line and primary rat islet cells: New insights into apoptotic pathways involved. Cell Signal 2010; 22:1773-82. [DOI: 10.1016/j.cellsig.2010.07.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 07/07/2010] [Indexed: 11/25/2022]
|
33
|
Cho HJ, Baek KE, Yoo J. RhoGDI2 as a therapeutic target in cancer. Expert Opin Ther Targets 2010; 14:67-75. [PMID: 20001211 DOI: 10.1517/14728220903449251] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
IMPORTANCE OF THE FIELD Rho GDP dissociation inhibitor 2 (RhoGDI2) has been identified as a regulator of Rho GTPases that play important roles in the development of numerous aspects of the malignant phenotype, including cell cycle progression, resistance to apoptotic stimuli, neovascularization, tumor cell motility, invasiveness, and metastasis. Although RhoGDI2 has been known to be expressed only in hematopoietic tissues, recent studies suggest that this protein is also aberrantly expressed in several human cancers and contributes to aggressive phenotypes, such as invasion and metastasis. Hence, RhoGDI2 appears to be a target of interest for therapeutic manipulation. AREAS COVERED IN THIS REVIEW Here, we summarize the role of RhoGDI2 in human cancers, specifically metastasis-related processes, and discuss its potential as a therapeutic target. WHAT THE READER WILL GAIN RhoGDI2 modulates the invasiveness and metastatic ability of cancer cells through regulation of Rac1 activity. TAKE HOME MESSAGE RhoGDI2 may be a useful marker for tumor progression in human cancers, and interruption of the RhoGDI2-mediated cancer cell invasion and metastasis by an interfacial inhibitor may be a powerful therapeutic approach to cancer.
Collapse
Affiliation(s)
- Hee Jun Cho
- Gyeongsang National University, College of Natural Sciences, Research Institute of Life Science, Department of Microbiology, Jinju 660-701, Korea
| | | | | |
Collapse
|
34
|
Lee WY, Lee PPF, Yan YK, Lau M. Cytotoxic copper(ii) salicylaldehyde semicarbazone complexes: Mode of action and proteomic analysis. Metallomics 2010; 2:694-705. [DOI: 10.1039/c0mt00016g] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
35
|
Bielek H, Anselmo A, Dermardirossian C. Morphological and proliferative abnormalities in renal mesangial cells lacking RhoGDI. Cell Signal 2009; 21:1974-83. [PMID: 19765647 DOI: 10.1016/j.cellsig.2009.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Accepted: 09/09/2009] [Indexed: 11/28/2022]
Abstract
The regulation of Rho GTPase activities and expression is critical in the development and function of the kidney. Rho GTPase activities and cytosol-membrane cycling are regulated by Rho GDP Dissociation Inhibitor (RhoGDI), and RhoGDI knockout mice develop defects in kidney structure and function that lead to death due to renal failure. It is therefore important to understand the changes in RhoGDI-regulated Rho GTPase activities and cell morphology that lead to kidney failure in RhoGDI (-/-) mice. Here, we characterize a renal mesangial cell line derived from the RhoGDI (-/-) mouse in which we verify the absence of GDI proteins. In the absence of RhoGDI, we show an increase in the specific activity of Rac1, and to a lesser extent, RhoA and Cdc42 GTPases in these cells. This is accompanied by a compensatory decrease in the steady-state protein levels of Rho GTPases. Morphological analysis of RhoGDI (-/-) mesangial cells reveals a decrease in cell spreading and in focal contacts compared to wild-type cells. Finally, RhoGDI (-/-) mesangial cells show a decreased ability to proliferate and survive. These functional and structural changes are likely to contribute to the defects in renal architecture and function observed in the RhoGDI (-/-) mouse.
Collapse
Affiliation(s)
- Heike Bielek
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, United States
| | | | | |
Collapse
|
36
|
Cho HJ, Baek KE, Park SM, Kim IK, Choi YL, Cho HJ, Nam IK, Hwang EM, Park JY, Han JY, Kang SS, Kim DC, Lee WS, Lee MN, Oh GT, Kim JW, Lee CW, Yoo J. RhoGDI2 expression is associated with tumor growth and malignant progression of gastric cancer. Clin Cancer Res 2009; 15:2612-9. [PMID: 19351766 DOI: 10.1158/1078-0432.ccr-08-2192] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Rho GDP dissociation inhibitor 2 (RhoGDI2) has been identified as a regulator of Rho family GTPase. However, there is currently no direct evidence suggesting whether RhoGDI2 activates or inhibits Rho family GTPase in vivo (and which type), and the role of RhoGDI2 in tumor remains controversial. Here, we assessed the effects of RhoGDI2 expression on gastric tumor growth and metastasis progression. EXPERIMENTAL DESIGN Proteomic analysis was done to investigate the tumor-specific protein expression in gastric cancer and RhoGDI2 was selected for further study. Immunohistochemistry was used to detect RhoGDI2 expression in clinical samples of primary gastric tumor tissues which have different pathologic stages. Gain-of-function and loss-of-function approaches were done to examine the malignant phenotypes of the RhoGDI2-expressing or RhoGDI2-depleting cells. RESULTS RhoGDI2 expression was correlated positively with tumor progression and metastasis potential in human gastric tumor tissues, as well as cell lines. The forced expression of RhoGDI2 caused a significant increase in gastric cancer cell invasion in vitro, and tumor growth, angiogenesis, and metastasis in vivo, whereas RhoGDI2 depletion evidenced opposite effects. CONCLUSION Our findings indicate that RhoGDI2 is involved in gastric tumor growth and metastasis, and that RhoGDI2 may be a useful marker for tumor progression of human gastric cancer.
Collapse
Affiliation(s)
- Hee Jun Cho
- Department of Microbiology/Research Institute of Life Science, College of Natural Sciences, Physiology, Anatomy and Neurobiology, Institute of Health Science, Gyeongsang National University, Jinju, Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Minagar A, Steven Alexander J, Kelley RE, Harper M, Jennings MH. Proteomic Analysis of Human Cerebral Endothelial Cells Activated by Glutamate/MK-801: Significance in Ischemic Stroke Injury. J Mol Neurosci 2008; 38:182-92. [DOI: 10.1007/s12031-008-9149-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 08/29/2008] [Indexed: 01/28/2023]
|
38
|
Kondoh K, Nakata Y, Yamaoka T, Itakura M, Hayashi M, Yamada K, Hata JI, Yamada T. Altered cellular immunity in transgenic mice with T cell-specific expression of human D4-guanine diphosphate-dissociation inhibitor (D4-GDI). Int Immunol 2008; 20:1299-311. [DOI: 10.1093/intimm/dxn084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
|
39
|
Zhao L, Wang H, Li J, Liu Y, Ding Y. Overexpression of Rho GDP-Dissociation Inhibitor Alpha Is Associated with Tumor Progression and Poor Prognosis of Colorectal Cancer. J Proteome Res 2008; 7:3994-4003. [PMID: 18651761 DOI: 10.1021/pr800271b] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Liang Zhao
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China, Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China, State Key Laboratory of Oncology in Southern China and Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, China, and Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Hui Wang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China, Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China, State Key Laboratory of Oncology in Southern China and Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, China, and Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Jianming Li
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China, Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China, State Key Laboratory of Oncology in Southern China and Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, China, and Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yawei Liu
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China, Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China, State Key Laboratory of Oncology in Southern China and Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, China, and Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yanqing Ding
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China, Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China, State Key Laboratory of Oncology in Southern China and Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, China, and Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| |
Collapse
|
40
|
Kostapanos MS, Milionis HJ, Elisaf MS. An overview of the extra-lipid effects of rosuvastatin. J Cardiovasc Pharmacol Ther 2008; 13:157-74. [PMID: 18460672 DOI: 10.1177/1074248408318628] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Statins, in addition to their beneficial lipid modulation effects, exert a variety of several so-called "pleiotropic" actions that may result in clinical benefits. Rosuvastatin, the last agent of the class to be introduced, has proved remarkably potent in reducing low-density lipoprotein cholesterol levels. At present, no large-scale primary or secondary prevention clinical trials document either its long-term safety or its effectiveness in preventing cardiovascular events. A substantial number of experimental and clinical studies have indicate favorable effects of rosuvastatin on endothelial function, oxidized low-density lipoprotein, inflammation, plaque stability, vascular remodeling, hemostasis, cardiac muscle, and components of the nervous system. Available data regarding the effects of rosuvastatin on renal function and urine protein excretion do not seem to raise any safety concerns. Whether the established "pleiotropy" and/or lipid-lowering efficacy of rosuvastatin may translate into reduced morbidity and mortality remains to be shown in ongoing clinical outcome trials.
Collapse
Affiliation(s)
- Michael S Kostapanos
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | | | | |
Collapse
|
41
|
Lu W, Wang J, Wen T. Downregulation of Rho-GDI gamma promotes differentiation of neural stem cells. Mol Cell Biochem 2008; 311:233-40. [PMID: 18273563 DOI: 10.1007/s11010-008-9713-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2007] [Accepted: 01/29/2008] [Indexed: 11/28/2022]
Abstract
Rho-GDIgamma belongs to the Rho-GDI protein family, which was observed to have high level expression in the entire brain. Although it exists in neuronal population, its physiological function is poorly understood. This study shows that Rho-GDIgamma is a key factor in the G13 signaling pathway based on an analysis of global gene expression. By using RNAi technology to downregulate expression of Rho-GDIgamma we found distinct morphological changes in neural stem cell line C17.2. More important, RT-PCR confirmed that RNAi-mediated downregulation of Rho-GDIgamma decreased expression of Rho-GDIgamma-regulated genes RhoA, Cdc42, Limk2, and N-WASP and slightly increased expression of Rac1. Further, immunochemical staining indicated that downregulation of Rho-GDIgamma increased the tendency of C17.2 cells to differentiate. These data strongly suggest that Rho-GDIgamma plays a key role in the differentiation of neural stem cells.
Collapse
Affiliation(s)
- Wei Lu
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 99 Shang Da Road, Shanghai 200444, China
| | | | | |
Collapse
|
42
|
Maddala R, Reneker LW, Pendurthi B, Rao PV. Rho GDP dissociation inhibitor-mediated disruption of Rho GTPase activity impairs lens fiber cell migration, elongation and survival. Dev Biol 2008; 315:217-31. [PMID: 18234179 DOI: 10.1016/j.ydbio.2007.12.039] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 12/19/2007] [Accepted: 12/20/2007] [Indexed: 01/06/2023]
Abstract
To explore the role of the Rho GTPases in lens morphogenesis, we overexpressed bovine Rho GDP dissociation inhibitor (Rho GDI alpha), which serves as a negative regulator of Rho, Rac and Cdc42 GTPase activity, in a lens-specific manner in transgenic mice. This was achieved using a chimeric promoter of delta-crystallin enhancer and alpha A-crystallin, which is active at embryonic day 12. Several individual transgenic (Tg) lines were obtained, and exhibited ocular specific phenotype comprised of microphthalmic eyes with lens opacity. The overexpression of bovine Rho GDI alpha disrupted membrane translocation of Rho, Rac and Cdc42 GTPases in Tg lenses. Transgenic lenses also revealed abnormalities in the migration pattern, elongation and organization of lens fibers. These changes appeared to be associated with impaired organization of the actin cytoskeleton and cell-cell adhesions. At E14.5, the size of the Rho GDI alpha Tg lenses was larger compared to wild type (WT) and the central lens epithelium and differentiating fibers exhibited an abnormal increase of bromo-deoxy-uridine incorporation. Postnatal Tg eyes, however, were much smaller in size compared to WT eyes, revealing increased apoptosis in the disrupted lens fibers. Taken together, these data demonstrate a critical role for Rho GTPase-dependent signaling pathways in processes underlying morphogenesis, fiber cell migration, elongation and survival in the developing lens.
Collapse
Affiliation(s)
- Rupalatha Maddala
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27710, USA
| | | | | | | |
Collapse
|
43
|
Nakata Y, Kondoh K, Fukushima S, Hashiguchi A, Du W, Hayashi M, Fujimoto JI, Hata JI, Yamada T. Mutated D4-guanine diphosphate-dissociation inhibitor is found in human leukemic cells and promotes leukemic cell invasion. Exp Hematol 2007; 36:37-50. [PMID: 18037226 DOI: 10.1016/j.exphem.2007.08.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 07/23/2007] [Accepted: 08/13/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Rho GTPase may be involved in human cancer invasion via the augmentation of cell motility and adhesion. We report on two point mutations of the D4-guanine diphosphate (GDP)-dissociation inhibitor (GDI) gene, one of the Rho-GDIs, which were found in a human leukemic cell line, Reh, and the mutated D4-GDI functions as an accelerator of leukemic cell invasion. MATERIAL AND METHODS We investigated the altered activity of GDP dissociation by mutated (mt) D4-GDI and the functions of this mt and wild-type (wt) D4-GDI in invasion. The mice inoculated with wt or mt D4-GDI vector-transfected Raji cells were observed and examined pathologically. Adhesiveness and cell motility of wt or mt D4-GDI vector-transfected Raji cells were examined. Finally, it was examined whether Rho activation was changed by mutation of D4-GDI under the condition of Rho-GDI knockdown. RESULTS Two point mutations of the D4-GDI gene were found in Reh cells. The region of mutations is conserved among members of the Rho-GDI family at the amino acid level. D4-GDI with two mutations (V68L and V69A) functioned in a dominant negative manner in the inhibition of GDP dissociation from Rho. Severe combined immune-deficient mice inoculated with Raji cells developed hemiparalysis. The Raji cells were present in bone marrow and peripheral blood, and hepatic invasion was observed in 20% of the mice. Mice inoculated with wt D4-GDI vector-transfected Raji cells (wt D4) showed later paralysis and none developed hepatic invasion. Mice inoculated with mt D4-GDI-transfected Raji cells (mt D4) showed a 5-day reduction in the time to paraplegia and death. In addition, hepatic invasion was evident in 80% of mice transplanted with mt D4 cells. There were no differences in growth rates and amounts of guanine triphosphate (GTP)-bound Rho, cdc42, or Rac among all clones, however, GTP-bound Rho in mt D4 clone with short hairpin RNA (shRNA) vector for Rho-GDI knockdown was increased compared with wt D4 clone with shRNA vector for Rho-GDI knockdown. The mt D4 cells showed an augmentation of adhesiveness and cell motility. On the other hand, wt D4 cells showed a decreased ability of cell motility. CONCLUSION These results suggest the mutated D4-GDI functions as a dominant negative molecule against the wt D4-GDI and accelerates invasion via regulation of cytoskeletal machinery.
Collapse
Affiliation(s)
- Yuji Nakata
- Department of Pathology, Keio University School of Medicine, Tokyo, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Schmandke A, Schmandke A, Strittmatter SM. ROCK and Rho: biochemistry and neuronal functions of Rho-associated protein kinases. Neuroscientist 2007; 13:454-69. [PMID: 17901255 PMCID: PMC2849133 DOI: 10.1177/1073858407303611] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Rho-associated protein kinases (ROCKs) play key roles in mediating the control of the actin cytoskeleton by Rho family GTPases in response to extracellular signals. Such signaling pathways contribute to diverse neuronal functions from cell migration to axonal guidance to dendritic spine morphology to axonal regeneration to cell survival. In this review, the authors summarize biochemical knowledge of ROCK function and categorize neuronal ROCK-dependent signaling pathways. Further study of ROCK signal transduction mechanisms and specificities will enhance our understanding of brain development, plasticity, and repair. The ROCK pathway also provides a potential site for therapeutic intervention to promote neuronal regeneration and to limit degeneration.
Collapse
Affiliation(s)
- André Schmandke
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Neurology Yale University School of Medicine, New Haven, CT 06510, USA
| | | | | |
Collapse
|
45
|
Choi MR, Groot M, Drexler HCA. Functional implications of caspase-mediated RhoGDI2 processing during apoptosis of HL60 and K562 leukemia cells. Apoptosis 2007; 12:2025-35. [PMID: 17726646 DOI: 10.1007/s10495-007-0121-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RhoGDI2, a cytosolic regulator of Rho GTPase, is cleaved during apoptosis in a caspase-3 dependent fashion. By using 2D-gel electrophoresis, mass spectrometry and Western blotting we investigate in this paper the functional consequences of RhoGDI2 processing. We can show that loss of the N-terminal 19 amino acids results in a shift of the isoelectric point of the truncated RhoGDI2 (NDelta19) to a more basic value due to the removal of 9 acidic amino acids from the N-terminus, which may be responsible for enhanced retention of the N-terminally truncated protein within the nuclear compartment. Fusion of the p53 nuclear export signaling sequence MFRELNEALELK to NDelta19 (NDelta19NES) abolished its apoptosis promoting properties, while overexpression of NDelta19 significantly increased the susceptibility to apoptosis induction by the proteasome inhibitor PSI and by staurosporine. These results suggest that cleavage of RhoGDI2 by caspase-3 is not a functionally irrelevant bystander effect of caspase activation during apoptosis, but rather expedites progression of the apoptotic process.
Collapse
MESH Headings
- Amino Acid Sequence
- Apoptosis/genetics
- Apoptosis/physiology
- Caspases/physiology
- Electrophoresis, Gel, Two-Dimensional
- Guanine Nucleotide Dissociation Inhibitors/genetics
- Guanine Nucleotide Dissociation Inhibitors/metabolism
- HL-60 Cells
- Humans
- K562 Cells
- Leukemia, Erythroblastic, Acute/metabolism
- Leukemia, Erythroblastic, Acute/pathology
- Leukemia, Promyelocytic, Acute/metabolism
- Leukemia, Promyelocytic, Acute/pathology
- Molecular Sequence Data
- RNA Processing, Post-Transcriptional
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Tumor Cells, Cultured
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/metabolism
- U937 Cells
- rho Guanine Nucleotide Dissociation Inhibitor beta
- rho-Specific Guanine Nucleotide Dissociation Inhibitors
Collapse
Affiliation(s)
- Mi-Ran Choi
- Max-Planck-Institute for Heart and Lung Research, Parkstr.1, Bad Nauheim 61231, Germany
| | | | | |
Collapse
|
46
|
Srisomsap C, Subhasitanont P, Sawangareetrakul P, Chokchaichamnankit D, Ngiwsara L, Chiablaem K, Svasti J. Comparison of membrane-associated proteins in human cholangiocarcinoma and hepatocellular carcinoma cell lines. Proteomics Clin Appl 2006; 1:89-106. [PMID: 21136613 DOI: 10.1002/prca.200600168] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Indexed: 11/06/2022]
Abstract
Cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC) occur with relatively high incidence in Thailand. Cell line models, originating from Thai patients, are available for both diseases, including the human bile duct epithelial carcinoma cell line (HuCCA-1) and the HCC cell line HCC-S102. Here, we have prepared subproteomes enriched in membrane proteins or in cytosolic proteins from the HuCCA-1 and the HCC-S102 cell lines. Study of differential protein expression by 2-DE and LC/MS/MS showed 195 proteins expressed in the two cell lines, including both membrane-associated and cytosolic proteins. Eighteen proteins were found in both membrane and cytosolic fractions of HuCCA-1, but not in HCC-S102, while nine proteins were found in both membrane and cytosolic fractions of HCC-S102, but not in HuCCA-1. Ten membrane proteins were found in HuCCA-1 but not in HCC-S102, including integrin alpha-6 precursor, ezrin, hippocalcin-like protein 1, mitogen-activated protein kinase kinase kinase 2 (MAPK/ERK kinase kinase 2), and calgizzarin. Proteins showing increased expression in the membrane fraction of HuCCA-1 were mainly cytoskeletal proteins (40.9%), while proteins showing increased expression in the membrane fraction of HCC-S102 were mainly metabolic proteins (39.4%). The subproteomic approach used here facilitates detection of potential biomarkers undetected by regular proteomic methods.
Collapse
|
47
|
Pechlivanis M, Kuhlmann J. Hydrophobic modifications of Ras proteins by isoprenoid groups and fatty acids--More than just membrane anchoring. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:1914-31. [PMID: 17110180 DOI: 10.1016/j.bbapap.2006.09.017] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2006] [Revised: 09/26/2006] [Accepted: 09/29/2006] [Indexed: 01/25/2023]
Abstract
During the last years, post-translational modification of peripheral membrane proteins with hydrophobic side groups has been attributed to a couple of additional functions than just simple anchoring into lipid bilayers. In particular isoprenylation and N- and S-acylation did quicken interest in terms of specific recognition elements for protein-protein interactions and as hydrophobic switches that allow for temporal regulated association with distinct target structures. Furthermore new insights into the heterogeneity of natural membranes have connected the physical properties of e.g. farnesyl or palmitoyl side chains with a preference for such sub-compartments as lipid rafts or caveolae. In this review the impact of the two frequently realized modifications by isoprenylation and S-acylation on the process of cellular signal transduction is exemplified with proteins of the Ras and Rab family of small GTP-binding proteins.
Collapse
Affiliation(s)
- Markos Pechlivanis
- Department of Structural Biology, Max Planck Institute for Molecular Physiology, D-44227 Dortmund, Germany
| | | |
Collapse
|
48
|
Ugolev Y, Molshanski-Mor S, Weinbaum C, Pick E. Liposomes comprising anionic but not neutral phospholipids cause dissociation of Rac(1 or 2) x RhoGDI complexes and support amphiphile-independent NADPH oxidase activation by such complexes. J Biol Chem 2006; 281:19204-19. [PMID: 16702219 DOI: 10.1074/jbc.m600042200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Activation of the phagocyte NADPH oxidase involves the assembly of a membrane-localized cytochrome b559 with the cytosolic components p47(phox), p67(phox), p40(phox), and the GTPase Rac (1 or 2). In resting phagocytes, Rac is found in the cytosol as a prenylated protein in the GDP-bound form, associated with the Rho GDP dissociation inhibitor (RhoGDI). In the process of NADPH oxidase activation, Rac is dissociated from RhoGDI and translocates to the membrane, in concert with the other cytosolic components. The mechanism responsible for dissociation of Rac from RhoGDI is poorly understood. We generated Rac(1 or 2) x RhoGDI complexes in vitro from recombinant Rac(1 or 2), prenylated enzymatically, and recombinant RhoGDI, and purified these by anion exchange chromatography. Exposing Rac(1 or 2)(GDP) x RhoGDI complexes to liposomes containing four different anionic phospholipids caused the dissociation of Rac(1 or 2)(GDP) from RhoGDI and its binding to the anionic liposomes. Rac2(GDP) x RhoGDI complexes were more resistant to dissociation, reflecting the lesser positive charge of Rac2. Liposomes consisting of neutral phospholipid did not cause dissociation of Rac(1 or 2) x RhoGDI complexes. Rac1 exchanged to the hydrolysis-resistant GTP analogue, GMPPNP, associated with RhoGDI with lower affinity than Rac1(GDP) and Rac1(GMPPNP) x RhoGDI complexes were more readily dissociated by anionic liposomes. Rac1(GMPPNP) x RhoGDI complexes elicited NADPH oxidase activation in native phagocyte membrane liposomes in the presence of p67(phox), without the need for an anionic amphiphile, as activator. Both Rac1(GDP) x RhoGDI and Rac1(GMPPNP) x RhoGDI complexes elicited amphiphile-independent, p67(phox)-dependent NADPH oxidase activation in phagocyte membrane liposomes enriched in anionic phospholipids but not in membrane liposomes enriched in neutral phospholipids.
Collapse
Affiliation(s)
- Yelena Ugolev
- Julius Friedrich Cohnheim-Minerva Center for Phagocyte Research and the Ela Kodesz Institute of Host Defense against Infectious Diseases, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | | | | | | |
Collapse
|
49
|
Abstract
Rho GTPase activation is partially regulated at the level of guanine nucleotide dissociation inhibitors, or GDIs. The binding of Rho GTPases to GDIs has been shown to dramatically reduce the action of guanine nucleotide exchange factors (GEFs) to initiate Rho GTPase activation. The GDI-GTPase complex thus serves as a major point of regulation of Rho GTPase activity and function. It is likely that specific mechanisms exist to dissociate individual members of the Rho GTPase family from cytosolic Rho GDI complexes to facilitate the activation process. Such dissociation would likely be tightly coupled to GEF-mediated guanine nucleotide exchange and membrane association of the activated GTPase, resulting in effector binding and functional responses. Accumulating evidence suggests that the phosphorylation of either the Rho GTPases themselves and/or phosphorylation of GDIs might serve as a mechanism for regulating the formation and/or dissociation of Rho GTPase-GDI complexes. Indeed, the selective release of Rac1 from RhoGDI complexes induced by the p21-activated kinase-regulated phosphorylation of RhoGDI has been reported. We describe here methods for the analysis of RhoGDI phosphorylation and regulation by p21-activated kinase 1 (Pak1).
Collapse
|
50
|
Dovas A, Couchman J. RhoGDI: multiple functions in the regulation of Rho family GTPase activities. Biochem J 2005; 390:1-9. [PMID: 16083425 PMCID: PMC1184558 DOI: 10.1042/bj20050104] [Citation(s) in RCA: 313] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
RhoGDI (Rho GDP-dissociation inhibitor) was identified as a down-regulator of Rho family GTPases typified by its ability to prevent nucleotide exchange and membrane association. Structural studies on GTPase-RhoGDI complexes, in combination with biochemical and cell biological results, have provided insight as to how RhoGDI exerts its effects on nucleotide binding, the membrane association-dissociation cycling of the GTPase and how these activities are controlled. Despite the initial negative roles attributed to RhoGDI, recent evidence has come to suggest that it may also act as a positive regulator necessary for the correct targeting and regulation of Rho activities by conferring cues for spatial restriction, guidance and availability to effectors. These potential functions are discussed in the context of RhoGDI-associated multimolecular complexes, the newly emerged shuttling capability and the importance of the particular membrane microenvironment that represents the site of action for GTPases. All these results point to a wider role for RhoGDI than initially perceived, making it a binding partner that can tightly control Rho GTPases, but which also allows them to reach their full spectrum of activities.
Collapse
Affiliation(s)
- Athanassios Dovas
- Division of Biomedical Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, U.K
| | - John R. Couchman
- Division of Biomedical Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, U.K
- To whom correspondence should be addressed (email )
| |
Collapse
|