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Cornish J, Owen D, Mott HR. RLIP76: A Structural and Functional Triumvirate. Cancers (Basel) 2021; 13:cancers13092206. [PMID: 34064388 PMCID: PMC8124665 DOI: 10.3390/cancers13092206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/12/2021] [Accepted: 04/29/2021] [Indexed: 11/16/2022] Open
Abstract
RLIP76/RalBP1 is an ATP-dependent transporter of glutathione conjugates, which is overexpressed in various human cancers, but its diverse functions in normal cells, which include endocytosis, stress response and mitochondrial dynamics, are still not fully understood. The protein can be divided into three distinct regions, each with its own structural properties. At the centre of the protein are two well-defined domains, a GTPase activating protein domain targeting Rho family small G proteins and a small coiled-coil that binds to the Ras family small GTPases RalA and RalB. In engaging with Rho and Ral proteins, RLIP76 bridges these two distinct G protein families. The N-terminal region is predicted to be disordered and is rich in basic amino acids, which may mediate membrane association, consistent with its role in transport. RLIP76 is an ATP-dependent transporter with ATP-binding sites within the N-terminus and the Ral binding domain. Furthermore, RLIP76 is subject to extensive phosphorylation, particularly in the N-terminal region. In contrast, the C-terminal region is thought to form an extensive coiled-coil that could mediate dimerization. Here, we review the structural features of RLIP76, including experimental data and computational predictions, and discuss the implications of its various post-translational modifications.
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2
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Zhang Y, Li G. A tumor suppressor DLC1: The functions and signal pathways. J Cell Physiol 2019; 235:4999-5007. [DOI: 10.1002/jcp.29402] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/27/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Yang Zhang
- Shandong Provincial Key Laboratory of Animal Resistant, School of Life SciencesShandong Normal UniversityJinan China
| | - Guorong Li
- Shandong Provincial Key Laboratory of Animal Resistant, School of Life SciencesShandong Normal UniversityJinan China
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3
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Structural evidence of a phosphoinositide-binding site in the Rgd1-RhoGAP domain. Biochem J 2017; 474:3307-3319. [DOI: 10.1042/bcj20170331] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/26/2017] [Accepted: 07/31/2017] [Indexed: 11/17/2022]
Abstract
Phosphoinositide lipids recruit proteins to the plasma membrane involved in the regulation of cytoskeleton organization and in signalling pathways that control cell polarity and growth. Among those, Rgd1p is a yeast GTPase-activating protein (GAP) specific for Rho3p and Rho4p GTPases, which control actin polymerization and stress signalling pathways. Phosphoinositides not only bind Rgd1p, but also stimulate its GAP activity on the membrane-anchored form of Rho4p. Both F-BAR (F-BAR FCH, and BAR) and RhoGAP domains of Rgd1p are involved in lipid interactions. In the Rgd1p–F-BAR domain, a phosphoinositide-binding site has been recently characterized. We report here the X-ray structure of the Rgd1p–RhoGAP domain, identify by NMR spectroscopy and confirm by docking simulations, a new but cryptic phosphoinositide-binding site, comprising contiguous A1, A1′ and B helices. The addition of helix A1′, unusual among RhoGAP domains, seems to be crucial for lipid interactions. Such a site was totally unexpected inside a RhoGAP domain, as it was not predicted from either the protein sequence or its three-dimensional structure. Phosphoinositide-binding sites in RhoGAP domains have been reported to correspond to polybasic regions, which are located at the unstructured flexible termini of proteins. Solid-state NMR spectroscopy experiments confirm the membrane interaction of the Rgd1p–RhoGAP domain upon the addition of PtdIns(4,5)P2 and indicate a slight membrane destabilization in the presence of the two partners.
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4
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Abstract
The spatial regulation of cellular Rho signaling by GEF and GAP proteins and the molecular mechanisms controlling the Rho regulators themselves are still incompletely understood. We previously reported that the poorly characterized RhoGAP protein DLC3 localizes to cell-cell adhesions and Rab8-positive membrane tubules. However, it was unclear how DLC3 is targeted to these subcellular sites to execute its functions. In our recent work, protein partners of DLC3 were identified by mass spectrometry, identifying the basolateral polarity protein Scribble as a scaffold for DLC3 at cell-cell contacts. We found that the PDZ-mediated interaction of DLC3 and Scribble is essential for junctional DLC3 recruitment and its role as a local regulator of RhoA-ROCK signaling controlling adherens junction integrity and Scribble localization. Furthermore, DLC3 and Scribble depletion interfered with polarized lumen formation in a 3D model of cyst morphogenesis, emphasizing the relevance of both proteins in epithelial polarity. These findings reveal a new mechanism for spatial Rho regulation at adherens junctions in polarized epithelial cells and highlight the necessity to investigate DLC3 localization and function also in cellular contexts that require cell junction remodeling.
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Affiliation(s)
- Janina Hendrick
- a Institute of Cell Biology and Immunology, University of Stuttgart , Stuttgart , Germany
| | - Monilola A Olayioye
- a Institute of Cell Biology and Immunology, University of Stuttgart , Stuttgart , Germany
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5
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Amin E, Jaiswal M, Derewenda U, Reis K, Nouri K, Koessmeier KT, Aspenström P, Somlyo AV, Dvorsky R, Ahmadian MR. Deciphering the Molecular and Functional Basis of RHOGAP Family Proteins: A SYSTEMATIC APPROACH TOWARD SELECTIVE INACTIVATION OF RHO FAMILY PROTEINS. J Biol Chem 2016; 291:20353-71. [PMID: 27481945 PMCID: PMC5034035 DOI: 10.1074/jbc.m116.736967] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/15/2016] [Indexed: 12/30/2022] Open
Abstract
RHO GTPase-activating proteins (RHOGAPs) are one of the major classes of regulators of the RHO-related protein family that are crucial in many cellular processes, motility, contractility, growth, differentiation, and development. Using database searches, we extracted 66 distinct human RHOGAPs, from which 57 have a common catalytic domain capable of terminating RHO protein signaling by stimulating the slow intrinsic GTP hydrolysis (GTPase) reaction. The specificity of the majority of the members of RHOGAP family is largely uncharacterized. Here, we comprehensively investigated the sequence-structure-function relationship between RHOGAPs and RHO proteins by combining our in vitro data with in silico data. The activity of 14 representatives of the RHOGAP family toward 12 RHO family proteins was determined in real time. We identified and structurally verified hot spots in the interface between RHOGAPs and RHO proteins as critical determinants for binding and catalysis. We have found that the RHOGAP domain itself is nonselective and in some cases rather inefficient under cell-free conditions. Thus, we propose that other domains of RHOGAPs confer substrate specificity and fine-tune their catalytic efficiency in cells.
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Affiliation(s)
- Ehsan Amin
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Mamta Jaiswal
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Urszula Derewenda
- the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, and
| | - Katarina Reis
- the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Kazem Nouri
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Katja T Koessmeier
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Pontus Aspenström
- the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Avril V Somlyo
- the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, and
| | - Radovan Dvorsky
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany,
| | - Mohammad R Ahmadian
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany,
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6
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Puig-Oliveras A, Revilla M, Castelló A, Fernández AI, Folch JM, Ballester M. Expression-based GWAS identifies variants, gene interactions and key regulators affecting intramuscular fatty acid content and composition in porcine meat. Sci Rep 2016; 6:31803. [PMID: 27666082 PMCID: PMC4989154 DOI: 10.1038/srep31803] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 07/26/2016] [Indexed: 12/20/2022] Open
Abstract
The aim of this work is to better understand the genetic mechanisms determining two complex traits affecting porcine meat quality: intramuscular fat (IMF) content and its fatty acid (FA) composition. With this purpose, expression Genome-Wide Association Study (eGWAS) of 45 lipid-related genes associated with meat quality traits in swine muscle (Longissimus dorsi) of 114 Iberian × Landrace backcross animals was performed. The eGWAS identified 241 SNPs associated with 11 genes: ACSM5, CROT, FABP3, FOS, HIF1AN, IGF2, MGLL, NCOA1, PIK3R1, PLA2G12A and PPARA. Three expression Quantitative Trait Loci (eQTLs) for IGF2, ACSM5 and MGLL were identified, showing cis-acting effects, whereas 16 eQTLs had trans regulatory effects. A polymorphism in the ACSM5 promoter region associated with its expression was identified. In addition, strong candidate genes regulating ACSM5, FOS, PPARA, PIK3R1, PLA2G12A and HIF1AN gene expression were also seen. Notably, the analysis highlighted the NR3C1 transcription factor as a strong candidate gene involved in the regulation of the 45 genes analysed. Finally, the IGF2, MGLL, MC2R, ARHGAP6, and NR3C1 genes were identified as potential regulators co-localizing within QTLs for fatness and growth traits in the IBMAP population. The results obtained increase our knowledge in the functional regulatory mechanisms involved in these complex traits.
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Affiliation(s)
- Anna Puig-Oliveras
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain.,Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (CRAG), 08193 Bellaterra, Spain
| | - Manuel Revilla
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain.,Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (CRAG), 08193 Bellaterra, Spain
| | - Anna Castelló
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain.,Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (CRAG), 08193 Bellaterra, Spain
| | - Ana I Fernández
- Departamento de Genética Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28040 Madrid, Spain
| | - Josep M Folch
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain.,Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (CRAG), 08193 Bellaterra, Spain
| | - Maria Ballester
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain.,Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (CRAG), 08193 Bellaterra, Spain.,Departament de Genètica i Millora Animal, Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Torre Marimon, 08140 Caldes de Montbui, Spain
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7
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Hendrick J, Franz-Wachtel M, Moeller Y, Schmid S, Macek B, Olayioye MA. The polarity protein Scribble positions DLC3 at adherens junctions to regulate Rho signaling. J Cell Sci 2016; 129:3583-3596. [PMID: 27505894 DOI: 10.1242/jcs.190074] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 08/01/2016] [Indexed: 12/31/2022] Open
Abstract
The spatial regulation of cellular Rho signaling by GAP proteins is still poorly understood. By performing mass spectrometry, we here identify the polarity protein Scribble as a scaffold for the RhoGAP protein DLC3 (also known as StarD8) at cell-cell adhesions. This mutually dependent interaction is mediated by the PDZ domains of Scribble and a PDZ ligand (PDZL) motif in DLC3. Both Scribble depletion and PDZL deletion abrogated DLC3 junctional localization. Using a RhoA biosensor and a targeted GAP domain, we demonstrate that DLC3 activity locally regulates RhoA-ROCK signaling at and Scribble localization to adherens junctions, and is required for their functional integrity. In a 3D model of cyst development, we furthermore show that DLC3 depletion impairs polarized morphogenesis, phenocopying the effects observed upon Scribble knockdown. We thus propose a new function for Scribble in Rho regulation that entails positioning of DLC3 GAP activity at cell junctions in polarized epithelial cells.
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Affiliation(s)
- Janina Hendrick
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, Stuttgart 70569, Germany
| | - Mirita Franz-Wachtel
- Proteome Center Tübingen, University of Tübingen, Auf der Morgenstelle 15, Tübingen 72076, Germany
| | - Yvonne Moeller
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, Stuttgart 70569, Germany
| | - Simone Schmid
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, Stuttgart 70569, Germany
| | - Boris Macek
- Proteome Center Tübingen, University of Tübingen, Auf der Morgenstelle 15, Tübingen 72076, Germany
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, Stuttgart 70569, Germany
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8
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Hernandez-Flores A, Almaraz-Barrera MDJ, Lozano-Amado D, Correa-Basurto J, Rojo-Dominguez A, Luna-Rivera E, Schnoor M, Guillen N, Hernandez-Rivas R, Vargas M. A new nucleocytoplasmic RhoGAP protein contributes to control the pathogenicity ofEntamoeba histolyticaby regulating EhRacC and EhRacD activity. Cell Microbiol 2016; 18:1653-1672. [DOI: 10.1111/cmi.12603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 03/29/2016] [Accepted: 04/18/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Araceli Hernandez-Flores
- Department of Molecular Biomedicine; Center of Research and Advanced Studies of the I.P.N; Mexico City, D.F. Mexico
| | - Ma de Jesus Almaraz-Barrera
- Department of Molecular Biomedicine; Center of Research and Advanced Studies of the I.P.N; Mexico City, D.F. Mexico
| | - Daniela Lozano-Amado
- Department of Molecular Biomedicine; Center of Research and Advanced Studies of the I.P.N; Mexico City, D.F. Mexico
| | - Jose Correa-Basurto
- High School of Medicine of the I.P.N; Molecular Modeling Laboratory and Drug Design; Mexico City, D.F. Mexico
| | - Arturo Rojo-Dominguez
- Cuajimalpa Unit., Department of Natural Sciences; Metropolitan Autonomous University; Mexico City, D.F. Mexico
| | - Eva Luna-Rivera
- Department of Molecular Biomedicine; Center of Research and Advanced Studies of the I.P.N; Mexico City, D.F. Mexico
| | - Michael Schnoor
- Department of Molecular Biomedicine; Center of Research and Advanced Studies of the I.P.N; Mexico City, D.F. Mexico
| | - Nancy Guillen
- Institut Pasteur; Department of Cell Biology and Infection; Paris France
| | - Rosaura Hernandez-Rivas
- Department of Molecular Biomedicine; Center of Research and Advanced Studies of the I.P.N; Mexico City, D.F. Mexico
| | - Miguel Vargas
- Department of Molecular Biomedicine; Center of Research and Advanced Studies of the I.P.N; Mexico City, D.F. Mexico
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9
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Jin P, Wu X, Xu S, Zhang H, Li Y, Cao Z, Li H, Wang S. Differential expression of six genes and correlation with fatness traits in a unique broiler population. Saudi J Biol Sci 2015; 24:945-949. [PMID: 28490969 PMCID: PMC5415145 DOI: 10.1016/j.sjbs.2015.04.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 04/16/2015] [Accepted: 04/22/2015] [Indexed: 11/20/2022] Open
Abstract
Previous results from genome wide association studies (GWASs) in chickens divergently selected for abdominal fat content of Northeast Agricultural University (NEAUHLF) showed that many single nucleotide polymorphism (SNP) variants were associated with abdominal fat content. Of them, six top significant SNPs at the genome level were located within SRD5A3, SGCZ, DLC1, GBE1, GALNT9 and DNAJB6 genes. Here, expression levels of these six candidate genes were investigated in abdominal fat and liver tissue between fat and lean broilers from the 14th generation population of NEAUHLF. The results showed that expression levels of SRD5A3, SGCZ and DNAJB6 in the abdominal fat and SRD5A3, DLC1, GALNT9, DNAJB6 and GBE1 in the liver tissue differed significantly between the fat and lean birds, and were correlated with abdominal fat traits. The findings will provide important references for further function investigation of the six candidate genes involved in abdominal fat deposition in chickens.
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Affiliation(s)
- Pengcheng Jin
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
| | - Xianwen Wu
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
| | - Songsong Xu
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
| | - Hui Zhang
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
| | - Yumao Li
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
| | - Zhiping Cao
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
| | - Hui Li
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
| | - Shouzhi Wang
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China
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10
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Braun AC, Olayioye MA. Rho regulation: DLC proteins in space and time. Cell Signal 2015; 27:1643-51. [PMID: 25889896 DOI: 10.1016/j.cellsig.2015.04.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/08/2015] [Indexed: 12/19/2022]
Abstract
Rho GTPases function as molecular switches that connect changes of the external environment to intracellular signaling pathways. They are active at various subcellular sites and require fast and tight regulation to fulfill their role as transducers of extracellular stimuli. New imaging technologies visualizing the active states of Rho proteins in living cells elucidated the necessity of precise spatiotemporal activation of the GTPases. The local regulation of Rho proteins is coordinated by the interaction with different guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) that turn on and off GTPase signaling to downstream effectors. GEFs and GAPs thus serve as critical signaling nodes that specify the amplitude and duration of a particular Rho signaling pathway. Despite their importance in Rho regulation, the molecular aspects underlying the spatiotemporal control of the regulators themselves are still largely elusive. In this review we will focus on the Deleted in Liver Cancer (DLC) family of RhoGAP proteins and summarize the evidence gathered over the past years revealing their different subcellular localizations that might account for isoform-specific functions. We will also highlight the importance of their tightly controlled expression in the context of neoplastic transformation.
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Affiliation(s)
- Anja C Braun
- University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, 70569 Stuttgart, Germany
| | - Monilola A Olayioye
- University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, 70569 Stuttgart, Germany.
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11
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Braun AC, Hendrick J, Eisler SA, Schmid S, Hausser A, Olayioye MA. The Rho-specific GAP protein DLC3 coordinates endocytic membrane trafficking. J Cell Sci 2015; 128:1386-99. [PMID: 25673874 DOI: 10.1242/jcs.163857] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Membrane trafficking is known to be coordinated by small GTPases, but the identity of their regulators, the guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) that ensure balanced GTPase activation at different subcellular sites is largely elusive. Here, we show in living cells that deleted in liver cancer 3 (DLC3, also known as STARD8) is a functional Rho-specific GAP protein, the loss of which enhances perinuclear RhoA activity. DLC3 is recruited to Rab8-positive membrane tubules and is required for the integrity of the Rab8 and Golgi compartments. Depletion of DLC3 impairs the transport of internalized transferrin to the endocytic recycling compartment (ERC), which is restored by the simultaneous downregulation of RhoA and RhoB. We further demonstrate that DLC3 loss interferes with epidermal growth factor receptor (EGFR) degradation associated with prolonged receptor signaling. Taken together, these findings identify DLC3 as a novel component of the endocytic trafficking machinery, wherein it maintains organelle integrity and regulates membrane transport through the control of Rho activity.
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Affiliation(s)
- Anja C Braun
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Janina Hendrick
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Stephan A Eisler
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Simone Schmid
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Angelika Hausser
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
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12
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Kaushik S, Ravi A, Hameed FM, Low BC. Concerted modulation of paxillin dynamics at focal adhesions by deleted in liver cancer-1 and focal adhesion kinase during early cell spreading. Cytoskeleton (Hoboken) 2015; 71:677-94. [DOI: 10.1002/cm.21201] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 11/25/2014] [Indexed: 01/24/2023]
Affiliation(s)
- Shelly Kaushik
- Cell Signaling and Developmental Biology Laboratory; Department of Biological Sciences; National University of Singapore; Singapore
- Mechanobiology Institute, National University of Singapore; Singapore
| | - Archna Ravi
- Cell Signaling and Developmental Biology Laboratory; Department of Biological Sciences; National University of Singapore; Singapore
- Mechanobiology Institute, National University of Singapore; Singapore
| | - Feroz M. Hameed
- Mechanobiology Institute, National University of Singapore; Singapore
| | - Boon Chuan Low
- Cell Signaling and Developmental Biology Laboratory; Department of Biological Sciences; National University of Singapore; Singapore
- Mechanobiology Institute, National University of Singapore; Singapore
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13
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Barras D, Chevalier N, Zoete V, Dempsey R, Lapouge K, Olayioye MA, Michielin O, Widmann C. A WXW motif is required for the anticancer activity of the TAT-RasGAP317-326 peptide. J Biol Chem 2014; 289:23701-11. [PMID: 25008324 DOI: 10.1074/jbc.m114.576272] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
TAT-RasGAP317-326, a cell-permeable 10-amino acid-long peptide derived from the N2 fragment of p120 Ras GTPase-activating protein (RasGAP), sensitizes tumor cells to apoptosis induced by various anticancer therapies. This RasGAP-derived peptide, by targeting the deleted in liver cancer-1 (DLC1) tumor suppressor, also hampers cell migration and invasion by promoting cell adherence and by inhibiting cell movement. Here, we systematically investigated the role of each amino acid within the RasGAP317-326 sequence for the anticancer activities of TAT-RasGAP317-326. We report here that the first three amino acids of this sequence, tryptophan, methionine, and tryptophan (WMW), are necessary and sufficient to sensitize cancer cells to cisplatin-induced apoptosis and to reduce cell migration. The WMW motif was found to be critical for the binding of fragment N2 to DLC1. These results define the interaction mode between the active anticancer sequence of RasGAP and DLC1. This knowledge will facilitate the design of small molecules bearing the tumor-sensitizing and antimetastatic activities of TAT-RasGAP317-326.
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Affiliation(s)
- David Barras
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Nadja Chevalier
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Vincent Zoete
- the Molecular Modeling Group, Swiss Institute of Bioinformatics (SIB), Quartier Sorge, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Rosemary Dempsey
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Karine Lapouge
- the Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland, and
| | - Monilola A Olayioye
- the Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
| | - Olivier Michielin
- the Molecular Modeling Group, Swiss Institute of Bioinformatics (SIB), Quartier Sorge, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Christian Widmann
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland,
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14
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Jaiswal M, Dvorsky R, Amin E, Risse SL, Fansa EK, Zhang SC, Taha MS, Gauhar AR, Nakhaei-Rad S, Kordes C, Koessmeier KT, Cirstea IC, Olayioye MA, Häussinger D, Ahmadian MR. Functional cross-talk between ras and rho pathways: a Ras-specific GTPase-activating protein (p120RasGAP) competitively inhibits the RhoGAP activity of deleted in liver cancer (DLC) tumor suppressor by masking the catalytic arginine finger. J Biol Chem 2014; 289:6839-6849. [PMID: 24443565 DOI: 10.1074/jbc.m113.527655] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The three deleted in liver cancer genes (DLC1-3) encode Rho-specific GTPase-activating proteins (RhoGAPs). Their expression is frequently silenced in a variety of cancers. The RhoGAP activity, which is required for full DLC-dependent tumor suppressor activity, can be inhibited by the Src homology 3 (SH3) domain of a Ras-specific GAP (p120RasGAP). Here, we comprehensively investigated the molecular mechanism underlying cross-talk between two distinct regulators of small GTP-binding proteins using structural and biochemical methods. We demonstrate that only the SH3 domain of p120 selectively inhibits the RhoGAP activity of all three DLC isoforms as compared with a large set of other representative SH3 or RhoGAP proteins. Structural and mutational analyses provide new insights into a putative interaction mode of the p120 SH3 domain with the DLC1 RhoGAP domain that is atypical and does not follow the classical PXXP-directed interaction. Hence, p120 associates with the DLC1 RhoGAP domain by targeting the catalytic arginine finger and thus by competitively and very potently inhibiting RhoGAP activity. The novel findings of this study shed light on the molecular mechanisms underlying the DLC inhibitory effects of p120 and suggest a functional cross-talk between Ras and Rho proteins at the level of regulatory proteins.
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Affiliation(s)
- Mamta Jaiswal
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Radovan Dvorsky
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Ehsan Amin
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Sarah L Risse
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Eyad K Fansa
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Si-Cai Zhang
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Mohamed S Taha
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Aziz R Gauhar
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Saeideh Nakhaei-Rad
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Claus Kordes
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf
| | - Katja T Koessmeier
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Ion C Cirstea
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf; Leibniz Institute for Age Research, 07745 Jena
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf
| | - Mohammad R Ahmadian
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf.
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15
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Ko FCF, Ping Yam JW. Regulation of deleted in liver cancer 1 tumor suppressor by protein-protein interactions and phosphorylation. Int J Cancer 2013; 135:264-9. [DOI: 10.1002/ijc.28505] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/16/2013] [Indexed: 12/26/2022]
Affiliation(s)
- Frankie Chi Fat Ko
- Department of Pathology and Centre for Cancer Research; Li Ka Shing Faculty of Medicine, State Key Laboratory for Liver Research, The University of Hong Kong; Hong Kong
| | - Judy Wai Ping Yam
- Department of Pathology and Centre for Cancer Research; Li Ka Shing Faculty of Medicine, State Key Laboratory for Liver Research, The University of Hong Kong; Hong Kong
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16
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Cho H, Wu M, Bilgin B, Walton SP, Chan C. Latest developments in experimental and computational approaches to characterize protein-lipid interactions. Proteomics 2013; 12:3273-85. [PMID: 22997137 DOI: 10.1002/pmic.201200255] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 08/30/2012] [Accepted: 09/05/2012] [Indexed: 12/16/2022]
Abstract
Understanding the functional roles of all the molecules in cells is an ultimate goal of modern biology. An important facet is to understand the functional contributions from intermolecular interactions, both within a class of molecules (e.g. protein-protein) or between classes (e.g. protein-DNA). While the technologies for analyzing protein-protein and protein-DNA interactions are well established, the field of protein-lipid interactions is still relatively nascent. Here, we review the current status of the experimental and computational approaches for detecting and analyzing protein-lipid interactions. Experimental technologies fall into two principal categories, namely solution-based and array-based methods. Computational methods include large-scale data-driven analyses and predictions/dynamic simulations based on prior knowledge of experimentally identified interactions. Advances in the experimental technologies have led to improved computational analyses and vice versa, thereby furthering our understanding of protein-lipid interactions and their importance in biological systems.
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Affiliation(s)
- Hyunju Cho
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI, USA
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17
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Ko FCF, Chan LK, Man-Fong Sze K, Yeung YS, Yuk-Ting Tse E, Lu P, Yu MH, Oi-Lin Ng I, Yam JWP. PKA-induced dimerization of the RhoGAP DLC1 promotes its inhibition of tumorigenesis and metastasis. Nat Commun 2013; 4:1618. [DOI: 10.1038/ncomms2604] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 02/14/2013] [Indexed: 12/27/2022] Open
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18
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Vázquez-Calvo Á, Sobrino F, Martín-Acebes MA. Plasma membrane phosphatidylinositol 4,5 bisphosphate is required for internalization of foot-and-mouth disease virus and vesicular stomatitis virus. PLoS One 2012; 7:e45172. [PMID: 23028825 PMCID: PMC3460999 DOI: 10.1371/journal.pone.0045172] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 08/17/2012] [Indexed: 12/20/2022] Open
Abstract
Phosphatidylinositol-4,5-bisphosphate, PI(4,5)P2, is a phospholipid which plays important roles in clathrin-mediated endocytosis. To investigate the possible role of this lipid on viral entry, two viruses important for animal health were selected: the enveloped vesicular stomatitis virus (VSV) − which uses a well characterized clathrin mediated endocytic route − and two different variants of the non-enveloped foot-and-mouth disease virus (FMDV) with distinct receptor specificities. The expression of a dominant negative dynamin, a PI(4,5)P2 effector protein, inhibited the internalization and infection of VSV and both FMDV isolates. Depletion of PI(4,5)P2 from plasma membrane using ionomycin or an inducible system, and inhibition of its de novo synthesis with 1-butanol revealed that VSV as well as FMDV C-S8c1, which uses integrins as receptor, displayed a high dependence on PI(4,5)P2 for internalization. Expression of a kinase dead mutant (KD) of phosphatidylinositol-4-phosphate-5-kinase Iα (PIP5K-Iα), an enzyme responsible for PI(4,5)P2 synthesis that regulates clathrin-dependent endocytosis, also impaired entry and infection of VSV and FMDV C-S8c1. Interestingly FMDV MARLS variant that uses receptors other than integrins for cell entry was less sensitive to PI(4,5)P2 depletion, and was not inhibited by the expression of the KD PIP5K-Iα mutant suggesting the involvement of endocytic routes other than the clathrin-mediated on its entry. These results highlight the role of PI(4,5)P2 and PIP5K-Iα on clathrin-mediated viral entry.
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Affiliation(s)
- Ángela Vázquez-Calvo
- Centro de Biología Molecular “Severo Ochoa” (UAM/CSIC), Cantoblanco, Madrid Spain
| | - Francisco Sobrino
- Centro de Biología Molecular “Severo Ochoa” (UAM/CSIC), Cantoblanco, Madrid Spain
- Centro de Investigación en Sanidad Animal, INIA, Valdeolmos, Madrid, Spain
- * E-mail:
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19
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van Rahden VA, Brand K, Najm J, Heeren J, Pfeffer SR, Braulke T, Kutsche K. The 5-phosphatase OCRL mediates retrograde transport of the mannose 6-phosphate receptor by regulating a Rac1-cofilin signalling module. Hum Mol Genet 2012; 21:5019-38. [PMID: 22907655 DOI: 10.1093/hmg/dds343] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mutations in the OCRL gene encoding the phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) 5-phosphatase OCRL cause Lowe syndrome (LS), which is characterized by intellectual disability, cataracts and selective proximal tubulopathy. OCRL localizes membrane-bound compartments and is implicated in intracellular transport. Comprehensive analysis of clathrin-mediated endocytosis in fibroblasts of patients with LS did not reveal any difference in trafficking of epidermal growth factor, low density lipoprotein or transferrin, compared with normal fibroblasts. However, LS fibroblasts displayed reduced mannose 6-phosphate receptor (MPR)-mediated re-uptake of the lysosomal enzyme arylsulfatase B. In addition, endosome-to-trans Golgi network (TGN) transport of MPRs was decreased significantly, leading to higher levels of cell surface MPRs and their enrichment in enlarged, retromer-positive endosomes in OCRL-depleted HeLa cells. In line with the higher steady-state concentration of MPRs in the endosomal compartment in equilibrium with the cell surface, anterograde transport of the lysosomal enzyme, cathepsin D was impaired. Wild-type OCRL counteracted accumulation of MPR in endosomes in an activity-dependent manner, suggesting that PI(4,5)P(2) modulates the activity state of proteins regulated by this phosphoinositide. Indeed, we detected an increased amount of the inactive, phosphorylated form of cofilin and lower levels of the active form of PAK3 upon OCRL depletion. Levels of active Rac1 and RhoA were reduced or enhanced, respectively. Overexpression of Rac1 rescued both enhanced levels of phosphorylated cofilin and MPR accumulation in enlarged endosomes. Our data suggest that PI(4,5)P(2) dephosphorylation through OCRL regulates a Rac1-cofilin signalling cascade implicated in MPR trafficking from endosomes to the TGN.
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Affiliation(s)
- Vanessa A van Rahden
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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20
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Holeiter G, Bischoff A, Braun AC, Huck B, Erlmann P, Schmid S, Herr R, Brummer T, Olayioye MA. The RhoGAP protein Deleted in Liver Cancer 3 (DLC3) is essential for adherens junctions integrity. Oncogenesis 2012; 1:e13. [PMID: 23552697 PMCID: PMC3412646 DOI: 10.1038/oncsis.2012.13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Epithelial cell-cell contacts are mediated by E-cadherin interactions, which are regulated by the balanced local activity of Rho GTPases. Despite the known function of Rho at adherens junctions (AJs), little is known about the spatial control of Rho activity at these sites. Here we provide evidence that in breast epithelial cells the Deleted in Liver Cancer 3 (DLC3) protein localizes to AJs and is essential for E-cadherin function. DLC3 is a still poorly characterized RhoA-specific GTPase-activating protein that is frequently downregulated in various types of cancer. We demonstrate that DLC3 depletion leads to mislocalization of E-cadherin and catenins, which was associated with impaired cell aggregation and increased migration. This is explained by aberrant local Rho signaling because ROCK inhibition restored cell-cell contacts in DLC3 knockdown cells. We thus identify DLC3 as a novel negative regulator of junctional Rho and propose that DLC3 loss contributes to carcinogenesis by compromising epithelial integrity.
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Affiliation(s)
- G Holeiter
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
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21
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Chen L, Liu C, Ko FCF, Xu N, Ng IOL, Yam JWP, Zhu G. Solution structure of the phosphotyrosine binding (PTB) domain of human tensin2 protein in complex with deleted in liver cancer 1 (DLC1) peptide reveals a novel peptide binding mode. J Biol Chem 2012; 287:26104-14. [PMID: 22645138 DOI: 10.1074/jbc.m112.360206] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protein deleted in liver cancer 1 (DLC1) interacts with the tensin family of focal adhesion proteins to play a role as a tumor suppressor in a wide spectrum of human cancers. This interaction has been proven to be crucial to the oncogenic inhibitory capacity and focal adhesion localization of DLC1. The phosphotyrosine binding (PTB) domain of tensin2 predominantly interacts with a novel site on DLC1, not the canonical NPXY motif. In this study, we characterized this interaction biochemically and determined the complex structure of tensin2 PTB domain with DLC1 peptide by NMR spectroscopy. Our HADDOCK-derived complex structure model elucidates the molecular mechanism by which tensin2 PTB domain recognizes DLC1 peptide and reveals a PTB-peptide binding mode that is unique in that peptide occupies the binding site opposite to the canonical NPXY motif interaction site with the peptide utilizing a non-canonical binding motif to bind in an extended conformation and that the N-terminal helix, which is unique to some Shc- and Dab-like PTB domains, is required for binding. Mutations of crucial residues defined for the PTB-DLC1 interaction affected the co-localization of DLC1 and tensin2 in cells and abolished DLC1-mediated growth suppression of hepatocellular carcinoma cells. This tensin2 PTB-DLC1 peptide complex with a novel binding mode extends the versatile binding repertoire of the PTB domains in mediating diverse cellular signaling pathways as well as provides a molecular and structural basis for better understanding the tumor-suppressive activity of DLC1 and tensin2.
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Affiliation(s)
- Lihong Chen
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077 Hong Kong, China
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22
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Zimonjic DB, Popescu NC. Role of DLC1 tumor suppressor gene and MYC oncogene in pathogenesis of human hepatocellular carcinoma: potential prospects for combined targeted therapeutics (review). Int J Oncol 2012; 41:393-406. [PMID: 22580498 PMCID: PMC3583004 DOI: 10.3892/ijo.2012.1474] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 02/17/2012] [Indexed: 02/07/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is the third leading cause of cancer death, and its incidence is increasing worldwide in an alarming manner. The development of curative therapy for advanced and metastatic HCC is a high clinical priority. The HCC genome is complex and heterogeneous; therefore, the identification of recurrent genomic and related gene alterations is critical for developing clinical applications for diagnosis, prognosis and targeted therapy of the disease. This article focuses on recent research progress and our contribution in identifying and deciphering the role of defined genetic alterations in the pathogenesis of HCC. A significant number of genes that promote or suppress HCC cell growth have been identified at the sites of genomic reorganization. Notwithstanding the accumulation of multiple genetic alterations, highly recurrent changes on a single chromosome can alter the expression of oncogenes and tumor suppressor genes (TSGs) whose deregulation may be sufficient to drive the progression of normal hepatocytes to malignancy. A distinct and highly recurrent pattern of genomic imbalances in HCC includes the loss of DNA copy number (associated with loss of heterozygosity) of TSG-containing chromosome 8p and gain of DNA copy number or regional amplification of protooncogenes on chromosome 8q. Even though 8p is relatively small, it carries an unusually large number of TSGs, while, on the other side, several oncogenes are dispersed along 8q. Compelling evidence demonstrates that DLC1, a potent TSG on 8p, and MYC oncogene on 8q play a critical role in the pathogenesis of human HCC. Direct evidence for their role in the genesis of HCC has been obtained in a mosaic mouse model. Knockdown of DLC1 helps MYC in the induction of hepatoblast transformation in vitro, and in the development of HCC in vivo. Therapeutic interventions, which would simultaneously target signaling pathways governing both DLC1 and MYC functions in hepatocarcinogenesis, could result in progress in the treatment of liver cancer.
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Affiliation(s)
- Drazen B Zimonjic
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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23
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Karimzadeh F, Primeau M, Mountassif D, Rouiller I, Lamarche-Vane N. A stretch of polybasic residues mediates Cdc42 GTPase-activating protein (CdGAP) binding to phosphatidylinositol 3,4,5-trisphosphate and regulates its GAP activity. J Biol Chem 2012; 287:19610-21. [PMID: 22518840 DOI: 10.1074/jbc.m112.344606] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Rho family of small GTPases are membrane-associated molecular switches involved in the control of a wide range of cellular activities, including cell migration, adhesion, and proliferation. Cdc42 GTPase-activating protein (CdGAP) is a phosphoprotein showing GAP activity toward Rac1 and Cdc42. CdGAP activity is regulated in an adhesion-dependent manner and more recently, we have identified CdGAP as a novel molecular target in signaling and an essential component in the synergistic interaction between TGFβ and Neu/ErbB-2 signaling pathways in breast cancer cells. In this study, we identified a small polybasic region (PBR) preceding the RhoGAP domain that mediates specific binding to negatively charged phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3). In vitro reconstitution of membrane vesicles loaded with prenylated Rac1 demonstrates that the PBR is required for full activation of CdGAP in the presence of PI(3,4,5)P3. In fibroblast cells, the expression of CdGAP protein mutants lacking an intact PBR shows a significant reduced ability of the protein mutants to induce cell rounding or to mediate negative effects on cell spreading. Furthermore, an intact PBR is required for CdGAP to inactivate Rac1 signaling into cells, whereas it is not essential in an in vitro context. Altogether, these studies reveal that specific interaction between negatively charged phospholipid PI(3,4,5)P3 and the stretch of polybasic residues preceding the RhoGAP domain regulates CdGAP activity in vivo and is required for its cellular functions.
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Affiliation(s)
- Fereshteh Karimzadeh
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 2B2, Canada
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Chan LK, Ko FCF, Sze KMF, Ng IOL, Yam JWP. Nuclear-targeted deleted in liver cancer 1 (DLC1) is less efficient in exerting its tumor suppressive activity both in vitro and in vivo. PLoS One 2011; 6:e25547. [PMID: 21966542 PMCID: PMC3180446 DOI: 10.1371/journal.pone.0025547] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 09/06/2011] [Indexed: 01/01/2023] Open
Abstract
Background Deleted in liver cancer 1 (DLC1) serves as an important RhoGTPase activating protein (RhoGAP) protein that terminates active RhoA signaling in human cancers. Increasing evidence has demonstrated that the tumor suppressive activity of DLC1 depends not only on RhoGAP activity, but also relies on proper focal adhesion localization through its interaction with tensin family proteins. Recently, there are reports showing that DLC1 can also be found in the nucleus; however, the existence and the relative tumor suppressive activity of nuclear DLC1 have never been clearly addressed. Methodology and Principal Findings We herein provide new evidence that DLC1 protein, which predominantly associated with focal adhesions and localized in cytosol, dynamically shuttled between cytoplasm and nucleus. Treatment of cells with nuclear export blocker, Leptomycin B (LMB), retained DLC1 in the nucleus. To understand the nuclear entry of DLC1, we identified amino acids 600–700 of DLC1 as a novel region that is important for its nuclear localization. The tumor suppressive activity of nuclear DLC1 was directly assessed by employing a nuclear localization signal (NLS) fusion variant of DLC1 (NLS-DLC1) with preferential nuclear localization. In SMMC-7721 HCC cells, expression of NLS-DLC1 failed to suppress colony formation and actin stress fiber formation in vitro. The abrogated tumor suppressive activity of nuclear DLC1 was demonstrated for the first time in vivo by subcutaneously injecting p53−/− RasV12 hepatoblasts with stable NLS-DLC1 expression in nude mice. The injected hepatoblasts with NLS-DLC1 expression effectively formed tumors when compared with the non-nuclear targeted DLC1. Conclusions/Significance Our study identified a novel region responsible for the nuclear entry of DLC1 and demonstrated the functional difference of DLC1 in different cellular compartments both in vitro and in vivo.
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Affiliation(s)
- Lo-Kong Chan
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
- Centre for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Frankie Chi Fat Ko
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
- Centre for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Karen Man-Fong Sze
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
| | - Irene Oi-Lin Ng
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
- Centre for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- * E-mail: (JWPY); (IO-LN)
| | - Judy Wai Ping Yam
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong
- Centre for Cancer Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- * E-mail: (JWPY); (IO-LN)
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Odaert B, Prouzet-Mauleon V, Dupuy JW, Crouzet M, Bonneu M, Santarelli X, Vieillemard A, Thoraval D, Doignon F, Hugues M. Evidence for specific interaction between the RhoGAP domain from the yeast Rgd1 protein and phosphoinositides. Biochem Biophys Res Commun 2011; 405:74-8. [DOI: 10.1016/j.bbrc.2010.12.130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 12/29/2010] [Indexed: 10/18/2022]
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26
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Schönichen A, Geyer M. Fifteen formins for an actin filament: a molecular view on the regulation of human formins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:152-63. [PMID: 20102729 DOI: 10.1016/j.bbamcr.2010.01.014] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Revised: 12/24/2009] [Accepted: 01/11/2010] [Indexed: 10/19/2022]
Abstract
The regulation of the actin cytoskeleton is a key process for the stability and motility of eukaryotic cells. Besides the Arp2/3 complex and its nucleation promoting factors, WH2 domain-containing proteins and a diverse family of formin proteins have recently been recognized as actin nucleators and potent polymerization factors of actin filaments. Formins are defined by the presence of a catalytic formin homology 2 (FH2) domain, yet, the modular domain architecture appears significantly different for the eight formin families identified in humans. A diverse picture of protein localization, interaction partners and cell specific regulation emerged, suggesting various functions of formins in the building and maintenance of actin filaments. This review focuses on the domain architecture of human formins, the regulation mechanisms of their activation and the diversity in formin cellular functions.
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Affiliation(s)
- André Schönichen
- Max-Planck-Institut für Molekulare Physiologie, Abteilung Physikalische Biochemie, Otto-Hahn-Str. 11, 44227 Dortmund, Germany
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