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Castillo-Azofeifa D, Wald T, Reyes EA, Gallagher A, Schanin J, Vlachos S, Lamarche-Vane N, Bomidi C, Blutt S, Estes MK, Nystul T, Klein OD. A DLG1-ARHGAP31-CDC42 axis is essential for the intestinal stem cell response to fluctuating niche Wnt signaling. Cell Stem Cell 2023; 30:188-206.e6. [PMID: 36640764 PMCID: PMC9922544 DOI: 10.1016/j.stem.2022.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 10/13/2022] [Accepted: 12/12/2022] [Indexed: 01/15/2023]
Abstract
A central factor in the maintenance of tissue integrity is the response of stem cells to variations in the levels of niche signals. In the gut, intestinal stem cells (ISCs) depend on Wnt ligands for self-renewal and proliferation. Transient increases in Wnt signaling promote regeneration after injury or in inflammatory bowel diseases, whereas constitutive activation of this pathway leads to colorectal cancer. Here, we report that Discs large 1 (Dlg1), although dispensable for polarity and cellular turnover during intestinal homeostasis, is required for ISC survival in the context of increased Wnt signaling. RNA sequencing (RNA-seq) and genetic mouse models demonstrated that DLG1 regulates the cellular response to increased canonical Wnt ligands. This occurs via the transcriptional regulation of Arhgap31, a GTPase-activating protein that deactivates CDC42, an effector of the non-canonical Wnt pathway. These findings reveal a DLG1-ARHGAP31-CDC42 axis that is essential for the ISC response to increased niche Wnt signaling.
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Affiliation(s)
- David Castillo-Azofeifa
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA, USA; Department of Regenerative Medicine, Genentech, Inc., South San Francisco, CA, USA
| | - Tomas Wald
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Efren A Reyes
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA, USA; Department of Pharmaceutical Chemistry and TETRAD Program, University of California, San Francisco, San Francisco, CA, USA
| | - Aaron Gallagher
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Julia Schanin
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Stephanie Vlachos
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, USA
| | - Nathalie Lamarche-Vane
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC, Canada
| | - Carolyn Bomidi
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Sarah Blutt
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Mary K Estes
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Todd Nystul
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, USA
| | - Ophir D Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA, USA; Department of Pediatrics and Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA; Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
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2
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Tian H, Chu F, Li Y, Xu M, Li W, Li C. Synergistic effects of rare variants of ARHGAP31 and FBLN1 in vitro in terminal transverse limb defects. Front Genet 2022; 13:946854. [PMID: 36176297 PMCID: PMC9513373 DOI: 10.3389/fgene.2022.946854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/22/2022] [Indexed: 11/20/2022] Open
Abstract
Background: Aplasia cutis congenita (ACC) and terminal transverse limb defects (TTLDs) are the most common features of Adams-Oliver syndrome (AOS). ARHGAP31 is one of the causative genes for autosomal dominant forms of AOS, meanwhile its variants may only cause isolated TTLD. Here, we report a proband presented with apparent TTLD but not ACC. Methods: Whole exome sequencing (WES) and Sanger sequencing were applied to identify causative genes. Expression vectors were constructed for transfections in mammalian cell cultures followed by biochemical and functional analysis including immunoblotting, immunofluorescence staining, and cell counting kit-8 assay. Results: WES and Sanger sequencing suggested that the proband inherited rare ARHGAP31 variant [c.2623G > A (p.Glu875Lys)] and a rare FBLN1 variant [c.1649G > A (p.Arg550His)] from one of her asymptomatic parents, respectively. Given FBLN1 variation has also been linked to syndactyly, we suspected that the two genes together contributed to the TTLD phenotype and explored their possible roles in vitro. Mutant FBLN1 showed reduced expression resulted from impaired protein stability, whereas ARHGAP31 protein expression was unaltered by mutation. Functional assays showed that only in the co-transfected group of two mutants cell viability was decreased, cell proliferation was impaired, and apoptosis was activated. Cdc42 activity was declined by both ARHGAP31 mutation and FBLN1 mutation alone, and the two together. Furthermore, the MAPK/ERK pathway was only activated by two mutants co-transfected group compared with two wild-type transfections. Conclusion: We report a case carrying two rare variants of limb defects associated genes, ARHGAP31 and FBLN1, and provide in vitro evidence that synergistic disruption of cellular functions attributed by the two mutants may potentiate the penetrance of clinical manifestations, expanding our knowledge of clinical complexity of causal gene interactions in TTLD and other genetic disorders.
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Affiliation(s)
- Hong Tian
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Hong Tian, ; Chuanzhou Li,
| | - Fan Chu
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yingjie Li
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Mengmeng Xu
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wenjiao Li
- Department of Clinical Laboratory, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Chuanzhou Li
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Hong Tian, ; Chuanzhou Li,
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3
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The roles of Cdc42 and Rac1 in the formation of plasma membrane protrusions in cancer epithelial HeLa cells. Mol Biol Rep 2021; 48:4285-4294. [PMID: 34110575 DOI: 10.1007/s11033-021-06443-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/27/2021] [Indexed: 10/21/2022]
Abstract
The inducible model of clones generated from the cervical cancer epithelial HeLa cell line has shown the role of DOCK10 as a guanine-nucleotide exchange factor for Rho GTPases Cdc42 and Rac1 and as an inducer of filopodia and plasma membrane (PM) ruffles. In this model, constitutively active (CA) mutants of Cdc42 and Rac1 promote filopodia and ruffles, respectively, as in other models. DOCK9 also induces filopodia and ruffles, although ruffling activity is less prominent. By exploiting this model further, the aim of this work is to provide a more complete understanding of the role of Cdc42 and Rac1, and their interactions with DOCK10 and DOCK9, in regulation of PM protrusions. New clones have been generated from HeLa, including single clones expressing one form of wild-type (WT) or dominant negative (DN) Cdc42 or Rac1, and double clones co-expressing one of them together with either DOCK10 or DOCK9. Expression of WT- and DN-Cdc42 induced filopodia. WT-Cdc42 and, especially, DN-Cdc42 also gave rise to veil protrusions, which were neutralized by DOCK10. Moreover, DN-Cdc42 stimulated the emergence of ruffles, further increased by DOCK10, and WT-Cdc42 also augmented ruffles in presence of DOCK9 and DOCK10. WT-Rac1 greatly increased PM blebbing, as did DN-Rac1 more moderately. In both cases, blebs were enhanced by DOCK10. DN-Rac1 and CA-Rac1 moderately raised filopodia, and DOCK10 and DOCK9 had opposed effects on filopodia (up and down, respectively) in presence of WT-Rac1. As conclusions, we highlight that Cdc42 promotes filopodia regardless of its conformational state, and Rac1 induces blebs in conformations other than CA, especially WT-Rac1, in the inducible HeLa clones. The model could be useful to learn more about the mechanisms underlying PM protrusions.
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4
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Schnabel F, Kamphausen SB, Funke R, Kaulfuß S, Wollnik B, Zenker M. Aplasia cutis congenita in a CDC42-related developmental phenotype. Am J Med Genet A 2020; 185:850-855. [PMID: 33283961 DOI: 10.1002/ajmg.a.62009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/11/2020] [Accepted: 11/14/2020] [Indexed: 11/09/2022]
Abstract
Cell division cycle 42 (CDC42) is a small Rho GTPase, which serves as a fundamental intracellular signal node regulating actin cytoskeletal dynamics and several other integral cellular processes. CDC42-associated disorders encompass a broad clinical spectrum including Takenouchi-Kosaki syndrome, autoinflammatory syndromes and neurodevelopmental phenotypes mimicking RASopathies. Dysregulation of CDC42 signaling by genetic defects in either DOCK6 or ARHGAP31 is also considered to play a role in the pathogenesis of Adams-Oliver syndrome (AOS). Here, we report a mother and her child carrying the previously reported pathogenic CDC42 variant c.511G>A (p.Glu171Lys). Both affected individuals presented with short stature, distinctive craniofacial features, pectus deformity as well as heart and eye anomalies, similar to the recently described Noonan syndrome-like phenotype associated with this variant. Remarkably, one of the patients additionally exhibited aplasia cutis congenita of the scalp. Multi-gene panel sequencing of the known AOS-causative genes and whole exome sequencing revealed no second pathogenic variant in any disease-associated gene explaining the aplasia cutis phenotype in our patient. This observation further expands the phenotypic spectrum of CDC42-associated disorders and underscores the role of CDC42 dysregulation in the pathogenesis of aplasia cutis congenita.
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Affiliation(s)
- Franziska Schnabel
- Institute of Human Genetics, University Medical Center, Göttingen, Germany
| | | | - Rudolf Funke
- Department of Neuropediatrics, Sozialpädiatrisches Zentrum, Kassel, Germany
| | - Silke Kaulfuß
- Institute of Human Genetics, University Medical Center, Göttingen, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines To Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Martin Zenker
- Institute of Human Genetics, University Hospital Magdeburg, Magdeburg, Germany
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5
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Bae DJ, Seo J, Kim SY, Park SY, Do Yoo J, Pyo JH, Cho W, Cho JY, Kim S, Kim IS. ArhGAP12 plays dual roles in Stabilin-2 mediated efferocytosis: Regulates Rac1 basal activity and spatiotemporally turns off the Rac1 to orchestrate phagosome maturation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:1595-1607. [PMID: 31301364 DOI: 10.1016/j.bbamcr.2019.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/01/2019] [Accepted: 07/08/2019] [Indexed: 12/13/2022]
Abstract
The rapid and precise clearance of apoptotic cells (efferocytosis) involves a series of phagocytic processes through which apoptotic cells are recognized, engulfed, and degraded within phagocytes. The Rho-family GTPases critically rearrange the cytoskeleton for these phagocytic processes, but we know little about the mechanisms by which regulatory proteins control the spatiotemporal activities of the Rho-family GTPases. Here, we identify ArhGAP12 as a functional GTPase-activating protein (GAP) of Rac1 during Stabilin-2 mediated efferocytosis. ArhGAP12 constitutively forms a complex with the phosphatidylserine receptor, Stabilin-2, via direct interaction with the downstream protein, GULP, but is released from the complex when Stabilin-2 interacts with apoptotic cells. When the phagocytic cup is closed and the apoptotic cell is surrounded by the phagosomal membrane, ArhGAP12 localizes to the phagocytic cup via a specific interaction with phosphatidylinositol-4,5-bisphosphate, which is transiently biosynthesized in the phagocytic cup. Down-regulation of ArhGAP12 results in sustained Rac1 activity, arrangement of F-actin, and delayed phagosome-lysosome fusion. Our results collectively suggest that ArhGAP12 carries dual roles in Stabilin-2 mediated efferocytosis: it binds to GULP/Stabilin-2 and switches off Rac1 basal activity and switches on the Rac1 by releasing itself from the complex. In addition, the spatiotemporal membrane targeting of ArhGAP12 inactivates Rac1 in a time-specific and spatially coordinated manner to orchestrate phagosome maturation. This may shed light on how other RhoGAPs spatiotemporally inactivate Rac or Cdc42 during phagocytosis by various cells, in different circumstances.
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Affiliation(s)
- Dong-Jun Bae
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea; ASAN Institute for Life Sciences, ASAN Medical Center, Seoul 138-736, Republic of Korea
| | - Junyoung Seo
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea
| | - Sang-Yeob Kim
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea; ASAN Institute for Life Sciences, ASAN Medical Center, Seoul 138-736, Republic of Korea; Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea
| | - Seung-Yoon Park
- Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea
| | - Jae Do Yoo
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea
| | - Jae-Hoon Pyo
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea
| | - Wonhwa Cho
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Je-Yoel Cho
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Republic of Korea
| | - Soyoun Kim
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea.
| | - In-San Kim
- Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea; KU-KIST school, Korea University, Seoul 136-701, Republic of Korea.
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6
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Connexin 43 Loss Triggers Cell Cycle Entry and Invasion in Non-Neoplastic Breast Epithelium: A Role for Noncanonical Wnt Signaling. Cancers (Basel) 2019; 11:cancers11030339. [PMID: 30857262 PMCID: PMC6468895 DOI: 10.3390/cancers11030339] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/15/2019] [Accepted: 03/04/2019] [Indexed: 12/26/2022] Open
Abstract
(1) Background: The expression of connexin 43 (Cx43) is disrupted in breast cancer, and re-expression of this protein in human breast cancer cell lines leads to decreased proliferation and invasiveness, suggesting a tumor suppressive role. This study aims to investigate the role of Cx43 in proliferation and invasion starting from non-neoplastic breast epithelium. (2) Methods: Nontumorigenic human mammary epithelial HMT-3522 S1 cells and Cx43 shRNA-transfected counterparts were cultured under 2-dimensional (2-D) and 3-D conditions. (3) Results: Silencing Cx43 induced mislocalization of β-catenin and Scrib from apicolateral membrane domains in glandular structures or acini formed in 3-D culture, suggesting the loss of apical polarity. Cell cycle entry and proliferation were enhanced, concomitantly with c-Myc and cyclin D1 upregulation, while no detectable activation of Wnt/β-catenin signaling was observed. Motility and invasion were also triggered and were associated with altered acinar morphology and activation of ERK1/2 and Rho GTPase signaling, which acts downstream of the noncanonical Wnt pathway. The invasion of Cx43-shRNA S1 cells was observed only under permissive stiffness of the extracellular matrix (ECM). (4) Conclusion: Our results suggest that Cx43 controls proliferation and invasion in the normal mammary epithelium in part by regulating noncanonical Wnt signaling.
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7
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Southgate L. Current opinion in the molecular genetics of Adams-Oliver syndrome. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2019.1559049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Laura Southgate
- Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK
- Department of Medical and Molecular Genetics, King’s College London, London, UK
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8
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Ben Djoudi Ouadda A, He Y, Calabrese V, Ishii H, Chidiac R, Gratton JP, Roux PP, Lamarche-Vane N. CdGAP/ARHGAP31 is regulated by RSK phosphorylation and binding to 14-3-3β adaptor protein. Oncotarget 2018; 9:11646-11664. [PMID: 29545927 PMCID: PMC5837747 DOI: 10.18632/oncotarget.24126] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 12/03/2017] [Indexed: 12/29/2022] Open
Abstract
Cdc42 GTPase-activating protein (CdGAP, also named ARHGAP31) is a negative regulator of the GTPases Rac1 and Cdc42. Associated with the rare developmental disorder Adams-Oliver Syndrome (AOS), CdGAP is critical for embryonic vascular development and VEGF-mediated angiogenesis. Moreover, CdGAP is an essential component in the synergistic interaction between TGFβ and ErbB-2 signaling pathways during breast cancer cell migration and invasion, and is a novel E-cadherin transcriptional co-repressor with Zeb2 in breast cancer. CdGAP is highly phosphorylated on serine and threonine residues in response to growth factors and is a substrate of ERK1/2 and GSK-3. Here, we identified Ser1093 and Ser1163 in the C-terminal region of CdGAP, which are phosphorylated by RSK in response to phorbol ester. These phospho-residues create docking sites for binding to 14-3-3 adaptor proteins. The interaction between CdGAP and 14-3-3 proteins inhibits the GAP activity of CdGAP and sequesters CdGAP into the cytoplasm. Consequently, the nucleocytoplasmic shuttling of CdGAP is inhibited and CdGAP-induced cell rounding is abolished. In addition, 14-3-3β inhibits the ability of CdGAP to repress the E-cadherin promoter and to induce cell migration. Finally, we show that 14-3-3β is unable to regulate the activity and subcellular localization of the AOS-related mutant proteins lacking these phospho-residues. Altogether, we provide a novel mechanism of regulation of CdGAP activity and localization, which impacts directly on a better understanding of the role of CdGAP as a promoter of breast cancer and in the molecular causes of AOS.
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Affiliation(s)
- Ali Ben Djoudi Ouadda
- Cancer Research Program, Research Institute of the MUHC, Montreal, Quebec, H4A 3J1, Canada.,McGill University, Department of Anatomy and Cell Biology, Montreal, Quebec, H3A 2B2, Canada
| | - Yi He
- Cancer Research Program, Research Institute of the MUHC, Montreal, Quebec, H4A 3J1, Canada.,McGill University, Department of Anatomy and Cell Biology, Montreal, Quebec, H3A 2B2, Canada
| | - Viviane Calabrese
- Institute for Research in Immunology and Cancer (IRIC), Montreal, Quebec, H3T 1J4, Canada
| | - Hidetaka Ishii
- Cancer Research Program, Research Institute of the MUHC, Montreal, Quebec, H4A 3J1, Canada.,McGill University, Department of Anatomy and Cell Biology, Montreal, Quebec, H3A 2B2, Canada
| | - Rony Chidiac
- Department of Pharmacology, Faculty of Medicine, Université de Montréal, Department of pharmacology, Montreal, Quebec, H3T 1J4, Canada
| | - Jean-Philippe Gratton
- Department of Pharmacology, Faculty of Medicine, Université de Montréal, Department of pharmacology, Montreal, Quebec, H3T 1J4, Canada
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer (IRIC), Montreal, Quebec, H3T 1J4, Canada
| | - Nathalie Lamarche-Vane
- Cancer Research Program, Research Institute of the MUHC, Montreal, Quebec, H4A 3J1, Canada.,McGill University, Department of Anatomy and Cell Biology, Montreal, Quebec, H3A 2B2, Canada
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9
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McCormack JJ, Bruche S, Ouadda ABD, Ishii H, Lu H, Garcia-Cattaneo A, Chávez-Olórtegui C, Lamarche-Vane N, Braga VMM. The scaffold protein Ajuba suppresses CdGAP activity in epithelia to maintain stable cell-cell contacts. Sci Rep 2017; 7:9249. [PMID: 28835688 PMCID: PMC5569031 DOI: 10.1038/s41598-017-09024-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/20/2017] [Indexed: 12/28/2022] Open
Abstract
Levels of active Rac1 at epithelial junctions are partially modulated via interaction with Ajuba, an actin binding and scaffolding protein. Here we demonstrate that Ajuba interacts with the Cdc42 GTPase activating protein CdGAP, a GAP for Rac1 and Cdc42, at cell-cell contacts. CdGAP recruitment to junctions does not require Ajuba; rather Ajuba seems to control CdGAP residence at sites of cell-cell adhesion. CdGAP expression potently perturbs junctions and Ajuba binding inhibits CdGAP activity. Ajuba interacts with Rac1 and CdGAP via distinct domains and can potentially bring them in close proximity at junctions to facilitate activity regulation. Functionally, CdGAP-Ajuba interaction maintains junctional integrity in homeostasis and diseases: (i) gain-of-function CdGAP mutants found in Adams-Oliver Syndrome patients strongly destabilize cell-cell contacts and (ii) CdGAP mRNA levels are inversely correlated with E-cadherin protein expression in different cancers. We present conceptual insights on how Ajuba can integrate CdGAP binding and inactivation with the spatio-temporal regulation of Rac1 activity at junctions. Ajuba provides a novel mechanism due to its ability to bind to CdGAP and Rac1 via distinct domains and influence the activation status of both proteins. This functional interplay may contribute towards conserving the epithelial tissue architecture at steady-state and in different pathologies.
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Affiliation(s)
- J J McCormack
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, SW7 2AZ, London, UK
| | - S Bruche
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, SW7 2AZ, London, UK
| | - A B D Ouadda
- Cancer Research Program, Research Institute-McGill University Hospital Centre and Department of Anatomy and Cell Biology, McGill University, H4A 3J1, Montreal, Quebec, Canada
| | - H Ishii
- Cancer Research Program, Research Institute-McGill University Hospital Centre and Department of Anatomy and Cell Biology, McGill University, H4A 3J1, Montreal, Quebec, Canada
| | - H Lu
- Cancer Division, Faculty of Medicine, Imperial College London, SW7 2AZ, London, UK
| | - A Garcia-Cattaneo
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, SW7 2AZ, London, UK
| | - C Chávez-Olórtegui
- Department of Biochemistry and Immunology, Institute of Cell Biology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - N Lamarche-Vane
- Cancer Research Program, Research Institute-McGill University Hospital Centre and Department of Anatomy and Cell Biology, McGill University, H4A 3J1, Montreal, Quebec, Canada
| | - V M M Braga
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, SW7 2AZ, London, UK.
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10
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Gazdagh G, Tobias ES, Ahmed SF, McGowan R. Novel Genetic Associations and Range of Phenotypes in Children with Disorders of Sex Development and Neurodevelopment: Insights from the Deciphering Developmental Disorders Study. Sex Dev 2016; 10:130-5. [PMID: 27598577 PMCID: PMC5079067 DOI: 10.1159/000447958] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2016] [Indexed: 11/30/2022] Open
Abstract
A range of phenotypes that are associated with disorders of sex development (DSD) may also be encountered in patients with neurodevelopmental delay. In this study we have undertaken a collaborative retrospective review of anonymised phenotypic and genotypic data from the UK-wide Deciphering Developmental Disorders (DDD) study. Our objectives were to determine the frequency and range of DSD phenotypes observed in participants in the DDD study and to identify novel genetic associations. We found that of 7,439 DDD participants, 603 (8%) had at least one genital abnormality. In addition, we found that DSD occurs in 5% of patients with learning difficulties. Causative mutations were found in 13 developmental genes, of which, crucially, 6 had no previous reported association with DSD. Our findings indicate that recognition of these associations should not be overlooked in the management of patients with complex conditions and that exomic sequencing through projects like DDD increases diagnostic yield.
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Affiliation(s)
- Gabriella Gazdagh
- West of Scotland Regional Genetics Service, Laboratory Medicine Building, Queen Elizabeth University Hospital, Glasgow, UK
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11
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CdGAP/ARHGAP31, a Cdc42/Rac1 GTPase regulator, is critical for vascular development and VEGF-mediated angiogenesis. Sci Rep 2016; 6:27485. [PMID: 27270835 PMCID: PMC4895392 DOI: 10.1038/srep27485] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/17/2016] [Indexed: 02/06/2023] Open
Abstract
Mutations in the CdGAP/ARHGAP31 gene, which encodes a GTPase-activating protein for Rac1 and Cdc42, have been reported causative in the Adams-Oliver developmental syndrome often associated with vascular defects. However, despite its abundant expression in endothelial cells, CdGAP function in the vasculature remains unknown. Here, we show that vascular development is impaired in CdGAP-deficient mouse embryos at E15.5. This is associated with superficial vessel defects and subcutaneous edema, resulting in 44% embryonic/perinatal lethality. VEGF-driven angiogenesis is defective in CdGAP(-/-) mice, showing reduced capillary sprouting from aortic ring explants. Similarly, VEGF-dependent endothelial cell migration and capillary formation are inhibited upon CdGAP knockdown. Mechanistically, CdGAP associates with VEGF receptor-2 and controls VEGF-dependent signaling. Consequently, CdGAP depletion results in impaired VEGF-mediated Rac1 activation and reduced phosphorylation of critical intracellular mediators including Gab1, Akt, PLCγ and SHP2. These findings are the first to demonstrate the importance of CdGAP in embryonic vascular development and VEGF-induced signaling, and highlight CdGAP as a potential therapeutic target to treat pathological angiogenesis and vascular dysfunction.
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12
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Enomoto S, Mitsui K, Kawamura T, Iwanari H, Daigo K, Horiuchi K, Minami T, Kodama T, Hamakubo T. Suppression of Slit2/Robo1 mediated HUVEC migration by Robo4. Biochem Biophys Res Commun 2016; 469:797-802. [PMID: 26713366 DOI: 10.1016/j.bbrc.2015.12.075] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 12/18/2015] [Indexed: 01/15/2023]
Abstract
Slit proteins and their receptors, the Roundabout (Robo) family, are known to have a pivotal role in the vascular system. Slit2/Robo1 regulates the migration of human umbilical vein endothelial cells (HUVECs) and tumor-associated endothelial cells. Robo4, the endothelial-specific Robo, is also considered to be involved in vascular cell migration. However, the Slit/Robo signaling pathway is still unclear. Using a Boyden chamber assay, we found that Slit2 induces the migration of HUVECs under a Robo4 knockdown condition. This effect disappeared in Robo1 knockdown cells. The co-existence of the N-terminal extracellular portion of Robo1 blocked the Slit2-evoked migration of HUVECs, while that of Robo4 caused no effect. These results show that the Slit2 signal is transduced through Robo1, while the negative regulation of Robo4 is an intracellular event. Targeted proteomics using an anti-Robo1 monoclonal antibody identified CdGAP, an adhesion-localized Rac1-and Cdc42-specific GTPase activating protein, as a candidate for Slit2/Robo1 signaling. Robo1 and CdGAP were co-immunoprecipitated from CHO cells co-transfected with Robo1 and CdGAP genes. These results suggest that Slit2/Robo1 binding exerts an effect on cell migration, which is negatively regulated by Robo4, and Robo1 may function by interacting with CdGAP in HUVECs.
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Affiliation(s)
- Satoshi Enomoto
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kenichi Mitsui
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Takeshi Kawamura
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan; Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Hiroko Iwanari
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kenji Daigo
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Keiko Horiuchi
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Takashi Minami
- Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Tatsuhiko Kodama
- Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Takao Hamakubo
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
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13
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Sukalo M, Tilsen F, Kayserili H, Müller D, Tüysüz B, Ruddy DM, Wakeling E, Ørstavik KH, Snape KM, Trembath R, De Smedt M, van der Aa N, Skalej M, Mundlos S, Wuyts W, Southgate L, Zenker M. DOCK6 mutations are responsible for a distinct autosomal-recessive variant of Adams-Oliver syndrome associated with brain and eye anomalies. Hum Mutat 2015; 36:593-8. [PMID: 25824905 DOI: 10.1002/humu.22795] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/27/2015] [Indexed: 12/18/2022]
Abstract
Adams-Oliver syndrome (AOS) is characterized by the association of aplasia cutis congenita with terminal transverse limb defects, often accompanied by additional cardiovascular or neurological features. Both autosomal-dominant and autosomal-recessive disease transmission have been observed, with recent gene discoveries indicating extensive genetic heterogeneity. Mutations of the DOCK6 gene were first described in autosomal-recessive cases of AOS and only five DOCK6-related families have been reported to date. Recently, a second type of autosomal-recessive AOS has been attributed to EOGT mutations in three consanguineous families. Here, we describe the identification of 13 DOCK6 mutations, the majority of which are novel, across 10 unrelated individuals from a large cohort comprising 47 sporadic cases and 31 AOS pedigrees suggestive of autosomal-recessive inheritance. DOCK6 mutations were strongly associated with structural brain abnormalities, ocular anomalies, and intellectual disability, thus suggesting that DOCK6-linked disease represents a variant of AOS with a particularly poor prognosis.
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Affiliation(s)
- Maja Sukalo
- Institute of Human Genetics, University Hospital Magdeburg, Magdeburg, Germany
| | - Felix Tilsen
- Institute of Human Genetics, University Hospital Magdeburg, Magdeburg, Germany
| | - Hülya Kayserili
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul, Turkey.,Medical Genetics Department, School of Medicine, Koc University, Istanbul, Turkey
| | - Dietmar Müller
- Institut für Medizinische Genetik, Klinikum Chemnitz, Chemnitz, Germany
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, Istanbul University, Istanbul, Turkey
| | | | - Emma Wakeling
- North West Thames Regional Genetics Service, North West London Hospitals NHS Trust, Harrow, UK
| | | | - Katie M Snape
- Department of Clinical Genetics, St. George's Healthcare NHS Trust, London, UK
| | - Richard Trembath
- Department of Clinical Genetics, Guy's Hospital, London, UK.,Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Maryse De Smedt
- Department of Medical Genetics, Leuven University Hospital, Leuven, Belgium
| | - Nathalie van der Aa
- Department of Medical Genetics, Antwerp University Hospital, Antwerp, Belgium
| | - Martin Skalej
- Institute of Neuroradiology, University Hospital Magdeburg, Magdeburg, Germany
| | - Stefan Mundlos
- Institute for Medical and Human Genetics Charité, Universitätsmedizin Berlin and Max Planck Institute for Molecular Genetics Berlin, Berlin, Germany
| | - Wim Wuyts
- Department of Medical Genetics, Antwerp University Hospital, Antwerp, Belgium.,Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Laura Southgate
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.,Division of Genetics and Molecular Medicine, King's College London, London, UK
| | - Martin Zenker
- Institute of Human Genetics, University Hospital Magdeburg, Magdeburg, Germany
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14
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Ohshima H. Oral Biosciences: The annual review 2014. J Oral Biosci 2015. [DOI: 10.1016/j.job.2014.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Buchtova M, Oralova V, Aklian A, Masek J, Vesela I, Ouyang Z, Obadalova T, Konecna Z, Spoustova T, Pospisilova T, Matula P, Varecha M, Balek L, Gudernova I, Jelinkova I, Duran I, Cervenkova I, Murakami S, Kozubik A, Dvorak P, Bryja V, Krejci P. Fibroblast growth factor and canonical WNT/β-catenin signaling cooperate in suppression of chondrocyte differentiation in experimental models of FGFR signaling in cartilage. Biochim Biophys Acta Mol Basis Dis 2015; 1852:839-50. [PMID: 25558817 DOI: 10.1016/j.bbadis.2014.12.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 11/30/2014] [Accepted: 12/27/2014] [Indexed: 11/29/2022]
Abstract
Aberrant fibroblast growth factor (FGF) signaling disturbs chondrocyte differentiation in skeletal dysplasia, but the mechanisms underlying this process remain unclear. Recently, FGF was found to activate canonical WNT/β-catenin pathway in chondrocytes via Erk MAP kinase-mediated phosphorylation of WNT co-receptor Lrp6. Here, we explore the cellular consequences of such a signaling interaction. WNT enhanced the FGF-mediated suppression of chondrocyte differentiation in mouse limb bud micromass and limb organ cultures, leading to inhibition of cartilage nodule formation in micromass cultures, and suppression of growth in cultured limbs. Simultaneous activation of the FGF and WNT/β-catenin pathways resulted in loss of chondrocyte extracellular matrix, expression of genes typical for mineralized tissues and alteration of cellular shape. WNT enhanced the FGF-mediated downregulation of chondrocyte proteoglycan and collagen extracellular matrix via inhibition of matrix synthesis and induction of proteinases involved in matrix degradation. Expression of genes regulating RhoA GTPase pathway was induced by FGF in cooperation with WNT, and inhibition of the RhoA signaling rescued the FGF/WNT-mediated changes in chondrocyte cellular shape. Our results suggest that aberrant FGF signaling cooperates with WNT/β-catenin in suppression of chondrocyte differentiation.
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Affiliation(s)
- Marcela Buchtova
- Department of Anatomy, Histology and Embryology, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic; Institute of Animal Physiology and Genetics AS CR, v.v.i., Brno, Czech Republic
| | - Veronika Oralova
- Institute of Animal Physiology and Genetics AS CR, v.v.i., Brno, Czech Republic
| | - Anie Aklian
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jan Masek
- Institute of Experimental Biology, Faculty of Sciences, Masaryk University, Brno, Czech Republic
| | - Iva Vesela
- Department of Anatomy, Histology and Embryology, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
| | - Zhufeng Ouyang
- Department of Orthopaedics, Case Western Reserve University, Cleveland, OH, USA
| | - Tereza Obadalova
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Zaneta Konecna
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Tereza Spoustova
- Institute of Experimental Biology, Faculty of Sciences, Masaryk University, Brno, Czech Republic
| | - Tereza Pospisilova
- Institute of Experimental Biology, Faculty of Sciences, Masaryk University, Brno, Czech Republic
| | - Petr Matula
- Centre for Biomedical Image Analysis, Faculty of Informatics, Masaryk University, Brno, Czech Republic
| | - Miroslav Varecha
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lukas Balek
- Institute of Experimental Biology, Faculty of Sciences, Masaryk University, Brno, Czech Republic
| | - Iva Gudernova
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Iva Jelinkova
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Ivan Duran
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Iveta Cervenkova
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Shunichi Murakami
- Department of Orthopaedics, Case Western Reserve University, Cleveland, OH, USA
| | - Alois Kozubik
- Institute of Experimental Biology, Faculty of Sciences, Masaryk University, Brno, Czech Republic; Department of Cytokinetics, Institute of Biophysics AS CR, v.v.i., Brno, Czech Republic
| | - Petr Dvorak
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Vitezslav Bryja
- Institute of Experimental Biology, Faculty of Sciences, Masaryk University, Brno, Czech Republic; Department of Cytokinetics, Institute of Biophysics AS CR, v.v.i., Brno, Czech Republic
| | - Pavel Krejci
- Institute of Experimental Biology, Faculty of Sciences, Masaryk University, Brno, Czech Republic; Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.
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16
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17
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Bozóky B, Savchenko A, Csermely P, Korcsmáros T, Dúl Z, Pontén F, Székely L, Klein G. Novel signatures of cancer-associated fibroblasts. Int J Cancer 2013; 133:286-93. [DOI: 10.1002/ijc.28035] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 12/08/2012] [Accepted: 01/02/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Benedek Bozóky
- Department of Microbiology; Tumor and Cell Biology (MTC), Karolinska Institutet; Stockholm; Sweden
| | - Andrii Savchenko
- Department of Microbiology; Tumor and Cell Biology (MTC), Karolinska Institutet; Stockholm; Sweden
| | - Péter Csermely
- Department of Medical Chemistry, Faculty of Medicine; Semmelweis University; Budapest; Hungary
| | | | | | - Fredrik Pontén
- Department of Immunology; Genetics and Pathology, Rudbecklaboratoriet; Uppsala; Sweden
| | - László Székely
- Department of Microbiology; Tumor and Cell Biology (MTC), Karolinska Institutet; Stockholm; Sweden
| | - George Klein
- Department of Microbiology; Tumor and Cell Biology (MTC), Karolinska Institutet; Stockholm; Sweden
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18
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Wormer D, Deakin NO, Turner CE. CdGAP regulates cell migration and adhesion dynamics in two-and three-dimensional matrix environments. Cytoskeleton (Hoboken) 2012; 69:644-58. [PMID: 22907917 DOI: 10.1002/cm.21057] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/18/2012] [Accepted: 07/19/2012] [Indexed: 12/23/2022]
Abstract
CdGAP is a Rac1/Cdc42 specific GTPase activating protein (GAP) that localizes to cell-matrix adhesions through an interaction with the adhesion scaffold α-parvin/actopaxin to regulate lamellipodia formation and cell spreading. Herein, we demonstrate, using a combination of siRNA-mediated silencing and overexpression, that cdGAP negatively regulates directed and random migration by controlling adhesion maturation and dynamics through the regulation of both adhesion assembly and disassembly. Interestingly, cdGAP was also localized to adhesions formed in three-dimensional (3D) matrix environments and cdGAP depletion promoted cancer cell migration and invasion through 3D matrices. These findings highlight the importance of GAP proteins in the regulation of Rho family GTPases and the coordination of the cell migration machinery..
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Affiliation(s)
- Duncan Wormer
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, New York 13210, USA
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19
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Liu M, Bi F, Zhou X, Zheng Y. Rho GTPase regulation by miRNAs and covalent modifications. Trends Cell Biol 2012; 22:365-73. [PMID: 22572609 DOI: 10.1016/j.tcb.2012.04.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/05/2012] [Accepted: 04/10/2012] [Indexed: 12/15/2022]
Abstract
To date, most studies of Rho GTPase regulation have focused on the classic GTPase cycle - GTP binding and hydrolysis - controlled by guanine nucleotide exchange factors (GEFs), GTPase-activating proteins (GAPs) and GDP-dissociation inhibitors (GDIs). Recent investigations have unveiled important additional regulatory mechanisms: microRNA (miRNA) regulating post-transcriptional processing of Rho GTPase-encoding mRNAs; palmitoylation and nuclear targeting affecting intracellular distribution; post-translational phosphorylation, transglutamination and AMPylation impacting Rho GTPase signaling; and ubiquitination controlling Rho GTPase protein stability and turnover. These modes of regulation add to the complexity of the Rho GTPase signaling network and allow precise spatiotemporal control of individual Rho GTPases. This review discusses these 'unconventional' modes of regulation and their contribution to cellular function, focusing on post-transcriptional and post-translational events beyond the classic GTPase cycle regulatory model.
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Affiliation(s)
- Ming Liu
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Research Foundation, University of Cincinnati, Cincinnati, OH 45229, USA
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20
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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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21
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Gomez G, Lee JH, Veldman MB, Lu J, Xiao X, Lin S. Identification of vascular and hematopoietic genes downstream of etsrp by deep sequencing in zebrafish. PLoS One 2012; 7:e31658. [PMID: 22438865 PMCID: PMC3306315 DOI: 10.1371/journal.pone.0031658] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 01/17/2012] [Indexed: 11/18/2022] Open
Abstract
The transcription factor etsrp/Er71/Etv2 is a master control gene for vasculogenesis in all species studied to date. It is also required for hematopoiesis in zebrafish and mice. Several novel genes expressed in vasculature have been identified through transcriptional profiling of zebrafish embryos overexpressing etsrp by microarrays. Here we re-examined this transcriptional profile by Illumina RNA-sequencing technology, revealing a substantially increased number of candidate genes regulated by etsrp. Expression studies of 50 selected candidate genes from this dataset resulted in the identification of 39 new genes that are expressed in vascular cells. Regulation of these genes by etsrp was confirmed by their ectopic induction in etsrp overexpressing and decreased expression in etsrp deficient embryos. Our studies demonstrate the effectiveness of the RNA-sequencing technology to identify biologically relevant genes in zebrfish and produced a comprehensive profile of genes previously unexplored in vascular endothelial cell biology.
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Affiliation(s)
- Gustavo Gomez
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
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22
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Shaheen R, Faqeih E, Sunker A, Morsy H, Al-Sheddi T, Shamseldin H, Adly N, Hashem M, Alkuraya. F. Recessive mutations in DOCK6, encoding the guanidine nucleotide exchange factor DOCK6, lead to abnormal actin cytoskeleton organization and Adams-Oliver syndrome. Am J Hum Genet 2011; 89:328-33. [PMID: 21820096 DOI: 10.1016/j.ajhg.2011.07.009] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 07/13/2011] [Accepted: 07/17/2011] [Indexed: 12/26/2022] Open
Abstract
Adams-Oliver syndrome (AOS) is defined by the combination of aplasia cutis congenita (ACC) and terminal transverse limb defects (TTLD). It is usually inherited as an autosomal-dominant trait, but autosomal-recessive inheritance has also been documented. In an individual with autosomal-recessive AOS, we combined autozygome analysis with exome sequencing to identify a homozygous truncating mutation in dedicator of cytokinesis 6 gene (DOCK6) which encodes an atypical guanidine exchange factor (GEF) known to activate two members of the Rho GTPase family: Cdc42 and Rac1. Another homozygous truncating mutation was identified upon targeted sequencing of DOCK6 in an unrelated individual with AOS. Consistent with the established role of Cdc42 and Rac1 in the organization of the actin cytoskeleton, we demonstrate a cellular phenotype typical of a defective actin cytoskeleton in patient cells. These findings, combined with a Dock6 expression profile that is consistent with an AOS phenotype as well as the very recent demonstration of dominant mutations of ARHGAP31 in AOS, establish Cdc42 and Rac1 as key molecules in the pathogenesis of AOS and suggest that other regulators of these Rho GTPase proteins might be good candidates in the quest to define the genetic spectrum of this genetically heterogeneous condition.
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23
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Southgate L, Machado R, Snape K, Primeau M, Dafou D, Ruddy D, Branney P, Fisher M, Lee G, Simpson M, He Y, Bradshaw T, Blaumeiser B, Winship W, Reardon W, Maher E, FitzPatrick D, Wuyts W, Zenker M, Lamarche-Vane N, Trembath R. Gain-of-function mutations of ARHGAP31, a Cdc42/Rac1 GTPase regulator, cause syndromic cutis aplasia and limb anomalies. Am J Hum Genet 2011; 88:574-85. [PMID: 21565291 DOI: 10.1016/j.ajhg.2011.04.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 04/19/2011] [Accepted: 04/20/2011] [Indexed: 12/21/2022] Open
Abstract
Regulation of cell proliferation and motility is essential for normal development. The Rho family of GTPases plays a critical role in the control of cell polarity and migration by effecting the cytoskeleton, membrane trafficking, and cell adhesion. We investigated a recognized developmental disorder, Adams-Oliver syndrome (AOS), characterized by the combination of aplasia cutis congenita (ACC) and terminal transverse limb defects (TTLD). Through a genome-wide linkage analysis, we detected a locus for autosomal-dominant ACC-TTLD on 3q generating a maximum LOD score of 4.93 at marker rs1464311. Candidate-gene- and exome-based sequencing led to the identification of independent premature truncating mutations in the terminal exon of the Rho GTPase-activating protein 31 gene, ARHGAP31, which encodes a Cdc42/Rac1 regulatory protein. Mutant transcripts are stable and increase ARHGAP31 activity in vitro through a gain-of-function mechanism. Constitutively active ARHGAP31 mutations result in a loss of available active Cdc42 and consequently disrupt actin cytoskeletal structures. Arhgap31 expression in the mouse is substantially restricted to the terminal limb buds and craniofacial processes during early development; these locations closely mirror the sites of impaired organogenesis that characterize this syndrome. These data identify the requirement for regulated Cdc42 and/or Rac1 signaling processes during early human development.
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24
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CdGAP is required for transforming growth factor β- and Neu/ErbB-2-induced breast cancer cell motility and invasion. Oncogene 2010; 30:1032-45. [PMID: 21042277 DOI: 10.1038/onc.2010.477] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
RhoA, Rac1 and Cdc42, the best-characterized members of the Rho family of small GTPases, are critical regulators of many cellular activities. Cdc42 GTPase-activating protein (CdGAP) is a serine- and proline-rich RhoGAP protein showing GAP activity against both Cdc42 and Rac1 but not RhoA. CdGAP is phosphorylated downstream of the MEK-ERK (extracellular signal-regulated kinase) pathway in response to serum and is required for normal cell spreading and polarized lamellipodia formation. In this study, we found that CdGAP protein and mRNA levels are highly increased in mammary tumor explants expressing an activated Neu/ErbB-2 (Neu-NT) receptor. In response to transforming growth factor-β (TGFβ) stimulation, Neu-NT-expressing mammary tumor explants demonstrate a clear induction in cell motility and invasion. We show that downregulation of CdGAP expression by small interfering RNA abrogates the ability of TGFβ to induce cell motility and invasion of Neu-NT-expressing mammary tumor explants. However, it has no effect on TGFβ-mediated cell adhesion on type 1 collagen and fibronectin. Interestingly, protein expression of E-Cadherin is highly increased in Neu-NT-expressing mammary tumor explants depleted of CdGAP. In addition, complete loss of E-Cadherin expression is not observed in CdGAP-depleted cells during TGFβ-mediated epithelial to mesenchymal transition. Downregulation of the CdGAP expression also decreases cell proliferation of Neu-NT-expressing mammary tumor explants independently of TGFβ. Rescue analysis using re-expression of various CdGAP deletion-mutant proteins revealed that the proline-rich domain (PRD) but not the GAP domain of CdGAP is essential to mediate TGFβ-induced cell motility and invasion. Finally, we found that TGFβ induces the expression and phosphorylation of CdGAP in mammary epithelial NMuMG cells. Taken together, these studies identify CdGAP as a novel molecular target in TGFβ signaling and implicate CdGAP as an essential component in the synergistic interaction between TGFβ and Neu/ErbB-2 signaling pathways in breast cancer cells.
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25
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Zhou YT, Chew LL, Lin SC, Low BC. The BNIP-2 and Cdc42GAP homology (BCH) domain of p50RhoGAP/Cdc42GAP sequesters RhoA from inactivation by the adjacent GTPase-activating protein domain. Mol Biol Cell 2010; 21:3232-46. [PMID: 20660160 PMCID: PMC2938388 DOI: 10.1091/mbc.e09-05-0408] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The BNIP-2 and Cdc42GAP Homology (BCH) domain from p50RhoGAP sequesters RhoA from inactivation by the adjacent GAP domain and it confers unique Rho-binding profile from that of GAP domain. This suppression is further augmented by an intramolecular interaction, adding to a new paradigm for regulating p50RhoGAP signaling. The BNIP-2 and Cdc42GAP homology (BCH) domain is a novel regulator for Rho GTPases, but its impact on p50-Rho GTPase-activating protein (p50RhoGAP or Cdc42GAP) in cells remains elusive. Here we show that deletion of the BCH domain from p50RhoGAP enhanced its GAP activity and caused drastic cell rounding. Introducing constitutively active RhoA or inactivating GAP domain blocked such effect, whereas replacing the BCH domain with endosome-targeting SNX3 excluded requirement of endosomal localization in regulating the GAP activity. Substitution with homologous BCH domain from Schizosaccharomyces pombe, which does not bind mammalian RhoA, also led to complete loss of suppression. Interestingly, the p50RhoGAP BCH domain only targeted RhoA, but not Cdc42 or Rac1, and it was unable to distinguish between GDP and the GTP-bound form of RhoA. Further mutagenesis revealed a RhoA-binding motif (residues 85-120), which when deleted, significantly reduced BCH inhibition on GAP-mediated cell rounding, whereas its full suppression also required an intramolecular interaction motif (residues 169-197). Therefore, BCH domain serves as a local modulator in cis to sequester RhoA from inactivation by the adjacent GAP domain, adding to a new paradigm for regulating p50RhoGAP signaling.
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Affiliation(s)
- Yi Ting Zhou
- Cell Signaling and Developmental Biology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117543, Republic of Singapore.
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26
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Abstract
The Rho GTPases are implicated in almost every fundamental cellular process. They act as molecular switches that cycle between an active GTP-bound and an inactive GDP-bound state. Their slow intrinsic GTPase activity is greatly enhanced by RhoGAPs (Rho GTPase-activating proteins), thus causing their inactivation. To date, more than 70 RhoGAPs have been identified in eukaryotes, ranging from yeast to human, and based on sequence homology of their RhoGAP domain, we have grouped them into subfamilies. In the present Review, we discuss their regulation, biological functions and implication in human diseases.
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Affiliation(s)
- Joseph Tcherkezian
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 2B2
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Danek EI, Tcherkezian J, Triki I, Meriane M, Lamarche-Vane N. Glycogen synthase kinase-3 phosphorylates CdGAP at a consensus ERK 1 regulatory site. J Biol Chem 2006; 282:3624-31. [PMID: 17158447 DOI: 10.1074/jbc.m610073200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rho GTPases regulate a multitude of cellular processes from cytoskeletal reorganization to gene transcription and are negatively regulated by GTPase-activating proteins (GAPs). Cdc42 GTPase-activating protein (CdGAP) is a ubiquitously expressed GAP for Rac1 and Cdc42. In this study, we set out to identify CdGAP-binding partners and, using a yeast two-hybrid approach, glycogen synthase kinase 3alpha (GSK-3alpha) was identified as a partner for CdGAP. GSK-3 exists in two isoforms, alpha and beta, and is involved in regulating many cellular functions from insulin response to tumorigenesis. We show that GSK-3alpha and -beta interact with CdGAP in mammalian cells. We also demonstrate that GSK-3 phosphorylates CdGAP both in vitro and in vivo on Thr-776, which we have previously shown to be an ERK 1/2 phosphorylation site involved in CdGAP regulation. We report that the mRNA and protein levels of CdGAP are increased upon serum stimulation and that GSK-3 activity is necessary for the up-regulation of the protein levels of CdGAP but not for the increase in mRNA. We conclude that GSK-3 is an important regulator of CdGAP and that regulation of CdGAP protein levels by serum presents a novel mechanism for cells to control Cdc42/Rac1 GTPase signaling pathways.
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Affiliation(s)
- Eric Ian Danek
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 2B2, Canada
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