title: p190B RhoGAP regulates endothelial-cell-associated proteolysis through MT1-MMP and MMP2.
abstract: The two isoforms of p190 RhoGAP (p190A and p190B) are important regulators of RhoGTPase activity in mammalian cells. Both proteins are ubiquitously expressed, are involved in the same signalling pathways and interact with the same identified binding partners. In search of isoform functional specificity, we knocked down the expression of each p190 protein using siRNA and examined the resulting phenotypic changes in human umbilical vein endothelial cells (HUVECs). We provide evidence that p190B plays a crucial role in the regulation of MT1-MMP expression and cell-surface presentation, as well as subsequent MMP2 activation. p190B is involved in both local extracellular matrix degradation at podosomes and endothelial cell assembly into tube-like structures in Matrigel. In addition, whereas p190B knockdown does not affect podosome formation, p190A knockdown increases the number of cells showing podosome structures in HUVECs. We conclude that the two p190 RhoGAP isoforms play distinct roles in endothelial cells. In addition, our data reveal an unsuspected role for p190B in the expression of the two collaborative proteases MT1-MMP and MMP2, thereby affecting matrix remodelling and angiogenesis.
authors.affiliation: Institut Européen de Chimie-Biologie, Pessac, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Guegan
authors.forename: Florence
authors.initials: F
authors.lastname: Tatin
authors.forename: Thierry
authors.initials: T
authors.lastname: Leste-Lasserre
authors.forename: Guillaume
authors.initials: G
authors.lastname: Drutel
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Genot
authors.forename: Violaine
authors.initials: V
authors.lastname: Moreau
mesh_terms: D003094:Collagen; D004338:Drug Combinations; D004727:Endothelium / Q000378:metabolism* / Q000473:pathology; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D005260:Female; D022001:Focal Adhesions / Q000201:enzymology / Q000235:genetics; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007797:Laminin; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D008870:Microtubules / Q000201:enzymology / Q000235:genetics; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D011247:Pregnancy; D011499:Protein Processing, Post-Translational; D011509:Proteoglycans; D034741:RNA, Small Interfering / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism
chemical_list: C074560:ARHGAP35 protein, human; C513043:ARHGAP5 protein, human; D004338:Drug Combinations; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D007797:Laminin; D061965:Matrix Metalloproteinase Inhibitors; D011509:Proteoglycans; D034741:RNA, Small Interfering; D012097:Repressor Proteins; C059485:matrigel; D003094:Collagen; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D020778:Matrix Metalloproteinase 2; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14