title: Deciphering the Molecular and Functional Basis of RHOGAP Family Proteins: A SYSTEMATIC APPROACH TOWARD SELECTIVE INACTIVATION OF RHO FAMILY PROTEINS.
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.
authors.affiliation: From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Amin
authors.affiliation: From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany.
authors.forename: Mamta
authors.initials: M
authors.lastname: Jaiswal
authors.affiliation: the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, and.
authors.forename: Urszula
authors.initials: U
authors.lastname: Derewenda
authors.affiliation: the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Reis
authors.affiliation: From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany.
authors.forename: Kazem
authors.initials: K
authors.lastname: Nouri
authors.affiliation: From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany.
authors.forename: Katja T
authors.initials: KT
authors.lastname: Koessmeier
authors.affiliation: the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
authors.forename: Pontus
authors.initials: P
authors.lastname: Aspenström
authors.affiliation: the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, and.
authors.forename: Avril V
authors.initials: AV
authors.lastname: Somlyo
authors.affiliation: From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany, radovan.dvorsky@uni-duesseldorf.de.
authors.forename: Radovan
authors.initials: R
authors.lastname: Dvorsky
authors.affiliation: From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany, reza.ahmadian@uni-duesseldorf.de.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Ahmadian
mesh_terms: D020690:GTPase-Activating Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000072417:Protein Domains; D013329:Structure-Activity Relationship; D020741:rho GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D020690:GTPase-Activating Proteins; C085379:rho GTPase-activating protein; D020741:rho GTP-Binding Proteins
keywords: GTPase; GTPase-activating protein (GAP); RAC (RAC GTPase); Ras homolog gene family, member A (RHOA); arginine finger; crystal structure; deleted in liver cancer 1 (DLC1); protein-protein interaction; signal transduction; substrate specificity