title: Drosophila RhoGAP68F is a putative GTPase activating protein for RhoA participating in gastrulation.
abstract: The Rho family small GTPases Rho, Rac, and Cdc42 regulate cell shape and motility through the actin cytoskeleton. These proteins cycle between a GTP-bound "on" state and a GDP-bound "off" state and are negatively regulated by GTPase-activating proteins (GAPs), which accelerate the small GTPase's intrinsic hydrolysis of bound GTP to GDP. Drosophila RhoGAP68F is similar to the mammalian protein p50RhoGAP/Cdc42GAP, which exhibits strong GAP activity toward Cdc42. We find that, despite the strong similarities between RhoGAP68F and p50RhoGAP/Cdc42GAP, RhoGAP68F is most effective as a GAP for RhoA. These in vitro data are supported by the in vivo analysis of mutants in RhoGAP68F. We demonstrate through the characterization of two alleles of the RhoGAP68F gene that RhoGAP68F participates in gastrulation of the embryo, a morphogenetic event driven by cell constriction that involves RhoA signaling. We propose that RhoGAP68F functions as a regulator of RhoA signaling during gastrulation.
authors.affiliation: Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.
authors.forename: Justina
authors.initials: J
authors.lastname: Sanny
authors.forename: Vincent
authors.initials: V
authors.lastname: Chui
authors.forename: Caillin
authors.initials: C
authors.lastname: Langmann
authors.forename: Carla
authors.initials: C
authors.lastname: Pereira
authors.forename: Baharak
authors.initials: B
authors.lastname: Zahedi
authors.forename: Nicholas
authors.initials: N
authors.lastname: Harden
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D004330:Drosophila / Q000033:anatomy & histology / Q000196:embryology* / Q000201:enzymology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000502:physiology*; D005775:Gastrula / Q000201:enzymology*; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D009154:Mutation; D016415:Sequence Alignment; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D020690:GTPase-Activating Proteins; C519487:RhoGAP68F protein, Drosophila; C511153:Rho1 protein, Drosophila; D020741:rho GTP-Binding Proteins