title: The Drosophila homologue of Arf-GAP GIT1, dGIT, is required for proper muscle morphogenesis and guidance during embryogenesis.
abstract: GIT1-like proteins are GTPase-activating proteins (GAPs) for Arfs and interact with a variety of signaling molecules to function as integrators of pathways controlling cytoskeletal organization and cell motility. In this report, we describe the characterization of a Drosophila homologue of GIT1, dGIT, and show that it is required for proper muscle morphogenesis and myotube guidance in the fly embryo. The dGIT protein is concentrated at the termini of growing myotubes and localizes to muscle attachment sites in late stage embryos. dgit mutant embryos show muscle patterning defects and aberrant targeting in subsets of their muscles. dgit mutant muscles fail to localize the p21-activated kinase, dPak, to their termini. dPak and dGIT form a complex in the presence of dPIX and dpak mutant embryos show similar muscle morphogenesis and targeting phenotypes to that of dgit. We propose that dGIT and dPak are part of a complex that promotes proper muscle morphogenesis and myotube targeting during embryogenesis.
authors.affiliation: Institute of Molecular and Cell Biology, Singapore 138673, Singapore. mcbsb@imcb.a-star.edu.sg
authors.forename: Sami M
authors.initials: SM
authors.lastname: Bahri
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Choy
authors.forename: Edward
authors.initials: E
authors.lastname: Manser
authors.forename: Louis
authors.initials: L
authors.lastname: Lim
authors.forename: Xiaohang
authors.initials: X
authors.lastname: Yang
mesh_terms: D000483:Alleles; D000818:Animals; D002448:Cell Adhesion; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000201:enzymology; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000201:enzymology; D047108:Embryonic Development; D020690:GTPase-Activating Proteins / Q000378:metabolism*; D009024:Morphogenesis; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism; D009132:Muscles / Q000166:cytology / Q000196:embryology* / Q000201:enzymology; D009154:Mutation / Q000235:genetics; D019683:Penetrance; D010641:Phenotype; D021381:Protein Transport; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014921:Wings, Animal / Q000002:abnormalities; D054462:p21-Activated Kinases / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D020690:GTPase-Activating Proteins; C534509:Git protein, Drosophila; C099277:Pak protein, Drosophila; D054462:p21-Activated Kinases