title: The actin-binding protein UNC-115 is an effector of Rac signaling during axon pathfinding in C. elegans.
abstract: Rac GTPases control cell shape by regulating downstream effectors that influence the actin cytoskeleton. UNC-115, a putative actin-binding protein similar to human abLIM/limatin, has previously been implicated in axon pathfinding. We have discovered the role of UNC-115 as a downstream cytoskeletal effector of Rac signaling in axon pathfinding. We show that unc-115 double mutants with ced-10 Rac, mig-2 Rac or unc-73 GEF but not with rac-2/3 Rac displayed synthetic axon pathfinding defects, and that loss of unc-115 function suppressed the formation of ectopic plasma membrane extensions induced by constitutively-active rac-2 in neurons. Furthermore, we show that UNC-115 can bind to actin filaments. Thus, UNC-115 is an actin-binding protein that acts downstream of Rac signaling in axon pathfinding.
authors.affiliation: Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045-7534, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Struckhoff
authors.forename: Erik A
authors.initials: EA
authors.lastname: Lundquist
mesh_terms: D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D017386:Sequence Homology, Amino Acid; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000097766:RAC2 GTP-Binding Protein
chemical_list: D000199:Actins; D029742:Caenorhabditis elegans Proteins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D020744:rac GTP-Binding Proteins; D000097766:RAC2 GTP-Binding Protein; C407268:CED-10 protein, C elegans; C472306:UNC-115 protein, C elegans; C111263:UNC-73 protein, C elegans; C442327:Mig-2 protein, C elegans