Identification of a novel Cdc42 GEF that is localized to the PAT-3-mediated adhesive structure

Biochem Biophys Res Commun. 2005 Sep 16;335(1):139-45. doi: 10.1016/j.bbrc.2005.07.068.

Abstract

In the model organism Caenorhabditis elegans, UNC-112 is colocalized with PAT-3/beta-integrin and is a critical protein in the formation of PAT-3-mediated adhesive structure in body-wall muscle cells. However, the signaling pathway downstream of PAT-3/UNC-112 is largely unknown. To clarify the signaling pathway from PAT-3/UNC-112 to the actin cytoskeleton, we searched for and identified a novel Dbl homology/pleckstrin homology (DH/PH) domain containing protein, UIG-1 (UNC-112-interacting guanine nucleotide exchange factor-1). UIG-1 was colocalized with UNC-112 at dense bodies in body-wall muscle cells. UIG-1 showed CDC-42-specific GEF activity in vitro and induced filopodia formation in NIH 3T3 cells. Depletion of CDC-42 or PAT-3 in the developmental stage, by RNAi, prevented the formation of continuous actin filament in body-wall muscle cells. Taken together, these results suggest that UIG-1 links a PAT-3/UNC-112 complex to the CDC-42 signaling pathway during muscle formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Adhesion Molecules / metabolism
  • Cell Differentiation
  • Cell Line
  • Chlorocebus aethiops
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Integrin beta Chains / metabolism*
  • Integrins / metabolism
  • Mice
  • Muscles / cytology
  • Muscles / metabolism
  • Protein Binding
  • Pseudopodia / metabolism
  • Signal Transduction
  • Tissue Adhesions
  • cdc42 GTP-Binding Protein / metabolism*

Substances

  • Caenorhabditis elegans Proteins
  • Cell Adhesion Molecules
  • Guanine Nucleotide Exchange Factors
  • Integrin beta Chains
  • Integrins
  • UIG-1 protein, C elegans
  • UNC-112 protein, C elegans
  • pat-3 protein, C elegans
  • cdc42 GTP-Binding Protein