SRC-1 mediates UNC-5 signaling in Caenorhabditis elegans

Mol Cell Biol. 2005 Aug;25(15):6485-95. doi: 10.1128/MCB.25.15.6485-6495.2005.

Abstract

The secreted molecule unc-6/netrin is important for guiding axon projections and cell migrations. unc-5 and unc-40/DCC are identified as receptors for unc-6/netrin. The downstream factors of unc-6 receptors are beginning to be elucidated, and some key factors have been identified in various organisms. Here, we showed that SRC-1 interacts with the cytosolic domain of UNC-5 through its SH2 domain. This interaction also requires the intact kinase activity of SRC-1. Downregulation of src-1 by RNA interference decreases the biological processes initiated by the UNC-5 protein and decreases UNC-5 tyrosine phosphorylation. We also generated a chimeric protein consisting of the extracellular domain and transmembrane domain of UNC-5 and an intracellular domain of SRC-1. This fusion protein is able to partially rescue mutant phenotypes caused by unc-5 but not unc-6, unc-40, and unc-34. Our results support a model in which SRC-1 is required for UNC-5-induced axon repulsion and gonad migration signaling pathways and in which localizing SRC-1 activity to UNC-5 is crucial for proper signal transduction in response to unc-6/netrin.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Caenorhabditis elegans Proteins / physiology*
  • Cell Line
  • Female
  • Humans
  • Male
  • Ovary / metabolism
  • Phosphorylation
  • Protein Kinases / genetics
  • Protein Kinases / physiology*
  • RNA Interference
  • RNA, Double-Stranded / metabolism
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism*
  • Receptors, Cell Surface / physiology*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / physiology*
  • Testis / metabolism
  • Tyrosine / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • RNA, Double-Stranded
  • Receptors, Cell Surface
  • Recombinant Fusion Proteins
  • UNC-5 protein, C elegans
  • Tyrosine
  • Protein Kinases
  • SRC-1 protein, C elegans