SYD-1, a presynaptic protein with PDZ, C2 and rhoGAP-like domains, specifies axon identity in C. elegans

Nat Neurosci. 2002 Nov;5(11):1137-46. doi: 10.1038/nn959.


Axons are defined by the presence of presynaptic specializations at specific locations. We show here that loss-of-function mutations in the C. elegans gene syd-1 cause presynaptic specializations to form in the dendritic processes of GABA-expressing motor neurons during initial differentiation. At a later developmental stage, however, syd-1 is not required for the polarity respecification of a subset of these neurons. The SYD-1 protein contains PDZ, C2 and rho-GTPase activating protein (GAP)-like domains, and is localized to presynaptic terminals in mature neurons. A truncated SYD-1 that lacks the rhoGAP domain interferes with neurite outgrowth and guidance. Our data indicate that syd-1 may be involved in specifying axon identity during initial polarity acquisition.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Axons / chemistry
  • Axons / physiology*
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism*
  • GTPase-Activating Proteins / chemistry
  • Gene Expression Regulation, Developmental
  • Larva
  • Molecular Sequence Data
  • Mutation, Missense / physiology
  • Neurites / chemistry
  • Neurites / physiology
  • Neurons / physiology
  • Presynaptic Terminals / chemistry
  • Presynaptic Terminals / physiology*
  • Protein Structure, Tertiary
  • Sequence Homology, Amino Acid
  • Spinal Cord / cytology
  • Spinal Cord / embryology


  • Caenorhabditis elegans Proteins
  • GTPase-Activating Proteins
  • SYD-1 protein, C elegans
  • rho GTPase-activating protein

Associated data

  • GENBANK/AF546880