SYD-1, a presynaptic protein with PDZ, C2 and rhoGAP-like domains, specifies axon identity in C. elegans.
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.
Hallam
Steven J
SJ
Department of Molecular, Cellular and Developmental Biology, Sinsheimer Laboratories, University of California, Santa Cruz, California 95064, USA.
Goncharov
Alexandr
A
McEwen
Jason
J
Baran
Renee
R
Jin
Yishi
Y
D000818:Animals; D001369:Axons / Q000737:chemistry / Q000502:physiology*; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000737:chemistry; D018507:Gene Expression Regulation, Developmental; D007814:Larva; D008969:Molecular Sequence Data; D020125:Mutation, Missense / Q000502:physiology; D016501:Neurites / Q000737:chemistry / Q000502:physiology; D009474:Neurons / Q000502:physiology; D017729:Presynaptic Terminals / Q000737:chemistry / Q000502:physiology*; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology
D029742:Caenorhabditis elegans Proteins; D020690:GTPase-Activating Proteins; C468652:SYD-1 protein, C elegans; C085379:rho GTPase-activating protein