Worm Breeder's Gazette 12(1): 26 (September 1, 1991)
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
We have recently initiated a two-pronged approach aimed at examining synapse formation and synapse function in C. elegans. First, we are isolating new mutants with phenotypes reminiscent of unc-104 (null)mutants [curled up, starved and Unc L1 arrested lethals], which have been demonstrated to form almost no synapses. Secondly, we have begun to isolate C. elegans homologs of known conserved synapse-associated proteins.
Here we report the cloning of a synaptic vesicle protein using PCR methodology. VAMP-1 (also known as synaptobrevin) is a small ~120 a.a. integral membrane protein found specifically in synaptic vesicles. Structurally, VAMP consists of a large cytoplasmic domain, a portion of which is highly conserved from Drosophila to man (see below), a conserved transmembrane domain, and a small (5 a.a.) non-conserved intravesicular carboxy terminus. VAMP's function in neurotransmitter release is unknown, although the lack of a substantial intravesicular domain suggests a cytoplasmic function.
A C. elegans homolog of VAMP was isolated from cDNA utilizing degenerate-oligonucleotide-based PCR amplification. Sequence information obtained to date indicates that C. elegans VAMP is 85% homologous to the human VAMP-1 gene. Interestingly, the C. elegans homolog seems more closely related to its mammalian counterpart than the Drosophila gene. We plan to continue the molecular analysis of the gene and to initiate its genetic characterization. Furthermore, we are presently isolating C. elegans clones of other conserved synaptic vesicle proteins including p65 (also known as synaptotagmin), and the vesicle associated GTP-binding protein rab3 .We hope that a reverse genetic approach will help elucidate the functional role of VAMP and other synaptic vesicle proteins in synapse function and modulation. Additionally, identifying the VAMP(-) phenotype should either support the hypothesis that other synaptic defective mutants will look similar to unc-104 (null)phenotype or identify other phenotypes indicative of synaptic defects.
[See Figure 1]