Worm Breeder's Gazette 13(4): 70 (October 1, 1994)

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.

Molecular Genetics of SNAP-25 in C. elegans.

Junho Lee, Barbara Meyer

Department of Molecular and Cell Biology 401 Barker Hall, University of California at Berkeley Berkeley, CA 94720 leejh@mendel.berkeley.edu

Figure 1

  Recent discoveries of components used in various types of membrane fusion
events, from neurotransmitter release in mammalian neuronal cells to protein
secretion in yeast cells, have led to a unified hypothesis. In order to extend our
understanding of the biology of vesicle trafficking and membrane fusion events, it is
important to study the roles of all the components of the fusion machinery. SNAP-25
is one of the components of the membrane fusion apparatus, and its molecular and
biological functions have not been fully determined. It has been proposed that
SNAP-25 is important in axonal growth during neural development and that it acts as
a plasma membrane receptor in vesicle docking and fusion. Because this protein was
shown to be conserved during evolution, it would be useful to investigate the molecular
and biological functions of the SNAP-25 protein in a simpler model system such as the
nematode C. elegans in order to test these hypotheses.
  We cloned a homolog of SNAP-25 by PCR using a set of degenerate primers that
had been successfully used by C. Risinger and D. Larhammer to clone Drosophila
SNAP-25 homologs. They kindly provided the primers to us. We subcloned
PCR-amplified products in a pBluescript vector, and determined the DNA sequence of
the clones. The preliminary sequence comparison shows that C. elegans SNAP-25 is
about 57% identical to the fly homolog, and 52% to the human homolog. The C.
elegans SNAP-25 also shows a limited similarity to the yeast S ec9 protein (36% identity
in a stretch of 50 amino acids). We screened the Barstead and Waterston cDNA library
to identify full length cDNA clones. One of the cDNA clones contained 7 nucleotides
identical to the 3' end of the SL-1 leader sequence indicating that this clone contains a
full length transcript. Sequencing of the clone is under way. We performed a YAC
grid filter hybridization experiment using the PCR clone as a probe and identified three
apparently positive YACs on chromosome V. Further physical mapping of the gene is
under way. (see figure)

Figure 1