[Abstract Title]. - Society for Neuroscience

Title: Regulation of levels of UNC-13 at synapses in Caenorhabditis elegans
Authors: *B. M. KAAS, R. WENNELL, T. LIMOUZE, R. LAWSON, R. KOHN;
Ursinus Col., Collegeville, PA
Abstract: Synaptic neurotransmission is a highly regulated process. The nematode
Caenorhabditis elegans has a well-characterized nervous system that has been intensively
investigated in the study of neurotransmission. This organism‟s nervous system has functional
similarity to those of higher organisms. The UNC-13 protein, which operates at the pre-synaptic
membrane of C. elegans, participates in the fusion of synaptic vesicles to allow neurotransmitter
release into the synapse. Defects in unc-13 result in decreased release of neurotransmitters and
paralysis. We identified an F-box protein that interacts with UNC-13. F-box proteins participate
in ubiquitin ligase complexes and in Drosophila, DUNC-13 is degraded via the ubiquitin
proteasome pathway. This UNC-13/F-box interaction may therefore indicate that UNC-13 is
tagged for proteasomal degradation with ubiquitin by the ligase complex in C. elegans. The C.
elegans knockout consortium isolated a strain with a large deletion in the coding region of the
gene that codes for the F-box protein. If the F-box protein is indeed involved in the degradation
of UNC-13, this strain would be expected to have higher levels of UNC-13, which could result in
changes in phenotypes. We characterized the F-box deletion mutant by assaying brood size,
developmental rate, and body bends per minute. Aldicarb assays were used to determine whether
a deletion in the gene coding for the F-box protein alters the response to inhibitors of
acetylcholinesterase. We found that the deletion resulted in changes in developmental rate and in
aldicarb sensitivity. We are continuing to study strains with mutations in both the gene coding
for the F-box protein and in unc-13.
Disclosures: B.M. Kaas , None; R. Wennell, None; T. Limouze, None; R. Lawson, None; R.
Kohn, None.
Poster
236. Neurotransmitter Release: Docking and Fusion
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 236.20/D20
Topic: B.06.a. Docking and fusion
Title: Carboxypeptidase E cytoplasmic tail mediates docking/exocytosis of synaptic vesicles
Authors: *J. J. PARK 1 , H. LOU 1 , N. X. CAWLEY 1 , A. SARCON 1 , T. ADAMS 2 , Y. LOH 1 ;
1 NICHD, NIH, Bethesda, MD; 2 QIAGEN, Germantown, MD