RT Journal Article
SR Electronic
T1 Attenuated Influx of Calcium Ions at Nerve Endings of <em>csp</em>and <em>shibire </em>Mutant <em>Drosophila</em>
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3233
OP 3240
DO 10.1523/JNEUROSCI.18-09-03233.1998
VO 18
IS 9
A1 Joy A. Umbach
A1 Minoru Saitoe
A1 Yoshi Kidokoro
A1 Cameron B. Gundersen
YR 1998
UL http://www.jneurosci.org/content/18/9/3233.abstract
AB Previous work has shown that cysteine-string proteins (csps) are synaptic vesicle proteins that are important for evoked neurotransmitter release at Drosophila neuromuscular junctions. Indirect evidence has implicated csps in a regulatory link between synaptic vesicles and presynaptic calcium (Ca) channels. In this report, we use Ca Crimson to monitor stimulus-dependent changes of cytosolic Ca at motor nerve terminals of csp mutantDrosophila. These mutants display temperature-sensitive (TS) paralysis and a presynaptic failure of evoked synaptic transmission. We show that this TS inhibition of neuromuscular transmission is correlated with a block of Ca ion entry at nerve endings of csp mutants. These data support the hypothesis that csps mediate a regulatory interaction between synaptic vesicles and presynaptic Ca channels. Moreover, these results predict that if one depletes nerve endings of synaptic vesicles, one may see a reduction of presynaptic Ca ion entry. Defects of thedynamin gene in TS shibire mutantDrosophila interfere with synaptic vesicle recycling and lead to an activity-dependent depletion of these organelles. Our results show that Ca influx is blocked at nerve terminals ofshibire mutant larvae at the same time that synaptic transmission fails in these organisms. Thus, using two completely independent Drosophila mutants, we demonstrate that synaptic vesicles and csps are vital for the function of presynaptic Ca channels.