Cameron B. Gundersen

Learn More
A novel strategy, termed suppression cloning, was used to identify a 7.4 kb cDNA encoding a putative subunit of the calcium channels that regulate transmitter release at nerve endings of Torpedo californica. The 585 nt open reading frame of this cDNA encodes a polypeptide of about 21.7 kd that is essential for the expression in frog oocytes of(More)
Presynaptic calcium channels are key regulators of neurotransmitter release. Oocyte expression studies suggest that cysteine string proteins are essential subunits or modulators of these channels. Subcellular fractionation revealed that cysteine string proteins copurify with synaptic vesicles. An average vesicle had eight protein monomers with both the(More)
Cysteine string proteins are synapse-specific proteins. In Drosophila, csp deletion mutants exhibit temperature-sensitive paralysis and early death. Here, we report that neuromuscular transmission is impaired presynaptically in these csp mutant larvae. At 22 degrees C, evoked transmitter release is depressed relative to wild type and rescued controls, and(More)
Cysteine string proteins are relatively low mass components of synaptic vesicle membranes. Structurally, their primary sequence is distinguished by a remarkable, cysteine-rich motif. Investigations revealed an unprecedented degree of lipidation of these cysteine residues. At least 11 of the 13 cysteines of the Torpedo protein were modified, principally by(More)
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(More)
Activation of serotonin, glutamate or muscarinic receptors, incorporated into the membrane of Xenopus oocytes following injection of messenger RNA from rat brain, caused the development of a transient inward (Tin) current when the membrane was hyperpolarized. A detailed study was made of the Tin current induced during serotonin activation. The current is(More)
Cysteine string proteins are novel, heavily lipidated components of synaptic vesicles. They have previously been studied in Drosophila (insect) and Torpedo (fish). To facilitate further investigation of the structure and function of these proteins in mammals, we isolated and sequenced the cDNA and conducted an initial characterization of a rat cysteine(More)
The fast, tightly regulated release of neurotransmitters from presynaptic nerve terminals is effected by a complex molecular apparatus. The precise roles of the various proteins involved remain largely conjectural. Cysteine string proteins (CSPs) are novel synaptic vesicle components that have been conserved in evolution. They are characterized by an(More)
Little is known about the functional significance of spontaneous miniature synaptic potentials, which are the result of vesicular exocytosis at nerve terminals. Here, by using Drosophila mutants with specific defects in presynaptic function, we found that glutamate receptors clustered normally at neuromuscular junctions of mutants that retained spontaneous(More)
Previous work indicated that the temperature-dependent block of synaptic transmission in cysteine string protein (csp) mutants of Drosophila was attributable to a failure of nerve impulses to trigger transmitter release. The current investigations were undertaken to resolve in more detail the mechanism of this transmission deficit. Our studies reveal that(More)