title: A temperature-sensitive paralytic mutant defines a primary synaptic calcium channel in Drosophila.
abstract: Neurotransmission at chemical synapses involves regulated exocytosis of neurotransmitter from the presynaptic terminal. Neurotransmitter release is thought to be triggered by calcium influx through specific classes of voltage-gated calcium channels. Here we report genetic and functional analysis implicating a specific calcium channel gene product in neurotransmitter release. We have isolated a temperature-sensitive paralytic allele of the Drosophila calcium channel alpha1 subunit gene, cacophony (cac). This mutant, referred to as cac(TS2), allows functional analysis of synaptic transmission after acute perturbation of a specific alpha1 subunit. Electrophysiological analysis at neuromuscular synapses revealed that neurotransmitter release in cac(TS2) is markedly reduced at elevated temperatures, indicating that cac encodes a primary alpha1 subunit functioning in synaptic transmission. These observations further define the molecular basis of voltage-gated calcium entry at synapses and provide a new starting point for further genetic analysis of synaptic mechanisms.
authors.affiliation: Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: F
authors.initials: F
authors.lastname: Kawasaki
authors.forename: R
authors.initials: R
authors.lastname: Felling
authors.forename: R W
authors.initials: RW
authors.lastname: Ordway
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000235:genetics* / Q000502:physiology; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D009469:Neuromuscular Junction / Q000502:physiology; D010243:Paralysis; D010641:Phenotype; D013569:Synapses / Q000502:physiology*; D013696:Temperature
chemical_list: D015220:Calcium Channels