title: Distinct roles for two synaptotagmin isoforms in synchronous and asynchronous transmitter release at zebrafish neuromuscular junction.
abstract: An obligatory role for the calcium sensor synaptotagmins in stimulus-coupled release of neurotransmitter is well established, but a role for synaptotagmin isoform involvement in asynchronous release remains conjecture. We show, at the zebrafish neuromuscular synapse, that two separate synaptotagmins underlie these processes. Specifically, knockdown of synaptotagmin 2 (syt2) reduces synchronous release, whereas knockdown of synaptotagmin 7 (syt7) reduces the asynchronous component of release. The zebrafish neuromuscular junction is unique in having a very small quantal content and a high release probability under conditions of either low-frequency stimulation or high-frequency augmentation. Through these features, we further determined that during the height of shared synchronous and asynchronous transmission these two modes compete for the same release sites.
authors.affiliation: Vollum Institute, Oregon Health and Sciences University, Portland, OR 97239, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Wen
authors.forename: Michael W
authors.initials: MW
authors.lastname: Linhoff
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: McGinley
authors.forename: Geng-Lin
authors.initials: GL
authors.lastname: Li
authors.forename: Glen M
authors.initials: GM
authors.lastname: Corson
authors.forename: Gail
authors.initials: G
authors.lastname: Mandel
authors.forename: Paul
authors.initials: P
authors.lastname: Brehm
mesh_terms: D000818:Animals; D008969:Molecular Sequence Data; D009469:Neuromuscular Junction / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D009435:Synaptic Transmission; D050857:Synaptotagmins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D020033:Protein Isoforms; D050857:Synaptotagmins