title: Synaptic PI(3,4,5)P3 is required for Syntaxin1A clustering and neurotransmitter release.
abstract: PI(3,4,5)P3 is a low-abundance lipid thought to play a role in the regulation of synaptic activity; however, the mechanism remains obscure. We have constructed novel split Venus-based probes and used superresolution imaging to localize PI(3,4,5)P3 at Drosophila larval neuromuscular synapses. We find the lipid in membrane domains at neurotransmitter release sites, where it concentrates with Syntaxin1A, a protein essential for vesicle fusion. Reducing PI(3,4,5)P3 availability disperses Syntaxin1A clusters and increasing PI(3,4,5)P3 levels rescues this defect. In artificial giant unilamellar vesicles, PI(3,4,5)P3 also induces Syntaxin1A domain formation and this clustering, in vitro and in vivo, is dependent on positively charged residues in the Syntaxin1A-juxtamembrane domain. Functionally, reduced PI(3,4,5)P3 causes temperature-sensitive paralysis and reduced neurotransmitter release, a phenotype also seen in animals expressing a Syntaxin1A with a mutated juxtamembrane domain. Thus, our data indicate that PI(3,4,5)P3, based on electrostatic interactions, clusters Syntaxin1A at release sites to regulate neurotransmitter release.
authors.affiliation: VIB Center for the Biology of Disease, 3000 Leuven, Belgium.
authors.forename: Thang Manh
authors.initials: TM
authors.lastname: Khuong
authors.forename: Ron L P
authors.initials: RL
authors.lastname: Habets
authors.forename: Sabine
authors.initials: S
authors.lastname: Kuenen
authors.forename: Agata
authors.initials: A
authors.lastname: Witkowska
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Kasprowicz
authors.forename: Jef
authors.initials: J
authors.lastname: Swerts
authors.forename: Reinhard
authors.initials: R
authors.lastname: Jahn
authors.forename: Geert
authors.initials: G
authors.lastname: van den Bogaart
authors.forename: Patrik
authors.initials: P
authors.lastname: Verstreken
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D016000:Cluster Analysis; D004330:Drosophila; D008969:Molecular Sequence Data; D018377:Neurotransmitter Agents / Q000235:genetics / Q000378:metabolism; D016716:PC12 Cells; D010716:Phosphatidylinositols / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D050827:Syntaxin 1 / Q000235:genetics / Q000378:metabolism*
chemical_list: D018377:Neurotransmitter Agents; D010716:Phosphatidylinositols; D050827:Syntaxin 1; C118303:phosphoinositide-3,4,5-triphosphate