Search Organism: All OrganismsArabidopsis thalianaBacillus subtilis 168Bos taurusCaenorhabditis elegansCanis familiarisDanio rerioDrosophila melanogasterEquus caballusEscherichia coli K12Gallus gallusHomo sapiensMacaca mulattaMus musculusNematostella vectensisOryza sativaPan troglodytesRattus norvegicusSaccharomyces cerevisiaeSchizosaccharomyces pombeStrongylocentrotus purpuratusTakifugu rubripesXenopus laevis home help / support contribute downloads mirrors about us Mol. Cell. Neurosci. Jun (2002); 20(2):169-80 Munc 18a binding to syntaxin 1A and 1B isoforms defines its localization at the plasma membrane and blocks SNARE assembly in a three-hybrid system assay. Perez-Branguli F, Muhaisen A, Blasi J Departament de Biologia Cel.lular i Anatomia Patologica, Campus de Bellvitge, Universitat de Barcelona, C/Feixa Llarga s/n, E-08907 L'Hospitalet de Llobregat, Spain. Abstract: Syntaxin 1 and synaptobrevin/VAMP play an essential role in synaptic vesicle exocytosis. Two isoforms for each of these proteins, syntaxins 1A and 1B and synaptobrevin/VAMPs 1 and 2, have been found in nerve endings. Morphological and biochemical studies have revealed a characteristic colocalization and selective interactions patterns of syntaxin 1 and synaptobrevin/VAMP isoforms in nervous and endocrine systems. Moreover, studies in vitro with recombinant proteins have shown characteristic interaction patterns for each syntaxin 1-synaptobrevin/VAMP pair. The cytosolic protein Munc-18a modulates neurotransmission by inhibiting the binding of synaptobrevin/VAMP and SNAP-25 to syntaxin 1A. In the present study, several binding assays were used to demonstrate that Munc-18a significantly binds both isoforms of syntaxin 1 (syntaxins 1A and 1B). Moreover, the coexpression of Munc-18a and syntaxin 1A or syntaxin 1B in 29.3 T cells revealed syntaxin 1-dependent localization of Munc-18a in the plasma membrane. By using the three-hybrid system, we showed the inhibitory role of Munc-18a in the formation of syntaxin 1-synaptobrevin/VAMP complexes regardless of the isoforms. Since Munc-18a can bind both isoforms of syntaxin 1, the present data suggest that this protein is a general modulator of the formation of different SNARE complexes in the nerve endings. [PUBMED: 12093152] Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. terms and conditions - privacy policy - Osprey Network Visualization System BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9.