RGD Reference Report - 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. - Rat Genome Database
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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.

Authors: Perez-Branguli, F  Muhaisen, A  Blasi, J 
Citation: Perez-Branguli F, etal., Mol Cell Neurosci 2002 Jun;20(2):169-80.
RGD ID: 730238
Pubmed: (View Article at PubMed) PMID:12093152

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.

Annotation

Gene Ontology Annotations    

Biological Process

Cellular Component

Molecular Function

Objects Annotated

Genes (Rattus norvegicus)
Stx1a  (syntaxin 1A)
Stx1b  (syntaxin 1B)
Stxbp1  (syntaxin binding protein 1)


Additional Information