Distinct protein domains are responsible for the interaction of Hrs-2 with SNAP-25. The role of Hrs-2 in 7 S complex formation.
J Biol Chem
; 275(4): 2938-42, 2000 Jan 28.
Article
em En
| MEDLINE
| ID: mdl-10644763
ABSTRACT
Regulated secretion of neurotransmitter at the synapse is likely to be mediated by dynamic protein interactions involving components of the vesicle (vesicle-associated membrane protein; VAMP) and plasma membrane (syntaxin and synaptosomal associated protein of 25 kDa (SNAP-25)) along with additional molecules that allow for the regulation of this process. Recombinant Hrs-2 interacts with SNAP-25 in a calcium-dependent manner (they dissociate at elevated calcium levels) and inhibits neurotransmitter release. Thus, Hrs-2 has been hypothesized to serve a negative regulatory role in secretion through its interaction with SNAP-25. In this report, we show that Hrs-2 and SNAP-25 interact directly through specific coiled-coil domains in each protein. The presence of syntaxin enhances the binding of Hrs-2 to SNAP-25. Moreover, while both Hrs-2 and VAMP can separately bind to SNAP-25, they cannot bind simultaneously. Additionally, the presence of Hrs-2 reduces the incorporation of VAMP into the syntaxin.SNAP-25.VAMP (7 S) complex. These findings suggest that Hrs-2 may modulate exocytosis by regulating the assembly of a protein complex implicated in membrane fusion.
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Base de dados:
MEDLINE
Assunto principal:
Fosfoproteínas
/
Adenosina Trifosfatases
/
Proteínas do Tecido Nervoso
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article