Structure and dynamics of a two-helix SNARE complex in live cells.
Traffic
; 11(3): 394-404, 2010 Mar.
Article
em En
| MEDLINE
| ID: mdl-20002656
ABSTRACT
SNAREs are clustered membrane proteins essential for intracellular fusion steps. During fusion, three to four SNAREs with a Q(a)-, Q(b)-, Q(c)- and R-SNARE-motif form a complex. The core complex represents a Q(a)Q(b)Q(c)R-SNARE-motif bundle, most certainly assembling in steps. However, to date it is unknown which intermediate SNARE complex observed in vitro also exists in vivo. Here we have applied comparative fluorescence recovery after photobleaching (FRAP)-studies as a novel approach for studying in intact cells a SNARE interaction involved in synaptic vesicle fusion [catalyzed by syntaxin 1A (Q(a)), SNAP25 (Q(b)/Q(c)) and synaptobrevin 2 (R)]. We find that the Q(b)-SNARE-motif of SNAP25 interacts reversibly with clustered syntaxin. The interaction requires most of the alpha helical Q(b)-SNARE-motif and depends on its position within the molecule. We conclude that a zippered Q(a)Q(b)-SNARE complex represents a short-lived SNARE intermediate in intact cells, most likely providing an initial molecular platform toward membrane fusion.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vesículas Sinápticas
/
Proteínas SNARE
Limite:
Animals
Idioma:
En
Revista:
Traffic
Ano de publicação:
2010
Tipo de documento:
Article