A presynaptic role for the ADP ribosylation factor (ARF)-specific GDP/GTP exchange factor msec7-1.

ABSTRACT: ADP ribosylation factors (ARFs) represent a family of small monomeric G proteins that switch from an inactive, GDP-bound state to an active, GTP-bound state. One member of this family, ARF6, translocates on activation from intracellular compartments to the plasma membrane and has been implicated in regulated exocytosis in neuroendocrine cells. Because GDP release in vivo is rather slow, ARF activation is facilitated by specific guanine nucleotide exchange factors like cytohesin-1 or ARNO. Here we show that msec7-1, a rat homologue of cytohesin-1, translocates ARF6 to the plasma membrane in living cells. Overexpression of msec7-1 leads to an increase in basal synaptic transmission at the Xenopus neuromuscular junction. msec7-1-containing synapses have a 5-fold higher frequency of spontaneou

SUBMITTER: Ashery U 

PROVIDER: S-EPMC15356 | biostudies-literature | 1999 Feb

REPOSITORIES: biostudies-literature