Rab GDP dissociation inhibitor (Rab GDI), will induce the dissociation of GDP-bound rab3A from synaptic membranes and will inhibit GDP dissociation from Sec4, a member of the Rab subgroup of the Ras GTPase superfamily which is required for exocytosis in Saccharomyces cerevisiae. We report that Rab GDI releases GDP-bound Sec4 from yeast membranes. dGDI, a Drosophila homologue can similarly inhibit GDP dissociation from Sec4 and release GDP-bound Sec4 from yeast membranes. An activity partially purified from yeast cytosol dissociates GDP-bound Sec4 from yeast membranes, suggesting that yeast also possess a GDI protein that functions to recycle Sec4 from its target membrane.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology
- Cell Biology