Structural highlights
Function
[GDI1_YEAST] Regulates the GDP/GTP exchange reaction of SEC4 by inhibiting the dissociation of GDP from it, and the subsequent binding of GTP to SEC4. Plays an essential role in the yeast secretory pathway.[1] [SEC4_YEAST] Involved in exocytosis. Maybe by regulating the binding and fusion of secretory vesicles with the cell surface. The GTP-bound form of SEC4 may interact with an effector, thereby stimulating its activity and leading to exocytotic fusion. SEC4 may be an upstream activator of the 19.5S SEC8/SEC15 particle. SEC4 probably interacts directly with SEC8; it could serve as the attachment site for the SEC8/SEC15 particle.[2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Rab GDP dissociation inhibitors (GDI)-facilitated extraction of prenylated Rab proteins from membranes plays an important role in vesicular membrane trafficking. The investigated thermodynamic properties of yeast Rab.GDI and Rab.MRS6 complexes demonstrated differences in the Rab binding properties of the closely related Rab GDI and MRS6 proteins, consistent with their functional diversity. The importance of the Rab C terminus and its prenylation for GDI/MRS6 binding was demonstrated using both biochemical and structural data. The presented structures of the apo-form yeast Rab GDI and its two complexes with unprenylated Rab proteins, together with the earlier published structures of the prenylated Ypt1.GDI, provide evidence of allosteric regulation of the GDI lipid binding site opening, which plays a key role in the proposed mechanism of GDI-mediated Rab extraction. We suggest a model for the interaction of GDI with prenylated Rab proteins that incorporates a stepwise increase in affinity as the three different partial interactions are successively formed.
A structural model of the GDP dissociation inhibitor rab membrane extraction mechanism.,Ignatev A, Kravchenko S, Rak A, Goody RS, Pylypenko O J Biol Chem. 2008 Jun 27;283(26):18377-84. Epub 2008 Apr 20. PMID:18426803[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Garrett MD, Zahner JE, Cheney CM, Novick PJ. GDI1 encodes a GDP dissociation inhibitor that plays an essential role in the yeast secretory pathway. EMBO J. 1994 Apr 1;13(7):1718-28. PMID:8157010
- ↑ Grosshans BL, Andreeva A, Gangar A, Niessen S, Yates JR 3rd, Brennwald P, Novick P. The yeast lgl family member Sro7p is an effector of the secretory Rab GTPase Sec4p. J Cell Biol. 2006 Jan 2;172(1):55-66. PMID:16390997 doi:http://dx.doi.org/10.1083/jcb.200510016
- ↑ Ignatev A, Kravchenko S, Rak A, Goody RS, Pylypenko O. A structural model of the GDP dissociation inhibitor rab membrane extraction mechanism. J Biol Chem. 2008 Jun 27;283(26):18377-84. Epub 2008 Apr 20. PMID:18426803 doi:10.1074/jbc.M709718200
