GDP dissociation inhibitors are proteins that regulate the GDP-GTP exchange reaction of members of the rab family, small GTP-binding proteins of the ras superfamily, that are involved in vesicular trafficking of molecules between cellular organelles. GDIs slow the rate of dissociation of GDP from rab proteins and release GDP from membrane-bound rabs. GDI1 is expressed primarily in neural and sensory tissues. Mutations in GDI1 have been linked to X-linked nonspecific mental retardation. [provided by RefSeq, Jul 2008],disease:Defects in GDI1 are the cause of mental retardation X-linked type 41 (MRX41) [MIM:300104]. Mental retardation is characterized by significantly sub-average general intellectual functioning associated with impairments in adaptative behavior and manifested during the developmental period. Non-syndromic mental retardation patients do not manifest other clinical signs.,disease:Defects in GDI1 are the cause of mental retardation X-linked type 48 (MRX48) [MIM:300104], also known as MRX3.,function:Regulates the GDP/GTP exchange reaction of most Rab proteins by inhibiting the dissociation of GDP from them, and the subsequent binding of GTP to them.,similarity:Belongs to the Rab GDI family.,tissue specificity:Brain, predominant in neural and sensory tissues.,
