RAB6B Polyclonal antibody

The human RAB genes share structural and biochemical properties with the Ras gene superfamily. Accumulating data suggests an important role for RAB proteins either in endocytosis or in biosynthetic protein transport. The transport of newly synthesized proteins from endoplasmic reticulum to the Golgi complex and to secretory vesicles involves the movement of carrier vesicles, a process that appears to involve RAB protein function. Rab6A has been shown to be a regulator of membrane traffic from the Golgi apparatus towards the endoplasmic reticulum (ER). Rab6B is encoded by an independent gene which is located on chromosome 3 region q21-q23. In contrast to Rab6A whose expression is ubiquitous, Rab6B is expressed in a tissue and cell-type specific manner. Rab6B is predominantly expressed in brain and the neuroblastoma cells. In brain, Rab6B was found to be specifically expressed in microglia, pericytes and Purkinje cells. Endogenous Rab6B localises to the Golgi apparatus and to ERGIC-53-positive vesicles. Comparable studies between Rab6A and Rab6B revealed distinct biochemical and cellular properties. Rab6B displays lower GTP-binding activities and is distributed over Golgi and ER membranes, whereas Rab6A is more restricted to the Golgi apparatus. Since the GTP-bound form of Rab6B does interact with all known Rab6A effectors, including Rabkinesin-6, the results suggest a cell-type specific role for Rab6B in retrograde membrane traffic at the level of the Golgi complex.