RAB8 GEFs exchange GTP for GDP on RAB8

RAB8 is involved in trafficking from the trans-Golgi network (TGN) to the plasma membrane, contributes, with RAB10, 13 and 14 to GLUT4 transport, and plays a role in the formation of the primary cilium (Huber et al, 1993; Ishikura et al, 2008; Sun et al, 2010; Nachury et al, 2007; Yoshimura et al, 2007; reviewed in Hoffman and Elmendorf, 2011; Reiter et al, 2012). RAB8 also plays a role in regulating G2/M transition in complex with Optineurin (OPTN) (Kachaner et al, 2012).<br><br>RAB3IP is the best characterized GEF for RAB8A, with established roles in ciliogenesis (Hatulla et al, 2002; Knodler et al, 2010; Westlake et al, 2012; Wang et al, 2012; Feng et al, 2012; reviewed in Sung and Leroux, 2013). Other potential RAB8 GEFs include RAB3IPL and DENND1C (Yoshimura et al, 2010; reviewed in Ishida et al, 2016). Interaction of RAB8 with its GEFs displaces the GDI or CHM protein that keeps the inactive RAB:GDP soluble in the cytosol and promotes membrane association of RAB8 (reviewed in Wandinger-Ness and Zerial, 2014; Ishida et al, 2016)

RAB8在跨越高尔基网络（TGN）至质膜的转运过程中扮演关键角色，与RAB10、13和14协同作用以促进GLUT4的运输，并在初级纤毛的形成中发挥重要作用（Huber等，1993；Ishikura等，2008；Sun等，2010；Nachury等，2007；Yoshimura等，2007；参见Hoffman和Elmendorf，2011；Reiter等，2012的综述）。此外，RAB8还与Optineurin（OPTN）复合体协同，在调节G2/M期转换中发挥作用（Kachaner等，2012）。RAB3IP是RAB8A最被广泛研究的GEF，其在纤毛发生中的作用已被确立（Hatulla等，2002；Knodler等，2010；Westlake等，2012；Wang等，2012；Feng等，2012；参见Sung和Leroux，2013的综述）。其他潜在的RAB8 GEF包括RAB3IPL和DENND1C（Yoshimura等，2010；参见Ishida等，2016的综述）。RAB8与GEFs的相互作用，移除了维持非活性RAB:GDP在细胞质中溶解的GDI或CHM蛋白，并促进RAB8与膜的结合（参见Wandinger-Ness和Zerial，2014；Ishida等，2016的综述）