The small GTPases Rab are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different sets of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion. That Rab may be involved in polarized vesicular trafficking and neurotransmitter release. May participate in cell junction dynamics in Sertoli cells (By similarity). Associated with actin, delta-catenin and alpha and beta tubulins (By similarity). Interacts with OTOF (By similarity). Interacts with PEX5R (By similarity). Interacts with RAB3IP (By similarity). Interacts with VIM (By similarity). Interacts with CDH1 (By similarity). Interacts with MICALL2 (By similarity). Interacts with GDI1, GDI2, CHML and CHM; phosphorylation at Thr-72 disrupts these interactions (By similarity). Recruited to phagosomes containing S.aureus or Mycobacterium. Phosphorylation of Thr-72 in the switch II region by LRRK2 prevents the association of RAB regulatory proteins, including CHM, CHML and RAB GDP dissociation inhibitors GDI1 and GDI2. Belongs to the small GTPase superfamily. Rab family.