Plays a role in the maturation and acidification of phagosomes that engulf pathogens, such as S.aureus and M.tuberculosis. Plays a role in vesicular trafficking. Plays a role in the fusion of phagosomes with lysosomes. Negatively regulates LPS-induced autophagosome formation in macrophages possibly by implicating PI3K (PubMed:24349490). May be involved in multiple neurite formation (By similarity). Interacts with BECN1. Probably associates with the PI3K (PI3KC3/PI3K-III/class III phosphatidylinositol 3-kinase) complex (PubMed:24349490). Interacts with UACA (By similarity). Interacts with isoform a of RASSF1 (By similarity). Does not interact with isoform c of RASSF1 (By similarity). Recruited to phagosomes containing S.aureus or M.tuberculosis. Belongs to the small GTPase superfamily. Rab family.