Small GTPase involved in membrane trafficking control (PubMed:18804435, PubMed:25648148). During the mitosis of adherent cells, controls the endosomal trafficking of integrins which is required for the successful completion of cytokinesis (PubMed:18804435). Regulates integrin internalization and recycling, but does not influence the traffic of endosomally translocated receptors in general (By similarity). As a result, may regulate cell adhesion and migration (By similarity). Involved in neurite growth (By similarity). Following SBF2/MTMT13-mediated activation in response to starvation-induced autophagy, binds to and regulates SNARE protein VAMP8 endolysosomal transport required for SNARE-mediated autophagosome-lysosome fusion (PubMed:25648148). Modulates protein levels of the cargo receptors TMED2 and TMED10, and required for appropriate Golgi localization of TMED10 (PubMed:31455601). Interacts with the cytoplasmic tail of integrins ITGA1, ITGA2, ITGA5, ITGA6, ITGA11 and ITGB1 (By similarity). Interacts with RABGEF1 (via VPS9 domain) (PubMed:17450153). Interacts with ANKRD27 (PubMed:16525121, PubMed:18477474). Interacts with VAMP7 (PubMed:25648148). Interacts (in GTP-bound form) with VAMP8 in response to starvation; the interaction probably regulates VAMP8 endolysosomal trafficking (PubMed:25648148). Interacts (active GTP-bound form) with TMED10; the interaction is indirect and regulates TMED10 abundance and localization at the Golgi (PubMed:31455601). Colocalizes with ANKRD27 and VAMP7 in neurites (By similarity). In nonpolarized epithelial Caco-2 cells, found in the endoplasmic reticulum; in polarized cells, observed in vesicles in the apical cytoplasm (PubMed:10887961). During mitosis, in mid-telophase, localized in the ingressing cleavage furrow (PubMed:18804435). In late telophase, detected at the opposite poles of the daughter cells, in vesicles at the base of lamellipodia formed by the separating daughter cells (PubMed:18804435). Widely expressed. In jejunal tissue, predominantly expressed in the apical region of the epithelial cell layer of the villi, weak expression, if any, in the crypt epithelium. Capillary endothelium and some cell types in the lamina propria also show expression. Belongs to the small GTPase superfamily. Rab family.