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 set of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion (PubMed:23100538, PubMed:26394140, PubMed:26633194). Required for basolateral endocytic recycling, the return of macromolecules and fluid from endosomes to the plasma membrane, in polarized epithelial cells of the intestine upstream of rme-1 (PubMed:16394106). Involved in the formation of the endosomal tubular network that is required for basolateral recycling of clathrin-independent endocytic cargo such as daf-4 in the intestine (PubMed:25301900). Required for the recruitment of cnt-1 effector to endosomal membranes in the intestinal epithelium, which is important for the regulation of levels of endosomal phosphatidylinositol-4,5-bisphosphate, a key phosphoinositide in membrane traffic, and for the recruitment of endosomal membrane-bending proteins, rme-1 and sdpn-1 (PubMed:22869721). Recruits the rab-5 GTPase-activating protein tbc-2 to endosomes where it then inactivates rab-5 resulting in removal of rab-5 from membranes, which is necessary for cargo transport from early endosomes to recycling endosomes in the basolateral intestine (PubMed:26393361). Regulates recycling of synaptic membrane AMPA glutamate receptor, glr-1, from intracellular endosomal compartments back to synapses in a cholesterol-dependent endocytosis pathway functioning after clathrin-independent endocytosis in command interneurons (PubMed:17761527). Regulates neuropeptide release from dense core vesicles (DCVs) of cholinergic motoneurons in cooperation with rab-5. They reciprocally recruite each other's inactivating GAP molecule leading to local exclusion of one or the other rab protein at the Golgi-endosomal interphase at an essential stage during DCV sorting (PubMed:23100538). Regulates membrane trafficking of membranes and dendrite proteins from the Golgi and/or endosomal compartments to plasma membrane during dendrite morphogenesis together with the exocyst complex in the multi-dendritic PVD sensory neurons acting in a cell-autonomous manner and requiring its GTPase activity (PubMed:26394140). Functions cell-autonomously together with the exocyst complex to regulate dendrite morphogenesis and anterior-posterior patterning of the PVD neurons dendritic arbor by balancing the anterograde and retrograde transport via molecular motors unc-116 (kinesin heavy chain) and dhc-1 (dynein heavy chain) to appropriately transport branching factors, such as dma-1, to the specific subcellular regions of the developing dendrite in its GTPase activity-dependent manner (PubMed:26633194).