Rab effector playing a role in late endocytic transport to degradative compartments. Involved in the regulation of lysosomal morphology and distribution. Induces recruitment of dynein-dynactin motor complexes to Rab7A-containing late endosome and lysosome compartments. Promotes centripetal migration of phagosomes and the fusion of phagosomes with the late endosomes and lysosomes. Homodimer. Interacts with RAB7A. Interacts with RAB34 (By similarity). Identified in a complex with MREG and DCTN1; interacts directly with MREG (PubMed:22275436). Interacts with CLN3 (By similarity). Interacts with FLCN; the interaction is direct and promotes association between RILP and RAB34 (By similarity). Associated with late endosomal, lysosomal and phagosomal membranes. The interaction with RAB7A is necessary for its recruitment to phagosomes.