Effector of small Rab GTPases which is involved in junctional complexes assembly through the regulation of cell adhesion molecules transport to the plasma membrane and actin cytoskeleton reorganization. Regulates the endocytic recycling of occludins, claudins and E-cadherin to the plasma membrane and may thereby regulate the establishment of tight junctions and adherens junctions. In parallel, may regulate actin cytoskeleton reorganization directly through interaction with F-actin or indirectly through actinins and filamins. Most probably involved in the processes of epithelial cell differentiation, cell spreading and neurite outgrowth. Interacts with RAB13 (GTP-bound form); competes with RAB8A and is involved in tight junctions assembly. Interacts with RAB8A; competes with RAB13 and is involved in E-cadherin endocytic recycling. Interacts with RAB8B. Interacts (preferentially in opened conformation) with ACTN1 and ACTN4; stimulated by RAB13 activation. Interacts (via calponin-homology (CH) domain) with the filamins FLNA, FLNB and FLNC (via actin-binding domain). Detected in brain, lung, liver and kidney (at protein level). Probably exists in a closed and an open conformation due to interaction of the C-terminal coiled-coil domain with an N-terminal region including the calponin-homology (CH) and the LIM zinc-binding domain. The conformational change is regulated by RAB13.