The RIC1-RGP1 complex acts as a guanine nucleotide exchange factor (GEF), which activates RAB6A by exchanging bound GDP for free GTP, and may thereby be required for efficient fusion of endosome-derived vesicles with the Golgi compartment. The RIC1-RGP1 complex participates in the recycling of mannose-6-phosphate receptors. Required for phosphorylation and localization of GJA1. Is a regulator of procollagen transport and secretion, and is required for correct cartilage morphogenesis and development of the craniofacial skeleton. Forms a complex with RGP1; the interaction enhances RAB6A GTPase activity. Interacts (via central domain) with RGP1. Interacts with RAB6A; the interaction is direct with a preference for RAB6A-GDP. Interacts (via C-terminus domain) with RAB33B; the interaction is direct with a preference for RAB33B-GTP. Interacts with GJA1. Expressed in the eye lens. Belongs to the RIC1 family.