Enables guanyl-nucleotide exchange factor activity and small GTPase binding activity. Involved in negative regulation of cellular protein catabolic process; positive regulation of GTPase activity; and retrograde transport, endosome to Golgi. Located in cytosol and plasma membrane. Part of Ric1-Rgp1 guanyl-nucleotide exchange factor complex. [provided by Alliance of Genome Resources, Apr 2022]