Enables GDP binding activity. Involved in several processes, including negative regulation of cell cycle; positive regulation of angiogenesis; and positive regulation of apoptotic process. Acts upstream of or within intracellular protein transport. Located in endosome; nucleus; and plasma membrane. Is expressed in several structures, including branchial arch; embryo ectoderm; heart; nervous system; and otocyst. Orthologous to human RHOB (ras homolog family member B). [provided by Alliance of Genome Resources, Apr 2022]