Predicted to enable GTP-dependent protein binding activity and guanyl-nucleotide exchange factor activity. Predicted to be involved in small GTPase mediated signal transduction. Predicted to be located in nuclear body. Is expressed in several structures, including alimentary system; branchial arch; central nervous system; heart and pericardium; and sensory organ. Orthologous to human RAPGEF5 (Rap guanine nucleotide exchange factor 5). [provided by Alliance of Genome Resources, Apr 2022]