Enables cAMP binding activity; guanyl-nucleotide exchange factor activity; and small GTPase binding activity. Involved in regulation of synaptic vesicle cycle. Acts upstream of or within adenylate cyclase-activating G protein-coupled receptor signaling pathway; regulation of exocytosis; and secretion by cell. Located in cytosol and hippocampal mossy fiber to CA3 synapse. Is expressed in several structures, including adrenal gland; ganglia; heart; lung; and metanephros. Human ortholog(s) of this gene implicated in autistic disorder. Orthologous to human RAPGEF4 (Rap guanine nucleotide exchange factor 4). [provided by Alliance of Genome Resources, Apr 2022]