Enables guanyl-nucleotide exchange factor activity. Involved in associative learning. Predicted to be located in several cellular components, including basolateral part of cell; brush border membrane; and distal axon. Predicted to colocalize with cortical actin cytoskeleton and plasma membrane. Is expressed in brain; heart; lung; and metanephros. Orthologous to human RAPGEF3 (Rap guanine nucleotide exchange factor 3). [provided by Alliance of Genome Resources, Apr 2022]