AGR Description: Exhibits cAMP binding activity and guanyl-nucleotide exchange factor activity  involved in several processes  including animal organ development  cellular response to nerve growth factor stimulus  and negative regulation of synaptic transmission  localizes to several cellular components  including the apical plasma membrane  basolateral plasma membrane  and neuron projection  orthologous to human RAPGEF4 (Rap guanine nucleotide exchange factor 4)