Rap guanine nucleotide exchange factor (GEF) 4 Adenovirus

Epac (exchange protein directly activated by cAMP; also designated cAMP-GEFI) and Epac2 (also designated cAMP-GEFII) compose a novel family of cyclic AMP activated guanine-nucleotide exchange factors (GEFs). Both Epac and Epac2 contain cAMP-binding motifs and a motif common to Ras superfamily GEFs. Epac and Epac2 both function to activate Rap1, a Ras-like GTPase that is known to suppress the oncogenic transformation of cells by Ras. Epac is ubiquitously expressed, whereas Epac2 is primarily expressed in the brain and adrenal glands.