Background of the antigen
AKAP associated sperm protein (encoded by the gene ROPN1L) is a sperm protein which interacts with A-kinase anchoring protein, AKAP3, through the amphipathic helix region of AKAP3. The Type II regulatory subunit of cAMP-dependent protein kinase (PKARII) also binds to this helical domain of AKAP3, allowing PKARII to be targeted to specific subcellular compartments. It is suggested that sperm contains several proteins that bind to AKAPs in a manner similar to PKARII, and this encoded protein may be one of them.