Ropporin 1 Like Protein (ROPN1L)

ROPN1L is a sperm protein, which interacts with A-kinase anchoring protein, AKAP3, through the amphipathic helix region of AKAP3. Type II regulatory subunit of cAMP-dependent protein kinase (PKARII) also binds to this helix domain of AKAP3, which allows 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.The deduced ROPN1L protein shares 39% amino acid identity to ropporin (ROPN1). Northern blot analysis of mouse tissues detected expression in testis only. The N-terminal regions of ROPN1L and ROPN1 share similarity with the N-terminus of type II regulatory subunit of PKA and 2 sperm-specific proteins, SPA17 and fibrousheathin II (CABYR).