Protein Names (UNIPROT)

A-kinase anchor protein 3

Protein function and interaction

Mammalian sperm motility is regulated by a cascade of cAMP-dependent protein phosphorylation events, mediated by protein kinase A. A-kinase anchor proteins (AKAPs) direct protein kinase A activity by tethering the enzyme near its physiological substrates (Turner et al., 1998 PMID: 9822690).

AKAP3 is synthesized in round spermatids and incorporated into the fibrous sheath, concurrently with formation of the rib precursors, with a possible function in organizing the basic structure of the fibrous sheath (Brown et al., 2003 PMID: 12606363).

PI 3-kinase negatively regulates sperm motility by interfering with AKAP3-PKA binding, providing an evidence of a molecular mechanism by which PKA can be targeted to sperm tails by interaction with tyrosine phosphorylated form of AKAP3 (Luconi et al., 2004 PMID: 14996943).

AKAP3, heterotrimeric G proteins (G alpha 13), rPKA (regulatory subunit of PKA), and cPKA (catalytic subunit of PKA) can form a complex, as shown by coimmunoprecipitation. AKAP3 significantly potentiates G alpha 13-induced activation of PKA, providing a link between heterotrimeric G proteins and cAMP-independent activation of PKA (Niu et al., 2001 PMID: 11696326).

Co-localization of AKAP3 and Sp17 by immunofluorescence was demonstrated along the length of the principal piece of the sperm flagella (Lea et al., 2004 PMID: 15257753).