A Kinase Anchor Protein 11 (AKAP11)

A-kinase anchor protein 11 is expressed at high levels throughout spermatogenesis and in mature sperm. It binds the RI and RII subunits of PKA in testis. It may serve a function in cell cycle control of both somatic cells and germ cells in addition to its putative role in spermatogenesis and sperm function. The AKAP11 protein has 1,129 amino acids and contains a PKA-binding region and a peroxisome targeting motif. Immunohistochemical analysis of rat testis cells showed that AKAP220 and a proportion of RII PKA are colocalized in microbodies that appear to be a subset of peroxisomes. By RT-PCR analysis, Ishikawa et al. (1998) detected expression of human AKAP11 in heart, brain, lung, liver, kidney, testis, and ovary, with weaker expression in skeletal muscle, pancreas, and spleen.