Testis Specific Serine Kinase 6 (TSSK6)

TSSK6 is a serine/threonine protein kinase that is required for postmeiotic chromatin remodeling and male fertility. The deduced 273-amino acid TSSK6 protein has a calculated molecular mass of 30.3 kD and consists almost entirely of the N and C lobes of a protein kinase domain. TSSK6 possesses several essential protein kinase features, including a conserved active site, ATP-binding region, and potential activation loop phosphorylation motif. Northern blot analysis detected high expression of a 1.5-kb transcript in adult testis, with lower expression in colon, small intestine, ovary, prostate, thymus, spleen, and peripheral blood leukocytes. A 3-kb transcript was expressed in spinal cord and medulla oblongata. RT-PCR analysis confirmed that highest TSSK6 expression was in testis.