Testis Specific Serine Kinase 1 (TSSK1)

TSSK1 belongs to a family of serine/threonine kinases highly expressed in testis (Hao et al., 2004).Using mouse Tssk1 to search a database, followed by PCR of a testis cDNA library, Hao et al. (2004) cloned human TSSK1. The deduced 367-amino acid protein contains the 12 subdomains characteristic of serine/threonine kinases.

TSSK1 and TSSK2 share 72% amino acid identity overall and 83% identity in the kinase domain. Mouse and human TSSK1 share 85% amino acid identity. Northern blot analysis of human tissues detected TSSK1 transcripts of 1.5 and 2.7 kb in testis only. Real-time PCR revealed abundant TSSK1 expression in testis, lower expression in pancreas, and weak expression in a few other tissues.