TSSK3

Despite its family name, TSSK3 (also known as DSCR3) is not restricted to testis; it is expressed in many tissues and its gene lies in the Down syndrome critical region of chromosome 21. The kinase localizes to the nucleus, can autophosphorylate, and has been implicated in cell-cycle regulation and in developmental phenotypes of trisomy 21. Relative to the germ-cell-restricted siblings TSSK1B, TSSK2 and TSSK6, the substrate repertoire of TSSK3 is far less defined, and no specific human disease has been firmly attributed to its mutation. Its dosage sensitivity and broad somatic expression distinguish it as the atypical member of the TSSK family.