PDZ Binding Kinase
is a serine/threonine kinase related to the dual specific mitogen-activated protein kinase kinase (MAPKK) family. Evidence suggests that mitotic phosphorylation is required for its catalytic activity. This mitotic kinase may be involved in the activation of lymphoid cells and support testicular functions, with a suggested role in the process of spermatogenesis.
The variants differ at their 5-prime ends and encode the same protein, a deduced 322-amino acid serine/threonine kinase with a calculated molecular mass of 37.4 kD. Northern blot analysis of 12 human tissues detected transcripts of 1.9 and 2 kb in testis only. RT-PCR detected TOPK in activated, but not deactivated, T-LAK cells.