Overview:

TOPK is a MAPK kinase that phosphorylates p38 MAPK and is activated in a cell-cycle-dependent manner in neuronal progenitor cells in vitro (1). Expression of TOPK is detected in male germ line progenitor cells, activated T-cells, and a variety of lymphomas and leukemias. In vitro studies have shown that activated TOPK phosphorylated p38 MAPK but not JNK or ERK. TOPK activation requires phosphorylation by both the M-phase CDK1/CyclinB kinase complex and another unknown kinase, possibly Raf C or Raf A. TOPK may play an important role in linking extracellular signals to an intracellular state, possibly allowing extracellular influence on the cell-cycle-related processes of proliferation or differentiation (2).

Gene Aliases:

PBK, SPK, Nori-3, FLJ14385

Genbank Number:

NM_018492

References:

1. Matsumoto, S. et al: Characterization of a MAPKK-like protein kinase TOPK. Biochem Biophys Res Commun. 2004; 325: 997-1004.

2. Simons-Evelyn, M. et al: PBK/TOPK is a novel mitotic kinase which is upregulated in Burkitt's lymphoma and other highly proliferative malignant cells. Blood Cells Mol Dis, 2001; 27: 825-829.