Purified (~70-90%). LOK is a member of the Ste20 family of serine/threonine protein kinases, and is similar to several known polo-like kinase kinases. LOK can associate with and phosphorylate polo-like kinase 1, and overexpression of a kinase-dead version of the protein interferes with normal cell cycle progression. LOK can also negatively regulate interleukin 2 expression in T-cells via the mitogen activated protein kinase kinase 1 pathway. MEKK1 and LOK have opposing roles in regulating the enhancer element of the IL-2 gene during T-cell activation. While MEKK1 is responsible for the CD28 signalling pathway that activates the CD28 response element, co-expression of LOK attenuates these effects. Source: Recombinant protein corresponding to human LOK, fused to GST-Tag at N-terminal expressed in Insect cells. Molecular Weight: ~65kD Specific Activity: 3.2nmol/min/mg as per activity assay protocol. Endotoxin: <1EU/ug (LAL)