COT, a member of the MAPKKK subfamily of Ser/Thr protein kinases, is able to activate NF-kappa-B 1 by stimulating proteasome-mediated proteolysis of NF-kappa-B 1/p105. It plays a role in the cell cycle. The longer form of cot has some transforming activity, although it is much weaker than the activated cot oncoprotein. This cytoplasmic protein is expressed in several normal tissues and human tumor-derived cell lines. The 58 kDa form is activated specifically during the S and G2/M phases of the cell cycle. The longer form undergoes phosphorylation on Ser residues mainly, and the shorter form on both Ser and Thr residues.

2-8°C (short-term); -20°C (long-term)