May be a negative regulator of NF-kappa-B and p53-mediated gene transcription. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. Was originally thought to originate from X.laevis. However, sequence identity with X.tropicalis is much higher than with X.laevis, suggesting that the sequence is from X.tropicalis.