Virulence factor acting as a pro-inflammatory protein that induces the secretion of the pro-inflammatory cytokines TNF-alpha (tumor necrosis factor-alpha) and IL-8 (interleukin-8) from human macrophages, as well as enhanced translocation of the transcription factor NF-kappa-B complex in macrophages. Is a kinase capable of autophosphorylating itself at a threonine residue near the N-terminus. Also leads to enhanced phosphorylation of the NF-kappa-B p65 subunit (RELA) at 'Ser-276' in human epithelial cancer cells; its kinase activity is required for this enhanced phosphorylation that up-regulates NF-kappa-B activity, but it does not directly phosphorylate this protein. Thus, the kinase activity of CtkA may play an important role in the induction of host inflammatory responses during H.pylori infection. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Translocates into cultured human cells. When examining the cellular location of the transiently expressed CtkA after 0, 12, 24, and 48 hours of transfection, the transiently expressed CtkA translocates from cytosol into nucleus in a time-dependent manner. Is strongly expressed in response to the interaction of H.pylori with the mammalian gastric mucosa. The C-terminal tail (residues 301-325) is not required for the kinase activity and for translocation into human cells. Autophosphorylates on either Thr-3 or Thr-7.