Lysine methylation of promoter-bound transcription factors and relevance to cancer

p53, NF kappa B, STAT3, and several other transcription factors are reversibly methylated on lysine residues by enzymes that also modify histones. The methylations of NF kappa B and STAT3 take place when they are bound to promoters, suggesting a more general model in which the binding of inducible transcription factors to DNA helps to recruit chromatin-modification machinery, which then may modify not only histones but also the bound transcription factors. Mutations of some histone-lysine methyltransferases and demethylases are linked to cancer, and these mutations may alter the methylation not only of histones but also of transcription factors, and thus may be tumorigenic through more than one mechanism.