The Bcl-6 is a zinc finger transcription factor and contains an N-terminal POZ domain. This protein acts as a sequence-specific repressor of transcription, and has been shown to modulate the transcription of START-dependent IL-4 responses of B cells. Additionally, Bcl-6 negatively regulates NFκB expression, thereby inhibiting NFκB-mediated cellular functions. Bcl-6 protein can bind to target DNA sequences of Stat6 and, analogous to Stat6, modulate the expression of interleukin-4-induced genes. Furthermore, Bcl-6 restrains p53-dependent senescence, making Bcl-6-active tumors functionally p53-negative.
