The phosphorylation of RelA on Ser547 does not modulate NF-kB activation after TNFa treatment like after a genotoxic stress

NF-kB controls the expression of hundred of genes involved in inflammatory and innate responses, proliferation, survival, cancer initiation and progression. Numerous post-translational modifications of p65 modulating NF-kB transcriptional activity are known. We identified Ser547 as a new site of p65 phosphorylation targeted by ATM kinase, which coordinates the “DNA Damage Response” pathway in the event of DNA double-strand breaks. We demonstrated that the phosphorylation of Ser547 regulates the transcription of a sub-set of NF-κB dependent genes after genotoxic stress by modifying HDAC1 recruitment(1). Presently, we are investigating the role of this specific phosphorylation in an inflammatory context. We observe that the mutations of p65 (S547A or S547D) also affect the transcriptional potential of the NF-κB in a promoter specific manner after an exposition to TNFα and H2O2. The study of the molecular mechanism of this regulation after TNFα and H2O2 exposition are both in progress.