Activation of the atypical NF-κB pathway induced by ionizing radiation is not affected by the p53 status
DNA double-strand breaks induced by ionizing radiation can activate the atypical NF-κB pathway via ATM-mediated phosphorylation of NEMO/IKKγ. We aimed to determine whether the status of p53 influenced the activation of this particular NF-κB pathway. The NF-κB signaling was activated either by irradiation with a single 8 Gy dose or by TNFα cytokine in p53-proficient and p53-deficient variants of HCT116, RKO, and U2-OS human cancer cell lines. To assess pathway activation the kinetics of phosphorylation (Ser32) and proteolytic degradation of IκBα inhibitor and phosphorylation (Ser536) of RelA(p65) NF-κB subunit were analyzed. Though activation of the radiation-induced atypical pathway was delayed and weakened when compared to the cytokine-induced canonical pathway, no significant differences were noted between p53-proficient and p53-deficient variants, which indicated that activation of both NF-κB pathways was not affected by the p53 status. In marked contrast, the presence of p53 significantly affected downstream effects of NF-κB activation, i.e. transcription of NF-κB-dependent genes. However, different patterns of such interference were observed, which indicated gene-specific and cell-specific mechanisms of interactions between NF-κB and p53 at the transcription regulation level.
Copyright (c) 2022 Gracjana Zając, Marek Rusin, Barbara Łasut-Szyszka, Krzysztof Puszyński, Piotr Widłak
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Acta Biochimica Polonica is an open access quarterly and publishes four issues a year. All contents are distributed under the Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license. Everybody may use the content following terms: Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made, ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. There are no additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
Copyright for all published papers © stays with the authors.
Copyright for the journal: © Polish Biochemical Society.