| Literature DB >> 31636182 |
Christopher Bianco1, Letitia Thompson1, Ian Mohr2,3.
Abstract
Gene expression is rapidly remodeled by infection and inflammation in part via transcription factor NF-κB activation and regulated protein synthesis. While protein synthesis is largely controlled by mRNA translation initiation, whether cellular translation elongation factors are responsive to inflammation and infection remains poorly understood. Here, we reveal a surprising mechanism whereby NF-κB restricts phosphorylation of the critical translation elongation factor eEF2, which catalyzes the protein synthesis translocation step. Upon exposure to NF-κB-activating stimuli, including TNFα, human cytomegalovirus infection, or double-stranded DNA, eEF2 phosphorylation on Thr56, which slows elongation to limit protein synthesis, and the overall abundance of eEF2 kinase (eEF2K) are reduced. Significantly, this reflected a p65 NF-κB subunit-dependent reduction in eEF2K pre-mRNA, indicating that NF-κB activation represses eEF2K transcription to decrease eEF2K protein levels. Finally, we demonstrate that reducing eEF2K abundance regulates protein synthesis in response to a bacterial toxin that inactivates eEF2. This establishes that NF-κB activation by diverse physiological effectors controls eEF2 activity via a transcriptional repression mechanism that reduces eEF2K polypeptide abundance to preclude eEF2 phosphorylation, thereby stimulating translation elongation and protein synthesis. Moreover, it illustrates how nuclear transcription regulation shapes translation elongation factor activity and exposes how eEF2 is integrated into innate immune response networks orchestrated by NF-κB.Entities:
Keywords: HCMV infection; NF-κB activation; double-strand DNA-sensing; eEF2 and eEF2K; translation elongation
Year: 2019 PMID: 31636182 PMCID: PMC6842605 DOI: 10.1073/pnas.1909143116
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205