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UVB-induced COX-2 expression requires histone H3 phosphorylation at Ser10 and Ser28

Cyclooxygenase-2 (COX-2) is an inducible enzyme that contributes to the generation of chronic inflammation in response to chemical carcinogens and environmental stresses, including ultraviolet B (UVB) irradiation. Although post-translational histone modifications are believed to play an important ro...

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Detalles Bibliográficos
Autores principales: Keum, Young-Sam, Kim, Hong-Gyum, Bode, Ann M., Surh, Young-Joon, Dong, Zigang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3504182/
https://www.ncbi.nlm.nih.gov/pubmed/22391560
http://dx.doi.org/10.1038/onc.2012.71
Descripción
Sumario:Cyclooxygenase-2 (COX-2) is an inducible enzyme that contributes to the generation of chronic inflammation in response to chemical carcinogens and environmental stresses, including ultraviolet B (UVB) irradiation. Although post-translational histone modifications are believed to play an important role in modulating transcriptional regulation of UVB-induced COX-2, the underlying biochemical mechanisms are completely unknown. Here, we show that UVB activates the p38 MAPK/MSK1 kinase cascade to phosphorylate histone H3 at Ser10 and Ser28, contributing to UVB-induced COX-2 expression. UVB has no effect on the global trimethylation level of histone H3 (H3K4me3, H3K9me3, and H3K27me3). We observed that selected mammalian 14-3-3 proteins bind to UVB-induced phosphorylated histone H3 (Ser10 and Ser28). In particular, 14-3-3ε is critical for recruiting MSK1 and Cdk9 to the chromatin and subsequently phosphorylating the C-terminal domain (CTD) of RNA polymerase II in the cox-2 promoter. We propose that histone H3 phosphorylation at Ser10 and Ser28 serve as critical switches to promote cox-2 gene expression by facilitating the recruitment of MSK1 and Cdk9 to the cox-2 promoter, thereby promoting RNA polymerase II phosphorylation.