Functional interplay between Mediator and RNA polymerase II in Rad2/XPG loading to the chromatin

Abstract

Transcription and maintenance of genome integrity are fundamental cellular functions. Deregulation of transcription and defects in DNA repair lead to serious pathologies. The Mediator complex links RNA polymerase (Pol) II transcription and nucleotide excision repair via Rad2/XPG endonuclease. However, the functional interplay between Rad2/XPG, Mediator and Pol II remains to be determined. In this study, we investigated their functional dynamics using genomic and genetic approaches. In a mutant affected in Pol II phosphorylation leading to Mediator stabilization on core promoters, Rad2 genome-wide occupancy shifts towards core promoters following that of Mediator, but decreases on transcribed regions together with Pol II. Specific Mediator mutations increase UV sensitivity, reduce Rad2 recruitment to transcribed regions, lead to uncoupling of Rad2, Mediator and Pol II and to colethality with deletion of Rpb9 Pol II subunit involved in transcription-coupled repair. We provide new insights into the functional interplay between Rad2, Mediator and Pol II and propose that dynamic interactions with Mediator and Pol II are involved in Rad2 loading to the chromatin. Our work contributes to the understanding of the complex link between transcription and DNA repair machineries, dysfunction of which leads to severe diseases.

CpG-Recoding in Zika Virus Genome Causes Host-Age-Dependent Attenuation of Infection With Protection Against Lethal Heterologous Challenge in Mice

“…Increasing the number of CpG dinucleotides in viral genomes is a promising vaccine approach; attenuated infection phenotypes caused by recoded vaccine candidates, however, may depend on the expression of cellular components targeting viral CpG dinucleotides (7,15). Thus, population-based studies on infection caused by CpG-recoded viruses will foster further application of the approach.…”

“…Third, restriction of infection is not mediated through translation impairment, disruption of an RNA structure, or stress, interferon, and apoptosis pathways activated through conventional pattern recognition receptors (4,(10)(11)(12). Finally, zinc-finger antiviral protein (ZAP) targets recoded human immunodeficiency virus 1 (HIV-1) and echovirus 7 by directly binding to CpG-enriched genomic regions (9,14); subsequently, synergy or complementation of ZAP function by oligoadenylate synthetase 3, RNase L (15) and cytoplasmic protein KHNYN (16) is capable of inhibiting replication of viruses containing the elevated number of CpG dinucleotides.…”

“…Attenuated infection caused by recoded vaccine candidates may depend on the expression of cellular components targeting CpG dinucleotides (15); thus, focused investigations on population-based differences in CpG-recoded vaccine attenuation to reassure safety and efficacy are crucial (7,15).…”

Comprehensive Bioinformatics Analysis Identifies POLR2I as a Key Gene in the Pathogenesis of Hypertensive Nephropathy

“…Finally, the results of our analysis were verified by an in vivo experiment. The maintenance of transcriptional fidelity and genome integrity is essential for cellular functions, while deregulation of transcription and defects in DNA repair can cause serious pathologies, including HN (Trudu et al, 2013;Georges et al, 2019). It was reported that the absence of POLR2I significantly reduces transcriptional accuracy (Nesser et al, 2006) and also leads to defects in replication fork progression (Felipe-Abrio et al, 2015).…”

Zika Virus with Increased CpG Dinucleotide Frequencies Shows Oncolytic Activity in Glioblastoma Stem Cells

“…Mechanistically, it has been demonstrated that cellular Zinc-finger antiviral protein (ZAP) targets recoded viruses by specifically binding to genomic regions enriched in CpG dinucleotides [3,4]. Subsequently, synergy or complementation of ZAP function by oligoadenylate synthetase 3, RNase L, and cytoplasmic protein KHNYN inhibits replication of viruses containing an elevated number of CpG dinucleotides [5,6].…”