Arabidopsis mediator subunit 17 connects transcription with DNA repair after UV‐B exposure

Abstract

Mediator 17 (MED17) is a subunit of the Mediator complex that regulates transcription initiation in eukaryotic organisms. In yeast and humans, MED17 also participates in DNA repair, physically interacting with proteins of the nucleotide excision DNA repair system, but this function in plants has not been investigated. We studied the role of MED17 in Arabidopsis plants exposed to UV-B radiation. Our results demonstrate that med17 and OE MED17 plants have altered responses to UV-B, and that MED17 participates in various aspects of the DNA damage response (DDR). Comparison of the med17 transcriptome with that of wild-type (WT) plants showed that almost one-third of transcripts with altered expression in med17 plants were also changed by UV-B exposure in WT plants. Increased sensitivity to DNA damage after UV-B in med17 plants could result from the altered regulation of UV-B responsive transcripts but MED17 also physically interacts with DNA repair proteins, suggesting a direct role of this Mediator subunit during repair. Finally, we show that MED17 is necessary to regulate the DDR activated by ataxia telangiectasia and Rad3 related (ATR), and that programmed cell death 5 (PDCD5) overexpression reverts the deficiencies in DDR shown in med17 mutants. Our data demonstrate that MED17 is an important regulator of DDR after UV-B irradiation in Arabidopsis.

Comparative phylogenetic analysis of the mediator complex subunit in asparagus bean (Vigna unguiculata ssp. sesquipedialis) and its expression profile under cold stress

“…AtMED16 and AtMED25 differentially regulate ABA signaling [ 30 ]. The promoter regions of all V un MED genes contain light-responsive elements, and the role of some MED genes in light response has been revealed: Arabidopsis AtMED25 plays a role in the light quality pathway that regulates flowering time [ 31 ], and AtMED17 responds to UV-B irradiation in Arabidopsis [ 32 ]. These results suggest that the potential functions of the VunMED gene require further study.…”

“…We screened for mutated MED genes in the SVs of the pan-genome of cowpeas and MED9/10b/12/13/17/23 had large variations. MED17 physically interacts with DNA repair proteins in yeast [ 36 ], humans [ 37 ], and Arabidopsis [ 32 ], and plays a direct role in repair processes. AtMED9 is required to interact with AtMED4/21/31 and respond to early thermal stress [ 38 ].…”

Explore the role of long noncoding RNAs and mRNAs in intracranial atherosclerotic stenosis: From the perspective of neutrophils

“…Generally, MED17 promotes transcription initiation and DNA repair. [ 34 ] Increasing evidence suggests that the transcriptional activity of neutrophils is vital in chronic inflammatory diseases. In early atherosclerosis, neutrophils present a nonresolving inflammatory state with the inhibition of homeostatic transcription factors in endotoxemia.…”

Causes of Mutation Rate Variability in Plant Genomes

“…While the TCR pathway provides a clear connection between elevated repair and active genes (99), the GGR pathway can also preferentially target active genes, with evidence that the underlying mechanism is mediated by epigenome scanning in NER proteins (2). MED17 is reported to contribute to the recruitment of multiple NER proteins (27,53) and, in Arabidopsis, interacts with PDS5C, a protein that specifically binds active gene bodies via H3K4me1 targeted by its Tudor domain (27,33,93,104). Also in Arabidopsis, MED14 was shown to be required for heterochromatin transcription during heat stress, together with UVH6 forming part of the IIH complex that participates in TCR and NER (9).…”