title: Regulation of transcription by the Arabidopsis UVR8 photoreceptor involves a specific histone modification.
abstract: The photoreceptor UV RESISTANCE LOCUS 8 (UVR8) specifically mediates photomorphogenic responses to UV-B wavelengths. UVR8 acts by regulating transcription of a set of genes, but the underlying mechanisms are unknown. Previous research indicated that UVR8 can associate with chromatin, but the specificity and functional significance of this interaction are not clear. Here we show, by chromatin immunoprecipitation, that UV-B exposure of Arabidopsis increases acetylation of lysines K9 and/or K14 of histone H3 at UVR8-regulated gene loci in a UVR8-dependent manner. The transcription factors HY5 and/or HYH, which mediate UVR8-regulated transcription, are also required for this chromatin modification, at least for the ELIP1 gene. Furthermore, sequencing of the immunoprecipitated DNA revealed that all UV-B-induced enrichments in H3K9,14diacetylation across the genome are UVR8-dependent, and approximately 40 % of the enriched loci contain known UVR8-regulated genes. In addition, inhibition of histone acetylation by anacardic acid reduces the UV-B induced, UVR8 mediated expression of ELIP1 and CHS. No evidence was obtained in yeast 2-hybrid assays for a direct interaction between either UVR8 or HY5 and several proteins involved in light-regulated histone modification, nor for the involvement of these proteins in UVR8-mediated responses in plants, although functional redundancy between proteins could influence the results. In summary, this study shows that UVR8 regulates a specific chromatin modification associated with transcriptional regulation of a set of UVR8-target genes.
authors.affiliation: Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK.
authors.forename: Christos N
authors.initials: CN
authors.lastname: Velanis
authors.affiliation: Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK.|Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Switchback Road, Bearsden, G61 1QH, UK.
authors.forename: Pawel
authors.initials: P
authors.lastname: Herzyk
authors.affiliation: Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK. Gareth.Jenkins@Glasgow.ac.uk.
authors.forename: Gareth I
authors.initials: GI
authors.lastname: Jenkins
mesh_terms: D017360:Arabidopsis / Q000378:metabolism* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism / Q000528:radiation effects; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000528:radiation effects; D042421:Histone Code; D006657:Histones / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; C525052:Uvr8 protein, Arabidopsis
keywords: Arabidopsis thaliana; Chromatin; HAT inhibitors; Histone modification; Transcription; UV-B; UVR8