title: HAG3, a Histone Acetyltransferase, Affects UV-B Responses by Negatively Regulating the Expression of DNA Repair Enzymes and Sunscreen Content in Arabidopsis thaliana.
abstract: Histone acetylation is regulated by histone acetyltransferases and deacetylases. In Arabidopsis, there are 12 histone acetyltransferases and 18 deacetylases. Histone acetyltransferases are organized in four families: the GNAT/HAG, the MYST, the p300/CBP and the TAFII250 families. Previously, we demonstrated that Arabidopsis mutants in the two members of the MYST acetyltransferase family show increased DNA damage after UV-B irradiation. To investigate further the role of other histone acetyltransferases in UV-B responses, a putative role for enzymes of the GNAT family, HAG1, HAG2 and HAG3, was analyzed. HAG transcripts are not UV-B regulated; however, hag3 RNA interference (RNAi) transgenic plants show a lower inhibition of leaf and root growth by UV-B, higher levels of UV-B-absorbing compounds and less UV-B-induced DNA damage than Wassilewskija (Ws) plants, while hag1 RNAi transgenic plants and hag2 mutants do not show significant differences from wild-type plants. Transcripts for UV-B-regulated genes are highly expressed under control conditions in the absence of UV-B in hag3 RNAi transgenic plants, suggesting that the higher UV-B tolerance may be due to increased levels of proteins that participate in UV-B responses. Together, our data provide evidence that HAG3, directly or indirectly, participates in UV-B-induced DNA damage repair and signaling.
authors.affiliation: Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
authors.forename: Julieta P
authors.initials: JP
authors.lastname: Fina
authors.affiliation: Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina casati@cefobi-conicet.gov.ar.
authors.forename: Paula
authors.initials: P
authors.lastname: Casati
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004249:DNA Damage; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000235:genetics* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D051548:Histone Acetyltransferases / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008857:Microscopy, Interference; D008969:Molecular Sequence Data; D009154:Mutation; D030821:Plants, Genetically Modified; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013473:Sunscreening Agents / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D007527:Isoenzymes; D013473:Sunscreening Agents; C502551:ELO3 protein, Arabidopsis; D051548:Histone Acetyltransferases; D045643:DNA Repair Enzymes
keywords: DNA damage; GNAT familiy; Histone acetyltransferases; UV-B damage