title: Arabidopsis HAF2 gene encoding TATA-binding protein (TBP)-associated factor TAF1, is required to integrate light signals to regulate gene expression and growth.
abstract: Plant growth and development are sensitive to light. Light-responsive DNA-binding transcription factors have been functionally identified. However, how transcription initiation complex integrates light signals from enhancer-bound transcription factors remains unknown. In this work, we characterized mutations within the Arabidopsis HAF2 gene encoding TATA-binding protein-associated factor TAF1 (or TAF(II)250). The mutation of HAF2 induced decreases on chlorophyll accumulation, light-induced mRNA levels, and promoter activity. Genetic analysis indicated that HAF2 is involved in the pathways of both red/far-red and blue light signals. Double mutants between haf2-1 and hy5-1, a mutation of a light signaling positive DNA-binding transcription factor gene, had a synergistic effect on photomorphogenic traits and light-activated gene expression under different light wavelengths, suggesting that HAF2 is required for interaction with additional light-responsive DNA-binding transcription factors to fully respond to light induction. Chromatin immunoprecipitation assays showed that the mutation of HAF2 reduced acetylation of histone H3 in light-responsive promoters. In addition, transcriptome analysis showed that the mutation altered the expression of about 9% of genes in young leaves. These data indicate that TAF1 encoded by the Arabidopsis HAF2 gene functions as a coactivator capable of integrating light signals and acetylating histones to activate light-induced gene transcription.
authors.affiliation: Institut de Biotechnologie des Plantes, UMR8618, Université Paris-sud XI, 91405 Orsay, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Bertrand
authors.forename: Moussa
authors.initials: M
authors.lastname: Benhamed
authors.forename: You-Fang
authors.initials: YF
authors.lastname: Li
authors.forename: Mira
authors.initials: M
authors.lastname: Ayadi
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Lemonnier
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Renou
authors.forename: Marianne
authors.initials: M
authors.lastname: Delarue
authors.forename: Dao-Xiu
authors.initials: DX
authors.lastname: Zhou
mesh_terms: D000107:Acetylation; D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D005816:Genetic Complementation Test; D006657:Histones / Q000378:metabolism; D018546:Hypocotyl / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008027:Light; D045342:Light-Harvesting Protein Complexes; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000235:genetics; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D011401:Promoter Regions, Genetic / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C423618:CAB2 protein, Arabidopsis; D002352:Carrier Proteins; D004269:DNA, Bacterial; C496704:HAF2 protein, Arabidopsis; D006657:Histones; D045342:Light-Harvesting Protein Complexes; C036483:T-DNA; D014157:Transcription Factors