Switch defective/sucrose non-fermentable(SWI/SNF)chromatin remodeling complexes are multi-subunit machines that play vital roles in the regulation of chromatin structure and gene expression.However,the mechanisms by w...Switch defective/sucrose non-fermentable(SWI/SNF)chromatin remodeling complexes are multi-subunit machines that play vital roles in the regulation of chromatin structure and gene expression.However,the mechanisms by which SWI/SNF complexes recognize their target loci in plants are not fully understood.Here,we show that the Arabidopsis thaliana bromodomain-containing proteins BRD1,BRD2,and BRD13 are core subunits of SWI/SNF complexes and critical for SWI/SNF genomic targeting.These three BRDs interact directly with multiple SWI/SNF subunits,including the BRAHMA(BRM)catalytic subunit.Phenotypic and transcriptomic analyses of the brd1 brd2 brd13 triple mutant revealed that these BRDs act largely redundantly to control gene expression and developmental processes that are also regulated by BRM.Genome-wide occupancy profiling demonstrated that these three BRDs extensively colocalize with BRM on chromatin.Simultaneous loss of function of three BRD genes results in reduced BRM protein levels and decreased occupancy of BRM on chromatin across the genome.Furthermore,we demonstrated that the bromodomains of BRDs are essential for genomic targeting of the BRD subunits of SWI/SNF complexes to their target sites.Collectively,these results demonstrate that BRD1,BRD2,and BRD13 are core subunits of SWI/SNF complexes and reveal their biological roles in facilitating genomic targeting of BRM-containing SWI/SNF complexes in plants.展开更多
SWI/SNF chromatin remodelers are evolutionarily conserved multiprotein complexes that use the energy of ATP hydrolysis to change chromatin structure.A characteristic feature of SWI/SNF remodelers is the occurrence in ...SWI/SNF chromatin remodelers are evolutionarily conserved multiprotein complexes that use the energy of ATP hydrolysis to change chromatin structure.A characteristic feature of SWI/SNF remodelers is the occurrence in both the catalytic ATPase subunit and some auxiliary subunits,of bromodomains,the protein motifs capable of binding acetylated histones.Here,we report that the Arabidopsis bromodomaincontaining proteins BRD1,BRD2,and BRD13 are likely true SWI/SNF subunits that interact with the core SWI/SNF components SWI3C and SWP73B.Loss of function of each single BRD protein caused early flowering but had a negligible effect on other developmental pathways.By contrast,a brd triple mutation(brdx3)led to more pronounced developmental abnormalities,indicating functional redundancy among the BRD proteins.The brdx3 phenotypes,including hypersensitivity to abscisic acid and the gibberellin biosynthesis inhibitor paclobutrazol,resembled those of swi/snf mutants.Furthermore,the BRM protein level and occupancy at the direct target loci SCL3,ABI5,and SVP were reduced in the brdx3 mutant background.Finally,a brdx3 brm-3 quadruple mutant,in which SWI/SNF complexes were devoid of all constituent bromodomains,phenocopied a loss-of-function mutation in BRM.Taken together,our results demonstrate the relevance of BRDs as SWI/SNF subunits and suggest their cooperation with the bromodomain of BRM ATPase.展开更多
基金supported by the National Natural Science Foundation of China to C.L.(32000380 and 31870289)Guangdong Basic and Applied Basic Research Foundation to C.L.(2021A1515011286)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University to C.L(18lgzd12).
文摘Switch defective/sucrose non-fermentable(SWI/SNF)chromatin remodeling complexes are multi-subunit machines that play vital roles in the regulation of chromatin structure and gene expression.However,the mechanisms by which SWI/SNF complexes recognize their target loci in plants are not fully understood.Here,we show that the Arabidopsis thaliana bromodomain-containing proteins BRD1,BRD2,and BRD13 are core subunits of SWI/SNF complexes and critical for SWI/SNF genomic targeting.These three BRDs interact directly with multiple SWI/SNF subunits,including the BRAHMA(BRM)catalytic subunit.Phenotypic and transcriptomic analyses of the brd1 brd2 brd13 triple mutant revealed that these BRDs act largely redundantly to control gene expression and developmental processes that are also regulated by BRM.Genome-wide occupancy profiling demonstrated that these three BRDs extensively colocalize with BRM on chromatin.Simultaneous loss of function of three BRD genes results in reduced BRM protein levels and decreased occupancy of BRM on chromatin across the genome.Furthermore,we demonstrated that the bromodomains of BRDs are essential for genomic targeting of the BRD subunits of SWI/SNF complexes to their target sites.Collectively,these results demonstrate that BRD1,BRD2,and BRD13 are core subunits of SWI/SNF complexes and reveal their biological roles in facilitating genomic targeting of BRM-containing SWI/SNF complexes in plants.
基金supported by grants from National Science Centre project nos.2014/15/N/NZ2/00396 to K.J.,2014/13/B/NZ1/00967 to A.J.,and 2017/26/E/NZ2/00899 to R.A.sponsored in part by the Center for Preclinical Research and Technology(CePT)+1 种基金a project co-sponsored by the European Regional Development Fund and Innovative EconomyThe National Cohesion Strategy of Poland.
文摘SWI/SNF chromatin remodelers are evolutionarily conserved multiprotein complexes that use the energy of ATP hydrolysis to change chromatin structure.A characteristic feature of SWI/SNF remodelers is the occurrence in both the catalytic ATPase subunit and some auxiliary subunits,of bromodomains,the protein motifs capable of binding acetylated histones.Here,we report that the Arabidopsis bromodomaincontaining proteins BRD1,BRD2,and BRD13 are likely true SWI/SNF subunits that interact with the core SWI/SNF components SWI3C and SWP73B.Loss of function of each single BRD protein caused early flowering but had a negligible effect on other developmental pathways.By contrast,a brd triple mutation(brdx3)led to more pronounced developmental abnormalities,indicating functional redundancy among the BRD proteins.The brdx3 phenotypes,including hypersensitivity to abscisic acid and the gibberellin biosynthesis inhibitor paclobutrazol,resembled those of swi/snf mutants.Furthermore,the BRM protein level and occupancy at the direct target loci SCL3,ABI5,and SVP were reduced in the brdx3 mutant background.Finally,a brdx3 brm-3 quadruple mutant,in which SWI/SNF complexes were devoid of all constituent bromodomains,phenocopied a loss-of-function mutation in BRM.Taken together,our results demonstrate the relevance of BRDs as SWI/SNF subunits and suggest their cooperation with the bromodomain of BRM ATPase.
