Chromatin Remodeling： ISWI.PDF

See online version for legend and references454 Cell 144,February 4,2011 2011 Elsevier Inc.DOI 10.1016/j.cell.2011.01.019SnapShot:Chromatin Remodeling:ISWIAdam N.Yadon and Toshio TsukiyamaFred Hutchinson Cancer Research Center,Seattle,WA 98109,USAGeneral domain structureDEXD ATPaseHANDHelicaseSANTSLIDEIsw2ACFCHRACIsw2Isw1aIsw1bReplication,transcription,andTy1 integration regulation1Nucleosome assembly,transcription,and replication regulation5Chromatin structure andtranscription regulation6Chromatin structure andtranscription regulation7Replication and transcription regulation9Transcription regulation13DNA replication and repair regulation14Functions unknownCell differentiation and transcription regulation15Functions unknownFunctions unknownChromatin structure andcentromere maintenance10Development and transcription regulation11CERFFunctions unknownHeterochromatin formation and/or replication regulation12Developmental cellular expansion andnuclear divisions8Functions unknownTranscription regulation2Cell fate determination3Transcription regulation4Itc1Isw2NoRCWICHNURFNucleosome slidingHistone replacementISWI-AISWI-DWCRFACF1SNF2HWCRF180SNF2HACFACF1WICHRSFp175ACF1ISWIWSTFISWIISWIRSF1Isw1Ioc3NURFISWINURFRSFCHR11CHR17CHRACSaccharomyces cerevisiaeCaenorhabditis elegansDrosophila melanogasterArabidopsis thalianaXenopus laevisMammalsBiochemical ActivitiesTrypanosoma bruceiItc1Isw2Dpb4Dls1Ioc2Ioc4Isw1NURF1Isw1?Isw1ACF1ISWIACF1ISWI?CHR11?CHR17NURF301ISWIACF1SNF2HRSF1SNF2HSNF2LCECR2ATPADPTIP5SNF2HWSTFSNF2HSNF2LBPTFRbAp46/48RbAp46/48ISWIp200p15p21p70p200p17ISWIp55ISWIISWIATPADP+HistonesNURF38NURF38CHRAC15CHRAC15CHRAC15CHRAC15CHRAC17CHRAC17CHRAC16CHRAC16454.e1 Cell 144,February 4,2011 2011 Elsevier Inc.DOI 10.1016/j.cell.2011.01.019 SnapShot:Chromatin Remodeling:ISWIAdam N.Yadon and Toshio TsukiyamaFred Hutchinson Cancer Research Center,Seattle,WA 98109,USAThe imitation switch(ISWI)family of ATP-dependent chromatin-remodeling enzymes comprises highly conserved protein complexes that utilize the energy of ATP hydrolysis to slide nucleosomes along DNA and/or replace histones within nucleosomes.All ATP-dependent chromatin-remodeling complexes,including the ISWI family,contain a conserved catalytic DEXD ATPase domain and a helicase domain.However,the combination of three C-terminally located domains,known as HAND,SANT,and SLIDE,is unique to ISWI family members.The SANT domain(structurally related to the c-Myb DNA-binding domains)binds unmodified histone tails,the SLIDE(SANT-like ISWI domain)domain binds nucleosomal DNA near the dyad axis,and the HAND domain is implicated in both histone and DNA binding/recognition.Representative ISWI-containing protein complexes from multiple species are depicted in this SnapShot,with specific in vivo biological functions for each listed below.Biological Functions of ISWI-Containing Complexes1.Replication,Transcription,and Ty Integration RegulationFacilitates replication fork progression through late-replicating regions;represses mRNA and cryptic noncoding RNA transcription by negatively regulating NFR size;required for the periodic integration pattern of the Ty1 retrotransposon.2.Transcription RegulationRepresses and activates transcription at a small number of loci and is implicated in transcription elongation and termination regulation.3.Cell Fate DeterminationPromotes the expression of vulval cell fates by antagonizing the transcriptional and chromatin-remodeling activities of complexes similar to Myb-MuvB/dREAM,NuRD,and Tip60/NuA4.4.Transcription RegulationDownregulates VSV expression sites.5.Nucleosome Assembly,Transcription,and Replication RegulationRequired for the establishment and/or maintenance of periodic nucleosome arrays that contributes to pericentric position-effect variegation(PEV)and heterochromatic Poly-comb-mediated transcriptional gene silencing;implicated in the regulation of S phase length/progression.6.Chromatin Structure and Transcription RegulationMaintains higher-order chromatin structure by mediating chromatin compaction;disrupts the enhancer-blocking function of Fab7 and SF1 while augmenting the function of Fab8;activates transcription of GAGA target genes and ecdysone-responsive genes and is a coactivator of Armadillo;regulates innate immunity by repressing transcription of JAK/STAT target genes.7.Chromatin Structure and Transcription RegulationInvolved in formation of silent heterochromatin by incorporating the histone variant H2Av,thus suppressing position-effect variegation(PEV).8.Developmental Cellular Expansion and Nuclear DivisionsNecessary for cell expansion during late-diploid(sporophytic)embryogenesis and mitotic nuclear divisions during haploid(gametophytic)phase.9.Replication and Transcription RegulationRequired for S phase progression and facilitates pericentromeric heterochromatin DNA replication;represses transcription of the vitamin D3 receptor-regulated genes in humans.10.Chromatin Structure and Centromere MaintenanceImplicated in chromatin assembly and actively supports the assembly of CENP-A chromatin in humans.11.Development and Transcription RegulationFunctions in neural tube formation and terminal differentiation of ovarian granulose cells through regulation of StAR gene expression in mice.12.Heterochromatin Formation and/or Replication RegulationTargeted to pericentromeric heterochromatin during early stages of chromosome condensation and DNA replication.13.Transcription RegulationInvolved in the transcriptional repression of ribosomal RNA genes.14.DNA Replication and Repair RegulationImplicated in heterochromatin DNA replication by binding PCNA in mice;necessary for cell survival following DNA damage by methyl methanesulfate(MMS);and facilitates a DNA damage response pathway by controlling histone H2A.Z function in mice.15.Cell Differentiation and Transcription RegulationPromotes neurite outgrowth and transcription of engrailed 1 and 2 in humans.AcknowledgmentsT.T.is funded by NIGMS.A.N.Y.was supported by a Developmental Biology Predoctoral Training Grant T32HD007183 from the National Institute of Child Health and Human Develop-ment.RefeRencesBowman,G.D.(2010).Mechanisms of ATP-dependent nucleosome sliding.Curr.Opin.Struct.Biol.20,7381.Clapier,C.R.,and Cairns,B.R.(2009).The biology of chromatin remodeling complexes.Annu.Rev.Biochem.78,273304.Dang,W.,and Bartholomew,B.(2007).Domain architecture of the catalytic subunit in the ISW2-nucleosome complex.Mol.Cell.Biol.27,83068317.Gangaraju,V.K.,Prasad,P.,Srour,A.,Kagalwala,M.N.,and Bartholomew,B.(2009).Conformational changes associated with template commitment in ATP-dependent chromatin remodeling by ISW2.Mol.Cell 35,5869.Whitehouse,I.,Rando,O.J.,Delrow,J.,and Tsukiyama,T.(2007).Chromatin remodelling at promoters suppresses antisense transcription.Nature 450,10311035.Yadon,A.N.,Van de Mark,D.,Basom,R.,Delrow,J.,Whitehouse,I.,and Tsukiyama,T.(2010).Chromatin remodeling around nucleosome-free regions leads to repression of noncod-ing RNA transcription.Mol.Cell.Biol.30,51105122.