1、See online version for references.SnapShot:Molecular Chaperones,Part II Yun-Chi Tang,Hung-Chun Chang,Manajit Hayer-Hartl,and F.Ulrich HartlDepartment of Cellular Biochemistry,Max Planck Institute of Biochemistry,Martinsried,Germany412 Cell 128,January 26,2007 2007 Elsevier Inc.DOI 10.1016/j.cell.200
2、7.01.013KingdomOrganismChaperone/Protein Data Bank IDMonomer(kDa)/Oligomeric StateCochaperone/CofactorSubcellular Localization/ActivityRibosome-Associated ChaperonesEubacteriaE.coliTrigger factor/1W2B;2AAR48/dimerCytosol/assists folding of nascent chains;catalyzes peptidyl-prolyl isomerization in vi
3、tro.EukaryotesS.cerevisiaeNAC(,)19,17/heterodimerSRPCytosol/interacts with ribosomes,SRP and translating polypeptide chains;role in protein folding/quality control?RAC(Ssz1,Zuotin)58,49/heterodimerSsbCytosol/interacts with Ssb;folding of nascent chains on ribosomes?Chaperonins Group IEubacteriaE.col
4、iGroEL/1AON57/14merGroESCytosol/folding of a cytosolic protein subset;stabilizes proteins during heat stress;promotes folding in vivo of overproduced proteins;refolding of many proteins in vitro.Archaea MethanosarcinaeGroEL58/14merGroESCytosol/folding of cytosolic proteins;the only archaeal species
5、that has GroEL.EukaryotesS.cerevisiae Hsp60 60/14merHsp10 Mitochondria/folding of newly imported proteins;binds to heat-denatured mitochondrial proteins and prevents aggregation.MammalsmtHsp6060/14merHsp10Mitochondria/folding of newly imported proteins.A.thalianaCpn60(and)57,58/Hetero 14merCpn10,Cpn
6、21Chloroplast/folding and assembly of chloroplast proteins,e.g.,ribulose bisphosphate carboxylase.Group IIArchaeaT.acidophilumThermosome(and)/1A6D58/Hetero 16merPrefoldin/GimCCytosol/stress-inducible,promotes folding of a protein subset;refolding of unfolded polypeptides in vitro.EukaryotesS.cerevis
7、iae/MammalsTRiC/CCT(-)5760/Hetero 16merPrefoldin/GimC,PhLP Cytosol/folding of a cytosolic protein subset,including actin,tubulins,and WD40 domain proteins;downstream of Hsp70 in de novo folding;assembly of polyglutamine expansion proteins into nontoxic oligomers.Hsp100EubacteriaE.coliClpA83/hexamerC
8、lpP,SspBCytosol/works with ClpP protease in ATP-dependent unfolding and proteolysis.ClpB/1QVR96/hexamerDnaK,DnaJ,GrpECytosol/ATP-dependent protein disaggregation with DnaK.EukaryotesS.cerevisiaeHsp104104/hexamerHsp70,Hsp40Cytosol/reactivates heat-damaged proteins;establishes and maintains the PSI ye
9、ast prion phenotype.Hsp7885Ssc1,Pim1Mitochondria/prevents aggregation;degradation and turnover of unassembled mitochondrial proteins.PlantsClpC100ClpPChloroplast/works with the ClpP protease to promote proteolysis.Small Heat Shock Proteins(sHsp)EubacteriaE.coliIbpA,IbpB16/A:monomer;B:dimer/multimer
10、Cytosol/prevents heat-denatured protein aggregation;associates with inclusion bodies;works with DnaK in protein refolding.Archaea M.jannashiiHsp16.5/1SHS16.5Cytosol/stabilizes unfolded polypeptides and prevents aggregation.EukaryotesS.cerevisiaeHsp26/2H5024/24merCytosol/prevention of protein aggrega
11、tion;temperature-dependent dissociation required for efficient non-native substrate binding.Mammals-crystallin32merCytosol/in the vertebrate eye lens;prevents heat-denatured protein aggregation.Other ChaperonesEubacteriaE.coliHsp33/1VZY33/dimer(active form)Cytosol/redox-regulated molecular chaperone
12、;prevents aggregation of thermally unfolded and oxidatively damaged proteins.SecB/1QYN17/tetramerSecACytosol/stabilizes some secretory proteins in an unfolded state for export.Skp/1SG217/trimerPeriplasm/interacts with outer membrane proteins,maintains solubility of folding intermediates in the perip
13、lasm.PapD/3DPA27/monomerPapCPeriplasm/P Pili assembly in the chaperone-usher pathway.FimC/1BF823/monomerFimDPeriplasm/Type 1 Pili assembly in the chaperone-usher pathway.EukaryotesMammalsCalnexin/1JHN90/monomerERp57,EDEMER membrane/works with glycosyltransferase to fold ER glycosylated proteins;inte
14、racts with some non-native proteins independent of glycosylation.Calreticulin60/monomerERp57,EDEMER lumen/similar to calnexin.Hsp4747P4HER/binds to collagen;chaperone in the collagen biosynthetic pathway.412.e1 Cell 128,January 26,2007 2007 Elsevier Inc.DOI 10.1016/j.cell.2007.01.013SnapShot:Molecul
15、ar Chaperones,Part II Yun-Chi Tang,Hung-Chun Chang,Manajit Hayer-Hartl,and F.Ulrich HartlDepartment of Cellular Biochemistry,Max Planck Institute of Biochemistry,Martinsried,GermanyREFERENCESBaker,T.A.,and Sauer,R.T.(2006).ATP-dependent proteases of bacteria:Recognition logic and operating principle
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17、.Mol.Biol.12,842846.Kleizen,B.,and Braakman,I.(2004).Protein folding and quality control in the endoplasmic reticulum.Curr.Opin.Cell Biol.16,343349.Lee,S.,Sowa,M.E.,Choi,J.M.,and Tsai,F.T.F.(2004).The ClpB/Hsp104 molecular chaperoneA protein disaggregating machine.J.Struct.Biol.146,99105.Leroux,M.,a
18、nd Hartl,F.U.(2000).Protein folding:Versatility of the cytosolic chaperonin TRIC/CCT.Curr.Biol.10,R260R264.Randall,L.L.,and Hardy,S.J.S.(2002).SecB,one small chaperone in the complex milieu of the cell.Cell.Mol.Life Sci.59,16171623.Saibil,H.R.,and Ranson,N.A.(2002).The chaperonin folding machine.Tre
19、nds Biochem.Sci.27,627632.Valpuesta,J.M.,Martin-Benito,J.,Gomez-Puertas,P.,Carrascosa,J.L.,and Willison,K.R.(2002).Structure and function of a protein folding machine:The eukaryotic cytosolic chaperonin.FEBS Lett.529,1116.Winter,J.,and Jakob,U.(2004).Beyond transcriptionNew mechanisms for the regulation of molecular chaperones.Crit.Rev.Biochem.Mol.Biol.39,297317.
