表观遗传课件组蛋白修饰

1、Epigenetic inheritance and histonemodificationsThe First Copy Pet CCRainbowCCCC is genetically identical to Rainbow but epigenetically and thus phenotypically differentOur cells are genetically identical表达调控!Cells have the same DNA elements and protein factors, but the expression patterns are differ

2、ent and heritableStorage of Genetic Information in Highly Compacted ChromosomesEukaryotic NucleusHumans have 23 pairs of chromosomesHuman genome consists of 3´109 bp of DNA, containing 30,000 genesHuman chromosomes range from 50 Mbp to 245 MbpIf fully extended, one human cell will have 2 m DNAH

3、ierarchy of Chromosome Structure核小体是真核生物染色质的基本结构单元11 nm染色质Beads on a StringEach Bead-NCPThe OlinsDon & Ada Olins Science 1974核小体结构模型Chromosome DigestionRoger Kornberg (1947- )Kornberg Science 1974组蛋白八聚体结构模型Cleavable cross-links in the analysis of histone-histone associationsThomas & Kornberg

4、 FEBS Lett. 1975生理及医学奖化学奖Arthur Kornberg (1918-2007), 1959年Roger Kornberg (1947- ), 2006Nucleosome core particle structure (NCP)Octamer: Arents NCP: Luger., PNAS 1991., Nature 1997Histones (组蛋白)Monomer: Histone FoldDimerTetramerFlexible Histone Tails Are Extensively ModifiedMethylation Lysine Argini

5、neGlutamineAcetylation Crotonylation 巴豆酰基LysineUbiquitinationSUMOylation LysinePhosphorylationSerine & ThreonineADP-ribosylationCitrullination胍基ArginineHigher Order Chromatin Structure andEpigenetic Control of Gene ExpressionHistone modificationsDNA methylationChemical changesPhysical changesChr

6、omatinAltered gene expressionThe “Histone Code” HypothesisRemingacac最早发现的组蛋白修饰-组蛋白乙酰化Chromatin co-activatorsCell. 1993 Jan 15; 72(1):73-84.A positive role for histone acetylation in transcription factor access to nucleosomal DNA.Lee DY, Hayes JJ, Pruss D, Wolffe AP.Alan Wolffe 1959-2001Cell. 1996 Ma

7、rch 22; 84:843-851.David Allis 1951-Identification of the first histone acetyltransferase GCN5Histone Modification - HistoryNature 2000Thomas JenuweinSu(var)3-9 is a histone methyltransferase for H3K9Suppressors of PEV2014-05-12Epigenetic Symposium inHistone ModificationsWritersErasersReadersHistone

8、 ModificationWritersHistone acetyltransferase (HAT)Structure of histone acetyltransferase GCN5Stephen K. Burley Cell 1998David Allis & Ronen Marmorstein Nature 1999Histone deacetylase (HDAC)ErasersStuart L. Schreiber (1956-)第一个组蛋白 去乙酰化酶Rpd3 (Science 1996)IVHDAC11HDAC类组蛋白去乙酰化酶结构和催化机制HDLP (HDAC1 h

9、omology)Nikola P. Pavletich, Nature 1999Sirtuin新型去乙酰化酶SIR2: NAD-dependent Histone DeacetylaseNADADP-RiboseNicotinamideYeast Mating type (HM) ortelomericlociSilencerORC ComplexOrc1 BAH: EMBO J 2002 Sir1-Orc1: PNAS 2005Sir3 BAH：MCB 2006ORC1BAHCSir1NOIDacSir2: Cell 2001 Cover StorySir2-Sir4: Genes &

10、; Dev. 2013NSir2Sir4NSIDSir3H4K16 deacetylationCCORC: Origin Recognition Complex Sir: Silent Information Regulator BAH: Bromo Adjacent HomologySir3-NCP: NSMB 2013Yeast Transcriptional Silencing酶的结构和催化机制afSir2 StructureMin., Cell 2001The NAD-binding pocketNADAsp101Asn99H2OHis80Ser24酶活性的调节-相互作用蛋白Sir1N

11、OIDNSir2Sir4NSIDSir3CTanny., MCB, 2004n Sir2-Sir4 interaction is required for HM and telomeric silencing.n Sir4 binding stimulates Sir2s enzymatic activity.n The structural basis for regulation of Sir2 activity may provide insights into rational design of small molecule Sirtuin modulators.Sir2-Sir4

12、ComplexSir2NNADSir4CNHsu., Genes & Dev. 2013Sir2 N-terminal domain likely not stably positioned in the absence of Sir4Sir2-NSir4 stabilizes Sir2 domains and occupies the substrate binding siteResveratrol白藜芦醇酶活性的调节-小激活剂未结果，外传，CH3S-Adenosyl-Methionine (SAM)S-Adenosyl-Homocysteine (SAH)Lysine Methy

13、lationWritersHistone Lysine MethyltransferasesSET-domain ProteinsNon-SET-domain ProteinsDot1-Like ProteinsClr4Dot1Min, Cell. 2003SET：SuVar 3-9, Enhancer of Zeste, TrithoraxSuv3-9, SET1, SET2, E(Z). Riz, SMYD, Suv2-20Min, Nat Struct Biol. 2002酶的底物特异性-修饰位点和修饰程度-不同的表达H3K9-Suv3-9, G9aH4K20-Suv4-20H3K27-

14、PRC2 ComplexH3K4-MLL1 ComplexH3K79-Dot1 Non-SETH3K36-NSD1H3K36 methylase NSD1Defects cause Sotos, Weaver, Beckwith-Wiedemann syndromes, and acute childhood myeloid leukemiaSotos patientsOverall Structure of NSD1NSD1Clr4Clr4酶的底物特异性：一二甲基化NSD1 is a H3K36 dimethylaseSotos mutations酶的底物特异性：核小体为底物Histone

15、binding siteH3K79 methylase Dot1 None histone tail, None SET., Nat. Genet. 2002ParkConservation of Dot1 proteinsOverall structure of hDot1SAM Binding PocketKey Residues in SAM BindingC-terminal positive charged regionErasersLSD1DemethylaseLSD FamilyMono- & Di-methylatedCell 2004 Yang ShiMol. Cel

16、l 2006 Hongtao YuJMJC FamilyMono-, Di- & Tri-methylatedJMJD2ANature 2006 Zhang YiCell 2006 Gongyi ZhangCell 2006 Rui-Ming Xu非对称双对称双甲基化单甲基化单甲基化Arginine MethylationWritersProtein Arginine MethyltransferaseWolf SS, Cell Mol Life Sci. 2009对称与非对称双甲基化修饰有着不同的生物学功能组蛋白为底物的表观遗传修饰调控表达！Joanna., Frontiers in

17、 Biosci. 2001p300ONOFFacZhao., NSMB 2009Wang., Science 2001Type I:非对称双甲基化修饰酶Type II:对称双甲基化修饰酶cePRMT5Sun., PNAS 2011hPRMT5+MEP50+H4xPRMT5+MEP50Stephen., PNAS 2012Ho., PLoS One 2013hPRMT5 Catalytic CoreA9145C : SAM analogIC50 =35 nMdouble-E loop, E435/E444F327Stephen., PNAS 2012PRMT5 活性关键残基:对称与非对称Sun.

18、, PNAS 2011cePRMT5hPRMT5PRMT1Double GluE499/E508E435/E444E/EPheF379F327MSerS503S438YPRMT5 为国际研发热门靶点Phenotype of knockout mouse Early embryonic lethality. Embryos die by E6.5. PRMT5 is required forembryonic epiblast cell differentiationDeregulation in cancers Overexpression or increase in enzymatic activity observed in gastric, colorectal and lung cancer, and lymphoma and leukaemia.Reduced activity by Phosphorylation by Jak2 mutant V617F frequently observed in patients with myeloproliferative neoplasms.表观遗传调控RNA剪接昼夜节律DNA损伤修复生殖细胞发育及多能性肿瘤发生发展？ErasersRegulation of enzymatic