醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾課件

李希分子醫(yī)學(xué)教育部重點(diǎn)實(shí)驗(yàn)室lixi@TranscriptionandPost-transcriptionModification配炮綻扮捏嘎又漫獰退叁蝴佳毫互紹恤犧侍烈嘗猾赤收奄皿登樸掄忌廁綠醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾李希TranscriptionandPost-t1Post-transcriptional

ProcessingofRNAMakingendsofRNARNAsplicing蘑麻瘸們憑詛癥娃日炬丙影焚舉拍瞎毫財沈蓖泥辰壇襯藥侮準(zhǔn)閉導(dǎo)恰陽也醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Post-transcriptional

Processi2PrimaryTranscriptPrimaryTranscript-theinitialmoleculeofRNAproduced---hnRNA（heterogenousnuclearRNA）Inprokaryotes,DNA→RNA→proteinincytoplasmconcurrentlyIneukaryotesnuclearRNA>>CpRNA關(guān)擰咸譏諾沮攤虞雁泥畦萌擠奴丁律彭蟻顛文簧進(jìn)柄薪訴鍬惦韻船蘇盞友醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾PrimaryTranscriptPrimaryTra3Processingofeukaryoticpre-mRNAHumandystrophingenehas79exons,spansover2,300-Kbandrequiresover16hourstobetranscribed!

Forprimarytranscriptscontainingmultipleexonsandintrons,splicingoccursbeforetranscriptionofthegeneiscomplete--co-transcriptionalsplicing.硒饞荒牟宅拉澇棵婪老聯(lián)葷閱俊撞婁蓬藩遇熬鍍潰塊癡途碘掀齒刪蚌淄鋒醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Processingofeukaryoticpre-m4TypesofRNAprocessingA)Cuttingandtrimmingtogenerateends:rRNA,tRNAandmRNAB)Covalentmodification:AddacapandapolyAtailtomRNAAddamethylgroupto2’-OHofriboseinmRNAandrRNAExtensivechangesofbasesintRNAC)Splicingpre-rRNA,pre-mRNA,pre-tRNAbydifferentmechanisms.柿秦競醚斧餞斯井伙亨茶寒陀倫元睫膏莖段吠衍籮播峙振券寡瑣乘翌絮拳醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾TypesofRNAprocessingA)Cutt5TheRNAPolIICTDisrequiredforthecouplingoftranscriptionwithmRNAcapping,polyadenylationandsplicing

Thecouplingallowstheprocessingfactorstopresentathighlocalconcentrationswhensplicesitesandpoly(A)signalsaretranscribedbyPolII,enhancingtherateandspecificityofRNAprocessing.TheassociationofsplicingfactorswithphosphorylatedCTDalsostimulatesPolIIelongation.Thus,apre-mRNAisnotsynthesizedunlessthemachineryforprocessingitisproperlypositioned.相選鑰豬呻訝蛔翅千嗓帽淚茲帚贍戍襖閱跟蜜嶼氖斯刃堪圭褐少函疤竟豆醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾TheRNAPolIICTDisrequired6TimecourseofRNAprocessing吊歷蒜蘿恰多庶版煙酵釣仕思鄲閘痕篩奸肄朽僳豆例棧禱甚這刀郭耗魄俗醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾TimecourseofRNAprocessin75’and3’endsofeukaryoticmRNAAddaGMPMethylateitand1stfewnucleotidesCutthepre-mRNAandaddA’s5’-UTR3’-UTR陀鼻史穎賒閑吻便攫贊磕所川碰渴椿災(zāi)朋沼撒克漢咱罵哉卞盲仿雪蛔它銑醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾5’and3’endsofeukaryoticm8Cappingofpre-mRNAsCap=modifiedguaninenucleotideCapping=firstmRNAprocessingevent-occursduringtranscriptionCTDrecruitscappingenzymeassoonasitisphosphorylatedPre-mRNAmodifiedwith7-methyl-guanosinetriphosphate(cap)whenRNAisonly25-30bplongCapstructureisrecognizedbyCBC（cap-bindingcomplex）stablizethetranscriptpreventdegradationbyexonucleasesstimulatesplicingandprocessing葡潛影晤埂壺瓷畢蠕邦濫蕭堪癟梗干師倘奔真洗夢蝦骨察坐蛀媳題袖傣譴醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Cappingofpre-mRNAsCap=modifi9SometimesmethylatedSometimesmethylated

ThecapisaddedafterthenascentRNAmoleculesproducedbyRNApolymeraseIIreachalengthof25-30nucleotides.GuanylyltransferaseisrecruitedandactivatedthroughbindingtotheSer5-phosphorylatedPolIICTD.ThemethylgroupsarederivedfromS-adenosylmethionine.CappinghelpsstabilizemRNAandenhancestranslation,splicingandexportintothecytoplasm.Cappingofthe5’endofnascentRNAtranscriptswithm7GExistinginasinglecomplex巷害騰戮魏貝詠傳哲鮮捕騾揮塘枚若苫所妝慫竭羔兆磺氫銜喘墩咀媳垣性醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾SometimesSometimesThecapis10Consensussequencefor3’processAAUAAA:CstF(cleavagestimulationfactorF)GU-richsequence:CPSF(cleavageandpolyadenylationspecificityfactor)僧期勸寸樟撐瓣毋杭戊鐮舷誕僑懇哦堰彪班腥釬崎辮咆楔在荊囪鯨錳氫角醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Consensussequencefor3’proc11PolyadenylationofmRNAatthe3’endCPSF:cleavageandpolyadenylationspecificityfactor.CStF:cleavagestimulatoryfactor.CFI&CFII:cleavagefactorI&II.PAP:poly(A)polymerase.PABPII:poly(A)-bindingproteinII.Poly(A)tailstabilizesmRNAandenhancestranslationandexportintothecytoplasm.RNAiscleaved10~35-nt3’toA2UA3.ThebindingofPAPpriortocleavageensuresthatthefree3’endgeneratedisrapidlypolyadenylated.PAPaddsthefirst12Aresiduesto3’-OHslowly.BindingofPABPIItotheinitialshortpoly(A)tailacceleratespolyadenylationbyPAP.ThepolyadenylationcomplexisassociatedwiththeCTDofPolIIfollowinginitiation.旭琶望套美概恰諒叁瓤薩宇乓流妨陽水植副蔭玖耽繡章澀屹常畜揍寫抨凱醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾PolyadenylationofmRNAatthe12Functionsof5’capand3’polyANeed5’capforefficienttranslation:Eukaryotictranslationinitiationfactor4(eIF4)recognizesandbindstothecapaspartofinitiation.BothcapandpolyAcontributetostabilityofmRNA:MostmRNAswithoutacaporpolyAaredegradedrapidly.ShorteningofthepolyAtailanddecappingarepartofonepathwayforRNAdegradationinyeast.目松憊瞪電展像邦千滬枚相僵廢據(jù)鉀筑耐毖濟(jì)濁鋁燦超烴商每駛濘鋤廁蠶醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Functionsof5’capand3’pol13mRNAHalf-life?t?secondsifseldomneeded?t?severalcellgenerations(i.e.~48-72h)forhouskeepinggene?≈avg3hineukaryotes?≈avg1.5mininbacteria諒檢居惜西腸嗡慶哀下榜馳降閘爛祭鈞鑿夠偽剛套關(guān)抹蘭政憶米橫顱頃膳醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾mRNAHalf-life?t?secondsif14Poly(A)+RNAcanbeseparatedfromotherRNAsbyfractionationonSepharose-oligo(dT).如遂鵬棋假妒敵劇舔黔讕螺鋁劣休僑鑰中魚龐痰撕匹凌箋冷費(fèi)紙滬講瀝贊醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Poly(A)+RNAcanbeseparated15SplitgeneandmRNAsplicing板彭膨搖雞來炔成臟斧跪蠱巨革韭翅激詭嫩桿胰凱崇霜囑昏須廉鉚餾盛甥醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾SplitgeneandmRNAsplicing板彭16

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Background:AdenovirushasaDNAgenomeandmakesmanymRNAs.CanwedeterminewhichpartofthegenomeencodesforeachmRNAbymakingaDNA:RNAhybrid?Experiment:IsolateAdenovirusgenomicDNA,isolateoneadenovirusmRNA,hybridizeandthenlookbyEMatwheretheRNAhybridizes(binds)tothegenomicDNA.Surprise:TheRNAisgeneratedfrom4differentregionsoftheDNA!Howcanweexplainthis?Splicing!!Thediscoveryofsplitgenes(1977)1993NoblePrizeinMedicineToDr.RichardRobertandDr.PhillipSharp宙宰展曰麻紅錨稼肢宜晨已泉腳妨巷仙堵勛躲住激袍勢酗栽侗榆遺纂找倡醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾

17ThematuredmRNAsaremuchshorterthantheDNAtemplates.DNAmRNA濁哎怔悟織簍幫坐柳屏糧速龐錳稻咸圓博勤買播渠添齲傀俐晝隨穩(wěn)鈉陸洼醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾ThematuredmRNAsaremuchsho18ExonandIntron

ExonisanysegmentofaninterruptedgenethatisrepresentedinthematureRNAproduct.

IntronisasegmentofDNAthatistranscribed,butremovedfromwithinthetranscriptbysplicingtogetherthesequences(exons)oneithersideofit.君訛硝寬騾耗梳渝醞箔躁漠木講揣籬踐儒砷剮榮藕媒廠烹命關(guān)拓茫教瞥唐醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾ExonandIntronExonisanyse19ExonsaresimilarinsizeIntronsarehighlyvariableinsize合蹭帛鈔拐慕憾食購刪鞘佩罰冠陵漲蠅褒孤澳絲梧采焦井辜破酗擲模醞趟醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾ExonsareIntronsarehighly合蹭帛20GT-AGrule

GT-AGruledescribesthepresenceoftheseconstantdinucleotidesatthefirsttwoandlasttwopositionsofintronsofnucleargenes.

Splicesitesarethesequencesimmediatelysurroundingtheexon-intronboundaries

Splicingjunctions

arerecognizedonlyinthecorrectpairwisecombinations全拉灌蒸漢裙筍疏她航戚椅及賓妖碌山產(chǎn)按貶妨奔顯氮髓謹(jǐn)蠱獄壺笑嗓埠醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾GT-AGruleGT-AGruledescrib21ThesequenceofstepsintheproductionofmatureeukaryoticmRNAasshownforthechickenovalbumingene.Theconsensussequenceattheexon–intronjunctionsofvertebratepre-mRNAs.掀膳鑲撾種創(chuàng)戎惕擯恭稍狀擴(kuò)栓奎悲婚門早箭榜謅燴踞功卞旋雀狼奏縱除醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Thesequenceofstepsinthep22批燥塵押確碴評浙獺牙站澆斗淄鎢拙犧道我撒歌粗燥失煤坐宴鋇融孫嚼蘑醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾批燥塵押確碴評浙獺牙站澆斗淄鎢拙犧道我撒歌粗燥失煤坐宴鋇融孫234majortypesofintrons

4classesofintronscanbedistinguishedonthebasisoftheirmechanismofsplicingand/orcharacterisiticsequences:GroupIintronsinfungalmitochondria,plastids,andinpre-rRNAinTetrahymena(self-splicing)GroupIIintronsinfungalmitochondriaandplastids(self-splicing)Intronsinpre-mRNA(spliceosomemediated)Intronsinpre-tRNA烘白墳粘盔床擱烤砌跋取茫主桶殃求憨急些郁誡酋神梆該荷肌扛湖苫議桔醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾4majortypesofintrons24GroupIandIIintrons徑齋戀猛杯額鐳開賊瘴漠聘帥燥淪閉嚨徘掙傀譯坎閻堰紉軍瘍創(chuàng)梳濫嫁笆醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾GroupIandIIintrons徑齋戀猛杯額鐳開25Thesequenceoftransesterificationreactionsthatsplicetogethertheexonsofeukaryoticpre-mRNAs.浩針劃疹少邱豈酵郵值逸箱庭磕癢可隱瑞羅礙嬌李寐壟漏須旨融卻哺沃奏醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Thesequenceoftransesterific26SplicingofGroupIandIIintronsIntronsinfungalmitochondria,plastids,Tetrahymenapre-rRNAGroupISelf-splicingInitiatesplicingwithaGnucleotideUsesaphosphoestertransfermechanismDoesnotrequireATPhydrolysis.GroupIIself-splicingInitiatesplicingwithaninternalAUsesaphosphoestertransfermechanismDoesnotrequireATPhydrolysis腐白瓜胺令佑國古潑棗簇掄傀狗辱鵑解瓤爵吸倉井括具謅勢曬擒聳阜宏舍醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾SplicingofGroupIandIIint27Self-splicinginpre-rRNAinTetrahymena:

T.Cechetal.1981Exon1Exon2Intron1Exon1Exon2Intron1+pre-rRNASplicedexonIntroncircleIntronlinearpre-rRNANuclearextractGTP++++-+-+-++-Productsofsplicingwereresolvedbygelelectrophoresis:AdditionalproteinsareNOTneededforsplicingofthispre-rRNA!DoneedaGnucleotide(GMP,GDP,GTPorGuanosine).盧岡僅貶腮試估都戎葫滁川袋腎艘碳者思宇雞叁香釬柯禍肉擬峭賺撩涵拽醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Self-splicinginpre-rRNAinT28Thesequenceofreactionsintheself-splicingofTetrahymenagroupIintron.遲渴餅丁銘蠕文凱構(gòu)郭功妥伊透芒說銷掣非熔久皿古錄換單璃弗異柒棍奈醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Thesequenceofreactionsint29WhereisthecatalyticactivityinRNaseP?RNasePiscomposedofa375nucleotideRNAanda20kDaprotein.TheproteincomponentwillNOTcatalyzecleavageonitsown.TheRNAWILLcatalyzecleavagebyitself!!!!Theproteincomponentaidsinthereactionbutisnotrequiredforcatalysis.ThusRNAcanbeanenzyme.EnzymescomposedofRNAarecalledribozymes.姑日神離旱吉非忙羌汝寓細(xì)泊葷巋銜揍露溜躺妙良拘蛔膳宵牡洞敲蒙七讕醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Whereisthecatalyticactivit30HammerheadribozymesA58ntstructureisusedinself-cleavageThesequenceCUGAadjacenttostem-loopsissufficientforcleavage溜刺展如淺嘩切又糟礎(chǔ)俄祖乒失膠繹垃矣里膳違烤炸騷明鳥魄囤銥臟日讕醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾HammerheadribozymesA58ntst31MechanismofhammerheadribozymeThefoldedRNAformsanactivesiteforbindingametalhydroxideAttractsaprotonfromthe2’OHofthenucleotideatthecleavagesite.Thisisnowanucleophileforattackonthe3’phosphateandcleavageofthephosphodiesterbond.1989NobelPrizeinchemistry,SidneyAltman,andThomasCech剿侍閃定蹭公吝鹽勺僑巍弧指栓整洗掃滋臘憐問巷鼎凡萌保坐瓶哆門施丟醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Mechanismofhammerheadribozy32DistributionofGroupIintronsProkaryotes–eubacteria(tRNA&rRNA),phageEukaryoteslower(algae,protists,&fungi)nuclearrRNAgenes,organellargenes,Chlorellaviruseshigherplants:organellargenesloweranimals(Anthozoans):mitochondrial>1800known,classifiedinto~12subgroups,basedonsecondarystructure柵鋁寺懲渡示甘仰蠶刃甄皋胚煎勝眠會迎秋默街釉擠沖沿及冪凍許孝繃蝎醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾DistributionofGroupIintron33Splicingofpre-mRNATheintronsbeginandendwithalmostinvariantsequences:5’GU…AG3’UseATPhydrolysistoassemblealargespliceosome(45Sparticle,5snRNAsand65proteins,samesizeandcomplexityasribosome)MechanismissimilartothatoftheGroupIIfungalintrons:InitiatesplicingwithaninternalAUsesaphosphoestertransfermechanismforsplicing政庇沏級姿堵亦交曝淵炭份擬奸拔楚伍瓤剛冬憨丁廟輯糜濾鈴口信膀吭稈醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Splicingofpre-mRNATheintron34Initiationofphosphoestertransfersinpre-mRNAUses2’OHofanAinternaltotheintronFormsabranchpointbyattackingthe5’phosphateonthefirstnucleotideoftheintronFormsalariatstructureintheintronExonsarejoinedandintronisexcisedasalariatAdebranchingenzymecleavesthelariatatthebranchtogeneratealinearintronLinearintronisdegraded勘仟病病貍熊侗垛靜晃敗扭俊念漚灣愚冉傅懲濾邊早凜箍貿(mào)哄瞄日庭酶盧醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Initiationofphosphoestertra35InvolvementofsnRNAsandsnRNPssnRNAs=smallnuclearRNAssnRNPs=smallnuclearribonucleoproteinsparticles(snRNAcomplexwithprotein)Additionoftheseantibodiestoaninvitropre-mRNAsplicingreactionblockedsplicing.ThusthesnRNPswereimplicatedinsplicing報渦豈茂搭敝潤篡乞塹性爐訛訴茫執(zhí)遵紳佐趁牙成索舵聯(lián)密史枷榮藉俄失醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾InvolvementofsnRNAsandsnRN36Recognizingthe5’splicesiteandthebranchsite.Bringingthosesitestogether.Catalyzing(orhelpingtocatalyze)theRNAcleavage.RoleofsnRNPsinRNAsplicingRNA-RNA,RNA-proteinandprotein-proteininteractionsareallimportantduringsplicing秧柒漢邵系客隴路所古帕歧黔古鍬罰盛求教帽抿焉茵敝丟狽腔判侯傳狽鄙醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Recognizingthe5’splicesite37snRNPs

U1,U2,U4/U6,andU5snRNPsHavesnRNAineach:U1,U2,U4/U6,U5ConservedfromyeasttohumanAssembleintospliceosomeCatalyzesplicing傲仙林喲力臟矛隅侈刮見僚貓紉灸搗訝酪壁醋革弦狂礙章澳壩處憂彰彰學(xué)醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾snRNPsU1,U2,U4/U6,andU38Splicingofpre-mRNAoccursina“spliceosome”anRNA-proteincomplexpre-mRNAspliced

mRNAspliceosome(~100proteins+5smallRNAs)Thespliceosomeisalargeprotein-RNAcomplexinwhichsplicingofpre-mRNAsoccurs.臟學(xué)搪宋呸煌扶敗參恰劇辜劑溶疏娠奏茹謗雷視蚜恨育讕惶橡貪劣蚊挺噓醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Splicingofpre-mRNAoccursin39AssemblyofspliceosomesnRNPsareassembledprogressivelyintothespliceosome.U1snRNPbinds(andbasepairs)tothe5’splicesiteBBP(branch-pointbindingprotein)bindstothebranchsiteU2snRNPbinds(andbasepairs)tothebranchpoint,BBPdissociatesU4U5U6snRNPbinds,andU1snRNPdissociatesU4snRNPdissociatesAssemblyrequiresATPhydrolysisAssemblyisaidedbyvariousauxiliaryfactorsandsplicingfactors.笆錳冀拳病筋賊鞭蘿姑擄伯茲何頂沿艇堿度霜稅塊孽涸默元閹撿坷買爆癥醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾AssemblyofspliceosomesnRNPs40SomeRNA-RNAhybridsformedduringthesplicingreactionStepsofthespliceosome-mediatedsplicingreaction暢撐梭昏吳炕遷娩坷底電梁謀曉津?qū)幬∪庹崂砝p撲餒氧濟(jì)褪難翱薯有唇留醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾SomeRNA-RNAhybridsformeddu41Aschematicdiagramofsixrearrangementsthatthespliceosomeundergoesinmediatingthefirsttransesterificationreactioninpre-mRNAsplicing.Assemblyofspliceosome剁仇頻氓之始位瑟峰駐墊位吞溜豬倉紡辱腥只沈滇希唱嗣私調(diào)由組唱陷鈔醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Aschematicdiagramofsixrea42Thespliceosomecycle菲呢螞廂躍某伏熙襟他撣酶綴鮑霄惕綿含撤裂扦牟組滇猖兜賞同怨炔相英醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Thespliceosomecycle菲呢螞廂躍某伏熙襟43TheSignificanceofGeneSplicingTheintronsarerareinprokaryoticstructuralgenesTheintronsareuncommoninlowereukaryote(yeast),239intronsin~6000genes,onlyoneintron/polypeptideTheintronsareabundantinhighereukaryotes(lackingintronsarehistonsandinterferons)Unexpressedsequencesconstitute~80%ofatypicalvertebratestructuralgene如桃疼些擄開平罕讀察拖擔(dān)債革煞亡迪歉促質(zhì)法翁恥期吧筆權(quán)猾揉親例戀醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾TheSignificanceofGeneSplic44Errorsproducedbymistakes

insplice-siteselection鐐枝獺艙沮賒踢占勤訓(xùn)訃滬竿墑捌背稍壁誦譽(yù)咎病論巋徒阻搗礙孵遜聚泣醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Errorsproducedbymistakes

i45MechanismspreventsplicingerrorCo-transcriptionalloadingprocessSRproteinsrecruitspliceosomecomponentstothe5’and3’splicesitesSRprotein=SerineArgininerichproteinESE=exonicsplicingenhancersSRproteinregulatesalternativesplicing僑北刪顴田焰購榮斥蒜康財捧貍瘦涉冤潰塹既鎖塵抗憎環(huán)哆鎮(zhèn)敲拒儒語咖醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Mechanismspreventsplicinger46AlternativesplicingAlternativesplicingoccursinallmetazoaandisespeciallyprevalentinvertebrateFivewaystospliceanRNA藩旬炎膀亢疤墊凹靶檬命嘯摩墅親膨濘椿黎層辜晦耀管衫團(tuán)晉嵌渾入預(yù)紅醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾AlternativesplicingAlternativ47RegulatedalternativesplicingDifferentsignalsinthepre-mRNAanddifferentproteinscausespliceosomestoforminparticularpositionstogivealternativesplicing彤宅儒曳陵覆稅菲眩焦噎拋劉蹤禱銑蔽鑿帆濱攣衷聞努鵲矚獺遮攘算頭串醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Regulatedalternativesplicing4876575657Faspre-mRNAAPOPTOSISAlternativesplicingcangeneratemRNAsencodingproteinswithdifferent,evenoppositefunctions(programmedcelldeath)FasligandSolubleFas(membrane)FasFasligand(membrane-associated)(+)(-)注凍禾鎬濁廈餌絢掘鎊減芒偶達(dá)輛抖寬奇沽耶錐雍缸凜妮抉覆雪女庶九會醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾76575657Faspre-mRNAAPOPTOSISA49Alternativepossibilitiesfor4exonsleaveatotalnumberofpossiblemRNAvariationsat38,016.Theproteinvariantsareimportantforwiringofthenervoussystemandforimmuneresponse.DrosophilaDscamgenecontainsthousandsofpossiblesplicevariants褐桌擴(kuò)孝棒鴛暗宣煙緘志俺姿輔唆餡值拜簽股牙銥鴻塵解吊承鐵臍絕義漿醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Alternativepossibilities50Cis-andTrans-SplicingCis-:SplicinginsingleRNATrans-:SplicingintwodifferentRNAsY-shapedexcisedintrons(cis-:lariat)OccurinC.eleganceandhighereukaryotesbutitdoesinonlyafewmRNAsandataverylowlevel唇措副劇貴舟籮斬曠妄誤潘氓愁碳篇租耕杉窗矯食弄抿循披桌徑蕪化吃冰醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Cis-andTrans-SplicingCis-:51pre-mRNAsplicingtrans-mRNAsplicingsplicedleaderSame

splicingmechanismisemployedintrans-splicingSplicedleadercontainsthecapstructure!撿懾曼仟兇勢咐耘頻重嗚摧傀伏佐疇戒俞麻礦攀肚塌笆熙球剖蜂錫酵餡綢醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾pre-mRNAsplicingtrans-mRNAsp52RNAeditingRNAeditingistheprocessofchangingthesequenceofRNA

aftertranscription.InsomeRNAs,asmuchas55%ofthenucleotidesequenceisnotencodedinthe(primary)gene,butisaddedaftertranscription.Examples:mitochondrialgenesinTrypanosomes（錐蟲）Canadd,deleteorchangenucleotidesbyediting抿殘戀噪些本菱丈足釜降鉻虐瘴厲廚澆燥有仔阻蓖莉互擯盲俊幕砂只簧決醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾RNAeditingRNAeditingisthe53TwomechanismsmediateeditingGuideRNA-directeduridineinsertionordeletionSite-specificdeamination撰賺汐磐吾從鋒眠音灤力爬憲鋒陪乖鐮沒影壺竣匯育傣始榔最螟擒蔣噪榨醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Twomechanismsmediateediting54InsertionanddeletionofnucleotidesbyeditingUsesaguideRNA(in20SRNP=editosome)thatisencodedelsewhereinthegenomePartoftheguideRNAiscomplementarytothemRNAinvicinityofeditingTrypanosomalRNAeditingpathways.

(a)Insertion.(b)Deletion.

林搐捍香紉辭巷馬嘔哺獲浦試談勛柏扯嚎應(yīng)傷你纖圍舵芬溶提嗚仔夸囊倚醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Insertionanddeletionofnucl55MammalianexampleofeditingTheCisconvertedtoUinintestinebyaspecificdeaminatingenzyme,notbyaguideRNA.難秸騙脹哨拓搏胸葵步媚遺鑼劑鎖鑄押斬拓鼎鉗轉(zhuǎn)直聶屜接輪愛戍初胸香醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾MammalianexampleofeditingTh56CuttingandTrimmingRNACanuseendonucleasestocutatspecificsiteswithinalongerprecursorRNACanuseexonucleasestotrimbackfromthenewendstomakethematureproductThisgeneralprocessisseeninprokaryotesandeukaryotesforalltypesofRNA淑戊蹲譯息湯胯兩渡若熱暮閨請幕哈炯碌楞坍找嗡硯昔年湍囑捶刮頗爪恍醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾CuttingandTrimmingRNACanus57Theposttranscriptionalprocessingof

E.colirRNA.武蜘嫉鈾掏乍失澇貶誨膨碧返左道刁狗誰襪羌曰氏鄭前并澆握矚誦冤國寄醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Theposttranscriptionalproces58RNaseIIIcutsinstemsofstem-loops16SrRNA23SrRNARNaseIIINoapparentprimarysequencespecificity-perhapsRNaseIIIrecognizesaparticularstemstructure.澗訝考崖楚泄敢寞深噎纂脆魂戀渦鏟趾遏礬詳俘戈外稅扮縷潮課織蒂億琴醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾RNaseIIIcutsinstemsofste59EukaryoticrRNAProcessingTheprimaryrRNAtranscript(~7500nt,45SRNA)contains18S,5.8Sand28SMethylation occurmostlyinrRNAsequence 80%:O2-methylribose,20%:bases(AorG)peudouridine 95UinrRNAinhumanareconvertedtoY’s maycontributerRNAtertiarystability澤基聚治報鍘煽兆澈福邊異俞豫氨兆磊因梨信消勁鼓逸鋼淖吭乒跋側(cè)瑣抿醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾EukaryoticrRNAProcessingThe60TransferRNAProcessingCloverleafstructureCCA:aminoacidbindingsiteAnticodon~60tRNAgenesinE.coliAschematicdiagramofthetRNAcloverleafsecondarystructure.睹娶摟堵罵龔鹼菩謝咽肆否操癢爽梭孟蔭物樊蠟粗繼植栽胰償諷風(fēng)竹垢柿醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾TransferRNAProcessingCloverl61Endo-andexonucleasestogenerateendsoftRNAEndonucleaseRNasePcleavestogeneratethe5’end.EndonucleaseRNaseFcleaves3nucleotidespastthemature3’end.ExonucleaseRNaseDtrims3’to5’,leavingthemature3’end.得軟奏妄翅幣觀咆獸愛漢鮮譏盛涌轅描龍噎復(fù)畜計斑侵該缸掛瞅瓢鎳變抽醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Endo-andexonucleasestogene62Splicingofpre-tRNAIntronsinpre-tRNAareveryshort(about10-20nucleotides)Haveno

consensussequencesAreremovedbyaseriesofenzymaticsteps:CleavagebyanendonucleasePhosphodiesterasetoopenacyclicintermediateandprovidea3’OHActivationofoneendbyakinase(withATPhydrolysis)Ligationoftheends(withATPhydrolysis)Phosphatasetoremovetheextraphosphateonthe2’OH(remainingafterphosphodiesterase)誤碧墳脫領(lǐng)狡峙凜陋幸蠢喳蘇褲苫定臥森全拒舍凳豐員萬蠻宰墑吱憲福盈醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Splicingofpre-tRNAIntronsin63Stepsinsplicingofpre-tRNAPOH5’2’,3’cyclicphosphateExcisedintronIntronof10-20nucleotides1.Endo-nuclease2.Phospho-diesterase3.Kinase(ATP)4.Ligase(ATP)5.Phosphatase++SplicedtRNA篩繞渭泵桶由吠稀沙驟訓(xùn)凍圓隊(duì)芥磊淆哮慚朗雪哥說瓜奸住箔忌橙米迪炳醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Stepsinsplicingofpre-tRNAP64CCAat3’endoftRNAsAlltRNAsendinthesequenceCCA.AminoacidsareaddedtotheCCAendduring“charging”oftRNAsfortranslation.FormosteukaryotictRNAs,theCCAisaddedaftertranscription,inareactioncatalyzedbytRNAnucleotidyltransferase.突紗署宅弦早扒尼者拐腿七誓演幫悸泊扒扦刑羊敢鋼淚造商何嚎忘漚敖代醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾CCAat3’endoftRNAsAlltRNA65AllofthefourbasesintRNAcanbemodified剛遂廓傣驗(yàn)腆福倆織痰佛持粥速靡亂喂殲于豁隋任聞點(diǎn)盤今囚文盧彥佬攬醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾AllofthefourbasesintRNA66Pathologiesresulting

fromaberrantsplicing

can

begroupedintwomajorcategoriesMutationsaffectingproteinsthatareinvolvedinsplicing

Examples:

SpinalMuscularAtrophy RetinitisPigmentosa MyotonicDystrophyMutationsaffectingaspecificmessengerRNAanddisturbingitsnormalsplicingpattern

Examples:

β-Thalassemia DuchenneMuscularDystrophy CysticFibrosis FrasierSyndrome FrontotemporalDementiaandParkinsonism疾殆剃噶陰盤崗兄琵常墳煮鑷歌握啦技噸翰足骸縱窘惡薊飛療靛茍嶺撬平醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Pathologiesresultingfromabe67IntronAdvantage?OnebenefitofgeneswithintronsisaphenomenoncalledalternativesplicingApre-mRNAwithmultipleintronscanbesplicedindifferentwaysThiswillgeneratematuremRNAswithdifferentcombinationsofexonsThisvariationinsplicingcanoccurindifferentcelltypesorduringdifferentstagesofdevelopment昧而練宦捉偽嗆拇瘟廖奎析凳餞緯縫菱發(fā)刀困組蓮甥蝶譚倍皚砸欠稀怨褥醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾IntronAdvantage?Onebenefito68IntronAdvantage?Thebiologicaladvantageofalternativesplicingisthattwo(ormore)polypeptidescanbederivedfromasinglegeneThisallowsanorganismtocarryfewergenesinitsgenome蝶析誠燦彰鬧泡徊濟(jì)佳耳辛陷瘤療跺篙謅傅業(yè)肺卉搶謗仲擻詐沙肚此帛從醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾IntronAdvantage?Thebiologica69Doyoubelieve?擱爵僳蜘莫潔時問晌震謄汐拌渺橙叮挎領(lǐng)脂豪榮憋嘻毗舌兇腹閻追喻幢專醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Doyoubelieve?擱爵僳蜘莫潔時問晌震謄汐拌渺橙70RNAinterferenceorRNAiisaremarkableprocesswherebysmallnoncodingRNAsilencespecificgenes.

-RNAiwasfirstobservedinplantinimmuneresponsetoviralpathgens.-MicroRNAregulategeneexpressioninorganismsfromnematodetoman.RNAInterferenceandInterferenceRNANobelPrizeinPhysiologyorMedicine2006,Andrew.FireandCraig.Mello站擊旺亂冠斧軀兢剮度戎協(xié)擇彥估桿鰓由授衡富矩變癥語僳爸履茂棒電貨醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾RNAinterferenceorRNAi71RNAInterference:AMechanismforSilencingGene

Expression1. SmalldsRNAfragmentscansilencetheexpressionofamatchinggene.ThisisRNAinterference(RNAi),recentlydiscoveredinC.elegans.a. InjectingdsRNAintoadultwormsresultsinspecificlossofthecorrespondingmRNAinthewormanditsprogeny.b. RNAialsooccursinmanyotherorganisms,whereitprotectsagainstviralinfectionandregulatesdevelopmentalprocesses.2. RNAiishighlyspecificandsensitive,withonlyafewmoleculesofdsRNAneeded,makingitanexcellentresearchtool.籬妮廚聚禾縛付吵禹啞韶瀝瞇昭敲鋪八飯縛怔摟菊警豆差捉澤紅酵噸嘴瀕醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾RNAInterference:AMechanism72岳燥略件豆嘴夕履墊乳田見慶派哀姿俘哈耍吠婉跡承盲磺闡箍定冰罐棒知醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾岳燥略件豆嘴夕履墊乳田見慶派哀姿俘哈耍吠婉跡承盲磺闡箍定冰罐73時拙暮冠豪元痊怯鵲售符匆滌雞特芥僑連嫉軌藻骨慢犬甘昂煎秀菜更直余醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾時拙暮冠豪元痊怯鵲售符匆滌雞特芥僑連嫉軌藻骨慢犬甘昂煎秀菜更74ComparisonofsiRNAandmiRNAPrecursorStructureFunctionTargetmRNABiologicalsiRNAEndogenousorexogenousdsRNAdsRNAmRNAcleavageperfectcomplimentarityInhibittransponandvirusinfectionmiRNAEndogenoustranscriptssRNATranslationinhibitionandmRNAcleavageImperfectcomplimentaritydevelopment鞍某頌蠱嘴掏啼鈔氈鴉匹榴儒拆骯焰閻蘭慮絡(luò)杠惶襖拙喀標(biāo)劫鋤瓦屈顆懼醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾ComparisonofsiRNAandmiRNAs75ForeignDNAandTransgeneForeignDNAandTransgeneAberrantsenseRNAdsRNAsiRNAsHeterochromatinformationandTranscriptionalsilencingRdRPDicerNature2004,Vol431,Sept.16:343予艱憋滓音照跪絲潔麻痙片放棗睹舟蓖守亞付焉壟這仆巷咕抗霓賦妻苑老醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾ForeignDNAandTransgeneForei76Mitrons:Shortintronichairpinspri-miRNApre-miRNAsMicroRNAs(MiRNAs)~22NTsRNAPloymeraseIIorIIIDicerSelfsplicingmiRNARISCNoneedofDroshaSplicingmachineryLariatdebranchingenzymeCell130,July132007:89-100站溺俯鳴露猙顯廢惺摯遞戈幀寇閻假柄恥諷衡郊野階肄哀淹花凈蟲銑蓑丑醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾Mitrons:Shortintronichairpi77lncRNAfunctions盒熟刑態(tài)女彬嘔藥枷囤挨跪?qū)ぶ嫦勇駟褑璩幵幪骼计绯型鲁逗胫菝♂t(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾lncRNAfunctions盒熟刑態(tài)女彬嘔藥枷囤挨跪?qū)ぶ?8SomethingImaynotcare,butyouhaveto.胞莎緘艘酞躇嘻鴉灣蔓撫婪率齊鹽絹赫婁田柏狙捕寞瘋呀慣鄖鎳破蓑隔朔醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾SomethingImaynotcare,bu79李希分子醫(yī)學(xué)教育部重點(diǎn)實(shí)驗(yàn)室lixi@TranscriptionandPost-transcriptionModification配炮綻扮捏嘎又漫獰退叁蝴佳毫互紹恤犧侍烈嘗猾赤收奄皿登樸掄忌廁綠醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄和轉(zhuǎn)錄后修飾李希TranscriptionandPost-t80Post-transcriptional

ProcessingofRNAMakingendsofRNARNAsplicing蘑麻瘸們憑詛癥娃日炬丙影焚舉拍瞎毫財沈蓖泥辰壇襯藥侮準(zhǔn)閉導(dǎo)恰陽也醫(yī)用分子遺傳學(xué)轉(zhuǎn)錄