microRNA技术介绍

miRNA-SmallRNAswithbigimpactsHuashengXiao,HuashengXiao,[e-mail],[e-mail]-(NCBI)YearofYearofmiRNAmiRNAPublicationsPublicationsNumberofNumberofmiRNAmiRNAPublicationsPublications01002003004005006007002001200220032004200520062007.8-¾¾naturallyinplantsandanimalsnaturallyinplantsandanimals¾¾Originatefromcapped&Originatefromcapped&polyadenylatedpolyadenylatedfulllengthfulllengthprecursors(precursors(pripri--miRNAmiRNA))¾¾Hairpinprecursor~70Hairpinprecursor~70ntnt(pre(pre--miRNAmiRNA))¾¾MatureMaturemiRNAmiRNA((miRNAmiRNA))◆◆SinglestrandedSinglestrandedRNAsRNAs◆◆19~2519~25ntnt,,non-codingRNAs◆◆AsingleAsinglemiRNAmiRNAmaytargetuptohundredsofmRNAsmaytargetuptohundredsofmRNAs◆◆Inhibitionoftranslational(animal)orDegradationoftargetRNA(plants)◆◆Regulationofcellproliferation,differentiation,apoptosis,carcinogenesisandviralinfection◆◆EvolutionarilyconservedEvolutionarilyconserved-•miRNAgenesaretranscribedbyRNApolymeraseIIintoprimarymiRNAs(pri-miRNAs).•pri-miRNAsareprocessedinto∼60to70ntmiRNAprecursors(pre-miRNAswithinthemicroprocessorcomplex.•exportedviaexportin-5,pre-miRNAsarecleavedbyDicer,generateanimperfectmiRNA:miRNA∗duplex.•mature∼22ntmiRNAsaretowardsspecificmRNAs,thetargetedmRNAwillbeinitiallysubjectedeithertocleavageortranslationrepression.Cancergenomics:SmallRNAswithbigimpactsNature435,745-746(9June2005)-:WhentheSmallestGovernsItAllJBiomedBiotechnol.2006;:69616.-•3’-UTRsequenceretrieval;ENSEMBLwebsite•ThematuremiRNAsequence•IdentifythetargetsofmiRNAs•GeneOntology(GO)annotations•Genome-widecomputationallypredictedmiRNAtargetsNatureGenetics2005:37,495–500Cell2005:Vol.120.Issue1.pp.15–20•Upto88%ofrandomlyselectedpredictedmiRNAtargetswereprovedtoberealtargetsCell,Vol.123,Issue6,pp.1133-1146-•(a)andLin-28(b);ThemicroRNAlin-4anditstarget-lin-14,controlthetimingoflarvaldevelopmentinCaenorhabditiselegans,alsoregulatelifespanintheadult.Reducingtheactivityoflin-4shortenedlifespanandacceleratedtissueaging,whereasoverexpressinglin-4orreducingtheactivityoflin-14extendedlifespan.TheC.elegansheterochronicgenelin-4encodessmallRNAswithantisensecomplementaritytolin-14.Cell.1993:75(5):843-854ADevelopmentalTimingMicroRNAandItsTargetRegulateLifeSpaninC.elegansScience23December2005:Vol.310.no.5756,pp.1954-1957lin-4andlin-14controltimingoflarvaldevelopmentandregulatelifespaninC.elegans-:257Nature2003,425:257––263Nature,2003263Nature,2003-–86-(2007)638(2007)-:FutureTherapeuticTargets?Cellular&molecularImmunology2006:3(6):411-419-(15):7390-4-•533humanmiRNAcurrentlyannotated(sangerdatabase)•miRNAsarepredictedtodirectlyregulatetheexpressionofatleast30%ofallhumanprotein-encodinggenes(lew