1、分子细胞生物学专题-转录延伸因子 P-TEFb及其活性调控生命科学学院陈瑞川细胞生物学博士研究生课程 Main PointsTranscription process of eukaryotic gene.P-TEFb: functions and its Activity regulationI. Transcription processSteps of class II gene transcriptionPromotor clearenceInitiationPIC assemblyTerminationElongationTFIIA, TFIIB, TFIID, TFIIE, TFI
2、IF, and TFIIH RNA polymerase II (Pol II)The class II pre-initiation complex (PIC)RNA polymerase II (Pol II)12 subunites: Rpb1- Rpb12About 500Kda of MWRpb1: largest subunit, CTD: Y1S2P3T4S5P6S7 Yest: 26 repeats C. elegans: 32 repeats Drosophila 42 repeatsMammals: 52 repeatsPre-initiationPol IICTDPIC
3、assemblyIIFIIH IIEPICIIFPol IICTDIIFII D II AIIBIIHIIE+1 DNA tempTATAPICPol IICTDII D II AIIBIIFIIHIIEInitiation55555II+1 DNA tempTATAPromoter clearance20-30 ntPol IICTD55 555DNA tempTATAIISDSIFNELFMTPausingCappingPol IICTD55 555DNA tempTATAIISRNADSIFNELFEarly elongation5-triphosphataseguanyltransferaseNCNCmethyltransferaseMTMTNCNCCapping
