分子生物學(xué)2--rnaprocessing(已修改)
2025-06-08 18:54 本頁面
【正文】 Posttranscriptional Gene Regulation (events) ?Processing ?Transport ?Localization ?RNA stability ?Translation ?Posttranslational modification and protein stability Anatomy of a Eukaryotic mRNA Anatomy of a eukaryotic mRNA RNA Processing ? Splicing ? Capping ? Polyadenylation ? Editing ? rRNA Maturation ? tRNA Maturation Splicing (The process by which introns are removed) ? Spliceosomal splicing (premRNA splicing) ? Selfsplicing Group I in some rRNAs Group II in some yeast and fungal mitochondrial transcripts ? Alternative splicing ? TranSplicing Spliceosomal cissplicing (premRNA splicing) ? History of discovery ? Overview of reaction mechanism Splicing signals in premRNAs Splicing via Two Transesterification Reactions SnRNPs assist in Splicing The spliceosomal splicing model WEAVER: FIG. Highly conserved sequences are indicated in red Consensus sequences at exonintron boundaries MECHANISM OF SPLICING OF EUKARYOTIC PREmRNA: AN OUTLINE CONSENSUS SEQUENCES AT 5’ SPLICE SITE, BRANCH SITE AND 5’ SPLICE SITE VERTEBRATES: 5’AG/GUAAGUintronYNCURAC(Y)nNAG/G3’ YEAST: 5’NN/GUAUGUintronUACUAACYAG/G3’ WEAVER: FIG. Analysis of RNA products formed in an in vitro splicing reaction. A nuclear extract from HeLa cells was incubated with a 497nucleotide radiolabeled RNA that contained portions of two exons (numbered 1 and 2) from human betaglobin mRNA separated by a 130nucleotide intron. After incubation for various times, the RNA was purified and subjected to electrophoresis and autoradiography. a snRNA(U1~U6) snRNP core proteins (., Sm) specific proteins Small Urich RNA (snRNA) are abundant in the nuclei Base pairing between snRNAs and premRNA ? U1: 539。 splice site recognition ? U2: branch site recognition ? U4: a chaperone for U6 ? U5: 539。 and 339。 splice site recognition ? U6: likely to be catalytic moiety, U4/U6 to U6/U2 brings U6 to branch site Basepairing between premRNA, U1, and U2 U1 snRNA basepairs with 539。 splice site of premRNA。 U2 snRNA basepairs with a sequence that includes the branchpoint A, although this residue is not basepaired. The y
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鄂ICP備17016276號-1