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(and some other important stuff)
Chapter 13 RNA Splicing (and some other important stuff) 13 and 15 October, 2004
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Overview Introns are removed after transcription - exons may comprise only a few percent of the primary transcript. The location of splicing is determined by splice site consensus sequences. The intron is released as a lariat structure. Splicing is carried out by a large ribonucleoprotein structure called the spliceosome. Spliceosome snRNPs use RNA base pairing to recognize splice sites. Spliceosome components assemble at the 5’ splice site (U1/U6), the Branch point (U2), and the 3’ splice site (U5). There are at lease two types of self-splicing introns. Splicing is highly regulated, including many instances of alternative splicing. Some RNAs are edited before translation. Polyadenylation is coupled to transport.
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Primary transcript and spliced product hybridization suggest splicing.
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Splicing
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Splicing Consensus Sequences
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Unusual Electrophoretic Behavior of Intron and Dependence on snRNPs
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The Splicing Reaction
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Structure of the Lariat Intermediate
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Trans Splicing
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snRNP-RNA Recognition
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Splicosome Purification
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Splicosome Assembly
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Base pairing between U2 and branch point sequences is demonstrated by second-site suppressor studies.
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4-thioU crosslinking demonstrates interactions between U6 and the 5’ splice site, U5 and the 3’ splice site.
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The Spliceosome Cycle
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The two-hybrid system demonstrates interactions between components of the commitment complex.
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Self-Splicing Introns
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Spliced and Self-splicing Introns
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Alternative Splice Sites
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Splicing Errors
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Regulation of Alternative Splicing
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Alternative Splicing
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Alternative Splicing
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Inhibition of Splicing
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AT-AC Spliceosome
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Conservation of Splicing Consenses
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Exons encode protein domains.
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Gene Assembly
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Protein Evolution
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RNA Editing
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C to U deamination
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Editing Mechanism
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mRNA Transport
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Purification of a poly-A binding protein that stimulates poly-A polymerase (PABII)
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Model for polyadenylation
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Title
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