1. 13 and 15 October, 2004 Chapter 13 RNA Splicing (and some other important stuff)

2. 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.

3. Primary transcript and spliced product hybridization suggest splicing.

4. Splicing

5. Splicing Consensus Sequences

6. Unusual Electrophoretic Behavior of Intron and Dependence on snRNPs

7. The Splicing Reaction

8. Structure of the Lariat Intermediate

9. Trans Splicing

10. snRNP-RNA Recognition

11. Splicosome Purification

12. Splicosome Assembly

13. Base pairing between U2 and branch point sequences is demonstrated by second-site suppressor studies.

14. 4-thioU crosslinking demonstrates interactions between U6 and the 5’ splice site, U5 and the 3’ splice site.

15. The Spliceosome Cycle

16. The two-hybrid system demonstrates interactions between components of the commitment complex.

17. Self-Splicing Introns

18. Spliced and Self-splicing Introns

19. Alternative Splice Sites

20. Splicing Errors

21. Regulation of Alternative Splicing

22. Alternative Splicing

24. Inhibition of Splicing

25. AT-AC Spliceosome

26. Conservation of Splicing Consenses

27. Exons encode protein domains.

28. Gene Assembly

29. Protein Evolution

30. RNA Editing

31. C to U deamination

32. Editing Mechanism

33. mRNA Transport

34. Purification of a poly-A binding protein that stimulates poly-A polymerase (PABII)

35. Model for polyadenylation

37. Title