Key points: summarized from chapter 14

1. Key points: summarized from chapter 14 RNA processing

2. Outline: we will focus on mRNA processing • Overview of the Central Dogma • Link DNA to RNA transcription to proteintranslation • What is a codon? • Gene organization • Introns and exons • What really is a gene? • Steps of pre-mRNA processing • Eukaryotes versus prokaryotes

4. Gene Organization: Is DNA and RNA co-linear?

5. 3 steps of mRNA processing occurs in the nucleus of eukaryotes 5’ CAP Poly-A tail Splicing

6. The 5’Cap

9. The Poly-A Tail

10. Cleavage by endonuclease

11. Basic steps of poly-Adenylation

12. Splicing Spliceosome Requires RNA + proteins Function as enzymes Self splicing Only RNA! Function as enzymes!

13. Spliceosome Meet the spliceosome

14. Splicesome: 3 components are required Note some important aspects of the 5’ and 3’ ends 5’ phosphodiester of G 2’ OH of A lariat

17. Where does splicing occurs?

18. Self-Splicing mRNA’s

19. Common characteristic of self-splicing mRNA’s

20. Comments on Alternative processing methods First: What are the methods of mRNA processing discussed so far? 5’ CAP 3’ Poly A Tail Intron Splicing

21. Alternative processing methods • Alternative splicing • Multiple 3’cleavage sites • RNA editing

24. And alternative splicing example Thryoid BRAIN

26. Silencing or interfering RNAs • siRNA • miRNA

28. Onto translation chapter 15