1. Eukaryotic Gene Regulation
Chapter 18 & 20

2. Goals: Gene Regulation in Eukaryotes Regulation at the DNA Level
Regulation at the transcription level
Regulation at the translation level
Regulation at the protein level
How might regulation change the function of a stem cell? Cause a cell to become cancerous?

3. Central Dogma in Eukaryotes
Transcription and Translation are separated!

4. DNA Level Control What does histone acetylation do?
What does DNA methylation do?

5. RNA Level Control (Transcription)
Transcription Factors
Alternative Splicing
Cap and Tail

6. Transcription factors
Bind enhancer region and promote RNA polymerase. Make TATA box recognizable!

7. Alternative Splicing One gene = many proteins
Original hypothesis (Beadle and Tatum)=one gene; one enzyme
Intron: intervening
Exon: expressed

8. Cap and Tail
The RNA transcript must be protected from DNAses in the cytoplasm!
5’ GTP cap: protects the end and helps the RNA bind to the ribosome
3’ polyA tail: protects the end and allows RNA to go tail first out of the nucleus

9. Control of Translation
RNAi:
Triggered by siRNA’s
dsRNA is chopped up by “dicer”
Can do two things:
Degrade RNA
RISC complex leads to chopping up of mRNA
Block Translation
RISC complex leads to hairpin shape that blocks translation by ribosome.

10. Dicer’s Role in RNA degredation

11. Model for translational repression

12. Further research NOVA video: (accelerated biology level)
NOVA, RNAi
Pdf review from Nature: Available on my website (college level).

13. Regulation of Gene Expression at the Protein Level
Activation or inhibition of proteins
Can the timing of when a protein is expressed be altered? Even if it is present the whole time?
Have we seen this already this year?
Many proteins functon as complexes working together.
P53 is often one a few transcription factors needed to activate transcription. Without its “friends” p53 activity is downregulated

14. p53 and its interaction with other proteins to regulate its activty

15. How can cancer genes be regulated at the various levels of regulation?

16. How can embryonic development be regulated at the various levels of regulation?