Wright 9 - Eukaryotic Gene Regulation

Question 1

What does RNA polymerase I transcribe? (eukaryotes)

Answer 1

Ribosomal RNA (rRNA) genes

Question 2

What does RNA polymerase II transcribe? (eukaryotes)

Answer 2

Messenger RNA (mRNA) genes

Question 3

What does RNA polymerase III transcribe? (eukaryotes)

Answer 3

Small RNAs, such as transfer RNAs (tRNA) and 5s RNA genes

Question 4

What are hormone receptors?

Answer 4

Allosteric proteins that undergo a conformational transition following binding of a ligand, a steroid hormone.

This regulates gene transcription.

Question 5

What are the steps of hormone receptors gene transcription regulation?

Answer 5

1. Steroid molecule binds to specific hormone receptor protein
2. Receptor protein conformationally changes and enters cytoplasm in complex with the steroid
3. Steroid-receptor complex binds to DNA and activates transcription through RNA polymerase II
4. Translation produces proteins relatted to hormone function

Question 6

What are 8 sites of gene regulation in eukaryotic cells?

Answer 6

1. Transcriptional initiation
2. Processing of RNA through alternate splicing of exons, multiple 3’ cleavage sites and 5’ cap and poly(A) addition
3. mRNA transport
4. mRNA storage (eg. eggs)
5. mRNA degradation
6. Translation
7. Protein modification (eg. phosphorylation)
8. Protein degradation (turnover)