Chapter 16.5.2 (Exam 4) Translational Regulation

Question 1

What are the ways translation can be regulated?

Answer 1

Inhibit mRNA with miRNAs and siRNAs

Modify the GTP cap on 5′ end of mRNA—if cap is unmodified, mRNA is not translated

Repressor proteins that block translation directly (Not the same repressor that binds the silencers)

Question 2

How do repressor proteins block translation directly?

Answer 2

By binding to noncoding regions of mRNA and block translation by preventing it from binding to a ribosome

Question 3

What is protein longevity regulated by?

Answer 3

Can be regulated by ubiquitin

Question 4

How is protein longevity regulated by ubiquitin?

Answer 4

Proteins can be targeted for destruction when ubiquitin attaches to it and attracts other ubiquitins, forming a polyubiquitin chain

Question 5

What happens to the protein after a polyubiquitin chain is formed?

Answer 5

The complex binds to proteasomes where ubiquitin is removed and the protein is digested by proteases