4-4: Post-Transcriptional Regulation Flashcards
Regulation involving prematurely terminating mRNA synthesis
Attenuation
How do you regulate at the RNA level
Attenuation, control mRNA stability (how long before degradation), translation efficiency
RNA regulation done by
RNA regulatory elements
What terminator leads to transcriptional attenuation
Rho-independent (intrinsic)
mRNA lifetime affects…
Protein levels
What enzyme degrades mRNAs
Ribonuclease
Function of sRNA
Regulate gene expression
How do sRNA work
Base-pair to mRNA which affects RBS availability or attracts ribonuclease
What is Hfq
RNA chaperone that helps sRNA bind to mRNA complementary sequence (binds both)
What are riboswitches
Ligand-binding RNAs
Bind molecule which helps them sense their environment
Where are riboswitches located
5’UTR of mRNAs
How do riboswitches work
Aptamer domain binds ligand which changes base pairing in 5’UTR of mRNA and forms:
1) A stem-loop that blocks RBS
or
2) transcriptional terminator
What is feedback inhibition
Enzyme in pathway inhibited by end product of pathway
Forms of post-translation regulation
Feedback inhibition, protein-protein interaction, post-translational modification
How do protein-protein interactions regulate
One protein binds another and controls its activity
What is post-translational modification
Chemical (P) added to aa residue of protein (changes activity)
What enzyme degrades protein
Protease
What do proteases do
Clear away/recycle misfolded proteins, or specific proteins
Some proteins need proteases to cleave linkage to be activated
What do sRNA and riboswitches do
Block translation
RNA chaperone that mediates sRNAs by finding complementary sequence on mRNA, stabilizes reaction
Hfq
Why is Hfq required
sRNAs have limited complementarity to target mRNA
