Post translational modification

Question 1

Why is postranslational modification important

Answer 1

Can alter protein function greatly by modifying specific amino acids

Question 2

Name 8 types of postranslational modification’s

Answer 2

Phosphorylations
cleavage by caspases
Acetylation
hydroxylation
methylation
N-link glycosylation
Asumulation
Ubiquitintion

Question 3

At what amino acid sites does phosphorylation occur

Answer 3

Serine, Threonine, Tyrosine and Histidine

Question 4

What ZIP channel drives tamoxifen resistance

Answer 4

ZIP 7 = 2X increased intracellular zinc due to phosphorylation at sites 275/276

Question 5

Give an example of cleavage

Answer 5

ZIP6 pro-protein is cleaved at its N-terminus to become active

Question 6

Give an example of ubiquitination

Answer 6

SNAIL TF becomes ubiquitinated (binds to lysine residues- K) –> Leads to the removal of proteins and enables protein rounding as it surpresses expression of E.cadherin.

Question 7

Give an example of N-linked glycosylation

Answer 7

Used to fold proteins correctly e.g- Glycosylation side chains attatch to N residues, to help protein folding.

Question 8

Give an example of the use of disulphide bonds

Answer 8

Disulphide bonds form between two cystine residues on amino acid chains to help protein folding e.g - in immunoglobulins