myristoylation

Question 1

what is added

Answer 1

c-14 FA

to N-terminal glycine

Question 2

how is it added

Answer 2

co-transcriptional process
via amide bond
uses myristoyl-Coa

Question 3

what is it a absolute requirement for

Answer 3

glycine

Question 4

recognisition is done by

Answer 4

ser or thr at 6

lys or arg at 7 and/or 8

Question 5

properties of modified protein

Answer 5

c-14 produces relatively weak hydrophobic interaction with membrane
reversible binding

Question 6

second signal is required for

Answer 6

efficient membrane binding

this provides a basis for regulation

Question 7

what do the reversible interactions between protein and membrane involve

Answer 7

myristic acid

Question 8

myristoyl elctrostatic switch what happens 1

Answer 8

basic +ve cluster of residues on protein also interact with anionic membrane phospholipids
ps

Question 9

myristoyl elctrostatic switch what happens 2

Answer 9

reversible phosphorylation of a serine residue within basic cluter prevets electrostatic interactions

Question 10

myristoyl elctrostatic switch what happens 3

Answer 10

thus phosphorylation will result in loss of membrane binding

Question 11

myristoyl elctrostatic switch what happens 4

Answer 11

dephosphorylation (protein phosphatase) will promote translocation back to the membrane surface
eg src protein - a non receptor tyrosine kinase

Question 12

phosphorylation of serine by pkc does what

Answer 12

neutralises +ve charge on protein and hence weakens electrostatic interaction with ps on membrane