protein translation and post-translational modification Flashcards
secretory pathway: explain the features of a newly-synthesised protein that are required for it to enter the secretory pathway
1
Q
where does the secretory pathway begin
A
rough endoplasmic reticulum
2
Q
what are the first 20 amino acids in a protein
A
hydrophobic signal sequence at N-terminus
3
Q
what recognises the signal sequence
A
SRP (protein-RNA complex) on RER surface
4
Q
secretory pathway: outline
A
signal sequence ecognised by SRP (protein-RNA complex); translation stops; SRP binds to SRP receptor (on RER surface); translation resumes; translocation of growing polypeptide into RER lumen via protein channel in RER membrane; signal sequence cleaved; folding occurs
5
Q
if it encodes a transmembrane protein containing extra hydrophobic sequences, what will it do
A
anchor to the membrane
6
Q
what cleaves the signal sequence
A
signal peptidase
