PTM and protein sorting Flashcards
What wraps around the ribosome/mRNA complex during the move to the ER?
signal recognition particle (SRP) which recognized lysing-argening repeats at the n terminis of the newly synthesized peptide.
halts translation and protects genetic material
What doe the SRP bind to on the surface of the ER?
the SRP r.
What purpose do chaperones serve in protein folding?
They facilitate the folding of larger proteins so that they dont aggregate and cause problems
What does proteolytic cleavage do during PTM?
activates enzymes (trypsinogen-> trypsin) converts precursor proteins to active ones (proinsulin -> insulin)
What are 2 main types of PTM?
glycosylation
phosphorylation
disulfide bond formation
What are the 2 types of glycosylation PTM and which aa do they interact with?
O-linked - serine
N-linked - asn
What is the most common form of protein glycosylation?
N-linked (asn)
What is the important enzyme that attaches the core oligosaccharide to Asn in N-glycosylation?
protein glycosyltransferase
What enzyme changes the oligosaccharide attached to Asn (N-glycosylation) to an O-type glycosylation?
O-glycosidase
What does Tunicamycin do?
inhibits the initial step in binding the oligosaccharide to dolichol
Which pathway is affected in I-cell disease?
M6P -> lysosome process of the secretory pathway
Ehlers Danlos Syndrome
Lysyl hydroxylase mutations result in skin, bone, and joint disorder. VItamin C is necessary for this.
