After the addition of three glucose molecules to the completed oligosacharide pr
ID: 65186 • Letter: A
Question
After the addition of three glucose molecules to the completed oligosacharide precursur (Glc3Man9(GlcNAc)2), which of the following reactions most likely occurs?
Wrong Answer:
The unfolded protein response
Answers:
The unfolded protein response
Folding and retention by lectin domain containing proteins
The recruitment of hnRNPs
Protein disulfide isomerase mediated oxidation
Glycosylation of a new protein which is/has entered the ER lumen catalyzed by oligosaccharyl transferase
After the addition of three glucose molecules to the completed oligosacharide precursur (Glc3Man9(GlcNAc)2), which of the following reactions most likely occurs?
Wrong Answer:
The unfolded protein response
Answers:
The unfolded protein response
Folding and retention by lectin domain containing proteins
The recruitment of hnRNPs
Protein disulfide isomerase mediated oxidation
Glycosylation of a new protein which is/has entered the ER lumen catalyzed by oligosaccharyl transferase
Explanation / Answer
SOLUTION:
After the addition of three glucose molecules to the completed oligosacharide precursur (Glc3Man9(GlcNAc)2), reaction is most likely occurs is that
Glycosylation of a new protein which is/has entered the ER lumen catalyzed by oligosaccharyl transferase.
N-linked glycosylation, is the attachment of the sugar molecule oligosaccharide known a glycan to a nitrogen atom (amide nitrogen of asparagine residue of a protein), in a process called N-glycosylation
The biosynthesis of N-linked glycans occurs via 3 major steps.
Synthesis, en bloc transfer and initial trimming of precursor oligosaccharide occurs in the endoplasmic reticulum (ER). Subsequent processing and modification of the oligosaccharide chain is carried out in the Golgi apparatus.
The synthesis of glycoproteins is thus spatially separated in different cellular compartments. Therefore, the type of N-glycan synthesised, depends on its accessibility to the different enzymes present within these cellular compartments.
Oligosaccharyltransferase is the enzyme responsible for the recognition of the consensus sequence and the transfer of the precursor glycan to a polypeptide acceptor which is being translated in the endoplasmic reticulum lumen. N-linked glycosylation is therefore, is a co-translational event.