TLS Online TPP Program

#Id: 7955

#Unit 2. Cellular Organization

Only asparagine residues in the tripeptide sequences Asn-X-Ser and Asn-X-Thr (where X is any amino acid except proline) are substrates for oligosaccharyl transferase.

TLS Online TPP Program

#Id: 7956

#Unit 2. Cellular Organization

A branched oligosaccharide containing 

3 glucose (Glc)

9 mannose (Man)

2 N-acetylglucosamine (GlcNAc)

Glc3Man9(GlcNAc)2

TLS Online TPP Program

#Id: 7957

#Unit 2. Cellular Organization

Immediately after the entire precursor, Glc3Man9(GlcNAc)2 is transferred to a nascent polypeptide, three different enzymes, called  glycosidases, remove all three glucose residues and one particular mannose residue.

TLS Online TPP Program

#Id: 7958

#Unit 2. Cellular Organization

The efficient formation of disulfide bonds in the lumen of the ER depends on the enzyme protein disulfide isomerase (PDI), which is present in all eukaryotic cells

TLS Online TPP Program

#Id: 7959

#Unit 2. Cellular Organization

Unfolded-protein response

Key protein –Ire1 promotes formation of Hac1

TLS Online TPP Program

#Id: 7960

#Unit 2. Cellular Organization

Binding of BiP to the luminal domain of monomeric Ire1 prevents formation of the Ire1 dimer.