Removal of the third glucose by glucosidase II and release from the chaperone

Stable Identifier
R-HSA-548890
Type
Reaction
Species
Homo sapiens
Compartment
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While the protein is bound to the chaperone complex, the glycan is still accessible to glucosidase II, which eventually removes the last remaining glucose residue. This also results in breaking the interaction between the chaperone and the glycoprotein, independently of whether the latter has achieved proper folding (Pelletier MF et al, 2000). This has been interpreted as a 'timing mechanism', in which a protein has only a limited period of time to achieve correct folding when bound to the chaperone, to avoid the scenario where proteins that take too long to fold would block the availability of CNX or CRT. Proteins with folding defects get transported to the Endoplasmic Reticulum Quality Control Compartment, while proteins with correct folding are transported to the cis-Golgi where the glycan is further modified.

Literature References
PubMed ID Title Journal Year
10929008 The heterodimeric structure of glucosidase II is required for its activity, solubility, and localization in vivo

Pelletier, MF, Marcil, A, Sevigny, G, Jakob, CA, Tessier, DC, Chevet, E, Menard, R, Bergeron, JJ, Thomas, DY

Glycobiology 2000
Participants
Participant Of
Catalyst Activity
Catalyst Activity
Title
glucan 1,3-alpha-glucosidase activity of glucosidase II [endoplasmic reticulum lumen]
Physical Entity
Activity
Cross References
Target Pathogen
Authored
Reviewed
Created