Glycoprotein tertiary and quaternary structures are monitored by the same quality control mechanism.
Folding of glycoproteins entering the secretory pathway is strictly surveyed in the endoplasmic reticulum by a quality control system. Folding intermediates and proteins irreparably misfolded are marked via glucosylation by the UDPglucose:glycoprotein glucosyltransferase, an enzyme that acts as a folding sensor by exclusively labeling glycoproteins not displaying their native structures. Here we show that this sensing mechanism also applies to the oligomerization of protein complexes, as the glucosyltransferase appeared to be able to glucosylate folded complex subunits lacking the full complement of oligomer components.
Keith
Natasha
N
Laboratory of Glycobiology, Fundación Instituto Leloir, Avenida Patricias Argentinas 435, Buenos Aires C1405 WE, Argentina.
Parodi
Armando J
AJ
Caramelo
Julio J
JJ
D006023:Glycoproteins / Q000737:chemistry* / Q000502:physiology; D017510:Protein Folding; D020836:Protein Structure, Quaternary / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D011786:Quality Control
D006023:Glycoproteins