Abstract
Machinery components of the protein quality control such as chaperones, protein disulfide isomerase, lectins (calnexin and calreticulin), ERp57, glucosidase II, and glucosyltransferase are all functioning in the endoplasmic reticulum. The scheme depicts the major steps in the quality control of glycoprotein folding. Glycoproteins bearing monoglucosylated oligosaccharides either due to trimming by glucosidase II (Gls II) or through reglucosylation by glucosyltransferase (GT) will be bound by calnexin or calreticulin. Dissociation of such glycoprotein-lectin complexes will be achieved by glucosidase II, and correctly folded glycoproteins may be processed by ER-mannosidase I (ER Man I) and exported from the endoplasmic reticulum. However, not correctly folded glycoproteins will be recognized and reglucosylated by glucosyltransferase and enter a new calnexin/calreticulin cycle. Thus, the opposing actions of glucosidase II and glucosyltransferase provide the basis for the on-and-off-cycle. If correct folding cannot be achieved, trimming by ER-mannosidase I and II will be followed by interaction with EDEM 1 and OS9, respectively.
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References
Christianson JC, Shaler TA, Tyler RE, and Kopito RR (2008) OS-9 and GRP94 deliver mutant alpha1-antitrypsin to the Hrd1/SEL1L ubiquitin ligase complex for ERAD. Nat Cell Biol 10: 272–282
Ellgaard L and Helenius A (2003) Quality control in the endoplasmic reticulum. Nat Rev Mol Cell Biol 4: 181
Fan JY, Roth J, and Zuber C (2007) Expression of mutant Ins2C96Y results in enhanced tubule formation causing enlargement of pre-Golgi intermediates of CHO cells. Histochem Cell Biol 128: 161
Lucocq JM, Brada D, and Roth J (1986) Immunolocalization of the oligosaccharide trimming enzyme glucosidase II. J Cell Biol 102: 2137
Roth J, Yam GH, Fan J, Hirano K, Gaplovska-Kysela K, Le Fourn V, Guhl B, Santimaria R, Torossi T, Ziak M, and Zuber C (2008) Protein quality control: the who’s who, the where’s and therapeutic escapes. Histochem Cell Biol 129: 163
Zuber C, Fan JY, Guhl B, Parodi A, Fessler JH, Parker C, and Roth J (2001) Immunolocalization of UDP-glucose: glycoprotein glucosyltransferase indicates involvement of pre-Golgi intermediates in protein quality control. Proc Natl Acad Sci USA 98: 10710
Vembar SS and Brodsky JL (2008) One step at a time: endoplasmic reticulum-associated degradation. Nat Rev Mol Cell Biol 9: 944
Zuber C, Fan JY, Guhl B, and Roth J (2004) Misfolded proinsulin accumulates in expanded pre-Golgi intermediates and endoplasmic reticulum subdomains in pancreatic beta cells of Akita mice. FASEB J 18: 917
Zuber C, Cormier JH, Guhl B, Santimaria R, Hebert DN, and Roth J (2007) EDEM1 reveals a quality control vesicular transport pathway out of the endoplasmic reticulum not involving the COPII exit sites. Proc Natl Acad Sci USA 104: 4407
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Pavelka, M., Roth, J. (2010). Pre-Golgi Intermediates: Oligosaccharide Trimming and Protein Quality control. In: Functional Ultrastructure. Springer, Vienna. https://doi.org/10.1007/978-3-211-99390-3_26
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DOI: https://doi.org/10.1007/978-3-211-99390-3_26
Publisher Name: Springer, Vienna
Print ISBN: 978-3-211-99389-7
Online ISBN: 978-3-211-99390-3
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