title: Glycoprotein Quality Control and Endoplasmic Reticulum Stress.
abstract: The endoplasmic reticulum (ER) supports many cellular processes and performs diverse functions, including protein synthesis, translocation across the membrane, integration into the membrane, folding, and posttranslational modifications including N-linked glycosylation; and regulation of Ca2+ homeostasis. In mammalian systems, the majority of proteins synthesized by the rough ER have N-linked glycans critical for protein maturation. The N-linked glycan is used as a quality control signal in the secretory protein pathway. A series of chaperones, folding enzymes, glucosidases, and carbohydrate transferases support glycoprotein synthesis and processing. Perturbation of ER-associated functions such as disturbed ER glycoprotein quality control, protein glycosylation and protein folding results in activation of an ER stress coping response. Collectively this ER stress coping response is termed the unfolded protein response (UPR), and occurs through the activation of complex cytoplasmic and nuclear signaling pathways. Cellular and ER homeostasis depends on balanced activity of the ER protein folding, quality control, and degradation pathways; as well as management of the ER stress coping response.
authors.affiliation: Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada. qw7@ualberta.ca.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada. jlg2@ualberta.ca.
authors.forename: Jody
authors.initials: J
authors.lastname: Groenendyk
authors.affiliation: Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada. marek.michalak@ualberta.ca.
authors.forename: Marek
authors.initials: M
authors.lastname: Michalak
mesh_terms: D000818:Animals; D059865:Endoplasmic Reticulum Stress / Q000502:physiology*; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D017510:Protein Folding; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology; D059748:Proteolysis; D056811:Unfolded Protein Response / Q000502:physiology*
chemical_list: D006023:Glycoproteins
keywords: calnexin; calreticulin; chaperone; endoplasmic reticulum; stress