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Published on: June 14, 2024
Thiol-mediated protein retention in the endoplasmic reticulum: the role of ERp44
Tiziana Anelli1, Massimo Alessio, Angela Bachi
1DiBiT-HSR and Università Vita-Salute San Raffaele, Via Olgettina 58, 20132 Milan, Italy.
Abstract:
Formation of disulfide bonds, an essential step for the maturation and exit of secretory proteins from the endoplasmic reticulum (ER), is controlled by specific ER-resident enzymes. A pivotal element in this process is Ero1alpha, an oxidoreductin that lacks known ER retention motifs. Here we show that ERp44 mediates Ero1alpha ER localization through the formation of reversible mixed disulfides. ERp44 also prevents the secretion of an unassembled cargo protein with unpaired cysteines. We conclude that ERp44 is a key element in thiol-mediated retention. It might also favour the maturation of disulfide-linked oligomeric proteins and their quality control.
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