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Updated: May 28, 2026

In Vitro Analysis of E3 Ubiquitin Ligase Function
Published on: May 14, 2021
The Gp78 ubiquitin ligase: probing endoplasmic reticulum complexity
Pascal St Pierre1, Ivan R Nabi
1Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
Abstract:
The endoplasmic reticulum (ER) has been classically divided, based on electron microscopy analysis, into parallel ribosome-studded rough ER sheets and a tubular smooth ER network. Recent studies have identified molecular constituents of the ER, the reticulons and DP1, that drive ER tubule formation and whose expression determines expression of ER sheets and tubules and thereby rough and smooth ER. However, segregation of the ER into only two domains remains simplistic and multiple functionally distinct ER domains necessarily exist. In this review, we will discuss the sub-organization of the ER in different domains focusing on the localization and role of the gp78 ubiquitin ligase in the mitochondria-associated smooth ER and on the evidence for a quality control ERAD domain.
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