Cargo selection in endoplasmic reticulum–to–Golgi transport and relevant diseases
Vi T. Tang, David Ginsburg
Vi T. Tang, David Ginsburg
Published January 3, 2023
Citation Information: J Clin Invest. 2023;133(1):e163838. https://doi.org/10.1172/JCI163838.
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Review Series

Cargo selection in endoplasmic reticulum–to–Golgi transport and relevant diseases

Abstract

Most proteins destined for the extracellular space or various intracellular compartments must traverse the intracellular secretory pathway. The first step is the recruitment and transport of cargoes from the endoplasmic reticulum (ER) lumen to the Golgi apparatus by coat protein complex II (COPII), consisting of five core proteins. Additional ER transmembrane proteins that aid cargo recruitment are referred to as cargo receptors. Gene duplication events have resulted in multiple COPII paralogs present in the mammalian genome. Here, we review the functions of each COPII protein, human disorders associated with each paralog, and evidence for functional conservation between paralogs. We also provide a summary of current knowledge regarding two prototypical cargo receptors in mammals, LMAN1 and SURF4, and their roles in human health and disease.

Authors

Vi T. Tang, David Ginsburg

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Figure 2

ER to Golgi transport of secreted proteins.

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ER to Golgi transport of secreted proteins. Secretory proteins in the ER...
Secretory proteins in the ER lumen are recruited into the COPII vesicle/tubule by COPII coat proteins. In the vesicular transport model, the vesicle buds from the ER and travels to the ERGIC/cis-Golgi network with COPII coat proteins accompanying the vesicle. In the tubular transport model, cargo proteins are transported in a continuous interwoven tubular network instead of discrete vesicles. COPII proteins remain on the ER membrane and function as a gatekeeper restricting entry of secretory proteins into tubules.