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Cargo receptor-assisted endoplasmic reticulum export of pathogenic α1-antitrypsin polymers.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Ordóñez, Adriana 
Harding, Heather P 
Marciniak, Stefan J 

Abstract

Circulating polymers of α1-antitrypsin (α1AT) are neutrophil chemo-attractants and contribute to inflammation, yet cellular factors affecting their secretion remain obscure. We report on a genome-wide CRISPR-Cas9 screen for genes affecting trafficking of polymerogenic α1ATH334D. A CRISPR enrichment approach based on recovery of single guide RNA (sgRNA) sequences from phenotypically selected fixed cells reveals that cells with high-polymer content are enriched in sgRNAs targeting genes involved in "cargo loading into COPII-coated vesicles," where "COPII" is coat protein II, including the cargo receptors lectin mannose binding1 (LMAN1) and surfeit protein locus 4 (SURF4). LMAN1- and SURF4-disrupted cells display a secretion defect extending beyond α1AT monomers to polymers. Polymer secretion is especially dependent on SURF4 and correlates with a SURF4-α1ATH334D physical interaction and with their co-localization at the endoplasmic reticulum (ER). These findings indicate that ER cargo receptors co-ordinate progression of α1AT out of the ER and modulate the accumulation of polymeric α1AT not only by controlling the concentration of precursor monomers but also by promoting secretion of polymers.

Description

Keywords

CHO CRISPR-Cas9 library, CHO cells, ERGIC-53, LMAN1, SURF4, cargo receptors, endoplasmic reticulum, genome-wide CRISPR-Cas9 screen, polymer trafficking, α1-antitrypsin, Endoplasmic Reticulum, Humans, Polymers, alpha 1-Antitrypsin

Journal Title

Cell Rep

Conference Name

Journal ISSN

2211-1247
2211-1247

Volume Title

35

Publisher

Elsevier BV

Rights

All rights reserved
Sponsorship
Wellcome Trust (200848/Z/16/Z)
Medical Research Council (G1002610)
MRC (MR/V028669/1)
Medical Research Council (MR/R009120/1)