SLC26A9 is selected for endoplasmic reticulum associated degradation (ERAD) via Hsp70-dependent targeting of the soluble STAS domain
Autor: | Patrick G. Needham, Adam R Wetzel, Jennifer L. Goeckeler-Fried, Casey Zhang, Zhihao Sun, Carol A. Bertrand, Jeffrey L. Brodsky |
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Rok vydání: | 2021 |
Předmět: |
biology
Protein family Chemistry Endoplasmic reticulum Cell Biology Endoplasmic Reticulum-Associated Degradation Saccharomyces cerevisiae Endoplasmic-reticulum-associated protein degradation Biochemistry Models Biological Antiporters Article Cell biology Protein structure HEK293 Cells Membrane protein Protein Domains Sulfate Transporters Chaperone (protein) biology.protein Humans HSP70 Heat-Shock Proteins Molecular Biology Secretory pathway Ion channel |
Zdroj: | Biochem J |
ISSN: | 1470-8728 |
Popis: | SLC26A9, a member of the solute carrier protein family, transports chloride ions across various epithelia. SLC26A9 also associates with other ion channels and transporters linked to human health, and in some cases these heterotypic interactions are essential to support the biogenesis of both proteins. Therefore, understanding how this complex membrane protein is initially folded might provide new therapeutic strategies to overcome deficits in the function of SLC26A9 partners, one of which is associated with Cystic Fibrosis. To this end, we developed a novel yeast expression system for SLC26A9. This facile system has been used extensively with other ion channels and transporters to screen for factors that oversee protein folding checkpoints. As commonly observed for other channels and transporters, we first noted that a substantial fraction of SLC26A9 is targeted for endoplasmic reticulum associated degradation (ERAD), which destroys folding-compromised proteins in the early secretory pathway. We next discovered that ERAD selection requires the Hsp70 chaperone, which can play a vital role in ERAD substrate selection. We then created SLC26A9 mutants and found that the transmembrane-rich domain of SLC26A9 was quite stable, whereas the soluble cytosolic STAS domain was responsible for Hsp70-dependent ERAD. To support data obtained in the yeast model, we were able to recapitulate Hsp70-facilitated ERAD of the STAS domain in human tissue culture cells. These results indicate that a critical barrier to nascent membrane protein folding can reside within a specific soluble domain, one that is monitored by components associated with the ERAD machinery. |
Databáze: | OpenAIRE |
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