Cell Structure and Function
Online ISSN : 1347-3700
Print ISSN : 0386-7196
ISSN-L : 0386-7196
Dispersion of Endoplasmic Reticulum-associated Compartments by 4-phenyl Butyric Acid in Yeast Cells
Thanh Chi MaiYuki Ishiwata-KimataQuynh Giang LeHiroyuki KidoYukio Kimata
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Supplementary material

2019 Volume 44 Issue 2 Pages 173-182


In yeast Saccharomyces cerevisiae cells, some aberrant multimembrane-spanning proteins are not transported to the cell surface but form and are accumulated in endoplasmic reticulum (ER)-derived subcompartments, known as the ER-associated compartments (ERACs), which are observed as puncta under fluorescence microscopy. Here we show that a mutant of the cell surface protein Pma1, Pma1-2308, was accumulated in the ERACs, as well as the heterologously expressed mammalian cystic fibrosis transmembrane conductance regulator (CFTR), in yeast cells. Pma1-2308 and CFTR were located on the same ERACs. We also note that treatment of cells with 4-phenyl butyric acid (4-PBA) compromised the ERAC formation by Pma1-2308 and CFTR, suggesting that 4-PBA exerts a chaperone-like function in yeast cells. Intriguingly, unlike ER stress induced by the canonical ER stressor tunicamycin, ER stress that was induced by Pma1-2308 was aggravated by 4-PBA. We assume that this observation demonstrates a beneficial aspect of ERACs, and thus propose that the ERACs are formed through aggregation of aberrant transmembrane proteins and work as the accumulation sites of multiple ERAC-forming proteins for their sequestration.

Key words: protein aggregation, organelle, unfolded protein response, ER stress, 4-PBA

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© 2019 The Author(s) CC-BY 4.0 (Submission before October 2016: Copyright © Japan Society for Cell Biology)

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