Attenuation of Yeast UPR is Essential for Survival and is Mediated by IRE1 Kinase
Overview
Affiliations
The unfolded protein response (UPR) activates Ire1, an endoplasmic reticulum (ER) resident transmembrane kinase and ribonuclease (RNase), in response to ER stress. We used an in vivo assay, in which disappearance of the UPR-induced spliced HAC1 messenger ribonucleic acid (mRNA) correlates with the recovery of the ER protein-folding capacity, to investigate the attenuation of the UPR in yeast. We find that, once activated, spliced HAC1 mRNA is sustained in cells expressing Ire1 carrying phosphomimetic mutations within the kinase activation loop, suggesting that dephosphorylation of Ire1 is an important step in RNase deactivation. Additionally, spliced HAC1 mRNA is also sustained after UPR induction in cells expressing Ire1 with mutations in the conserved DFG kinase motif (D828A) or a conserved residue (F842) within the activation loop. The importance of proper Ire1 RNase attenuation is demonstrated by the inability of cells expressing Ire1-D828A to grow under ER stress. We propose that the activity of the Ire1 kinase domain plays a role in attenuating its RNase activity when ER function is recovered.
RNA exosome-driven RNA processing instructs the duration of the unfolded protein response.
Matabishi-Bibi L, Goncalves C, Babour A Nucleic Acids Res. 2025; 53(4).
PMID: 39995043 PMC: 11850225. DOI: 10.1093/nar/gkaf088.
TUDCA modulates drug bioavailability to regulate resistance to acute ER stress in .
Chadwick S, Stack-Couture S, Berg M, Di Gregorio S, Lung B, Genereaux J Mol Biol Cell. 2024; 36(2):ar13.
PMID: 39661468 PMC: 11809307. DOI: 10.1091/mbc.E24-04-0147.
Unmasking the Antifungal Activity of Leaf Extract against .
Quejada L, Hernandez A, Chitiva L, Bravo-Chaucanes C, Vargas-Casanova Y, Faria R J Fungi (Basel). 2024; 10(7).
PMID: 39057348 PMC: 11277670. DOI: 10.3390/jof10070464.
Carrillo R, Iwai K, Albertson A, Dang G, Christopher D Front Plant Sci. 2024; 15:1389658.
PMID: 38817940 PMC: 11137178. DOI: 10.3389/fpls.2024.1389658.
Fundamental and Applicative Aspects of the Unfolded Protein Response in Yeasts.
Ishiwata-Kimata Y, Kimata Y J Fungi (Basel). 2023; 9(10).
PMID: 37888245 PMC: 10608004. DOI: 10.3390/jof9100989.