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Ishiwata-Kimata Y, Kimata Y. Fundamental and Applicative Aspects of the Unfolded Protein Response in Yeasts. J Fungi (Basel) 2023; 9:989. [PMID: 37888245 PMCID: PMC10608004 DOI: 10.3390/jof9100989] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/28/2023] Open
Abstract
Upon the dysfunction or functional shortage of the endoplasmic reticulum (ER), namely, ER stress, eukaryotic cells commonly provoke a protective gene expression program called the unfolded protein response (UPR). The molecular mechanism of UPR has been uncovered through frontier genetic studies using Saccharomyces cerevisiae as a model organism. Ire1 is an ER-located transmembrane protein that directly senses ER stress and is activated as an RNase. During ER stress, Ire1 promotes the splicing of HAC1 mRNA, which is then translated into a transcription factor that induces the expression of various genes, including those encoding ER-located molecular chaperones and protein modification enzymes. While this mainstream intracellular UPR signaling pathway was elucidated in the 1990s, new intriguing insights have been gained up to now. For instance, various additional factors allow UPR evocation strictly in response to ER stress. The UPR machineries in other yeasts and fungi, including pathogenic species, are another important research topic. Moreover, industrially beneficial yeast strains carrying an enforced and enlarged ER have been produced through the artificial and constitutive induction of the UPR. In this article, we review canonical and up-to-date insights concerning the yeast UPR, mainly from the viewpoint of the functions and regulation of Ire1 and HAC1.
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Affiliation(s)
| | - Yukio Kimata
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara 630-0192, Japan
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Wu Q, Zhou D, Shen Z, Chen B, Wang G, Wu L, Zhang L, Li X, Yuan L, Wu Y, Qu N, Zhou W. VPS34-IN1 induces apoptosis of ER + breast cancer cells via activating PERK/ATF4/CHOP pathway. Biochem Pharmacol 2023:115634. [PMID: 37290596 DOI: 10.1016/j.bcp.2023.115634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/18/2023] [Accepted: 05/31/2023] [Indexed: 06/10/2023]
Abstract
VPS34-IN1 is a specific selective inhibitor of Class III Phosphatidylinositol 3-kinase (PI3K) and has been shown to exhibit a significant antitumor effect in leukemia and liver cancer. In current study, we focused on the anticancer effect and potential mechanism of VPS34-IN1 in estrogen receptor positive (ER + ) breast cancer. Our results revealed that VPS34-IN1 inhibited the viability of ER + breast cancer cells in vitro and in vivo. Flow cytometry and western blot analyses showed that VPS34-IN1 treatment induced breast cancer cell apopotosis. Interestingly, VPS34-IN1 treatment activated protein kinase R (PKR)-like ER kinase (PERK) branch of endoplasmic reticulum (ER) stress. Furthermore, knockdown of PERK by siRNA or inhibition of PERK activity by chemical inhibitor GSK2656157 could attenuate VPS34-IN1-mediated apoptosis in ER + breast cancer cells. Collectively, VPS34-IN1 has an antitumor effect in breast cancer, and it may result from activating PERK/ATF4/CHOP pathway of ER stress to induce cell apoptosis. These findings broaden our understanding of the anti-breast cancer effects and mechanisms of VPS34-IN1 and provide new ideas and reference directions for the treatment of ER + breast cancer.
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Affiliation(s)
- Qiuya Wu
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Duanfang Zhou
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Zhengze Shen
- Department of Pharmacy, Yongchuan Hospital of Chongqing Medical University, 439 Xuanhua Road, Yongchuan District, Chongqing 402160, China
| | - Bo Chen
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Gang Wang
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Lihong Wu
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Limei Zhang
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Xiaoli Li
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China; Key Laboratory for Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, China
| | - Lie Yuan
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Yuanli Wu
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Na Qu
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China
| | - Weiying Zhou
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China; Chongqing Key Laboratory of Drug Metabolism, Chongqing Medical University, Chongqing 400016, China; Key Laboratory for Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, China.
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Lin Y, Feng Y, Zheng L, Zhao M, Huang M. Improved protein production in yeast using cell engineering with genes related to a key factor in the unfolded protein response. Metab Eng 2023; 77:152-161. [PMID: 37044356 DOI: 10.1016/j.ymben.2023.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 04/08/2023] [Accepted: 04/09/2023] [Indexed: 04/14/2023]
Abstract
The yeast Saccharomyces cerevisiae is a widely used cell factory for protein production. Increasing the protein production capacity of a yeast strain may be beneficial for obtaining recombinant proteins as a product or exerting its competence in consolidated bioprocessing. However, heterologous protein expression usually imposes stress on cells. Improving the cell's ability to cope with stress enhances protein yield. HAC1 is a key transcription factor in the unfolded protein response (UPR). In this study, several genes related to the UPR signal pathway, including unfolded protein sensing, HAC1 mRNA splicing, mRNA ligation, mRNA decay, translation, and Hac1p degradation, were selected as targets to engineer yeast strains. The final engineered strain produced α-amylase 3.3-fold, and human serum albumin 15.3-fold, greater than that of the control strain. Key regulation and metabolic network changes in the engineered strains were identified by transcriptome analysis and physiological characterizations. This study demonstrated that cell engineering with genes relevant to the key node HAC1 in UPR increased protein secretion substantially. The verified genetic modifications of this study provide useful targets in the construction of yeast cell factories for efficient protein production.
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Affiliation(s)
- Yeping Lin
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China
| | - Yunzi Feng
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China
| | - Lin Zheng
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China
| | - Mouming Zhao
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China
| | - Mingtao Huang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou, 510650, China.
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Induction of the Unfolded Protein Response at High Temperature in Saccharomyces cerevisiae. Int J Mol Sci 2022; 23:ijms23031669. [PMID: 35163590 PMCID: PMC8836091 DOI: 10.3390/ijms23031669] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 01/10/2023] Open
Abstract
Ire1 is an endoplasmic reticulum (ER)-located endoribonuclease that is activated in response to ER stress. In yeast Saccharomyces cerevisiae cells, Ire1 promotes HAC1-mRNA splicing to remove the intron sequence from the HAC1u mRNA (“u” stands for “uninduced”). The resulting mRNA, which is named HAC1i mRNA (“i” stands for “induced”), is then translated into a transcription factor that is involved in the unfolded protein response (UPR). In this study, we designed an oligonucleotide primer that specifically hybridizes to the exon-joint site of the HAC1i cDNA. This primer allowed us to perform real-time reverse transcription-PCR to quantify HAC1i mRNA abundance with high sensitivity. Using this method, we detected a minor induction of HAC1-mRNA splicing in yeast cells cultured at their maximum growth temperature of 39 °C. Based on our analyses of IRE1-gene mutant strains, we propose that when yeast cells are cultured at or near their maximum growth temperature, protein folding in the ER is disturbed, leading to a minor UPR induction that supports cellular growth.
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Uppala JK, Sathe L, Chakraborty A, Bhattacharjee S, Pulvino AT, Dey M. The cap-proximal RNA secondary structure inhibits preinitiation complex formation on HAC1 mRNA. J Biol Chem 2022; 298:101648. [PMID: 35101452 PMCID: PMC8881652 DOI: 10.1016/j.jbc.2022.101648] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 11/17/2022] Open
Abstract
Translation of HAC1 mRNA in the budding yeast Saccharomyces cerevisiae is derepressed when RNase Ire1 removes its intron via nonconventional cytosolic splicing in response to accumulation of unfolded proteins inside the endoplasmic reticulum. The spliced HAC1 mRNA is translated into a transcription factor that changes the cellular gene expression patterns to increase the protein folding capacity of cells. Previously, we showed that a segment of the intronic sequence interacts with the 5′-UTR of the unspliced mRNA, resulting in repression of HAC1 translation at the initiation stage. However, the exact mechanism of translational derepression is not clear. Here, we show that at least 11-base-pairing interactions between the 5′-UTR and intron (UI) are sufficient to repress HAC1 translation. We also show that overexpression of the helicase eukaryotic initiation factor 4A derepressed translation of an unspliced HAC1 mRNA containing only 11-bp interactions between the 5′-UTR and intronic sequences. In addition, our genetic screen identifies that single mutations in the UI interaction site could derepress translation of the unspliced HAC1 mRNA. Furthermore, we show that the addition of 24 RNA bases between the mRNA 5′-cap and the UI interaction site derepressed translation of the unspliced HAC1 mRNA. Together, our data provide a mechanistic explanation for why the cap-proximal UI–RNA duplex inhibits the recruitment of translating ribosomes to HAC1 mRNA, thus keeping mRNA translationally repressed.
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Affiliation(s)
- Jagadeesh Kumar Uppala
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Leena Sathe
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Abhijit Chakraborty
- Center for Autoimmunity and Inflammation, Center for Cancer Immunotherapy, La Jolla Institute for Immunology, La Jolla, California, USA
| | - Sankhajit Bhattacharjee
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Anthony Thomas Pulvino
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Madhusudan Dey
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.
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