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Haddadi M, Haghi M, Rezaei N, Kiani Z, Akkülah T, Celik A. APOE and Alzheimer's disease: Pathologic clues from transgenic Drosophila melanogaster. Arch Gerontol Geriatr 2024; 123:105420. [PMID: 38537387 DOI: 10.1016/j.archger.2024.105420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/03/2024] [Accepted: 03/19/2024] [Indexed: 06/06/2024]
Abstract
Alzheimer's disease (AD) is one of the most common forms of neurodegenerative diseases. Apolipoprotein E4 (ApoE4) is the main genetic risk factor in the development of late-onset AD. However, the exact mechanism underlying ApoE4-mediated neurodegeneration remains unclear. We utilized Drosophila melanogaster to examine the neurotoxic effects of various human APOE isoforms when expressed specifically in glial and neural cells. We assessed impacts on mitochondrial dynamics, ER stress, lipid metabolism, and bio-metal ion concentrations in the central nervous system (CNS) of the transgenic flies. Dachshund antibody staining revealed a reduction in the number of Kenyon cells. Behavioral investigations including ethanol tolerance and learning and memory performance demonstrated neuronal dysfunction in APOE4-expressing larvae and adult flies. Transcription level of marf and drp-1 were found to be elevated in APOE4 flies, while atf4, atf6, and xbp-1 s showed down regulation. Enhanced concentrations of triglyceride and cholesterol in the CNS were observed in APOE4 transgenic flies, with especially pronounced effects upon glial-specific expression of the gene. Spectrophotometry of brain homogenate revealed enhanced Fe++ and Zn++ ion levels in conjunction with diminished Cu++ levels upon APOE4 expression. To explore therapeutic strategies, we subjected the flies to heat-shock treatment, aiming to activate heat-shock proteins (HSPs) and assess their potential to mitigate the neurotoxic effects of APOE isoforms. The results showed potential therapeutic benefits for APOE4-expressing flies, hinting at an ability to attenuate memory deterioration. Overall, our findings suggest that APOE4 can alter lipid metabolism, bio metal ion homeostasis, and disrupt the harmonious fission-fusion balance of neuronal and glial mitochondria, ultimately inducing ER stress. These alterations mirror the main clinical manifestations of AD in patients. Therefore, our work underscores the suitability of Drosophila as a fertile model for probing the pathological roles of APOE and furthering our understanding of diverse isoform-specific functions.
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Affiliation(s)
- Mohammad Haddadi
- Department of Biology, Faculty of Basic Sciences, University of Zabol, Zabol, Iran; Genetics and Non-communicable Diseases Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
| | - Mehrnaz Haghi
- Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Niloofar Rezaei
- Department of Biology, Faculty of Basic Sciences, University of Zabol, Zabol, Iran
| | - Zahra Kiani
- Department of Biology, Faculty of Basic Sciences, University of Zabol, Zabol, Iran
| | - Taha Akkülah
- Department of Molecular Biology and Genetics, Bogazici University, Istanbul, Turkiye; Center for Life Sciences and Technologies, Bogazici University, Istanbul, Turkiye
| | - Arzu Celik
- Department of Molecular Biology and Genetics, Bogazici University, Istanbul, Turkiye; Center for Life Sciences and Technologies, Bogazici University, Istanbul, Turkiye
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2
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Guo X, Mutch M, Torres AY, Nano M, Rauth N, Harwood J, McDonald D, Chen Z, Montell C, Dai W, Montell DJ. The Zn 2+ transporter ZIP7 enhances endoplasmic-reticulum-associated protein degradation and prevents neurodegeneration in Drosophila. Dev Cell 2024; 59:1655-1667.e6. [PMID: 38670102 PMCID: PMC11233247 DOI: 10.1016/j.devcel.2024.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 12/15/2023] [Accepted: 04/03/2024] [Indexed: 04/28/2024]
Abstract
Proteotoxic stress drives numerous degenerative diseases. Cells initially adapt to misfolded proteins by activating the unfolded protein response (UPR), including endoplasmic-reticulum-associated protein degradation (ERAD). However, persistent stress triggers apoptosis. Enhancing ERAD is a promising therapeutic approach for protein misfolding diseases. The ER-localized Zn2+ transporter ZIP7 is conserved from plants to humans and required for intestinal self-renewal, Notch signaling, cell motility, and survival. However, a unifying mechanism underlying these diverse phenotypes was unknown. In studying Drosophila border cell migration, we discovered that ZIP7-mediated Zn2+ transport enhances the obligatory deubiquitination of proteins by the Rpn11 Zn2+ metalloproteinase in the proteasome lid. In human cells, ZIP7 and Zn2+ are limiting for deubiquitination. In a Drosophila model of neurodegeneration caused by misfolded rhodopsin (Rh1), ZIP7 overexpression degrades misfolded Rh1 and rescues photoreceptor viability and fly vision. Thus, ZIP7-mediated Zn2+ transport is a previously unknown, rate-limiting step for ERAD in vivo with therapeutic potential in protein misfolding diseases.
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Affiliation(s)
- Xiaoran Guo
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Morgan Mutch
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Alba Yurani Torres
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Maddalena Nano
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Nishi Rauth
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Jacob Harwood
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Drew McDonald
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Zijing Chen
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Craig Montell
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA
| | - Wei Dai
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA; Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China.
| | - Denise J Montell
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110, USA.
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3
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Zhu Y, Cho K, Lacin H, Zhu Y, DiPaola JT, Wilson BA, Patti GJ, Skeath JB. Loss of dihydroceramide desaturase drives neurodegeneration by disrupting endoplasmic reticulum and lipid droplet homeostasis in glial cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.01.573836. [PMID: 38260379 PMCID: PMC10802327 DOI: 10.1101/2024.01.01.573836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Dihydroceramide desaturases convert dihydroceramides to ceramides, the precursors of all complex sphingolipids. Reduction of DEGS1 dihydroceramide desaturase function causes pediatric neurodegenerative disorder hypomyelinating leukodystrophy-18 (HLD-18). We discovered that infertile crescent (ifc), the Drosophila DEGS1 homolog, is expressed primarily in glial cells to promote CNS development by guarding against neurodegeneration. Loss of ifc causes massive dihydroceramide accumulation and severe morphological defects in cortex glia, including endoplasmic reticulum (ER) expansion, failure of neuronal ensheathment, and lipid droplet depletion. RNAi knockdown of the upstream ceramide synthase schlank in glia of ifc mutants rescues ER expansion, suggesting dihydroceramide accumulation in the ER drives this phenotype. RNAi knockdown of ifc in glia but not neurons drives neuronal cell death, suggesting that ifc function in glia promotes neuronal survival. Our work identifies glia as the primary site of disease progression in HLD-18 and may inform on juvenile forms of ALS, which also feature elevated dihydroceramide levels.
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Affiliation(s)
- Yuqing Zhu
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Kevin Cho
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Mass Spectrometry and Metabolic Tracing, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Haluk Lacin
- Division of Biological and Biomedical Systems, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Yi Zhu
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Jose T DiPaola
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Beth A Wilson
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Gary J Patti
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Mass Spectrometry and Metabolic Tracing, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - James B Skeath
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
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4
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Cho B, Shin M, Chang E, Son S, Shin I, Shim J. S-nitrosylation-triggered unfolded protein response maintains hematopoietic progenitors in Drosophila. Dev Cell 2024; 59:1075-1090.e6. [PMID: 38521056 DOI: 10.1016/j.devcel.2024.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/27/2023] [Accepted: 02/29/2024] [Indexed: 03/25/2024]
Abstract
The Drosophila lymph gland houses blood progenitors that give rise to myeloid-like blood cells. Initially, blood progenitors proliferate, but later, they become quiescent to maintain multipotency before differentiation. Despite the identification of various factors involved in multipotency maintenance, the cellular mechanism controlling blood progenitor quiescence remains elusive. Here, we identify the expression of nitric oxide synthase in blood progenitors, generating nitric oxide for post-translational S-nitrosylation of protein cysteine residues. S-nitrosylation activates the Ire1-Xbp1-mediated unfolded protein response, leading to G2 cell-cycle arrest. Specifically, we identify the epidermal growth factor receptor as a target of S-nitrosylation, resulting in its retention within the endoplasmic reticulum and blockade of its receptor function. Overall, our findings highlight developmentally programmed S-nitrosylation as a critical mechanism that induces protein quality control in blood progenitors, maintaining their undifferentiated state by inhibiting cell-cycle progression and rendering them unresponsive to paracrine factors.
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Affiliation(s)
- Bumsik Cho
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Republic of Korea; Research Institute for Natural Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Mingyu Shin
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Eunji Chang
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Seogho Son
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Incheol Shin
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Republic of Korea; Research Institute for Natural Science, Hanyang University, Seoul 04763, Republic of Korea; Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Jiwon Shim
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Republic of Korea; Research Institute for Natural Science, Hanyang University, Seoul 04763, Republic of Korea; Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea; Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul 04763, Republic of Korea.
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Park YJ, Lu TC, Jackson T, Goodman LD, Ran L, Chen J, Liang CY, Harrison E, Ko C, Hsu AL, Yamamoto S, Qi Y, Bellen HJ, Li H. Whole organism snRNA-seq reveals systemic peripheral changes in Alzheimer's Disease fly models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.10.584317. [PMID: 38559164 PMCID: PMC10979927 DOI: 10.1101/2024.03.10.584317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Peripheral tissues become disrupted in Alzheimer's Disease (AD). However, a comprehensive understanding of how the expression of AD-associated toxic proteins, Aβ42 and Tau, in neurons impacts the periphery is lacking. Using Drosophila, a prime model organism for studying aging and neurodegeneration, we generated the Alzheimer's Disease Fly Cell Atlas (AD-FCA): whole-organism single-nucleus transcriptomes of 219 cell types from adult flies neuronally expressing human Aβ42 or Tau. In-depth analyses and functional data reveal impacts on peripheral sensory neurons by Aβ42 and on various non-neuronal peripheral tissues by Tau, including the gut, fat body, and reproductive system. This novel AD atlas provides valuable insights into potential biomarkers and the intricate interplay between the nervous system and peripheral tissues in response to AD-associated proteins.
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Affiliation(s)
- Ye-Jin Park
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
- Program in Development, Disease Models & Therapeutics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tzu-Chiao Lu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tyler Jackson
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Program in Cancer Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lindsey D Goodman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Lindsey Ran
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jiaye Chen
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chung-Yi Liang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Erin Harrison
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christina Ko
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ao-Lin Hsu
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Internal Medicine, Division of Geriatric and Palliative Medicine, University of Michigan, Ann Arbor, MI 28109, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
- Program in Development, Disease Models & Therapeutics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yanyan Qi
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
- Program in Development, Disease Models & Therapeutics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hongjie Li
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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6
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Li Y, Liu D, Zhang X, Rimal S, Lu B, Li S. RACK1 and IRE1 participate in the translational quality control of amyloid precursor protein in Drosophila models of Alzheimer's disease. J Biol Chem 2024; 300:105719. [PMID: 38311171 PMCID: PMC10907166 DOI: 10.1016/j.jbc.2024.105719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/17/2024] [Accepted: 01/29/2024] [Indexed: 02/10/2024] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by dysregulation of the expression and processing of the amyloid precursor protein (APP). Protein quality control systems are dedicated to remove faulty and deleterious proteins to maintain cellular protein homeostasis (proteostasis). Identidying mechanisms underlying APP protein regulation is crucial for understanding AD pathogenesis. However, the factors and associated molecular mechanisms regulating APP protein quality control remain poorly defined. In this study, we show that mutant APP with its mitochondrial-targeting sequence ablated exhibited predominant endoplasmic reticulum (ER) distribution and led to aberrant ER morphology, deficits in locomotor activity, and shortened lifespan. We searched for regulators that could counteract the toxicity caused by the ectopic expression of this mutant APP. Genetic removal of the ribosome-associated quality control (RQC) factor RACK1 resulted in reduced levels of ectopically expressed mutant APP. By contrast, gain of RACK1 function increased mutant APP level. Additionally, overexpression of the ER stress regulator (IRE1) resulted in reduced levels of ectopically expressed mutant APP. Mechanistically, the RQC related ATPase VCP/p97 and the E3 ubiquitin ligase Hrd1 were required for the reduction of mutant APP level by IRE1. These factors also regulated the expression and toxicity of ectopically expressed wild type APP, supporting their relevance to APP biology. Our results reveal functions of RACK1 and IRE1 in regulating the quality control of APP homeostasis and mitigating its pathogenic effects, with implications for the understanding and treatment of AD.
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Affiliation(s)
- Yu Li
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Dongyue Liu
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Xuejing Zhang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Suman Rimal
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Bingwei Lu
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Shuangxi Li
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China.
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Li Y, Liu D, Wang H, Zhang X, Lu B, Li S. The IRE1/Xbp1 axis restores ER and tissue homeostasis perturbed by excess Notch in Drosophila. Dev Biol 2024; 507:11-19. [PMID: 38142805 DOI: 10.1016/j.ydbio.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/15/2023] [Accepted: 12/17/2023] [Indexed: 12/26/2023]
Abstract
Notch signaling controls numerous key cellular processes including cell fate determination and cell proliferation. Its malfunction has been linked to many developmental abnormalities and human disorders. Overactivation of Notch signaling is shown to be oncogenic. Retention of excess Notch protein in the endoplasmic reticulum (ER) can lead to altered Notch signaling and cell fate, but the mechanism is not well understood. In this study, we show that V5-tagged or untagged exogenous Notch is retained in the ER when overexpressed in fly tissues. Furthermore, we show that Notch retention in the ER leads to robust ER enlargement and elicits a rough eye phenotype. Gain-of-function of unfolded protein response (UPR) factors IRE1 or spliced Xbp1 (Xbp1-s) alleviates Notch accumulation in the ER, restores ER morphology and ameliorates the rough eye phenotype. Our results uncover a pivotal role of the IRE1/Xbp1 axis in regulating the detrimental effect of ER-localized excess Notch protein during development and tissue homeostasis.
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Affiliation(s)
- Yu Li
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Dongyue Liu
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Haochuan Wang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Xuejing Zhang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Bingwei Lu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Shuangxi Li
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China.
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Dutta D, Kanca O, Shridharan RV, Marcogliese PC, Steger B, Morimoto M, Frost FG, Macnamara E, Wangler MF, Yamamoto S, Jenny A, Adams D, Malicdan MC, Bellen HJ. Loss of the endoplasmic reticulum protein Tmem208 affects cell polarity, development, and viability. Proc Natl Acad Sci U S A 2024; 121:e2322582121. [PMID: 38381787 PMCID: PMC10907268 DOI: 10.1073/pnas.2322582121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 01/26/2024] [Indexed: 02/23/2024] Open
Abstract
Nascent proteins destined for the cell membrane and the secretory pathway are targeted to the endoplasmic reticulum (ER) either posttranslationally or cotranslationally. The signal-independent pathway, containing the protein TMEM208, is one of three pathways that facilitates the translocation of nascent proteins into the ER. The in vivo function of this protein is ill characterized in multicellular organisms. Here, we generated a CRISPR-induced null allele of the fruit fly ortholog CG8320/Tmem208 by replacing the gene with the Kozak-GAL4 sequence. We show that Tmem208 is broadly expressed in flies and that its loss causes lethality, although a few short-lived flies eclose. These animals exhibit wing and eye developmental defects consistent with impaired cell polarity and display mild ER stress. Tmem208 physically interacts with Frizzled (Fz), a planar cell polarity (PCP) receptor, and is required to maintain proper levels of Fz. Moreover, we identified a child with compound heterozygous variants in TMEM208 who presents with developmental delay, skeletal abnormalities, multiple hair whorls, cardiac, and neurological issues, symptoms that are associated with PCP defects in mice and humans. Additionally, fibroblasts of the proband display mild ER stress. Expression of the reference human TMEM208 in flies fully rescues the loss of Tmem208, and the two proband-specific variants fail to rescue, suggesting that they are loss-of-function alleles. In summary, our study uncovers a role of TMEM208 in development, shedding light on its significance in ER homeostasis and cell polarity.
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Affiliation(s)
- Debdeep Dutta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX77030
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX77030
| | - Rishi V. Shridharan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX77030
| | - Paul C. Marcogliese
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX77030
| | - Benjamin Steger
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD20892
| | - Marie Morimoto
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD20892
| | - F. Graeme Frost
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD20892
| | - Ellen Macnamara
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD20892
| | | | - Michael F. Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX77030
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX77030
| | - Andreas Jenny
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, NY10461
- Department of Genetics, Albert Einstein College of Medicine, New York, NY10461
| | - David Adams
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD20892
| | - May C. Malicdan
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD20892
| | - Hugo J. Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX77030
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9
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Ito A, Matsuda N, Ukita Y, Okumura M, Chihara T. Akaluc/AkaLumine bioluminescence system enables highly sensitive, non-invasive and temporal monitoring of gene expression in Drosophila. Commun Biol 2023; 6:1270. [PMID: 38097812 PMCID: PMC10721803 DOI: 10.1038/s42003-023-05628-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023] Open
Abstract
Bioluminescence generated by luciferase and luciferin has been extensively used in biological research. However, detecting signals from deep tissues in vivo poses a challenge to traditional methods. To overcome this, the Akaluc and AkaLumine bioluminescent systems were developed, resulting in improved signal detection. We evaluate the potential of Akaluc/AkaLumine in Drosophila melanogaster to establish a highly sensitive, non-invasive, and temporal detection method for gene expression. Our results show that oral administration of AkaLumine to flies expressing Akaluc provided a higher luminescence signal than Luc/D-luciferin, with no observed harmful effects on flies. The Akaluc/AkaLumine system allows for monitoring of dynamic temporal changes in gene expression. Additionally, using the Akaluc fusion gene allows for mRNA splicing monitoring. Our findings indicate that the Akaluc/AkaLumine system is a powerful bioluminescence tool for analyzing gene expression in deep tissues and small numbers of cells in Drosophila.
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Affiliation(s)
- Akira Ito
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Nagisa Matsuda
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Yumiko Ukita
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Misako Okumura
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
- Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Takahiro Chihara
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan.
- Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan.
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10
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Zheng J, Guo Y, Shi C, Yang S, Xu W, Ma X. Differential Ire1 determines loser cell fate in tumor-suppressive cell competition. Cell Rep 2023; 42:113303. [PMID: 37924514 DOI: 10.1016/j.celrep.2023.113303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 08/31/2023] [Accepted: 10/03/2023] [Indexed: 11/06/2023] Open
Abstract
Tumor-suppressive cell competition (TSCC) is a conserved surveillance mechanism in which neighboring cells actively eliminate oncogenic cells. Despite overwhelming studies showing that the unfolded protein response (UPR) is dysregulated in various tumors, it remains debatable whether the UPR restrains or promotes tumorigenesis. Here, using Drosophila eye epithelium as a model, we uncover a surprising decisive role of the Ire1 branch of the UPR in regulating cell polarity gene scribble (scrib) loss-induced TSCC. Both mutation and hyperactivation of Ire1 accelerate elimination of scrib clones via inducing apoptosis and autophagy, respectively. Unexpectedly, relative Ire1 activity is also crucial for determining loser cell fate, as dysregulating Ire1 signaling in the surrounding healthy cells reversed the "loser" status of scrib clones by decreasing their apoptosis. Furthermore, we show that Ire1 is required for cell competition in mammalian cells. Together, these findings provide molecular insights into scrib-mediated TSCC and highlight Ire1 as a key determinant of loser cell fate.
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Affiliation(s)
- Jiadong Zheng
- Fudan University, Shanghai 200433, China; Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China
| | - Yifan Guo
- Fudan University, Shanghai 200433, China; Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China
| | - Changyi Shi
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China
| | - Shuai Yang
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China
| | - Wenyan Xu
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China.
| | - Xianjue Ma
- Fudan University, Shanghai 200433, China; Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China.
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11
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Park JE, Lee J, Ok S, Byun S, Chang EJ, Yoon SE, Kim YJ, Kang MJ. Wg/Wnt1 and Erasp link ER stress to proapoptotic signaling in an autosomal dominant retinitis pigmentosa model. Exp Mol Med 2023:10.1038/s12276-023-01044-7. [PMID: 37464094 PMCID: PMC10394004 DOI: 10.1038/s12276-023-01044-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/11/2023] [Accepted: 04/17/2023] [Indexed: 07/20/2023] Open
Abstract
The endoplasmic reticulum (ER) is a subcellular organelle essential for cellular homeostasis. Perturbation of ER functions due to various conditions can induce apoptosis. Chronic ER stress has been implicated in a wide range of diseases, including autosomal dominant retinitis pigmentosa (ADRP), which is characterized by age-dependent retinal degeneration caused by mutant rhodopsin alleles. However, the signaling pathways that mediate apoptosis in response to ER stress remain poorly understood. In this study, we performed an unbiased in vivo RNAi screen with a Drosophila ADRP model and found that Wg/Wnt1 mediated apoptosis. Subsequent transcriptome analysis revealed that ER stress-associated serine protease (Erasp), which has been predicted to show serine-type endopeptidase activity, was a downstream target of Wg/Wnt1 during ER stress. Furthermore, knocking down Erasp via RNAi suppressed apoptosis induced by mutant rhodopsin-1 (Rh-1P37H) toxicity, alleviating retinal degeneration in the Drosophila ADRP model. In contrast, overexpression of Erasp resulted in enhanced caspase activity in Drosophila S2 cells treated with apoptotic inducers and the stabilization of the initiator caspase Dronc (Death regulator Nedd2-like caspase) by stimulating DIAP1 (Drosophila inhibitor of apoptosis protein 1) degradation. These findings helped identify a novel cell death signaling pathway involved in retinal degeneration in an autosomal dominant retinitis pigmentosa model.
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Affiliation(s)
- Jung-Eun Park
- Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Jiyoun Lee
- School of Biopharmaceutical and Medical Sciences, Sungshin University, Seoul, 01133, Republic of Korea
| | - Soonhyuck Ok
- Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Seunghee Byun
- Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Eun-Ju Chang
- Department of Biochemistry and Molecular Biology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
- Biomedical Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea
| | - Sung-Eun Yoon
- Korea Drosophila Resource Center, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Young-Joon Kim
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Min-Ji Kang
- Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea.
- Biomedical Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.
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12
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Shekhar S, Moehlman AT, Park B, Ewnetu M, Tracy C, Titos I, Pawłowski K, Tagliabracci VS, Krämer H. Allnighter pseudokinase-mediated feedback links proteostasis and sleep in Drosophila. Nat Commun 2023; 14:2932. [PMID: 37217484 DOI: 10.1038/s41467-023-38485-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 05/04/2023] [Indexed: 05/24/2023] Open
Abstract
In nervous systems, retrograde signals are key for organizing circuit activity and maintaining neuronal homeostasis. We identify the conserved Allnighter (Aln) pseudokinase as a cell non-autonomous regulator of proteostasis responses necessary for normal sleep and structural plasticity of Drosophila photoreceptors. In aln mutants exposed to extended ambient light, proteostasis is dysregulated and photoreceptors develop striking, but reversible, dysmorphology. The aln gene is widely expressed in different neurons, but not photoreceptors. However, secreted Aln protein is retrogradely endocytosed by photoreceptors. Inhibition of photoreceptor synaptic release reduces Aln levels in lamina neurons, consistent with secreted Aln acting in a feedback loop. In addition, aln mutants exhibit reduced night time sleep, providing a molecular link between dysregulated proteostasis and sleep, two characteristics of ageing and neurodegenerative diseases.
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Affiliation(s)
- Shashank Shekhar
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX; O'Donnell Brain Institute, Dallas, USA.
| | - Andrew T Moehlman
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX; O'Donnell Brain Institute, Dallas, USA
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Brenden Park
- Department of Molecular Biology UT Southwestern Medical Center, Dallas, TX, USA
| | - Michael Ewnetu
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX; O'Donnell Brain Institute, Dallas, USA
| | - Charles Tracy
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX; O'Donnell Brain Institute, Dallas, USA
| | - Iris Titos
- Molecular Medicine Program, University of Utah, School of Medicine, Salt Lake City, UT, USA
| | - Krzysztof Pawłowski
- Department of Molecular Biology UT Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry and Microbiology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, 02-776, Poland
| | - Vincent S Tagliabracci
- Department of Molecular Biology UT Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, Maryland, USA
| | - Helmut Krämer
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX; O'Donnell Brain Institute, Dallas, USA.
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
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13
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Guo X, Mutch M, Torres AY, Nano M, McDonald D, Chen Z, Montell C, Dai W, Montell DJ. Rescue of proteotoxic stress and neurodegeneration by the Zn 2+ transporter ZIP7. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541645. [PMID: 37292980 PMCID: PMC10245811 DOI: 10.1101/2023.05.22.541645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Proteotoxic stress drives numerous degenerative diseases. In response to misfolded proteins, cells adapt by activating the unfolded protein response (UPR), including endoplasmic reticulum-associated protein degradation (ERAD). However persistent stress triggers apoptosis. Enhancing ERAD is a promising therapeutic approach for protein misfolding diseases. From plants to humans, loss of the Zn2+ transporter ZIP7 causes ER stress, however the mechanism is unknown. Here we show that ZIP7 enhances ERAD and that cytosolic Zn2+ is limiting for deubiquitination of client proteins by the Rpn11 Zn2+ metalloproteinase as they enter the proteasome in Drosophila and human cells. ZIP7 overexpression rescues defective vision caused by misfolded rhodopsin in Drosophila. Thus ZIP7 overexpression may prevent diseases caused by proteotoxic stress, and existing ZIP inhibitors may be effective against proteasome-dependent cancers.
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Affiliation(s)
- Xiaoran Guo
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
- present address: Biochemistry Department, Stanford University, Stanford, CA 94305
| | - Morgan Mutch
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
| | - Alba Yurani Torres
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
| | - Maddalena Nano
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
| | - Drew McDonald
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
| | - Zijing Chen
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
| | - Craig Montell
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
| | - Wei Dai
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China
| | - Denise J. Montell
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93110
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14
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Jipa A, Juhász G. Disagreement among the three musketeers of the unfolded protein response. J Cell Biol 2023; 222:e202304013. [PMID: 37052884 PMCID: PMC10114540 DOI: 10.1083/jcb.202304013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Jipa and Juhász preview results from the lab of Tao Wang (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202208147) which show a surprising antagonism between two branches of the unfolded protein response that dictates disease progression in a model of autosomal dominant retinitis pigmentosa.
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Affiliation(s)
- András Jipa
- Institute of Genetics, Biological Research Centre, Szeged, Hungary
| | - Gábor Juhász
- Institute of Genetics, Biological Research Centre, Szeged, Hungary
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
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15
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Zhao N, Li N, Wang T. PERK prevents rhodopsin degradation during retinitis pigmentosa by inhibiting IRE1-induced autophagy. J Cell Biol 2023; 222:e202208147. [PMID: 37022709 PMCID: PMC10082367 DOI: 10.1083/jcb.202208147] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 01/04/2023] [Accepted: 02/14/2023] [Indexed: 04/07/2023] Open
Abstract
Chronic endoplasmic reticulum (ER) stress is the underlying cause of many degenerative diseases, including autosomal dominant retinitis pigmentosa (adRP). In adRP, mutant rhodopsins accumulate and cause ER stress. This destabilizes wild-type rhodopsin and triggers photoreceptor cell degeneration. To reveal the mechanisms by which these mutant rhodopsins exert their dominant-negative effects, we established an in vivo fluorescence reporter system to monitor mutant and wild-type rhodopsin in Drosophila. By performing a genome-wide genetic screen, we found that PERK signaling plays a key role in maintaining rhodopsin homeostasis by attenuating IRE1 activities. Degradation of wild-type rhodopsin is mediated by selective autophagy of ER, which is induced by uncontrolled IRE1/XBP1 signaling and insufficient proteasome activities. Moreover, upregulation of PERK signaling prevents autophagy and suppresses retinal degeneration in the adRP model. These findings establish a pathological role for autophagy in this neurodegenerative condition and indicate that promoting PERK activity could be used to treat ER stress-related neuropathies, including adRP.
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Affiliation(s)
- Ning Zhao
- Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Ning Li
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Tao Wang
- Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- College of Biological Sciences, China Agricultural University, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
- National Institute of Biological Sciences, Beijing, China
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16
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Glashauser J, Camelo C, Hollmann M, Backer W, Jacobs T, Sanchez JI, Schleutker R, Förster D, Berns N, Riechmann V, Luschnig S. Acute manipulation and real-time visualization of membrane trafficking and exocytosis in Drosophila. Dev Cell 2023; 58:709-723.e7. [PMID: 37023749 DOI: 10.1016/j.devcel.2023.03.006] [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: 03/17/2022] [Revised: 01/05/2023] [Accepted: 03/07/2023] [Indexed: 04/08/2023]
Abstract
Intracellular trafficking of secretory proteins plays key roles in animal development and physiology, but so far, tools for investigating the dynamics of membrane trafficking have been limited to cultured cells. Here, we present a system that enables acute manipulation and real-time visualization of membrane trafficking through the reversible retention of proteins in the endoplasmic reticulum (ER) in living multicellular organisms. By adapting the "retention using selective hooks" (RUSH) approach to Drosophila, we show that trafficking of GPI-linked, secreted, and transmembrane proteins can be controlled with high temporal precision in intact animals and cultured organs. We demonstrate the potential of this approach by analyzing the kinetics of ER exit and apical secretion and the spatiotemporal dynamics of tricellular junction assembly in epithelia of living embryos. Furthermore, we show that controllable ER retention enables tissue-specific depletion of secretory protein function. The system is broadly applicable to visualizing and manipulating membrane trafficking in diverse cell types in vivo.
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Affiliation(s)
- Jade Glashauser
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Carolina Camelo
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Manuel Hollmann
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Wilko Backer
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Thea Jacobs
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Jone Isasti Sanchez
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Raphael Schleutker
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Dominique Förster
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Nicola Berns
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Veit Riechmann
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany.
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17
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Zhu Y, Liu L, Zhang C, Zhang C, Han T, Duan R, Jin Y, Guo H, She K, Xiao Y, Goto A, Cai Q, Ji S. Endoplasmic reticulum-associated protein degradation contributes to Toll innate immune defense in Drosophila melanogaster. Front Immunol 2023; 13:1099637. [PMID: 36741393 PMCID: PMC9893508 DOI: 10.3389/fimmu.2022.1099637] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 12/22/2022] [Indexed: 01/20/2023] Open
Abstract
In Drosophila, the endoplasmic reticulum-associated protein degradation (ERAD) is engaged in regulating pleiotropic biological processes, with regard to retinal degeneration, intestinal homeostasis, and organismal development. The extent to which it functions in controlling the fly innate immune defense, however, remains largely unknown. Here, we show that blockade of the ERAD in fat bodies antagonizes the Toll but not the IMD innate immune defense in Drosophila. Genetic approaches further suggest a functional role of Me31B in the ERAD-mediated fly innate immunity. Moreover, we provide evidence that silence of Xbp1 other than PERK or Atf6 partially rescues the immune defects by the dysregulated ERAD in fat bodies. Collectively, our study uncovers an essential function of the ERAD in mediating the Toll innate immune reaction in Drosophila.
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Affiliation(s)
- Yangyang Zhu
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Lei Liu
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Chuchu Zhang
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Chao Zhang
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Tingting Han
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Renjie Duan
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China,School of Preclinical Medicine, Wannan Medical College, Wuhu, Anhui, China
| | - Yiheng Jin
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Huimin Guo
- Center for Biological Technology, Anhui Agricultural University, Hefei, Anhui, China
| | - Kan She
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Yihua Xiao
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China
| | - Akira Goto
- Université de Strasbourg, Centre National de la Recherche Scientifique (CNRS), Insect Models of Innate Immunity (M3I; UPR9022), Strasbourg, France
| | - Qingshuang Cai
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China,Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France,*Correspondence: Qingshuang Cai, ; Shanming Ji,
| | - Shanming Ji
- Center for Developmental Biology, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China,*Correspondence: Qingshuang Cai, ; Shanming Ji,
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18
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Misra S, Buehner NA, Singh A, Wolfner MF. Female factors modulate Sex Peptide's association with sperm in Drosophila melanogaster. BMC Biol 2022; 20:279. [PMID: 36514080 PMCID: PMC9749180 DOI: 10.1186/s12915-022-01465-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 11/15/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Male-derived seminal fluid proteins (SFPs) that enter female fruitflies during mating induce a myriad of physiological and behavioral changes, optimizing fertility of the mating pair. Some post-mating changes in female Drosophila melanogaster persist for ~10-14 days. Their long-term persistence is because the seminal protein that induces these particular changes, the Sex Peptide (SP), is retained long term in females by binding to sperm, with gradual release of its active domain from sperm. Several other "long-term response SFPs" (LTR-SFPs) "prime" the binding of SP to sperm. Whether female factors play a role in this process is unknown, though it is important to study both sexes for a comprehensive physiological understanding of SFP/sperm interactions and for consideration in models of sexual conflict. RESULTS We report here that sperm in male ejaculates bind SP more weakly than sperm that have entered females. Moreover, we show that the amount of SP, and other SFPs, bound to sperm increases with time and transit of individual seminal proteins within the female reproductive tract (FRT). Thus, female contributions are needed for maximal and appropriate binding of SP, and other SFPs, to sperm. Towards understanding the source of female molecular contributions, we ablated spermathecal secretory cells (SSCs) and/or parovaria (female accessory glands), which contribute secretory proteins to the FRT. We found no dramatic change in the initial levels of SP bound to sperm stored in mated females with ablated or defective SSCs and/or parovaria, indicating that female molecules that facilitate the binding of SP to sperm are not uniquely derived from SSCs and parovaria. However, we observed higher levels of SP (and sperm) retention long term in females whose SSCs and parovaria had been ablated, indicating secretions from these female tissues are necessary for the gradual release of Sex Peptide's active region from stored sperm. CONCLUSION This study reveals that the SP-sperm binding pathway is not entirely male-derived and that female contributions are needed to regulate the levels of SP associated with sperm stored in their storage sites.
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Affiliation(s)
- Snigdha Misra
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.,Present address: School of Health Sciences and Technology, University of Petroleum and Energy Studies, Dehradun, UK, 248007, India
| | - Norene A Buehner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Akanksha Singh
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.,Present address: Centre for Life Sciences, Mahindra University, Hyderabad, Telangana, 500043, India
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.
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19
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Martínez Corrales G, Li M, Svermova T, Goncalves A, Voicu D, Dobson AJ, Southall TD, Alic N. Transcriptional memory of dFOXO activation in youth curtails later-life mortality through chromatin remodeling and Xbp1. NATURE AGING 2022; 2:1176-1190. [PMID: 37118537 PMCID: PMC7614430 DOI: 10.1038/s43587-022-00312-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 10/19/2022] [Indexed: 12/03/2022]
Abstract
A transient, homeostatic transcriptional response can result in transcriptional memory, programming subsequent transcriptional outputs. Transcriptional memory has great but unappreciated potential to alter animal ageing as animals encounter a multitude of diverse stimuli throughout their lifespan. Here we show that activating an evolutionarily conserved, longevity-promoting transcription factor, dFOXO, solely in early adulthood of female fruit flies is sufficient to improve their subsequent health and survival in mid- and late life. This youth-restricted dFOXO activation causes persistent changes to chromatin landscape in the fat body and requires chromatin remodellers such as the SWI/SNF and ISWI complexes to program health and longevity. Chromatin remodelling is accompanied by a long-lasting transcriptional programme that is distinct from that observed during acute dFOXO activation and includes induction of Xbp1. We show that this later-life induction of Xbp1 is sufficient to curtail later-life mortality. Our study demonstrates that transcriptional memory can profoundly alter how animals age.
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20
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Roles of ZnT86D in Neurodevelopment and Pathogenesis of Alzheimer Disease in a Drosophila melanogaster Model. Int J Mol Sci 2022; 23:ijms231911832. [PMID: 36233134 PMCID: PMC9569493 DOI: 10.3390/ijms231911832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 11/18/2022] Open
Abstract
Zinc is a fundamental trace element essential for numerous biological processes, and zinc homeostasis is regulated by the Zrt-/Irt-like protein (ZIP) and zinc transporter (ZnT) families. ZnT7 is mainly localized in the Golgi apparatus and endoplasmic reticulum (ER) and transports zinc into these organelles. Although previous studies have reported the role of zinc in animal physiology, little is known about the importance of zinc in the Golgi apparatus and ER in animal development and neurodegenerative diseases. In this study, we demonstrated that ZnT86D, a Drosophila ortholog of ZnT7, plays a pivotal role in the neurodevelopment and pathogenesis of Alzheimer disease (AD). When ZnT86D was silenced in neurons, the embryo-to-adult survival rate, locomotor activity, and lifespan were dramatically reduced. The toxic phenotypes were accompanied by abnormal neurogenesis and neuronal cell death. Furthermore, knockdown of ZnT86D in the neurons of a Drosophila AD model increased apoptosis and exacerbated neurodegeneration without significant changes in the deposition of amyloid beta plaques and susceptibility to oxidative stress. Taken together, our results suggest that an appropriate distribution of zinc in the Golgi apparatus and ER is important for neuronal development and neuroprotection and that ZnT7 is a potential protective factor against AD.
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21
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Dalton HM, Viswanatha R, Brathwaite R, Zuno JS, Berman AR, Rushforth R, Mohr SE, Perrimon N, Chow CY. A genome-wide CRISPR screen identifies DPM1 as a modifier of DPAGT1 deficiency and ER stress. PLoS Genet 2022; 18:e1010430. [PMID: 36166480 PMCID: PMC9543880 DOI: 10.1371/journal.pgen.1010430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/07/2022] [Accepted: 09/14/2022] [Indexed: 11/19/2022] Open
Abstract
Partial loss-of-function mutations in glycosylation pathways underlie a set of rare diseases called Congenital Disorders of Glycosylation (CDGs). In particular, DPAGT1-CDG is caused by mutations in the gene encoding the first step in N-glycosylation, DPAGT1, and this disorder currently lacks effective therapies. To identify potential therapeutic targets for DPAGT1-CDG, we performed CRISPR knockout screens in Drosophila cells for genes associated with better survival and glycoprotein levels under DPAGT1 inhibition. We identified hundreds of candidate genes that may be of therapeutic benefit. Intriguingly, inhibition of the mannosyltransferase Dpm1, or its downstream glycosylation pathways, could rescue two in vivo models of DPAGT1 inhibition and ER stress, even though impairment of these pathways alone usually causes CDGs. While both in vivo models ostensibly cause cellular stress (through DPAGT1 inhibition or a misfolded protein), we found a novel difference in fructose metabolism that may indicate glycolysis as a modulator of DPAGT1-CDG. Our results provide new therapeutic targets for DPAGT1-CDG, include the unique finding of Dpm1-related pathways rescuing DPAGT1 inhibition, and reveal a novel interaction between fructose metabolism and ER stress.
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Affiliation(s)
- Hans M. Dalton
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Raghuvir Viswanatha
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Roderick Brathwaite
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jae Sophia Zuno
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Alexys R. Berman
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Rebekah Rushforth
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Stephanie E. Mohr
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Boston, Massachusetts, United States of America
| | - Clement Y. Chow
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- * E-mail:
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22
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Vitamin A Deficiency Alters the Phototransduction Machinery and Distinct Non-Vision-Specific Pathways in the Drosophila Eye Proteome. Biomolecules 2022; 12:biom12081083. [PMID: 36008977 PMCID: PMC9405971 DOI: 10.3390/biom12081083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/25/2022] Open
Abstract
The requirement of vitamin A for the synthesis of the visual chromophore and the light-sensing pigments has been studied in vertebrate and invertebrate model organisms. To identify the molecular mechanisms that orchestrate the ocular response to vitamin A deprivation, we took advantage of the fact that Drosophila melanogaster predominantly requires vitamin A for vision, but not for development or survival. We analyzed the impacts of vitamin A deficiency on the morphology, the lipidome, and the proteome of the Drosophila eye. We found that chronic vitamin A deprivation damaged the light-sensing compartments and caused a dramatic loss of visual pigments, but also decreased the molar abundance of most phototransduction proteins that amplify and transduce the visual signal. Unexpectedly, vitamin A deficiency also decreased the abundances of specific subunits of mitochondrial TCA cycle and respiratory chain components but increased the levels of cuticle- and lens-related proteins. In contrast, we found no apparent effects of vitamin A deficiency on the ocular lipidome. In summary, chronic vitamin A deficiency decreases the levels of most components of the visual signaling pathway, but also affects molecular pathways that are not vision-specific and whose mechanistic connection to vitamin A remains to be elucidated.
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23
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Gerstner L, Chen M, Kampf LL, Milosavljevic J, Lang K, Schneider R, Hildebrandt F, Helmstädter M, Walz G, Hermle T. Inhibition of endoplasmic reticulum stress signaling rescues cytotoxicity of human apolipoprotein-L1 risk variants in Drosophila. Kidney Int 2022; 101:1216-1231. [PMID: 35120995 PMCID: PMC10061223 DOI: 10.1016/j.kint.2021.12.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 12/10/2021] [Accepted: 12/23/2021] [Indexed: 01/01/2023]
Abstract
Risk variants of the apolipoprotein-L1 (APOL1) gene are associated with severe kidney disease, putting homozygous carriers at risk. Since APOL1 lacks orthologs in all major model organisms, a wide range of mechanisms frequently in conflict have been described for APOL1-associated nephropathies. The genetic toolkit in Drosophila allows unique in vivo insights into disrupted cellular homeostasis. To perform a mechanistic analysis, we expressed human APOL1 control and gain-of-function kidney risk variants in the podocyte-like garland cells of Drosophila nephrocytes and a wing precursor tissue. Expression of APOL1 risk variants was found to elevate endocytic function of garland cell nephrocytes that simultaneously showed early signs of cell death. Wild-type APOL1 had a significantly milder effect, while a control transgene with deletion of the short BH3 domain showed no overt phenotype. Nephrocyte endo-lysosomal function and slit diaphragm architecture remained unaffected by APOL1 risk variants, but endoplasmic reticulum (ER) swelling, chaperone induction, and expression of the reporter Xbp1-EGFP suggested an ER stress response. Pharmacological inhibition of ER stress diminished APOL1-mediated cell death and direct ER stress induction enhanced nephrocyte endocytic function similar to expression of APOL1 risk variants. We confirmed APOL1-dependent ER stress in the Drosophila wing precursor where silencing the IRE1-dependent branch of ER stress signaling by inhibition with Xbp1-RNAi abrogated cell death, representing the first rescue of APOL1-associated cytotoxicity in vivo. Thus, we uncovered ER stress as an essential consequence of APOL1 risk variant expression in vivo in Drosophila, suggesting a central role of this pathway in the pathogenesis of APOL1-associated nephropathies.
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Affiliation(s)
- Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Mengmeng Chen
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Lina L Kampf
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Julian Milosavljevic
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Konrad Lang
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Ronen Schneider
- Renal Division, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Friedhelm Hildebrandt
- Renal Division, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany.
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24
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Myers RR, Sanchez-Garcia J, Leving DC, Melvin RG, Fernandez-Funez P. New Drosophila models to uncover the intrinsic and extrinsic factors that mediate the toxicity of the human prion protein. Dis Model Mech 2022; 15:dmm049184. [PMID: 35142350 PMCID: PMC9093039 DOI: 10.1242/dmm.049184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 02/01/2022] [Indexed: 11/20/2022] Open
Abstract
Misfolding of the prion protein (PrP) is responsible for devastating neurological disorders in humans and other mammals. An unresolved problem in the field is unraveling the mechanisms governing PrP conformational dynamics, misfolding, and the cellular mechanism leading to neurodegeneration. The variable susceptibility of mammals to prion diseases is a natural resource that can be exploited to understand the conformational dynamics of PrP. Here we present a new fly model expressing human PrP with new, robust phenotypes in brain neurons and the eye. By using comparable attP2 insertions, we demonstrated the heightened toxicity of human PrP compared to rodent PrP along with a specific interaction with the amyloid-β peptide. By using this new model, we started to uncover the intrinsic (sequence/structure) and extrinsic (interactions) factors regulating PrP toxicity. We described PERK (officially known as EIF2AK3 in humans) and activating transcription factor 4 (ATF4) as key in the cellular mechanism mediating the toxicity of human PrP and uncover a key new protective activity for 4E-BP (officially known as Thor in Drosophila and EIF4EBP2 in humans), an ATF4 transcriptional target. Lastly, mutations in human PrP (N159D, D167S, N174S) showed partial protective activity, revealing its high propensity to misfold into toxic conformations.
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Affiliation(s)
- Ryan R. Myers
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, MN 55812, USA
| | | | - Daniel C. Leving
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, MN 55812, USA
| | - Richard G. Melvin
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, MN 55812, USA
| | - Pedro Fernandez-Funez
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, MN 55812, USA
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25
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Pumilio protects Xbp1 mRNA from regulated Ire1-dependent decay. Nat Commun 2022; 13:1587. [PMID: 35332141 PMCID: PMC8948244 DOI: 10.1038/s41467-022-29105-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022] Open
Abstract
The unfolded protein response (UPR) maintains homeostasis of the endoplasmic reticulum (ER). Residing in the ER membrane, the UPR mediator Ire1 deploys its cytoplasmic kinase-endoribonuclease domain to activate the key UPR transcription factor Xbp1 through non-conventional splicing of Xbp1 mRNA. Ire1 also degrades diverse ER-targeted mRNAs through regulated Ire1-dependent decay (RIDD), but how it spares Xbp1 mRNA from this decay is unknown. Here, we identify binding sites for the RNA-binding protein Pumilio in the 3′UTR Drosophila Xbp1. In the developing Drosophila eye, Pumilio binds both the Xbp1unspliced and Xbp1spliced mRNAs, but only Xbp1spliced is stabilized by Pumilio. Furthermore, Pumilio displays Ire1 kinase-dependent phosphorylation during ER stress, which is required for its stabilization of Xbp1spliced. hIRE1 can phosphorylate Pumilio directly, and phosphorylated Pumilio protects Xbp1spliced mRNA against RIDD. Thus, Ire1-mediated phosphorylation enables Pumilio to shield Xbp1spliced from RIDD. These results uncover an unexpected regulatory link between an RNA-binding protein and the UPR. In Drosophila, ER-targeted mRNAs are degraded by Ire1-dependent pathway. Here the authors report that the fly mRNA binding protein Pumilio is phosphorylated by Ire1 and binds to Xbp1 mRNA, protecting it from the non-canonical endoribonuclease activity of Ire1.
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26
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iRhom pseudoproteases regulate ER stress-induced cell death through IP 3 receptors and BCL-2. Nat Commun 2022; 13:1257. [PMID: 35273168 PMCID: PMC8913617 DOI: 10.1038/s41467-022-28930-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/17/2022] [Indexed: 12/13/2022] Open
Abstract
The folding capacity of membrane and secretory proteins in the endoplasmic reticulum (ER) can be challenged by physiological and pathological perturbations, causing ER stress. If unresolved, this leads to cell death. We report a role for iRhom pseudoproteases in controlling apoptosis due to persistent ER stress. Loss of iRhoms causes cells to be resistant to ER stress-induced apoptosis. iRhom1 and iRhom2 interact with IP3 receptors, critical mediators of intracellular Ca2+ signalling, and regulate ER stress-induced transport of Ca2+ into mitochondria, a primary trigger of mitochondrial membrane depolarisation and cell death. iRhoms also bind to the anti-apoptotic regulator BCL-2, attenuating the inhibitory interaction between BCL-2 and IP3 receptors, which promotes ER Ca2+ release. The discovery of the participation of iRhoms in the control of ER stress-induced cell death further extends their potential pathological significance to include diseases dependent on protein misfolding and aggregation. Cells that cannot cope with persistent endoplasmic reticulum stress will die. Here, the authors show that iRhom pseudoproteases regulate cell death by modulating the ability of BCL-2 to inhibit calcium flow through IP3R channels.
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27
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Cluster-Based Analysis of Retinitis Pigmentosa Modifiers Using Drosophila Eye Size and Gene Expression Data. Genes (Basel) 2022; 13:genes13020386. [PMID: 35205430 PMCID: PMC8872475 DOI: 10.3390/genes13020386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/08/2022] [Accepted: 02/16/2022] [Indexed: 11/17/2022] Open
Abstract
The goal of this research is to computationally identify candidate modifiers for retinitis pigmentosa (RP), a group of rare genetic disorders that trigger the cellular degeneration of retinal tissue. RP being subject to phenotypic variation complicates diagnosis and treatment of the disease. In a previous study, modifiers of RP were identified by an association between genetic variation in the DNA sequence and variation in eye size in a well-characterized Drosophila model of RP. This study will instead focus on RNA expression data to identify candidate modifier genes whose expression is correlated with phenotypic variation in eye size. The proposed approach uses the K-Means algorithm to cluster 171 Drosophila strains based on their expression profiles for 18,140 genes in adult females. This algorithm is designed to investigate the correlation between Drosophila eye size and genetic expression and gather suspect genes from clusters with abnormally large or small eyes. The clustering algorithm was implemented using the R scripting language and successfully identified 10 suspected candidate modifiers for RP. This analysis was followed by a validation study that tested seven candidate modifiers and found that the loss of five of them significantly altered the degeneration phenotype and thus can be labeled as a bona fide modifier of disease.
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28
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Katow H, Vasudevan D, Ryoo HD. Drosophila Unfolded Protein Response (UPR) Assays In Vitro and In Vivo. Methods Mol Biol 2022; 2378:261-277. [PMID: 34985706 PMCID: PMC9764256 DOI: 10.1007/978-1-0716-1732-8_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Wildtype or mutant proteins expressed beyond the capacity of a cell's protein folding system could be detrimental to general cellular function and survival. In response to misfolded protein overload in the endoplasmic reticulum (ER), eukaryotic cells activate the Unfolded Protein Response (UPR) that helps cells restore protein homeostasis in the endoplasmic reticulum (ER). As part of the UPR, cells attenuate general mRNA translation and activate transcription factors that induce stress-responsive gene expression.UPR signaling draws research interest in part because conditions that cause chronic protein misfolding in the ER or those that impair UPR signaling underlie several diseases including neurodegeneration, diabetes, and cancers. Model organisms are frequently employed in the field as the UPR pathways are generally well-conserved throughout phyla. Here, we introduce experimental procedures to detect UPR in Drosophila melanogaster.
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Affiliation(s)
- Hidetaka Katow
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Deepika Vasudevan
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Hyung Don Ryoo
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA.
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29
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Vasudevan D, Katow H, Huang HW, Tang G, Ryoo HD. A Protein-trap allele reveals roles for Drosophila ATF4 in photoreceptor degeneration, oogenesis and wing development. Dis Model Mech 2021; 15:273766. [PMID: 34919148 PMCID: PMC8938396 DOI: 10.1242/dmm.049119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 12/08/2021] [Indexed: 11/20/2022] Open
Abstract
Metazoans have evolved various quality control mechanisms to cope with cellular stress inflicted by external and physiological conditions. ATF4 is a major effector of the Integrated Stress Response (ISR), an evolutionarily conserved pathway that mediates adaptation to various cellular stressors. Loss of function of Drosophila ATF4, encoded by the gene cryptocephal (crc), results in lethality during pupal development. The roles of crc in Drosophila disease models and in adult tissue homeostasis thus remain poorly understood. Here, we report that a protein-trap MiMIC insertion in the crc locus generates a crc-GFP fusion protein that allows visualization of crc activity in vivo. This allele also acts as a hypomorphic mutant that uncovers previously unknown roles for crc. Specifically, the crc protein-trap line shows crc-GFP induction in a Drosophila model for Retinitis Pigmentosa (RP). This crc allele renders flies more vulnerable to amino acid deprivation and age-dependent retinal degeneration. These mutants also show defects in wing veins and oocyte maturation. Together, our data reveal previously unknown roles for crc in development, cellular homeostasis and photoreceptor survival.
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Affiliation(s)
- Deepika Vasudevan
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA.,Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Hidetaka Katow
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | | | - Grace Tang
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Hyung Don Ryoo
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
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30
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Ochi N, Nakamura M, Nagata R, Wakasa N, Nakano R, Igaki T. Cell competition is driven by Xrp1-mediated phosphorylation of eukaryotic initiation factor 2α. PLoS Genet 2021; 17:e1009958. [PMID: 34871307 PMCID: PMC8675920 DOI: 10.1371/journal.pgen.1009958] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 12/16/2021] [Accepted: 11/19/2021] [Indexed: 12/19/2022] Open
Abstract
Cell competition is a context-dependent cell elimination via cell-cell interaction whereby unfit cells ('losers') are eliminated from the tissue when confronted with fitter cells ('winners'). Despite extensive studies, the mechanism that drives loser's death and its physiological triggers remained elusive. Here, through a genetic screen in Drosophila, we find that endoplasmic reticulum (ER) stress causes cell competition. Mechanistically, ER stress upregulates the bZIP transcription factor Xrp1, which promotes phosphorylation of the eukaryotic translation initiation factor eIF2α via the kinase PERK, leading to cell elimination. Surprisingly, our genetic data show that different cell competition triggers such as ribosomal protein mutations or RNA helicase Hel25E mutations converge on upregulation of Xrp1, which leads to phosphorylation of eIF2α and thus causes reduction in global protein synthesis and apoptosis when confronted with wild-type cells. These findings not only uncover a core pathway of cell competition but also open the way to understanding the physiological triggers of cell competition.
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Affiliation(s)
- Naotaka Ochi
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto, Japan
| | - Mai Nakamura
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto, Japan
| | - Rina Nagata
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto, Japan
| | - Naoki Wakasa
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto, Japan
| | - Ryosuke Nakano
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto, Japan
| | - Tatsushi Igaki
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto, Japan
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31
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Marzano M, Herzmann S, Elsbroek L, Sanal N, Tarbashevich K, Raz E, Krahn MP, Rumpf S. AMPK adapts metabolism to developmental energy requirement during dendrite pruning in Drosophila. Cell Rep 2021; 37:110024. [PMID: 34788610 DOI: 10.1016/j.celrep.2021.110024] [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: 03/15/2021] [Revised: 07/30/2021] [Accepted: 10/28/2021] [Indexed: 10/19/2022] Open
Abstract
To reshape neuronal connectivity in adult stages, Drosophila sensory neurons prune their dendrites during metamorphosis using a genetic degeneration program that is induced by the steroid hormone ecdysone. Metamorphosis is a nonfeeding stage that imposes metabolic constraints on development. We find that AMP-activated protein kinase (AMPK), a regulator of energy homeostasis, is cell-autonomously required for dendrite pruning. AMPK is activated by ecdysone and promotes oxidative phosphorylation and pyruvate usage, likely to enable neurons to use noncarbohydrate metabolites such as amino acids for energy production. Loss of AMPK or mitochondrial deficiency causes specific defects in pruning factor translation and the ubiquitin-proteasome system. Our findings distinguish pruning from pathological neurite degeneration, which is often induced by defects in energy production, and highlight how metabolism is adapted to fit energy-costly developmental transitions.
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Affiliation(s)
- Marco Marzano
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Svende Herzmann
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Leonardo Elsbroek
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Neeraja Sanal
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Katsiaryna Tarbashevich
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, 48149 Münster, Germany
| | - Erez Raz
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, 48149 Münster, Germany
| | - Michael P Krahn
- Department of Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Sebastian Rumpf
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany.
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32
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Yamazoe T, Nakahara Y, Katsube H, Inoue YH. Expression of Human Mutant Preproinsulins Induced Unfolded Protein Response, Gadd45 Expression, JAK-STAT Activation, and Growth Inhibition in Drosophila. Int J Mol Sci 2021; 22:12038. [PMID: 34769468 PMCID: PMC8584581 DOI: 10.3390/ijms222112038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 11/16/2022] Open
Abstract
Mutations in the insulin gene (INS) are frequently associated with human permanent neonatal diabetes mellitus. However, the mechanisms underlying the onset of this genetic disease is not sufficiently decoded. We induced expression of two types of human mutant INSs in Drosophila using its ectopic expression system and investigated the resultant responses in development. Expression of the wild-type preproinsulin in the insulin-producing cells (IPCs) throughout the larval stage led to a stimulation of the overall and wing growth. However, ectopic expression of human mutant preproinsulins, hINSC96Y and hINSLB15YB16delinsH, neither of which secreted from the β-cells, could not stimulate the Drosophila growth. Furthermore, neither of the mutant polypeptides induced caspase activation leading to apoptosis. Instead, they induced expression of several markers indicating the activation of unfolded protein response, such as ER stress-dependent Xbp1 mRNA splicing and ER chaperone induction. We newly found that the mutant polypeptides induced the expression of Growth arrest and DNA-damage-inducible 45 (Gadd45) in imaginal disc cells. ER stress induced by hINSC96Y also activated the JAK-STAT signaling, involved in inflammatory responses. Collectively, we speculate that the diabetes-like growth defects appeared as a consequence of the human mutant preproinsulin expression was involved in dysfunction of the IPCs, rather than apoptosis.
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Affiliation(s)
| | | | | | - Yoshihiro H. Inoue
- Department of Insect Biomedical Research, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-0962, Sakyo, Japan; (T.Y.); (Y.N.); (H.K.)
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33
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Brown B, Mitra S, Roach FD, Vasudevan D, Ryoo HD. The transcription factor Xrp1 is required for PERK-mediated antioxidant gene induction in Drosophila. eLife 2021; 10:74047. [PMID: 34605405 PMCID: PMC8514241 DOI: 10.7554/elife.74047] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 12/13/2022] Open
Abstract
PERK is an endoplasmic reticulum (ER) transmembrane sensor that phosphorylates eIF2α to initiate the Unfolded Protein Response (UPR). eIF2α phosphorylation promotes stress-responsive gene expression most notably through the transcription factor ATF4 that contains a regulatory 5’ leader. Possible PERK effectors other than ATF4 remain poorly understood. Here, we report that the bZIP transcription factor Xrp1 is required for ATF4-independent PERK signaling. Cell-type-specific gene expression profiling in Drosophila indicated that delta-family glutathione-S-transferases (gstD) are prominently induced by the UPR-activating transgene Rh1G69D. Perk was necessary and sufficient for such gstD induction, but ATF4 was not required. Instead, Perk and other regulators of eIF2α phosphorylation regulated Xrp1 protein levels to induce gstDs. The Xrp1 5’ leader has a conserved upstream Open Reading Frame (uORF) analogous to those that regulate ATF4 translation. The gstD-GFP reporter induction required putative Xrp1 binding sites. These results indicate that antioxidant genes are highly induced by a previously unrecognized UPR signaling axis consisting of PERK and Xrp1.
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Affiliation(s)
- Brian Brown
- NYU Grossman School of Medicine, New York, United States
| | - Sahana Mitra
- NYU Grossman School of Medicine, New York, United States
| | | | | | - Hyung Don Ryoo
- NYU Grossman School of Medicine, New York, United States
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34
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Huang HW, Ryoo HD. Drosophila fabp is required for light-dependent Rhodopsin-1 clearance and photoreceptor survival. PLoS Genet 2021; 17:e1009551. [PMID: 34714826 PMCID: PMC8580249 DOI: 10.1371/journal.pgen.1009551] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 11/10/2021] [Accepted: 10/20/2021] [Indexed: 12/30/2022] Open
Abstract
Rhodopsins are light-detecting proteins coupled with retinal chromophores essential for visual function. Coincidentally, dysfunctional Rhodopsin homeostasis underlies retinal degeneration in humans and model organisms. Drosophila ninaEG69D mutant is one such example, where the encoded Rh1 protein imposes endoplasmic reticulum (ER) stress and causes light-dependent retinal degeneration. The underlying reason for such light-dependency remains unknown. Here, we report that Drosophila fatty acid binding protein (fabp) is a gene induced in ninaEG69D/+ photoreceptors, and regulates light-dependent Rhodopsin-1 (Rh1) protein clearance and photoreceptor survival. Specifically, our photoreceptor-specific gene expression profiling study in ninaEG69D/+ flies revealed increased expression of fabp together with other genes that control light-dependent Rh1 protein degradation. fabp induction in ninaEG69D photoreceptors required vitamin A and its transporter genes. In flies reared under light, loss of fabp caused an accumulation of Rh1 proteins in cytoplasmic vesicles. The increase in Rh1 levels under these conditions was dependent on Arrestin2 that mediates feedback inhibition of light-activated Rh1. fabp mutants exhibited light-dependent retinal degeneration, a phenotype also found in other mutants that block light-induced Rh1 degradation. These observations reveal a previously unrecognized link between light-dependent Rh1 proteostasis and the ER-stress imposing ninaEG69D mutant that cause retinal degeneration.
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Affiliation(s)
- Huai-Wei Huang
- Department of Cell Biology NYU Grossman School of Medicine New York, New York, United States of America
| | - Hyung Don Ryoo
- Department of Cell Biology NYU Grossman School of Medicine New York, New York, United States of America
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Liu F, Zhao H, Kong R, Shi L, Li Z, Ma R, Zhao H, Li Z. Derlin-1 and TER94/VCP/p97 are required for intestinal homeostasis. J Genet Genomics 2021; 49:195-207. [PMID: 34547438 DOI: 10.1016/j.jgg.2021.08.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/15/2021] [Accepted: 08/19/2021] [Indexed: 12/30/2022]
Abstract
Adult stem cells are critical for the maintenance of residential tissue homeostasis and functions. However, the roles of cellular protein homeostasis maintenance in stem cell proliferation and tissue homeostasis are not fully understood. Here, we find that Derlin-1 and TER94/VCP/p97, components of the ER-associated degradation (ERAD) pathway, restrain intestinal stem cell proliferation to maintain intestinal homeostasis in adult Drosophila. Depleting any of them results in increased stem cell proliferation and midgut homeostasis disruption. Derlin-1 is specifically expressed in the ER of progenitors and its C-terminus is required for its function. Interestingly, we find that increased stem cell proliferation is resulted from elevated ROS levels and activated JNK signaling in Derlin-1- or TER94-deficient progenitors. Further removal of ROS or inhibition of JNK signaling almost completely suppressed increased stem cell proliferation. Together, these data demonstrate that the ERAD pathway is critical for stem cell proliferation and tissue homeostasis. Thus we provide insights into our understanding of the mechanisms underlying cellular protein homeostasis maintenance (ER protein quality control) in tissue homeostasis and tumor development.
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Affiliation(s)
- Fuli Liu
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Hang Zhao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ruiyan Kong
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Lin Shi
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Zhengran Li
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Rui Ma
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Huiqing Zhao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Zhouhua Li
- College of Life Sciences, Capital Normal University, Beijing 100048, China.
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Mitra S, Ryoo HD. The role of Ire1 in Drosophila eye pigmentation revealed by an RNase dead allele. Dev Biol 2021; 478:205-211. [PMID: 34265355 DOI: 10.1016/j.ydbio.2021.07.008] [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: 04/17/2021] [Revised: 06/25/2021] [Accepted: 07/10/2021] [Indexed: 11/29/2022]
Abstract
Ire1 is an endoplasmic reticulum (ER) transmembrane RNase that cleaves substrate mRNAs to help cells adapt to ER stress. Because there are cell types with physiological ER stress, loss of Ire1 results in metabolic and developmental defects in diverse organisms. In Drosophila, Ire1 mutants show developmental defects at early larval stages and in pupal eye photoreceptor differentiation. These Drosophila studies relied on a single Ire1 loss of function allele with a Piggybac insertion in the coding sequence. Here, we report that an Ire1 allele with a specific impairment in the RNase domain, H890A, unmasks previously unrecognized Ire1 phenotypes in Drosophila eye pigmentation. Specifically, we found that the adult eye pigmentation is altered, and the pigment granules are compromised in Ire1H890A homozygous mosaic eyes. Furthermore, the Ire1H890A mutant eyes had dramatically reduced Rhodopsin-1 protein levels. Drosophila eye pigment granules are most notably associated with late endosome/lysosomal defects. Our results indicate that the loss of Ire1, which would impair ER homeostasis, also results in altered adult eye pigmentation.
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Affiliation(s)
- Sahana Mitra
- Department of Cell Biology, NYU Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Hyung Don Ryoo
- Department of Cell Biology, NYU Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA.
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Joy J, Barrio L, Santos-Tapia C, Romão D, Giakoumakis NN, Clemente-Ruiz M, Milán M. Proteostasis failure and mitochondrial dysfunction leads to aneuploidy-induced senescence. Dev Cell 2021; 56:2043-2058.e7. [PMID: 34216545 DOI: 10.1016/j.devcel.2021.06.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 03/03/2021] [Accepted: 06/11/2021] [Indexed: 01/10/2023]
Abstract
Aneuploidy, an unbalanced number of chromosomes, is highly deleterious at the cellular level and leads to senescence, a stress-induced response characterized by permanent cell-cycle arrest and a well-defined associated secretory phenotype. Here, we use a Drosophila epithelial model to delineate the pathway that leads to the induction of senescence as a consequence of the acquisition of an aneuploid karyotype. Whereas aneuploidy induces, as a result of gene dosage imbalance, proteotoxic stress and activation of the major protein quality control mechanisms, near-saturation functioning of autophagy leads to compromised mitophagy, accumulation of dysfunctional mitochondria, and the production of radical oxygen species (ROS). We uncovered a role of c-Jun N-terminal kinase (JNK) in driving senescence as a consequence of dysfunctional mitochondria and ROS. We show that activation of the major protein quality control mechanisms and mitophagy dampens the deleterious effects of aneuploidy, and we identify a role of senescence in proteostasis and compensatory proliferation for tissue repair.
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Affiliation(s)
- Jery Joy
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Lara Barrio
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Celia Santos-Tapia
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Daniela Romão
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Nikolaos Nikiforos Giakoumakis
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Marta Clemente-Ruiz
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Marco Milán
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010 Barcelona, Spain.
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Sorge S, Theelke J, Yildirim K, Hertenstein H, McMullen E, Müller S, Altbürger C, Schirmeier S, Lohmann I. ATF4-Induced Warburg Metabolism Drives Over-Proliferation in Drosophila. Cell Rep 2021; 31:107659. [PMID: 32433968 DOI: 10.1016/j.celrep.2020.107659] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 01/30/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022] Open
Abstract
The mitochondrial electron transport chain (ETC) enables essential metabolic reactions; nonetheless, the cellular responses to defects in mitochondria and the modulation of signaling pathway outputs are not understood. We show that Notch signaling and ETC attenuation via knockdown of COX7a induces massive over-proliferation. The tumor-like growth is caused by a transcriptional response through the eIF2α-kinase PERK and ATF4, which activates the expression of metabolic enzymes, nutrient transporters, and mitochondrial chaperones. We find this stress adaptation to be beneficial for progenitor cell fitness, as it renders cells sensitive to proliferation induced by the Notch signaling pathway. Intriguingly, over-proliferation is not caused by transcriptional cooperation of Notch and ATF4, but it is mediated in part by pH changes resulting from the Warburg metabolism induced by ETC attenuation. Our results suggest that ETC function is monitored by the PERK-ATF4 pathway, which can be hijacked by growth-promoting signaling pathways, leading to oncogenic pathway activity.
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Affiliation(s)
- Sebastian Sorge
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Jonas Theelke
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Kerem Yildirim
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Helen Hertenstein
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Ellen McMullen
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Stephan Müller
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | | | - Stefanie Schirmeier
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Ingrid Lohmann
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany.
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The Uncovered Function of the Drosophila GBA1a-Encoded Protein. Cells 2021; 10:cells10030630. [PMID: 33809074 PMCID: PMC8000066 DOI: 10.3390/cells10030630] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 12/25/2022] Open
Abstract
Human GBA1 encodes lysosomal acid β-glucocerebrosidase (GCase), which hydrolyzes cleavage of the beta-glucosidic linkage of glucosylceramide (GlcCer). Mutations in this gene lead to reduced GCase activity, accumulation of glucosylceramide and glucosylsphingosine, and development of Gaucher disease (GD). Drosophila melanogaster has two GBA1 orthologs. Thus far, GBA1b was documented as a bone fide GCase-encoding gene, while the role of GBA1a encoded protein remained unclear. In the present study, we characterized a mutant variant of the fly GBA1a, which underwent ERAD and mildly activated the UPR machinery. RNA-seq analyses of homozygous mutant flies revealed upregulation of inflammation-associated as well as of cell-cycle related genes and reduction in programmed cell death (PCD)-associated genes, which was confirmed by qRT-PCR. We also observed compromised cell death in the midgut of homozygous larvae and a reduction in pupation. Our results strongly indicated that GBA1a-encoded protein plays a role in midgut maturation during larvae development.
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Giannios P, Casanova J. Systemic and local effect of the Drosophila headcase gene and its role in stress protection of Adult Progenitor Cells. PLoS Genet 2021; 17:e1009362. [PMID: 33556132 PMCID: PMC7895379 DOI: 10.1371/journal.pgen.1009362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/19/2021] [Accepted: 01/13/2021] [Indexed: 12/17/2022] Open
Abstract
During the development of a holometabolous insect such as Drosophila, specific group of cells in the larva survive during metamorphosis, unlike the other larval cells, and finally give rise to the differentiated adult structures. These cells, also known as Adult Progenitor Cells (APCs), maintain their multipotent capacity, differentially respond to hormonal and nutritional signals, survive the intrinsic and environmental stress and respond to the final differentiation cues. However, not much is known about the specific molecular mechanisms that account for their unique characteristics. Here we show that a specific Drosophila APC gene, headcase (hdc), has a dual role in the normal development of these cells. It acts at a systemic level by controlling the hormone ecdysone in the prothoracic gland and at the same time it acts locally as a tissue growth suppressor in the APC clusters, where it modulates the activity of the TOR pathway and promotes their survival by contributing in the regulation of the Unfolded Protein Response. We also show that hdc provides protection against stress in the APCs and that its ectopic expression in cells that do not usually express hdc can confer these cells with an additional stress protection. Hdc is the founding member of a group of homolog proteins identified from C. elegans to humans, where has been found associated with cancer progression. The finding that the Drosophila hdc is specifically expressed in progenitor cells and that it provides protection against stress opens up a new hypothesis to be explored regarding the role of the human Heca and its contribution to carcinogenesis.
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Affiliation(s)
- Panagiotis Giannios
- Institut de Biologia Molecular de Barcelona (CSIC), Barcelona, Catalonia, Spain
- Institut de Recerca Biomèdica de Barcelona, (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Jordi Casanova
- Institut de Biologia Molecular de Barcelona (CSIC), Barcelona, Catalonia, Spain
- Institut de Recerca Biomèdica de Barcelona, (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
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Xu J, Taubert S. Beyond Proteostasis: Lipid Metabolism as a New Player in ER Homeostasis. Metabolites 2021; 11:52. [PMID: 33466824 PMCID: PMC7830277 DOI: 10.3390/metabo11010052] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/04/2021] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Biological membranes are not only essential barriers that separate cellular and subcellular structures, but also perform other critical functions such as the initiation and propagation of intra- and intercellular signals. Each membrane-delineated organelle has a tightly regulated and custom-made membrane lipid composition that is critical for its normal function. The endoplasmic reticulum (ER) consists of a dynamic membrane network that is required for the synthesis and modification of proteins and lipids. The accumulation of unfolded proteins in the ER lumen activates an adaptive stress response known as the unfolded protein response (UPR-ER). Interestingly, recent findings show that lipid perturbation is also a direct activator of the UPR-ER, independent of protein misfolding. Here, we review proteostasis-independent UPR-ER activation in the genetically tractable model organism Caenorhabditis elegans. We review the current knowledge on the membrane lipid composition of the ER, its impact on organelle function and UPR-ER activation, and its potential role in human metabolic diseases. Further, we summarize the bi-directional interplay between lipid metabolism and the UPR-ER. We discuss recent progress identifying the different respective mechanisms by which disturbed proteostasis and lipid bilayer stress activate the UPR-ER. Finally, we consider how genetic and metabolic disturbances may disrupt ER homeostasis and activate the UPR and discuss how using -omics-type analyses will lead to more comprehensive insights into these processes.
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Affiliation(s)
- Jiaming Xu
- Graduate Program in Cell and Developmental Biology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, BC V5Z 4H4, Canada
- Healthy Starts Theme, British Columbia Children’s Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
| | - Stefan Taubert
- Graduate Program in Cell and Developmental Biology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, BC V5Z 4H4, Canada
- Healthy Starts Theme, British Columbia Children’s Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC V5Z 4H4, Canada
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Meep, a Novel Regulator of Insulin Signaling, Supports Development and Insulin Sensitivity via Maintenance of Protein Homeostasis in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2020; 10:4399-4410. [PMID: 32998936 PMCID: PMC7718763 DOI: 10.1534/g3.120.401688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Insulin signaling is critical for developmental growth and adult homeostasis, yet the downstream regulators of this signaling pathway are not completely understood. Using the model organism Drosophila melanogaster, we took a genomic approach to identify novel mediators of insulin signaling. These studies led to the identification of Meep, encoded by the gene CG32335. Expression of this gene is both insulin receptor- and diet-dependent. We found that Meep was specifically required in the developing fat body to tolerate a high-sugar diet (HSD). Meep is not essential on a control diet, but when reared on an HSD, knockdown of meep causes hyperglycemia, reduced growth, developmental delay, pupal lethality, and reduced longevity. These phenotypes stem in part from Meep’s role in promoting insulin sensitivity and protein stability. This work suggests a critical role for protein homeostasis in development during overnutrition. Because Meep is conserved and obesity-associated in mammals, future studies on Meep may help to understand the role of proteostasis in insulin-resistant type 2 diabetes.
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Martínez BA, Hoyle RG, Yeudall S, Granade ME, Harris TE, Castle JD, Leitinger N, Bland ML. Innate immune signaling in Drosophila shifts anabolic lipid metabolism from triglyceride storage to phospholipid synthesis to support immune function. PLoS Genet 2020; 16:e1009192. [PMID: 33227003 PMCID: PMC7721134 DOI: 10.1371/journal.pgen.1009192] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 12/07/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
During infection, cellular resources are allocated toward the metabolically-demanding processes of synthesizing and secreting effector proteins that neutralize and kill invading pathogens. In Drosophila, these effectors are antimicrobial peptides (AMPs) that are produced in the fat body, an organ that also serves as a major lipid storage depot. Here we asked how activation of Toll signaling in the larval fat body perturbs lipid homeostasis to understand how cells meet the metabolic demands of the immune response. We find that genetic or physiological activation of fat body Toll signaling leads to a tissue-autonomous reduction in triglyceride storage that is paralleled by decreased transcript levels of the DGAT homolog midway, which carries out the final step of triglyceride synthesis. In contrast, Kennedy pathway enzymes that synthesize membrane phospholipids are induced. Mass spectrometry analysis revealed elevated levels of major phosphatidylcholine and phosphatidylethanolamine species in fat bodies with active Toll signaling. The ER stress mediator Xbp1 contributed to the Toll-dependent induction of Kennedy pathway enzymes, which was blunted by deleting AMP genes, thereby reducing secretory demand elicited by Toll activation. Consistent with ER stress induction, ER volume is expanded in fat body cells with active Toll signaling, as determined by transmission electron microscopy. A major functional consequence of reduced Kennedy pathway induction is an impaired immune response to bacterial infection. Our results establish that Toll signaling induces a shift in anabolic lipid metabolism to favor phospholipid synthesis and ER expansion that may serve the immediate demand for AMP synthesis and secretion but with the long-term consequence of insufficient nutrient storage.
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Affiliation(s)
- Brittany A. Martínez
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Rosalie G. Hoyle
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Scott Yeudall
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
- Medical Scientist Training Program, University of Virginia, Charlottesville, VA, United States of America
| | - Mitchell E. Granade
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Thurl E. Harris
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - J. David Castle
- Department of Cell Biology, University of Virginia, Charlottesville, VA, United States of America
| | - Norbert Leitinger
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Michelle L. Bland
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
- * E-mail:
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Xu J, Zhao H, Wang T. Suppression of retinal degeneration by two novel ERAD ubiquitin E3 ligases SORDD1/2 in Drosophila. PLoS Genet 2020; 16:e1009172. [PMID: 33137101 PMCID: PMC7660902 DOI: 10.1371/journal.pgen.1009172] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 11/12/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations in the gene rhodopsin are one of the major causes of autosomal dominant retinitis pigmentosa (adRP). Mutant forms of Rhodopsin frequently accumulate in the endoplasmic reticulum (ER), cause ER stress, and trigger photoreceptor cell degeneration. Here, we performed a genome-wide screen to identify suppressors of retinal degeneration in a Drosophila model of adRP, carrying a point mutation in the major rhodopsin, Rh1 (Rh1G69D). We identified two novel E3 ubiquitin ligases SORDD1 and SORDD2 that effectively suppressed Rh1G69D-induced photoreceptor dysfunction and retinal degeneration. SORDD1/2 promoted the ubiquitination and degradation of Rh1G69D through VCP (valosin containing protein) and independent of processes reliant on the HRD1 (HMG-CoA reductase degradation protein 1)/HRD3 complex. We further demonstrate that SORDD1/2 and HRD1 function in parallel and in a redundant fashion to maintain rhodopsin homeostasis and integrity of photoreceptor cells. These findings identify a new ER-associated protein degradation (ERAD) pathway and suggest that facilitating SORDD1/2 function may be a therapeutic strategy to treat adRP. Misfolded rhodopsins accumulated in endoplasmic reticulum (ER) could disrupt the homeostasis of the ER and cause ER stress. Chronic ER stress would finally lead to photoreceptor cell death and retinal degeneration. To diminish the stress and sustain homeostasis cells develop alternative strategies to clear the misfolded rhodopsins. Previous studies have suggested that ubiquitin E3 ligase HRD1 is involved in the degradation of misfolded rhodopsins. In this study, we define novel ubiquitin E3 ligase SORDD1/2 based on a genetic screen and demonstrate that SORDD1/2 promotes the degradation of misfolded rhodopsins through ER-associated degradation (ERAD) pathway. Furthermore, we demonstrate that SORDD1/2 function independently of HRD1 in misfolded rhodopsins degradation. We also show SORDD1/2 and HRD1 play redundant roles in rhodopsin homeostasis. Finally, we demonstrate that SORDD1 works well in a Drosophila disease model. Our studies identify a novel ERAD pathway that acts in parallel to HRD1, and suggest that SORDD1 is a good candidate therapeutic target.
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Affiliation(s)
- Jaiwei Xu
- College of Biological Sciences, China Agricultural University, China
- National Institute of Biological Sciences, China
| | - Haifang Zhao
- National Institute of Biological Sciences, China
| | - Tao Wang
- National Institute of Biological Sciences, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, China
- * E-mail:
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Park JE, Trần TXT, Park N, Yeom J, Kim K, Kang MJ. The Function of Drosophila USP14 in Endoplasmic Reticulum Stress and Retinal Degeneration in a Model for Autosomal Dominant Retinitis Pigmentosa. BIOLOGY 2020; 9:biology9100332. [PMID: 33053617 PMCID: PMC7650538 DOI: 10.3390/biology9100332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 11/29/2022]
Abstract
Simple Summary The present study shows the role of Drosophila USP14 under ER stress and ER stress related disease, autosomal dominant retinitis pigmentosa. Drosophila USP14 protects cell from ER stress triggered by ER stress-causing chemicals Drosophila S2 cells and suppresses the retinal degeneration in disease model for retinitis pigmentosa by regulating the stability of Rhodopsin-1. This study also indicates the dynamic reorganization of proteasome complex under ER stress. The modulation of USP14 could be a potential therapeutic strategy for treating the diseases associated with protein folding. Abstract Endoplasmic reticulum (ER) stress and its adaptive cellular response, the unfolded protein response (UPR), are involved in various diseases including neurodegenerative diseases, metabolic diseases, and even cancers. Here, we analyzed the novel function of ubiquitin-specific peptidase 14 (USP14) in ER stress. The overexpression of Drosophila USP14 protected the cells from ER stress without affecting the proteasomal activity. Null Hong Kong (NHK) and alpha-1-antitrypsin Z (ATZ) are ER-associated degradation substrates. The degradation of NHK, but not of ATZ, was delayed by USP14. USP14 restored the levels of rhodopsin-1 protein in a Drosophila model for autosomal dominant retinitis pigmentosa and suppressed the retinal degeneration in this model. In addition, we observed that proteasome complex is dynamically reorganized in response to ER stress in human 293T cells. These findings suggest that USP14 may be a therapeutic strategy in diseases associated with ER stress.
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Affiliation(s)
- Jung-Eun Park
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (J.-E.P.); (T.X.T.T.); (N.P.)
| | - Thị Xuân Thùy Trần
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (J.-E.P.); (T.X.T.T.); (N.P.)
| | - Nayoung Park
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (J.-E.P.); (T.X.T.T.); (N.P.)
| | - Jeonghun Yeom
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88-gil, 43 Olympic-ro, Songpa-gu, Seoul 05505, Korea; (J.Y.); (K.K.)
| | - Kyunggon Kim
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88-gil, 43 Olympic-ro, Songpa-gu, Seoul 05505, Korea; (J.Y.); (K.K.)
| | - Min-Ji Kang
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (J.-E.P.); (T.X.T.T.); (N.P.)
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, 88-gil, 43 Olympic-ro, Songpa-gu, Seoul 05505, Korea; (J.Y.); (K.K.)
- Correspondence:
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Vasudevan D, Neuman SD, Yang A, Lough L, Brown B, Bashirullah A, Cardozo T, Ryoo HD. Translational induction of ATF4 during integrated stress response requires noncanonical initiation factors eIF2D and DENR. Nat Commun 2020; 11:4677. [PMID: 32938929 PMCID: PMC7495428 DOI: 10.1038/s41467-020-18453-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 08/17/2020] [Indexed: 01/25/2023] Open
Abstract
The Integrated Stress Response (ISR) helps metazoan cells adapt to cellular stress by limiting the availability of initiator methionyl-tRNA for translation. Such limiting conditions paradoxically stimulate the translation of ATF4 mRNA through a regulatory 5' leader sequence with multiple upstream Open Reading Frames (uORFs), thereby activating stress-responsive gene expression. Here, we report the identification of two critical regulators of such ATF4 induction, the noncanonical initiation factors eIF2D and DENR. Loss of eIF2D and DENR in Drosophila results in increased vulnerability to amino acid deprivation, susceptibility to retinal degeneration caused by endoplasmic reticulum (ER) stress, and developmental defects similar to ATF4 mutants. eIF2D requires its RNA-binding motif for regulation of 5' leader-mediated ATF4 translation. Consistently, eIF2D and DENR deficient human cells show impaired ATF4 protein induction in response to ER stress. Altogether, our findings indicate that eIF2D and DENR are critical mediators of ATF4 translational induction and stress responses in vivo.
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Affiliation(s)
- Deepika Vasudevan
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Sarah D Neuman
- Department of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Amy Yang
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Lea Lough
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Brian Brown
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Arash Bashirullah
- Department of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Timothy Cardozo
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Hyung Don Ryoo
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, 10016, USA.
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Lottes EN, Cox DN. Homeostatic Roles of the Proteostasis Network in Dendrites. Front Cell Neurosci 2020; 14:264. [PMID: 33013325 PMCID: PMC7461941 DOI: 10.3389/fncel.2020.00264] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/28/2020] [Indexed: 12/13/2022] Open
Abstract
Cellular protein homeostasis, or proteostasis, is indispensable to the survival and function of all cells. Distinct from other cell types, neurons are long-lived, exhibiting architecturally complex and diverse multipolar projection morphologies that can span great distances. These properties present unique demands on proteostatic machinery to dynamically regulate the neuronal proteome in both space and time. Proteostasis is regulated by a distributed network of cellular processes, the proteostasis network (PN), which ensures precise control of protein synthesis, native conformational folding and maintenance, and protein turnover and degradation, collectively safeguarding proteome integrity both under homeostatic conditions and in the contexts of cellular stress, aging, and disease. Dendrites are equipped with distributed cellular machinery for protein synthesis and turnover, including dendritically trafficked ribosomes, chaperones, and autophagosomes. The PN can be subdivided into an adaptive network of three major functional pathways that synergistically govern protein quality control through the action of (1) protein synthesis machinery; (2) maintenance mechanisms including molecular chaperones involved in protein folding; and (3) degradative pathways (e.g., Ubiquitin-Proteasome System (UPS), endolysosomal pathway, and autophagy. Perturbations in any of the three arms of proteostasis can have dramatic effects on neurons, especially on their dendrites, which require tightly controlled homeostasis for proper development and maintenance. Moreover, the critical importance of the PN as a cell surveillance system against protein dyshomeostasis has been highlighted by extensive work demonstrating that the aggregation and/or failure to clear aggregated proteins figures centrally in many neurological disorders. While these studies demonstrate the relevance of derangements in proteostasis to human neurological disease, here we mainly review recent literature on homeostatic developmental roles the PN machinery plays in the establishment, maintenance, and plasticity of stable and dynamic dendritic arbors. Beyond basic housekeeping functions, we consider roles of PN machinery in protein quality control mechanisms linked to dendritic plasticity (e.g., dendritic spine remodeling during LTP); cell-type specificity; dendritic morphogenesis; and dendritic pruning.
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Affiliation(s)
- Erin N Lottes
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Daniel N Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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Adames TR, Rondeau NC, Kabir MT, Johnston BA, Truong H, Snow JW. The IRE1 pathway regulates honey bee Unfolded Protein Response gene expression. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 121:103368. [PMID: 32229172 DOI: 10.1016/j.ibmb.2020.103368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 03/05/2020] [Accepted: 03/24/2020] [Indexed: 06/10/2023]
Abstract
Our molecular understanding of honey bee cellular stress responses is incomplete. Previously, we sought to identify and began functional characterization of the components of the Unfolded Protein Response (UPR) in honey bees. We observed that UPR stimulation resulted in induction of target genes upon IRE1 pathway activation, as assessed by splicing of Xbp1 mRNA. However, we were not able to determine the relative role of the various UPR pathways in gene activation. Our understanding of honey bee signal transduction and transcriptional regulation has been hampered by a lack of tools. After using RNA-seq to expand the known UPR targets in the honey bee, we used the Drosophila melanogaster S2 cell line and honey bee trans and cis elements to investigate the role of the IRE1 pathway in the transcriptional activation of one of these targets, the honey bee Hsc70-3 gene. Using a luciferase reporter, we show that honey bee Hsc70 promoter activity is inducible by UPR activation. In addition, we show that this activation is IRE1-dependent and relies on specific cis regulatory elements. Experiments using exogenous honey bee or fruit fly XBP1S proteins demonstrate that both factors can activate the Hsc70-3 promoter and further support a role for the IRE1 pathway in control of Hsc70-3 expression in the honey bee. By providing foundational knowledge about the UPR in the honey bee and demonstrating the usefulness of a heterologous cell line for molecular characterization of honey bee pathways, this work stands to improve our understanding of this critical species.
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Affiliation(s)
| | | | | | - Brittany A Johnston
- Biology Department, The City College of New York - CUNY, New York, NY, 10031, USA
| | - Henry Truong
- Biology Department, Barnard College, New York, NY, 10027, USA
| | - Jonathan W Snow
- Biology Department, Barnard College, New York, NY, 10027, USA.
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Lewy TG, Offerdahl DK, Grabowski JM, Kellman E, Mlera L, Chiramel A, Bloom ME. PERK-Mediated Unfolded Protein Response Signaling Restricts Replication of the Tick-Borne Flavivirus Langat Virus. Viruses 2020; 12:v12030328. [PMID: 32197325 PMCID: PMC7150897 DOI: 10.3390/v12030328] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/05/2020] [Accepted: 03/13/2020] [Indexed: 02/07/2023] Open
Abstract
The unfolded protein response (UPR) maintains protein-folding homeostasis in the endoplasmic reticulum (ER) and has been implicated as both beneficial and detrimental to flavivirus infection. Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), a sensor of the UPR, is commonly associated with antiviral effects during mosquito-borne flavivirus (MBFV) infection, but its relation to tick-borne flavivirus (TBFV) infection remains largely unexplored. In this study, we identified changes in UPR and autophagic activity during Langat virus (LGTV) infection. LGTV robustly activated UPR and altered autophagic flux. Knockdown of endogenous PERK in human cells resulted in increased LGTV replication, but not that of closely related Powassan virus (POWV). Finally, on examining changes in protein levels of components associated with UPR and autophagy in the absence of PERK, we could show that LGTV-infected cells induced UPR but did not lead to expression of C/EBP homologous protein (CHOP), an important downstream transcription factor of multiple stress pathways. From these data, we hypothesize that LGTV can antagonize other kinases that target eukaryotic initiation factor 2α (eIF2α), but not PERK, implicating PERK as a potential mediator of intrinsic immunity. This effect was not apparent for POWV, a more pathogenic TBFV, suggesting it may be better equipped to mitigate the antiviral effects of PERK.
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Affiliation(s)
- Tyler G. Lewy
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID/NIH, 903 S. 4th St, Hamilton, MT 59840, USA; (T.G.L.); (D.K.O.); (E.K.); (L.M.)
| | - Danielle K. Offerdahl
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID/NIH, 903 S. 4th St, Hamilton, MT 59840, USA; (T.G.L.); (D.K.O.); (E.K.); (L.M.)
| | - Jeffrey M. Grabowski
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID/NIH, 903 S. 4th St, Hamilton, MT 59840, USA; (T.G.L.); (D.K.O.); (E.K.); (L.M.)
- Correspondence: (J.M.G.); (M.E.B.); Tel.: +1-406-375-9789 (J.M.G.); +1-406-375-9707 (M.E.B.)
| | - Eliza Kellman
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID/NIH, 903 S. 4th St, Hamilton, MT 59840, USA; (T.G.L.); (D.K.O.); (E.K.); (L.M.)
| | - Luwanika Mlera
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID/NIH, 903 S. 4th St, Hamilton, MT 59840, USA; (T.G.L.); (D.K.O.); (E.K.); (L.M.)
| | - Abhilash Chiramel
- Innate Immunity and Pathogenesis Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID/NIH, 903 S. 4th St, Hamilton, MT 59840, USA;
| | - Marshall E. Bloom
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID/NIH, 903 S. 4th St, Hamilton, MT 59840, USA; (T.G.L.); (D.K.O.); (E.K.); (L.M.)
- Correspondence: (J.M.G.); (M.E.B.); Tel.: +1-406-375-9789 (J.M.G.); +1-406-375-9707 (M.E.B.)
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Reduced SERCA Function Preferentially Affects Wnt Signaling by Retaining E-Cadherin in the Endoplasmic Reticulum. Cell Rep 2020; 26:322-329.e3. [PMID: 30625314 PMCID: PMC6338334 DOI: 10.1016/j.celrep.2018.12.049] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 11/14/2018] [Accepted: 12/11/2018] [Indexed: 12/31/2022] Open
Abstract
Calcium homeostasis in the lumen of the endoplasmic reticulum is required for correct processing and trafficking of transmembrane proteins, and defects in protein trafficking can impinge on cell signaling pathways. We show here that mutations in the endoplasmic reticulum calcium pump SERCA disrupt Wingless signaling by sequestering Armadillo/β-catenin away from the signaling pool. Armadillo remains bound to E-cadherin, which is retained in the endoplasmic reticulum when calcium levels there are reduced. Using hypomorphic and null SERCA alleles in combination with the loss of the plasma membrane calcium channel Orai allowed us to define three distinct thresholds of endoplasmic reticulum calcium. Wingless signaling is sensitive to even a small reduction, while Notch and Hippo signaling are disrupted at intermediate levels, and elimination of SERCA function results in apoptosis. These differential and opposing effects on three oncogenic signaling pathways may complicate the use of SERCA inhibitors as cancer therapeutics. Suisse and Treisman describe genetic conditions that reduce calcium in the endoplasmic reticulum to three distinct extents. They find that Wnt signaling is more sensitive to changes in calcium levels than the Notch and Hippo pathways, potentially complicating the use of calcium pump inhibitors as cancer therapeutics.
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