51
|
Perrotta I. ER-phagy in human atherosclerosis: an exploratory ultrastructural study. Ultrastruct Pathol 2020; 44:489-495. [PMID: 33118423 DOI: 10.1080/01913123.2020.1840468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Autophagy is a vacuolar self-digesting mechanism responsible for the removal of damaged organelles, indigestible aggregates, and nonfunctional long-lived proteins by lysosome. Autophagy is dynamically connected to the endoplasmic reticulum (ER) in several ways. It is capable to counteract the possible harmful effects linked to the impairment of protein folding in the ER; the ER has been proposed as the source for autophagosomal membranes. Also, the ER itself can undergo a selective form of autophagy (called ER-phagy) which ensures the maintenance of ER's morphology and function. Autophagy has been widely investigated in the cardiovascular system however there is no evidence to date regarding the occurrence of ER-phagy into the blood vessel wall. This study has been undertaken to explore the existence of this selective control mechanism in the cells of human atherosclerotic plaques. Transmission Electron Microscopy (TEM) analysis revealed that in the plaque cells the smooth ER profiles reorganized into concentric whorls and closely packed membranes arranged in curved and parallel arrays. Circular, often ring-shaped, ER membranes studded with ribosomes and enclosed in a sequestering vesicle have been also frequently observed. This preliminary study demonstrates the existence of a distinct machinery for the specific turnover of ER membranes in human atherosclerosis and provides the first ultrastructural description of ER-phagy in the diseased vascular tissue. These results may open new perspectives for future investigation in the cardiovascular field.
Collapse
Affiliation(s)
- Ida Perrotta
- Centre for Microscopy and Microanalysis, Transmission Electron Microscopy Laboratory - Department of Biology, Ecology and Earth Sciences (Di.B.E.S.T.), University of Calabria , Cosenza, Italy
| |
Collapse
|
52
|
Ren Q, Brenner R, Boothby TC, Zhang Z. Membrane and lipid metabolism plays an important role in desiccation resistance in the yeast Saccharomyces cerevisiae. BMC Microbiol 2020; 20:338. [PMID: 33167888 PMCID: PMC7653879 DOI: 10.1186/s12866-020-02025-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/28/2020] [Indexed: 12/23/2022] Open
Abstract
Background Anhydrobiotes, such as the yeast Saccharomyces cerevisiae, are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis. Results In this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, decrease of lipid droplets, decrease in mitochondrial cristae and increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis. Conclusion Our study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondrial cristae coupled with a decrease in lipid droplets is indicative of a cellular response to reduce the production of reactive oxygen species.
Collapse
Affiliation(s)
- Qun Ren
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Ave, Laramie, WY, 82071, USA
| | - Rebecca Brenner
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Ave, Laramie, WY, 82071, USA
| | - Thomas C Boothby
- Department of Molecular Biology, University of Wyoming, Laramie, WY, 82071, USA
| | - Zhaojie Zhang
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Ave, Laramie, WY, 82071, USA.
| |
Collapse
|
53
|
Abstract
Autophagy is an adaptive catabolic process functioning to promote cell survival in the event of inappropriate living conditions such as nutrient shortage and to cope with diverse cytotoxic insults. It is regarded as one of the key survival mechanisms of living organisms. Cells undergo autophagy to accomplish the lysosomal digestion of intracellular materials including damaged proteins, organelles, and foreign bodies, in a bulk, non-selective or a cargo-specific manner. Studies in the past decades have shed light on the association of autophagy pathways with various diseases and also highlighted the therapeutic value of autophagy modulation. Hence, it is crucial to develop effective approaches for monitoring intracellular autophagy dynamics, as a comprehensive account of methodology establishment is far from complete. In this review, we aim to provide an overview of the major current fluorescence-based techniques utilized for visualizing, sensing or measuring autophagic activities in cells or tissues, which are categorized firstly by targets detected and further by the types of fluorescence tools. We will mainly focus on the working mechanisms of these techniques, put emphasis on the insight into their roles in biomedical science and provide perspectives on the challenges and future opportunities in this field.
Collapse
Affiliation(s)
- Siyang Ding
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne Victoria 3086, Australia.
| | | |
Collapse
|
54
|
Xu W, Ocak U, Gao L, Tu S, Lenahan CJ, Zhang J, Shao A. Selective autophagy as a therapeutic target for neurological diseases. Cell Mol Life Sci 2020; 78:1369-1392. [PMID: 33067655 PMCID: PMC7904548 DOI: 10.1007/s00018-020-03667-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 09/03/2020] [Accepted: 10/05/2020] [Indexed: 12/12/2022]
Abstract
The neurological diseases primarily include acute injuries, chronic neurodegeneration, and others (e.g., infectious diseases of the central nervous system). Autophagy is a housekeeping process responsible for the bulk degradation of misfolded protein aggregates and damaged organelles through the lysosomal machinery. Recent studies have suggested that autophagy, particularly selective autophagy, such as mitophagy, pexophagy, ER-phagy, ribophagy, lipophagy, etc., is closely implicated in neurological diseases. These forms of selective autophagy are controlled by a group of important proteins, including PTEN-induced kinase 1 (PINK1), Parkin, p62, optineurin (OPTN), neighbor of BRCA1 gene 1 (NBR1), and nuclear fragile X mental retardation-interacting protein 1 (NUFIP1). This review highlights the characteristics and underlying mechanisms of different types of selective autophagy, and their implications in various forms of neurological diseases.
Collapse
Affiliation(s)
- Weilin Xu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Umut Ocak
- Department of Emergency Medicine, Bursa Yuksek Ihtisas Training and Research Hospital, University of Health Sciences, 16310, Bursa, Turkey.,Department of Emergency Medicine, Bursa City Hospital, 16110, Bursa, Turkey
| | - Liansheng Gao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Sheng Tu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310009, Zhejiang, China
| | | | - Jianmin Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China. .,Brain Research Institute, Zhejiang University, Hangzhou, China. .,Collaborative Innovation Center for Brain Science, Zhejiang University, Hangzhou, China.
| | - Anwen Shao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| |
Collapse
|
55
|
Chadwick WL, Biswas SK, Bianco S, Chan YHM. Non-random distribution of vacuoles in Schizosaccharomyces pombe. Phys Biol 2020; 17:065004. [PMID: 33035200 DOI: 10.1088/1478-3975/aba510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A central question in eukaryotic cell biology asks, during cell division, how is the growth and distribution of organelles regulated to ensure each daughter cell receives an appropriate amount. For vacuoles in budding yeast, there are well described organelle-to-cell size scaling trends as well as inheritance mechanisms involving highly coordinated movements. It is unclear whether such mechanisms are necessary in the symmetrically dividing fission yeast, Schizosaccharomyces pombe, in which random partitioning may be utilized to distribute vacuoles to daughter cells. To address the increasing need for high-throughput analysis, we are augmenting existing semi-automated image processing by developing fully automated machine learning methods for locating vacuoles and segmenting fission yeast cells from brightfield and fluorescence micrographs. All strains studied show qualitative correlations in vacuole-to-cell size scaling trends, i.e. vacuole volume, surface area, and number all increase with cell size. Furthermore, increasing vacuole number was found to be a consistent mechanism for the increase in total vacuole size in the cell. Vacuoles are not distributed evenly throughout the cell with respect to available cytoplasm. Rather, vacuoles show distinct peaks in distribution close to the nucleus, and this preferential localization was confirmed in mutants in which nucleus position is perturbed. Disruption of microtubules leads to quantitative changes in both vacuole size scaling trends and distribution patterns, indicating the microtubule cytoskeleton is a key mechanism for maintaining vacuole structure.
Collapse
Affiliation(s)
- William L Chadwick
- Department of Biology, San Francisco State University, San Francisco, CA, United States of America. Center for Cellular Construction, San Francisco Bay Area, CA, United States of America
| | | | | | | |
Collapse
|
56
|
Garcia EJ, Liao PC, Tan G, Vevea JD, Sing CN, Tsang CA, McCaffery JM, Boldogh IR, Pon LA. Membrane dynamics and protein targets of lipid droplet microautophagy during ER stress-induced proteostasis in the budding yeast, Saccharomyces cerevisiae. Autophagy 2020. [PMID: 33021864 DOI: 10.1080/15548627.2020.1826691.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022] Open
Abstract
Our previous studies reveal a mechanism for lipid droplet (LD)-mediated proteostasis in the endoplasmic reticulum (ER) whereby unfolded proteins that accumulate in the ER in response to lipid imbalance-induced ER stress are removed by LDs and degraded by microlipophagy (µLP), autophagosome-independent LD uptake into the vacuole (the yeast lysosome). Here, we show that dithiothreitol- or tunicamycin-induced ER stress also induces µLP and identify an unexpected role for vacuolar membrane dynamics in this process. All stressors studied induce vacuolar fragmentation prior to µLP. Moreover, during µLP, fragmented vacuoles fuse to form cup-shaped structures that encapsulate and ultimately take up LDs. Our studies also indicate that proteins of the endosome sorting complexes required for transport (ESCRT) are upregulated, required for µLP, and recruited to LDs, vacuolar membranes, and sites of vacuolar membrane scission during µLP. We identify possible target proteins for LD-mediated ER proteostasis. Our live-cell imaging studies reveal that one potential target (Nup159) localizes to punctate structures that colocalizes with LDs 1) during movement from ER membranes to the cytosol, 2) during microautophagic uptake into vacuoles, and 3) within the vacuolar lumen. Finally, we find that mutations that inhibit LD biogenesis, homotypic vacuolar membrane fusion or ESCRT function inhibit stress-induced autophagy of Nup159 and other ER proteins. Thus, we have obtained the first direct evidence that LDs and µLP can mediate ER stress-induced ER proteostasis, and identified direct roles for ESCRT and vacuolar membrane fusion in that process.
Collapse
Affiliation(s)
- Enrique J Garcia
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Pin-Chao Liao
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Gary Tan
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Jason D Vevea
- HHMI and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA
| | - Cierra N Sing
- Institute of Human Nutrition, Columbia University, New York, NY, USA
| | - Catherine A Tsang
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - J Michael McCaffery
- Integrated Imaging Center, Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Istvan R Boldogh
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Liza A Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| |
Collapse
|
57
|
Garcia EJ, Liao PC, Tan G, Vevea JD, Sing CN, Tsang CA, McCaffery JM, Boldogh IR, Pon LA. Membrane dynamics and protein targets of lipid droplet microautophagy during ER stress-induced proteostasis in the budding yeast, Saccharomyces cerevisiae. Autophagy 2020; 17:2363-2383. [PMID: 33021864 PMCID: PMC8496710 DOI: 10.1080/15548627.2020.1826691] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Our previous studies reveal a mechanism for lipid droplet (LD)-mediated proteostasis in the endoplasmic reticulum (ER) whereby unfolded proteins that accumulate in the ER in response to lipid imbalance-induced ER stress are removed by LDs and degraded by microlipophagy (µLP), autophagosome-independent LD uptake into the vacuole (the yeast lysosome). Here, we show that dithiothreitol- or tunicamycin-induced ER stress also induces µLP and identify an unexpected role for vacuolar membrane dynamics in this process. All stressors studied induce vacuolar fragmentation prior to µLP. Moreover, during µLP, fragmented vacuoles fuse to form cup-shaped structures that encapsulate and ultimately take up LDs. Our studies also indicate that proteins of the endosome sorting complexes required for transport (ESCRT) are upregulated, required for µLP, and recruited to LDs, vacuolar membranes, and sites of vacuolar membrane scission during µLP. We identify possible target proteins for LD-mediated ER proteostasis. Our live-cell imaging studies reveal that one potential target (Nup159) localizes to punctate structures that colocalizes with LDs 1) during movement from ER membranes to the cytosol, 2) during microautophagic uptake into vacuoles, and 3) within the vacuolar lumen. Finally, we find that mutations that inhibit LD biogenesis, homotypic vacuolar membrane fusion or ESCRT function inhibit stress-induced autophagy of Nup159 and other ER proteins. Thus, we have obtained the first direct evidence that LDs and µLP can mediate ER stress-induced ER proteostasis, and identified direct roles for ESCRT and vacuolar membrane fusion in that process.
Collapse
Affiliation(s)
- Enrique J Garcia
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Pin-Chao Liao
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Gary Tan
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Jason D Vevea
- HHMI and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA
| | - Cierra N Sing
- Institute of Human Nutrition, Columbia University, New York, NY, USA
| | - Catherine A Tsang
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - J Michael McCaffery
- Integrated Imaging Center, Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Istvan R Boldogh
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Liza A Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| |
Collapse
|
58
|
COPII mitigates ER stress by promoting formation of ER whorls. Cell Res 2020; 31:141-156. [PMID: 32989223 PMCID: PMC8026990 DOI: 10.1038/s41422-020-00416-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/28/2020] [Indexed: 12/19/2022] Open
Abstract
Cells mitigate ER stress through the unfolded protein response (UPR). Here, we report formation of ER whorls as an effector mechanism of the ER stress response. We found that strong ER stress induces formation of ER whorls, which contain ER-resident proteins such as the Sec61 complex and PKR-like ER kinase (PERK). ER whorl formation is dependent on PERK kinase activity and is mediated by COPII machinery, which facilitates ER membrane budding to form tubular-vesicular ER whorl precursors. ER whorl precursors then go through Sec22b-mediated fusion to form ER whorls. We further show that ER whorls contribute to ER stress-induced translational inhibition by possibly modulating PERK activity and by sequestering translocons in a ribosome-free environment. We propose that formation of ER whorls reflects a new type of ER stress response that controls inhibition of protein translation.
Collapse
|
59
|
Snf1 AMPK positively regulates ER-phagy via expression control of Atg39 autophagy receptor in yeast ER stress response. PLoS Genet 2020; 16:e1009053. [PMID: 32986716 PMCID: PMC7544123 DOI: 10.1371/journal.pgen.1009053] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 10/08/2020] [Accepted: 08/14/2020] [Indexed: 12/13/2022] Open
Abstract
Autophagy is a fundamental process responsible for degradation and recycling of intracellular contents. In the budding yeast, non-selective macroautophagy and microautophagy of the endoplasmic reticulum (ER) are caused by ER stress, the circumstance where aberrant proteins accumulate in the ER. The more recent study showed that protein aggregation in the ER initiates ER-selective macroautophagy, referred to as ER-phagy; however, the mechanisms by which ER stress induces ER-phagy have not been fully elucidated. Here, we show that the expression levels of ATG39, encoding an autophagy receptor specific for ER-phagy, are significantly increased under ER-stressed conditions. ATG39 upregulation in ER stress response is mediated by activation of its promoter, which is positively regulated by Snf1 AMP-activated protein kinase (AMPK) and negatively by Mig1 and Mig2 transcriptional repressors. In response to ER stress, Snf1 promotes nuclear export of Mig1 and Mig2. Our results suggest that during ER stress response, Snf1 mediates activation of the ATG39 promoter and consequently facilitates ER-phagy by negatively regulating Mig1 and Mig2.
Collapse
|
60
|
Imaging-Based Reporter Systems to Define CVB-Induced Membrane Remodeling in Living Cells. Viruses 2020; 12:v12101074. [PMID: 32992749 PMCID: PMC7600424 DOI: 10.3390/v12101074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 08/19/2020] [Accepted: 09/23/2020] [Indexed: 11/16/2022] Open
Abstract
Enteroviruses manipulate host membranes to form replication organelles, which concentrate viral and host factors to allow for efficient replication. However, this process has not been well-studied in living cells throughout the course of infection. To define the dynamic process of enterovirus membrane remodeling of major secretory pathway organelles, we have developed plasmid-based reporter systems that utilize viral protease-dependent release of a nuclear-localized fluorescent protein from the endoplasmic reticulum (ER) membrane during infection, while retaining organelle-specific fluorescent protein markers such as the ER and Golgi. This system thus allows for the monitoring of organelle-specific changes induced by infection in real-time. Using long-term time-lapse imaging of living cells infected with coxsackievirus B3 (CVB), we detected reporter translocation to the nucleus beginning ~4 h post-infection, which correlated with a loss of Golgi integrity and a collapse of the peripheral ER. Lastly, we applied our system to study the effects of a calcium channel inhibitor, 2APB, on virus-induced manipulation of host membranes. We found that 2APB treatment had no effect on the kinetics of infection or the percentage of infected cells. However, we observed aberrant ER structures in CVB-infected cells treated with 2APB and a significant decrease in viral-dependent cell lysis, which corresponded with a decrease in extracellular virus titers. Thus, our system provides a tractable platform to monitor the effects of inhibitors, gene silencing, and/or gene editing on viral manipulation of host membranes, which can help determine the mechanism of action for antivirals.
Collapse
|
61
|
Lee C, Lamech L, Johns E, Overholtzer M. Selective Lysosome Membrane Turnover Is Induced by Nutrient Starvation. Dev Cell 2020; 55:289-297.e4. [PMID: 32916093 DOI: 10.1016/j.devcel.2020.08.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/02/2020] [Accepted: 08/17/2020] [Indexed: 12/20/2022]
Abstract
Lysosome function is essential for cellular homeostasis, but quality-control mechanisms that maintain healthy lysosomes remain poorly characterized. Here, we developed a method to measure lysosome turnover and use this to identify a selective mechanism of membrane degradation that involves lipidation of the autophagy protein LC3 onto lysosomal membranes and the formation of intraluminal vesicles through microautophagy. This mechanism is induced in response to metabolic stress resulting from glucose starvation or by treatment with pharmacological agents that induce osmotic stress on lysosomes. Cells lacking ATG5, an essential component of the LC3 lipidation machinery, show reduced ability to regulate lysosome size and degradative capacity in response to activation of this mechanism. These findings identify a selective mechanism of lysosome membrane turnover that is induced by stress and uncover a function for LC3 lipidation in regulating lysosome size and activity through microautophagy.
Collapse
Affiliation(s)
- Chan Lee
- Cell Biology Program, Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA; BCMB Allied Program, Weill Cornell Medical College, New York, NY 10065, USA
| | - Lilian Lamech
- Cell Biology Program, Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA
| | - Eleanor Johns
- Cell Biology Program, Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA; Louis V. Gerstner, Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Michael Overholtzer
- Cell Biology Program, Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA; BCMB Allied Program, Weill Cornell Medical College, New York, NY 10065, USA; Louis V. Gerstner, Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| |
Collapse
|
62
|
Schuck S. Microautophagy - distinct molecular mechanisms handle cargoes of many sizes. J Cell Sci 2020; 133:133/17/jcs246322. [PMID: 32907930 DOI: 10.1242/jcs.246322] [Citation(s) in RCA: 195] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Autophagy is fundamental for cell and organismal health. Two types of autophagy are conserved in eukaryotes: macroautophagy and microautophagy. During macroautophagy, autophagosomes deliver cytoplasmic constituents to endosomes or lysosomes, whereas during microautophagy lytic organelles take up cytoplasm directly. While macroautophagy has been investigated extensively, microautophagy has received much less attention. Nonetheless, it has become clear that microautophagy has a broad range of functions in biosynthetic transport, metabolic adaptation, organelle remodeling and quality control. This Review discusses the selective and non-selective microautophagic processes known in yeast, plants and animals. Based on the molecular mechanisms for the uptake of microautophagic cargo into lytic organelles, I propose to distinguish between fission-type microautophagy, which depends on ESCRT proteins, and fusion-type microautophagy, which requires the core autophagy machinery and SNARE proteins. Many questions remain to be explored, but the functional versatility and mechanistic diversity of microautophagy are beginning to emerge.
Collapse
Affiliation(s)
- Sebastian Schuck
- Center for Molecular Biology of Heidelberg University (ZMBH), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| |
Collapse
|
63
|
Zhao D, Zou CX, Liu XM, Jiang ZD, Yu ZQ, Suo F, Du TY, Dong MQ, He W, Du LL. A UPR-Induced Soluble ER-Phagy Receptor Acts with VAPs to Confer ER Stress Resistance. Mol Cell 2020; 79:963-977.e3. [PMID: 32735772 DOI: 10.1016/j.molcel.2020.07.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/01/2020] [Accepted: 07/20/2020] [Indexed: 01/07/2023]
Abstract
Autophagic degradation of the endoplasmic reticulum (ER-phagy) is triggered by ER stress in diverse organisms. However, molecular mechanisms governing ER stress-induced ER-phagy remain insufficiently understood. Here we report that ER stress-induced ER-phagy in the fission yeast Schizosaccharomyces pombe requires Epr1, a soluble Atg8-interacting ER-phagy receptor. Epr1 localizes to the ER through interacting with integral ER membrane proteins VAPs. Bridging an Atg8-VAP association is the main ER-phagy role of Epr1, as it can be bypassed by an artificial Atg8-VAP tether. VAPs contribute to ER-phagy not only by tethering Atg8 to the ER membrane, but also by maintaining the ER-plasma membrane contact. Epr1 is upregulated during ER stress by the unfolded protein response (UPR) regulator Ire1. Loss of Epr1 reduces survival against ER stress. Conversely, increasing Epr1 expression suppresses the ER-phagy defect and ER stress sensitivity of cells lacking Ire1. Our findings expand and deepen the molecular understanding of ER-phagy.
Collapse
Affiliation(s)
- Dan Zhao
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Chen-Xi Zou
- College of Life Sciences, Beijing Normal University, 100875 Beijing, China; National Institute of Biological Sciences, 102206 Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Zhong-Qiu Yu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Fang Suo
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Tong-Yang Du
- College of Life Sciences, Beijing Normal University, 100875 Beijing, China; National Institute of Biological Sciences, 102206 Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, 102206 Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
| | - Wanzhong He
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, 102206 Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China.
| |
Collapse
|
64
|
Kurokawa Y, Konishi R, Yoshida A, Tomioku K, Tanabe K, Fujita A. Microautophagy in the yeast vacuole depends on the activities of phosphatidylinositol 4-kinases, Stt4p and Pik1p. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183416. [PMID: 32726584 DOI: 10.1016/j.bbamem.2020.183416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 07/10/2020] [Accepted: 07/12/2020] [Indexed: 12/30/2022]
Abstract
Morphologically, the lipophagy in yeast cell mimics microautophagy, which includes a direct amendment of the vacuolar membrane that engulfs lipid droplets (LDs). The molecular mechanism of the membrane modifications that elicits microautophagy still remains elusive. In this study, an analysis of membrane lipid distribution at a nanoscale level showed that PtdIns(4)P is localized in the cytoplasmic leaflet of microautophagic vesicles, which are derived when the vacuole's membrane domains engulfed LDs both in the stationary phase and in acute nitrogen starvation. Furthermore, the PtdIns(4)P-positive raft-like domains engulf LDs through a microautophagic mechanism. When single temperature-conditional mutants of STT4 or PIK1 PtdIns 4-kinases were used, in the vacuole of STT4 and PIK1 mutant cells, microautophagic vesicles drastically decreased at restrictive temperatures, and the labeling density of PtdIns(4)P on the microautophagic vesicles and the sizes of the mutants' microautophagic vesicles also decreased. These results suggest that both Stt4p and Pik1p have important roles in the microautophagy of the vacuole in the stationary phase and under nitrogen starvation conditions.
Collapse
Affiliation(s)
- Yuna Kurokawa
- Department of Molecular and Cell Biology and Biochemistry, Basic Veterinary Science, Faculty of Veterinary Medicine, Kagoshima University, Korimoto 1-21-24, Kagoshima 890-0065, Japan
| | - Rikako Konishi
- Department of Molecular and Cell Biology and Biochemistry, Basic Veterinary Science, Faculty of Veterinary Medicine, Kagoshima University, Korimoto 1-21-24, Kagoshima 890-0065, Japan
| | - Akane Yoshida
- Department of Molecular and Cell Biology and Biochemistry, Basic Veterinary Science, Faculty of Veterinary Medicine, Kagoshima University, Korimoto 1-21-24, Kagoshima 890-0065, Japan
| | - Kanna Tomioku
- Department of Molecular and Cell Biology and Biochemistry, Basic Veterinary Science, Faculty of Veterinary Medicine, Kagoshima University, Korimoto 1-21-24, Kagoshima 890-0065, Japan
| | - Kenji Tanabe
- Medical Research Institute, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Akikazu Fujita
- Department of Molecular and Cell Biology and Biochemistry, Basic Veterinary Science, Faculty of Veterinary Medicine, Kagoshima University, Korimoto 1-21-24, Kagoshima 890-0065, Japan.
| |
Collapse
|
65
|
Goldsmith J, Marsh T, Asthana S, Leidal AM, Suresh D, Olshen A, Debnath J. Ribosome profiling reveals a functional role for autophagy in mRNA translational control. Commun Biol 2020; 3:388. [PMID: 32681145 PMCID: PMC7367890 DOI: 10.1038/s42003-020-1090-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 06/19/2020] [Indexed: 01/09/2023] Open
Abstract
Autophagy promotes protein degradation, and therefore has been proposed to maintain amino acid pools to sustain protein synthesis during metabolic stress. To date, how autophagy influences the protein synthesis landscape in mammalian cells remains unclear. Here, we utilize ribosome profiling to delineate the effects of genetic ablation of the autophagy regulator, ATG12, on translational control. In mammalian cells, genetic loss of autophagy does not impact global rates of cap dependent translation, even under starvation conditions. Instead, autophagy supports the translation of a subset of mRNAs enriched for cell cycle control and DNA damage repair. In particular, we demonstrate that autophagy enables the translation of the DNA damage repair protein BRCA2, which is functionally required to attenuate DNA damage and promote cell survival in response to PARP inhibition. Overall, our findings illuminate that autophagy impacts protein translation and shapes the protein landscape.
Collapse
Affiliation(s)
- Juliet Goldsmith
- Department of Pathology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Timothy Marsh
- Department of Pathology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Saurabh Asthana
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, 94158, USA
- Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Andrew M Leidal
- Department of Pathology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Deepthisri Suresh
- Department of Pathology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Adam Olshen
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, 94158, USA
- Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Jayanta Debnath
- Department of Pathology, University of California San Francisco, San Francisco, CA, 94143, USA.
- Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, 94158, USA.
| |
Collapse
|
66
|
Ho N, Yap WS, Xu J, Wu H, Koh JH, Goh WWB, George B, Chong SC, Taubert S, Thibault G. Stress sensor Ire1 deploys a divergent transcriptional program in response to lipid bilayer stress. J Cell Biol 2020; 219:e201909165. [PMID: 32349127 PMCID: PMC7337508 DOI: 10.1083/jcb.201909165] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/26/2020] [Accepted: 04/07/2020] [Indexed: 12/11/2022] Open
Abstract
Membrane integrity at the endoplasmic reticulum (ER) is tightly regulated, and its disturbance is implicated in metabolic diseases. Using an engineered sensor that activates the unfolded protein response (UPR) exclusively when normal ER membrane lipid composition is compromised, we identified pathways beyond lipid metabolism that are necessary to maintain ER integrity in yeast and in C. elegans. To systematically validate yeast mutants that disrupt ER membrane homeostasis, we identified a lipid bilayer stress (LBS) sensor in the UPR transducer protein Ire1, located at the interface of the amphipathic and transmembrane helices. Furthermore, transcriptome and chromatin immunoprecipitation analyses pinpoint the UPR as a broad-spectrum compensatory response wherein LBS and proteotoxic stress deploy divergent transcriptional UPR programs. Together, these findings reveal the UPR program as the sum of two independent stress responses, an insight that could be exploited for future therapeutic intervention.
Collapse
Affiliation(s)
- Nurulain Ho
- Lipid Regulation and Cell Stress Group, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Wei Sheng Yap
- Lipid Regulation and Cell Stress Group, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Jiaming Xu
- Centre for Molecular Medicine and Therapeutics, British Columbia Children’s Hospital Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Haoxi Wu
- Lipid Regulation and Cell Stress Group, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Jhee Hong Koh
- Lipid Regulation and Cell Stress Group, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Wilson Wen Bin Goh
- Bio-Data Science and Education Research Group, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Bhawana George
- Lipid Regulation and Cell Stress Group, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Shu Chen Chong
- Lipid Regulation and Cell Stress Group, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Stefan Taubert
- Centre for Molecular Medicine and Therapeutics, British Columbia Children’s Hospital Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Guillaume Thibault
- Lipid Regulation and Cell Stress Group, School of Biological Sciences, Nanyang Technological University, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore
| |
Collapse
|
67
|
Bello-Perez M, Sola I, Novoa B, Klionsky DJ, Falco A. Canonical and Noncanonical Autophagy as Potential Targets for COVID-19. Cells 2020; 9:E1619. [PMID: 32635598 PMCID: PMC7408018 DOI: 10.3390/cells9071619] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
The SARS-CoV-2 pandemic necessitates a review of the molecular mechanisms underlying cellular infection by coronaviruses, in order to identify potential therapeutic targets against the associated new disease (COVID-19). Previous studies on its counterparts prove a complex and concomitant interaction between coronaviruses and autophagy. The precise manipulation of this pathway allows these viruses to exploit the autophagy molecular machinery while avoiding its protective apoptotic drift and cellular innate immune responses. In turn, the maneuverability margins of such hijacking appear to be so narrow that the modulation of the autophagy, regardless of whether using inducers or inhibitors (many of which are FDA-approved for the treatment of other diseases), is usually detrimental to viral replication, including SARS-CoV-2. Recent discoveries indicate that these interactions stretch into the still poorly explored noncanonical autophagy pathway, which might play a substantial role in coronavirus replication. Still, some potential therapeutic targets within this pathway, such as RAB9 and its interacting proteins, look promising considering current knowledge. Thus, the combinatory treatment of COVID-19 with drugs affecting both canonical and noncanonical autophagy pathways may be a turning point in the fight against this and other viral infections, which may also imply beneficial prospects of long-term protection.
Collapse
Affiliation(s)
- Melissa Bello-Perez
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autónoma de Madrid, Darwin 3, 28049 Madrid, Spain; (M.B.-P.); (I.S.)
| | - Isabel Sola
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autónoma de Madrid, Darwin 3, 28049 Madrid, Spain; (M.B.-P.); (I.S.)
| | - Beatriz Novoa
- Institute of Marine Research (IIM), National Research Council (CSIC), 36208 Vigo, Spain;
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Alberto Falco
- Institute of Research, Development, and Innovation in Healthcare Biotechnology in Elche (IDiBE), Miguel Hernández University (UMH), 03202 Elche, Spain
| |
Collapse
|
68
|
Mookherjee D, Das S, Mukherjee R, Bera M, Jana SC, Chakrabarti S, Chakrabarti O. RETREG1/FAM134B mediated autophagosomal degradation of AMFR/GP78 and OPA1 -a dual organellar turnover mechanism. Autophagy 2020; 17:1729-1752. [PMID: 32559118 DOI: 10.1080/15548627.2020.1783118] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Turnover of cellular organelles, including endoplasmic reticulum (ER) and mitochondria, is orchestrated by an efficient cellular surveillance system. We have identified a mechanism for dual regulation of ER and mitochondria under stress. It is known that AMFR, an ER E3 ligase and ER-associated degradation (ERAD) regulator, degrades outer mitochondrial membrane (OMM) proteins, MFNs (mitofusins), via the proteasome and triggers mitophagy. We show that destabilized mitochondria are almost devoid of the OMM and generate "mitoplasts". This brings the inner mitochondrial membrane (IMM) in the proximity of the ER. When AMFR levels are high and the mitochondria are stressed, the reticulophagy regulatory protein RETREG1 participates in the formation of the mitophagophore by interacting with OPA1. Interestingly, OPA1 and other IMM proteins exhibit similar RETREG1-dependent autophagosomal degradation as AMFR, unlike most of the OMM proteins. The "mitoplasts" generated are degraded by reticulo-mito-phagy - simultaneously affecting dual organelle turnover.Abbreviations: AMFR/GP78: autocrine motility factor receptor; BAPTA: 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; BFP: blue fluorescent protein; CCCP: carbonyl cyanide m-chlorophenyl hydrazone; CNBr: cyanogen bromide; ER: endoplasmic reticulum; ERAD: endoplasmic-reticulum-associated protein degradation; FL: fluorescence, GFP: green fluorescent protein; HA: hemagglutinin; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; IMM: inner mitochondrial membrane; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MFN: mitofusin, MGRN1: mahogunin ring finger 1; NA: numerical aperature; OMM: outer mitochondrial membrane; OPA1: OPA1 mitochondrial dynamin like GTPase; PRNP/PrP: prion protein; RER: rough endoplasmic reticulum; RETREG1/FAM134B: reticulophagy regulator 1; RFP: red fluorescent protein; RING: really interesting new gene; ROI: region of interest; RTN: reticulon; SEM: standard error of the mean; SER: smooth endoplasmic reticulum; SIM: structured illumination microscopy; SQSTM1/p62: sequestosome 1; STED: stimulated emission depletion; STOML2: stomatin like 2; TOMM20: translocase of outer mitochondrial membrane 20; UPR: unfolded protein response.
Collapse
Affiliation(s)
- Debdatto Mookherjee
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
| | - Subhrangshu Das
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Rukmini Mukherjee
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India.,Buchmann Institute for Molecular Life Sciences, Frankfurt Am Main, Germany
| | - Manindra Bera
- Laboratory of Cell Biology, the Rockefeller University, New York, USA
| | | | - Saikat Chakrabarti
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Oishee Chakrabarti
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India.,Homi Bhabha National Institute, Mumbai, India
| |
Collapse
|
69
|
Bo Otto F, Thumm M. Nucleophagy-Implications for Microautophagy and Health. Int J Mol Sci 2020; 21:ijms21124506. [PMID: 32599961 PMCID: PMC7352367 DOI: 10.3390/ijms21124506] [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: 06/04/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 12/12/2022] Open
Abstract
Nucleophagy, the selective subtype of autophagy that targets nuclear material for autophagic degradation, was not only shown to be a model system for the study of selective macroautophagy, but also for elucidating the role of the core autophagic machinery within microautophagy. Nucleophagy also emerged as a system associated with a variety of disease conditions including cancer, neurodegeneration and ageing. Nucleophagic processes are part of natural cell development, but also act as a response to various stress conditions. Upon releasing small portions of nuclear material, micronuclei, the autophagic machinery transfers these micronuclei to the vacuole for subsequent degradation. Despite sharing many cargos and requiring the core autophagic machinery, recent investigations revealed the aspects that set macro- and micronucleophagy apart. Central to the discrepancies found between macro- and micronucleophagy is the nucleus vacuole junction, a large membrane contact site formed between nucleus and vacuole. Exclusion of nuclear pore complexes from the junction and its exclusive degradation by micronucleophagy reveal compositional differences in cargo. Regarding their shared reliance on the core autophagic machinery, micronucleophagy does not involve normal autophagosome biogenesis observed for macronucleophagy, but instead maintains a unique role in overall microautophagy, with the autophagic machinery accumulating at the neck of budding vesicles.
Collapse
|
70
|
Higuchi-Sanabria R, Shen K, Kelet N, Frankino PA, Durieux J, Bar-Ziv R, Sing CN, Garcia EJ, Homentcovschi S, Sanchez M, Wu R, Tronnes SU, Joe L, Webster B, Ahilon-Jeronimo A, Monshietehadi S, Dallarda S, Pender C, Pon LA, Zoncu R, Dillin A. Lysosomal recycling of amino acids affects ER quality control. SCIENCE ADVANCES 2020; 6:eaaz9805. [PMID: 32637599 PMCID: PMC7319768 DOI: 10.1126/sciadv.aaz9805] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
Recent work has highlighted the fact that lysosomes are a critical signaling hub of metabolic processes, providing fundamental building blocks crucial for anabolic functions. How lysosomal functions affect other cellular compartments is not fully understood. Here, we find that lysosomal recycling of the amino acids lysine and arginine is essential for proper ER quality control through the UPRER. Specifically, loss of the lysine and arginine amino acid transporter LAAT-1 results in increased sensitivity to proteotoxic stress in the ER and decreased animal physiology. We find that these LAAT-1-dependent effects are linked to glycine metabolism and transport and that the loss of function of the glycine transporter SKAT-1 also increases sensitivity to ER stress. Direct lysine and arginine supplementation, or glycine supplementation alone, can ameliorate increased ER stress sensitivity found in laat-1 mutants. These data implicate a crucial role in recycling lysine, arginine, and glycine in communication between the lysosome and ER.
Collapse
Affiliation(s)
- Ryo Higuchi-Sanabria
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Koning Shen
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Naame Kelet
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Phillip A. Frankino
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Jenni Durieux
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Raz Bar-Ziv
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Cierra N. Sing
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Enrique J. Garcia
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Stefan Homentcovschi
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Melissa Sanchez
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Rui Wu
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Sarah U. Tronnes
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Larry Joe
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Brant Webster
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Alex Ahilon-Jeronimo
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Samira Monshietehadi
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Sofia Dallarda
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Corinne Pender
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Liza A. Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Roberto Zoncu
- Department of Biochemistry, Biophysics, and Structural Biology, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Andrew Dillin
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| |
Collapse
|
71
|
Ren S, Ding C, Sun Y. Morphology Remodeling and Selective Autophagy of Intracellular Organelles during Viral Infections. Int J Mol Sci 2020; 21:ijms21103689. [PMID: 32456258 PMCID: PMC7279407 DOI: 10.3390/ijms21103689] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/14/2020] [Accepted: 05/21/2020] [Indexed: 12/17/2022] Open
Abstract
Viruses have evolved different strategies to hijack subcellular organelles during their life cycle to produce robust infectious progeny. Successful viral reproduction requires the precise assembly of progeny virions from viral genomes, structural proteins, and membrane components. Such spatial and temporal separation of assembly reactions depends on accurate coordination among intracellular compartmentalization in multiple organelles. Here, we overview the rearrangement and morphology remodeling of virus-triggered intracellular organelles. Focus is given to the quality control of intracellular organelles, the hijacking of the modified organelle membranes by viruses, morphology remodeling for viral replication, and degradation of intracellular organelles by virus-triggered selective autophagy. Understanding the functional reprogram and morphological remodeling in the virus-organelle interplay can provide new insights into the development of broad-spectrum antiviral strategies.
Collapse
Affiliation(s)
- Shanhui Ren
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute. Chinese Academy of Agricultural Science, Shanghai 200241, China;
| | - Chan Ding
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute. Chinese Academy of Agricultural Science, Shanghai 200241, China;
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Correspondence: (C.D.); (Y.S.); Tel.: +86-21-34293441 (C.D. & Y.S.); Fax: +86-21-54081818 (C.D. & Y.S.)
| | - Yingjie Sun
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute. Chinese Academy of Agricultural Science, Shanghai 200241, China;
- Correspondence: (C.D.); (Y.S.); Tel.: +86-21-34293441 (C.D. & Y.S.); Fax: +86-21-54081818 (C.D. & Y.S.)
| |
Collapse
|
72
|
Evans AS, Lennemann NJ, Coyne CB. BPIFB3 Regulates Endoplasmic Reticulum Morphology To Facilitate Flavivirus Replication. J Virol 2020; 94:e00029-20. [PMID: 32102874 PMCID: PMC7163128 DOI: 10.1128/jvi.00029-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 02/14/2020] [Indexed: 12/20/2022] Open
Abstract
Flaviviruses, including dengue virus (DENV) and Zika virus (ZIKV), rely heavily on the availability of endoplasmic reticulum (ER) membranes throughout their life cycle, and degradation of ER membranes restricts flavivirus replication. Accordingly, DENV and ZIKV restrict ER turnover by protease-mediated cleavage of reticulophagy regulator 1 (RETREG1), also known as FAM134B, an autophagy receptor responsible for targeted ER sheet degradation. Given that the induction of autophagy may play an important role in flavivirus replication, the antiviral role of RETREG1 suggests that specialized autophagic pathways may have differential effects on the flavivirus life cycle. We previously identified BPI fold-containing family B member 3 (BPIFB3) as a regulator of autophagy that negatively controls enterovirus replication. Here, we show that in contrast to enteroviruses, BPIFB3 functions as a positive regulator of DENV and ZIKV infection and that its RNA interference-mediated silencing inhibits the formation of viral replication organelles. Mechanistically, we show that depletion of BPIFB3 enhances RETREG1-dependent reticulophagy, leading to enhanced ER turnover and the suppression of viral replication. Consistent with this, the antiviral effects of BPIFB3 depletion can be reversed by RETREG1 silencing, suggesting a specific role for BPIFB3 in regulating ER turnover. These studies define BPIFB3 as a required host factor for both DENV and ZIKV replication and further contribute to our understanding of the requirements for autophagy during flavivirus infection.IMPORTANCE Flaviviruses and other arthropod-transmitted viruses represent a widespread global health problem, with limited treatment options currently available. Thus, a better understanding of the cellular requirements for their infection is needed. Both DENV and ZIKV rely on expansion of the endoplasmic reticulum (ER) and the induction of autophagy to establish productive infections. However, little is known regarding the interplay between the requirements for autophagy initiation during infection and the mechanisms used by these viruses to avoid clearance through the autophagic pathway. Our study highlights the importance of the host factor BPIFB3 in regulating flavivirus replication and further confirms that the RETREG1-dependent reticulophagy pathway is antiviral to both DENV and ZIKV.
Collapse
Affiliation(s)
- Azia S Evans
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Microbial Pathogenesis, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Nicholas J Lennemann
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Microbial Pathogenesis, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Carolyn B Coyne
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Microbial Pathogenesis, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Richard K. Mellon Institute for Pediatric Research, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
73
|
Sieńko K, Poormassalehgoo A, Yamada K, Goto-Yamada S. Microautophagy in Plants: Consideration of Its Molecular Mechanism. Cells 2020; 9:cells9040887. [PMID: 32260410 PMCID: PMC7226842 DOI: 10.3390/cells9040887] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 02/06/2023] Open
Abstract
Microautophagy is a type of autophagy. It is characterized by direct enclosing with the vacuolar/lysosomal membrane, which completes the isolation and uptake of cell components in the vacuole. Several publications present evidence that plants exhibit microautophagy. Plant microautophagy is involved in anthocyanin accumulation in the vacuole, eliminating damaged chloroplasts and degrading cellular components during starvation. However, information on the molecular mechanism of microautophagy is less available than that on the general macroautophagy, because the research focusing on microautophagy has not been widely reported. In yeast and animals, it is suggested that microautophagy can be classified into several types depending on morphology and the requirements of autophagy-related (ATG) genes. This review summarizes the studies on plant microautophagy and discusses possible techniques for a future study in this field while taking into account the information on microautophagy obtained from yeast and animals.
Collapse
|
74
|
Sharmin T, Morshed S, Ushimaru T. PP2A promotes ESCRT-0 complex formation on vacuolar membranes and microautophagy induction after TORC1 inactivation. Biochem Biophys Res Commun 2020; 524:614-620. [DOI: 10.1016/j.bbrc.2020.01.129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 11/29/2022]
|
75
|
Chen G, Kroemer G, Kepp O. Mitophagy: An Emerging Role in Aging and Age-Associated Diseases. Front Cell Dev Biol 2020; 8:200. [PMID: 32274386 PMCID: PMC7113588 DOI: 10.3389/fcell.2020.00200] [Citation(s) in RCA: 194] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/09/2020] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial dysfunction constitutes one of the hallmarks of aging and is characterized by irregular mitochondrial morphology, insufficient ATP production, accumulation of mitochondrial DNA (mtDNA) mutations, increased production of mitochondrial reactive oxygen species (ROS) and the consequent oxidative damage to nucleic acids, proteins and lipids. Mitophagy, a mitochondrial quality control mechanism enabling the degradation of damaged and superfluous mitochondria, prevents such detrimental effects and reinstates cellular homeostasis in response to stress. To date, there is increasing evidence that mitophagy is significantly impaired in several human pathologies including aging and age-related diseases such as neurodegenerative disorders, cardiovascular pathologies and cancer. Therapeutic interventions aiming at the induction of mitophagy may have the potency to ameliorate these dysfunctions. In this review, we summarize recent findings on mechanisms controlling mitophagy and its role in aging and the development of human pathologies.
Collapse
Affiliation(s)
- Guo Chen
- The State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Guido Kroemer
- Gustave Roussy Cancer Campus, Villejuif, France
- INSERM, UMR 1138, Centre de Recherche des Cordeliers, Paris, France
- Equipe 11 Labellisée par la Ligue Nationale Contre le Cancer, Centre de Recherche des Cordeliers, Paris, France
- Université de Paris, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Sorbonne Université, Paris, France
- Université Paris-Saclay, Faculté de Médecine, Kremlin-Bicêtre, France
- Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
- Suzhou Institute for Systems Medicine, Chinese Academy of Sciences, Suzhou, China
- Karolinska Institute, Department of Women’s and Children’s Health, Karolinska University Hospital, Stockholm, Sweden
| | - Oliver Kepp
- Gustave Roussy Cancer Campus, Villejuif, France
- INSERM, UMR 1138, Centre de Recherche des Cordeliers, Paris, France
- Equipe 11 Labellisée par la Ligue Nationale Contre le Cancer, Centre de Recherche des Cordeliers, Paris, France
- Université de Paris, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Sorbonne Université, Paris, France
- Université Paris-Saclay, Faculté de Médecine, Kremlin-Bicêtre, France
| |
Collapse
|
76
|
ER-Phagy: Quality Control and Turnover of Endoplasmic Reticulum. Trends Cell Biol 2020; 30:384-398. [PMID: 32302550 DOI: 10.1016/j.tcb.2020.02.001] [Citation(s) in RCA: 164] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/30/2020] [Accepted: 02/03/2020] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) is the largest organelle in cells and has fundamental functions, such as folding, processing, and trafficking of proteins, cellular metabolism, and ion storage. To maintain its function, it is turned over constitutively, and even more actively under certain stress conditions. Quality control of the ER is mediated primarily by two pathways: the ubiquitin-proteasome system and autophagy (termed 'ER-phagy'). The identification of ER-phagy adaptor molecules has shed light on the mechanisms and physiological significance of ER-phagy. Here, we describe recent findings on various types of ER-phagy and present unanswered questions related to their mechanism and regulation.
Collapse
|
77
|
Yao RQ, Ren C, Xia ZF, Yao YM. Organelle-specific autophagy in inflammatory diseases: a potential therapeutic target underlying the quality control of multiple organelles. Autophagy 2020; 17:385-401. [PMID: 32048886 PMCID: PMC8007140 DOI: 10.1080/15548627.2020.1725377] [Citation(s) in RCA: 210] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The structural integrity and functional stability of organelles are prerequisites for the viability and responsiveness of cells. Dysfunction of multiple organelles is critically involved in the pathogenesis and progression of various diseases, such as chronic obstructive pulmonary disease, cardiovascular diseases, infection, and neurodegenerative diseases. In fact, those organelles synchronously present with evident structural derangement and aberrant function under exposure to different stimuli, which might accelerate the corruption of cells. Therefore, the quality control of multiple organelles is of great importance in maintaining the survival and function of cells and could be a potential therapeutic target for human diseases. Organelle-specific autophagy is one of the major subtypes of autophagy, selectively targeting different organelles for quality control. This type of autophagy includes mitophagy, pexophagy, reticulophagy (endoplasmic reticulum), ribophagy, lysophagy, and nucleophagy. These kinds of organelle-specific autophagy are reported to be beneficial for inflammatory disorders by eliminating damaged organelles and maintaining homeostasis. In this review, we summarized the recent findings and mechanisms covering different kinds of organelle-specific autophagy, as well as their involvement in various diseases, aiming to arouse concern about the significance of the quality control of multiple organelles in the treatment of inflammatory diseases.Abbreviations: ABCD3: ATP binding cassette subfamily D member 3; AD: Alzheimer disease; ALS: amyotrophic lateral sclerosis; AMBRA1: autophagy and beclin 1 regulator 1; AMPK: AMP-activated protein kinase; ARIH1: ariadne RBR E3 ubiquitin protein ligase 1; ATF: activating transcription factor; ATG: autophagy related; ATM: ATM serine/threonine kinase; BCL2: BCL2 apoptosis regulator; BCL2L11/BIM: BCL2 like 11; BCL2L13: BCL2 like 13; BECN1: beclin 1; BNIP3: BCL2 interacting protein 3; BNIP3L/NIX: BCL2 interacting protein 3 like; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CANX: calnexin; CAT: catalase; CCPG1: cell cycle progression 1; CHDH: choline dehydrogenase; COPD: chronic obstructive pulmonary disease; CSE: cigarette smoke exposure; CTSD: cathepsin D; DDIT3/CHOP: DNA-damage inducible transcript 3; DISC1: DISC1 scaffold protein; DNM1L/DRP1: dynamin 1 like; EIF2AK3/PERK: eukaryotic translation initiation factor 2 alpha kinase 3; EIF2S1/eIF2α: eukaryotic translation initiation factor 2 alpha kinase 3; EMD: emerin; EPAS1/HIF-2α: endothelial PAS domain protein 1; ER: endoplasmic reticulum; ERAD: ER-associated degradation; ERN1/IRE1α: endoplasmic reticulum to nucleus signaling 1; FBXO27: F-box protein 27; FKBP8: FKBP prolyl isomerase 8; FTD: frontotemporal dementia; FUNDC1: FUN14 domain containing 1; G3BP1: G3BP stress granule assembly factor 1; GBA: glucocerebrosidase beta; HIF1A/HIF1: hypoxia inducible factor 1 subunit alpha; IMM: inner mitochondrial membrane; LCLAT1/ALCAT1: lysocardiolipin acyltransferase 1; LGALS3/Gal3: galectin 3; LIR: LC3-interacting region; LMNA: lamin A/C; LMNB1: lamin B1; LPS: lipopolysaccharide; MAPK8/JNK: mitogen-activated protein kinase 8; MAMs: mitochondria-associated membranes; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MFN1: mitofusin 1; MOD: multiple organelles dysfunction; MTPAP: mitochondrial poly(A) polymerase; MUL1: mitochondrial E3 ubiquitin protein ligase 1; NBR1: NBR1 autophagy cargo receptor; NLRP3: NLR family pyrin domain containing 3; NUFIP1: nuclear FMR1 interacting protein 1; OMM: outer mitochondrial membrane; OPTN: optineurin; PD: Parkinson disease; PARL: presenilin associated rhomboid like; PEX3: peroxisomal biogenesis factor 3; PGAM5: PGAM family member 5; PHB2: prohibitin 2; PINK1: PTEN induced putative kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; RB1CC1/FIP200: RB1 inducible coiled-coil 1; RETREG1/FAM134B: reticulophagy regulator 1; RHOT1/MIRO1: ras homolog family member T1; RIPK3/RIP3: receptor interacting serine/threonine kinase 3; ROS: reactive oxygen species; RTN3: reticulon 3; SEC62: SEC62 homolog, preprotein translocation factor; SESN2: sestrin2; SIAH1: siah E3 ubiquitin protein ligase 1; SNCA: synuclein alpha; SNCAIP: synuclein alpha interacting protein; SQSTM1/p62: sequestosome 1; STING1: stimulator of interferon response cGAMP interactor 1; TAX1BP1: Tax1 binding protein 1; TBK1: TANK binding kinase 1; TFEB: transcription factor EB; TICAM1/TRIF: toll-like receptor adaptor molecule 1; TIMM23: translocase of inner mitochondrial membrane 23; TNKS: tankyrase; TOMM: translocase of the outer mitochondrial membrane; TRIM: tripartite motif containing; UCP2: uncoupling protein 2; ULK1: unc-51 like autophagy activating kinase; UPR: unfolded protein response; USP10: ubiquitin specific peptidase 10; VCP/p97: valosin containing protein; VDAC: voltage dependent anion channels; XIAP: X-linked inhibitor of apoptosis; ZNHIT3: zinc finger HIT-type containing 3.
Collapse
Affiliation(s)
- Ren-Qi Yao
- Trauma Research Center, Fourth Medical Center of the Chinese PLA General Hospital, Beijing, People's Republic of China.,Department of Burn Surgery, Changhai Hospital, Navy Medical University, Shanghai, People's Republic of China
| | - Chao Ren
- Trauma Research Center, Fourth Medical Center of the Chinese PLA General Hospital, Beijing, People's Republic of China
| | - Zhao-Fan Xia
- Department of Burn Surgery, Changhai Hospital, Navy Medical University, Shanghai, People's Republic of China
| | - Yong-Ming Yao
- Trauma Research Center, Fourth Medical Center of the Chinese PLA General Hospital, Beijing, People's Republic of China
| |
Collapse
|
78
|
Abstract
Autophagy is a major intracellular degradation system that derives its degradative abilities from the lysosome. The most well-studied form of autophagy is macroautophagy, which delivers cytoplasmic material to lysosomes via the double-membraned autophagosome. Other forms of autophagy, namely chaperone-mediated autophagy and microautophagy, occur directly on the lysosome. Besides providing the means for degradation, lysosomes are also involved in autophagy regulation and can become substrates of autophagy when damaged. During autophagy, they exhibit notable changes, including increased acidification, enhanced enzymatic activity, and perinuclear localization. Despite their importance to autophagy, details on autophagy-specific regulation of lysosomes remain relatively scarce. This review aims to provide a summary of current understanding on the behaviour of lysosomes during autophagy and outline unexplored areas of autophagy-specific lysosome research.
Collapse
Affiliation(s)
- Willa Wen-You Yim
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan
| |
Collapse
|
79
|
Three-Dimensional Visualization of APEX2-Tagged Erg11 in Saccharomyces cerevisiae Using Focused Ion Beam Scanning Electron Microscopy. mSphere 2020; 5:5/1/e00981-19. [PMID: 32024705 PMCID: PMC7002314 DOI: 10.1128/msphere.00981-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The determination of the exact location of a protein in the cell is essential to the understanding of biological processes. Here, we report for the first time the visualization of a protein of interest in Saccharomyces cerevisiae using focused ion beam scanning electron microscopy (FIB-SEM). As a proof of concept, the integral endoplasmic reticulum (ER) membrane protein Erg11 has been C-terminally tagged with APEX2, which is an engineered peroxidase that catalyzes an electron-dense deposition of 3,3'-diaminobenzidine (DAB), as such marking the location of the fused protein of interest in electron microscopic images. As DAB is unable to cross the yeast cell wall to react with APEX2, cell walls have been partly removed by the formation of spheroplasts. This has resulted in a clear electron-dense ER signal for the Erg11 protein using FIB-SEM. With this study, we have validated the use of the APEX2 tag for visualization of yeast proteins in electron microscopy. Furthermore, we have introduced a methodology that enables precise and three-dimensional (3D) localization studies in yeast, with nanometer resolution and without the need for antibody staining. Because of these properties, the described technique can offer valuable information on the molecular functions of studied proteins.IMPORTANCE With this study, we have validated the use of the APEX2 tag to define the localization of proteins in the model yeast S. cerevisiae As such, FIB-SEM can identify the exact 3D location of a protein of interest in the cell with nanometer-scale resolution. Such detailed imaging could provide essential information on the elucidation of various biological processes. APEX2, which adds electron density to a fused protein of interest upon addition of the substrate DAB, originally was used in mammalian studies. With this study, we expand its use to protein localization studies in one of the most important models in molecular biology.
Collapse
|
80
|
Zhang X, Ding X, Marshall RS, Paez-Valencia J, Lacey P, Vierstra RD, Otegui MS. Reticulon proteins modulate autophagy of the endoplasmic reticulum in maize endosperm. eLife 2020; 9:51918. [PMID: 32011236 PMCID: PMC7046470 DOI: 10.7554/elife.51918] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 02/02/2020] [Indexed: 12/18/2022] Open
Abstract
Reticulon (Rtn) proteins shape tubular domains of the endoplasmic reticulum (ER), and in some cases are autophagy receptors for selective ER turnover. We have found that maize Rtn1 and Rtn2 control ER homeostasis and autophagic flux in endosperm aleurone cells, where the ER accumulates lipid droplets and synthesizes storage protein accretions metabolized during germination. Maize Rtn1 and Rtn2 are expressed in the endosperm, localize to the ER, and re-model ER architecture in a dose-dependent manner. Rtn1 and Rtn2 interact with Atg8a using four Atg8-interacting motifs (AIMs) located at the C-terminus, cytoplasmic loop, and within the transmembrane segments. Binding between Rtn2 and Atg8 is elevated upon ER stress. Maize rtn2 mutants display increased autophagy and up-regulation of an ER stress-responsive chaperone. We propose that maize Rtn1 and Rtn2 act as receptors for autophagy-mediated ER turnover, and thus are critical for ER homeostasis and suppression of ER stress.
Collapse
Affiliation(s)
- Xiaoguo Zhang
- Department of Botany, Laboratory of Cell and Molecular Biology, University of Wisconsin, Madison, United States
| | - Xinxin Ding
- Department of Botany, Laboratory of Cell and Molecular Biology, University of Wisconsin, Madison, United States
| | | | - Julio Paez-Valencia
- Department of Botany, Laboratory of Cell and Molecular Biology, University of Wisconsin, Madison, United States
| | - Patrick Lacey
- Department of Botany, Laboratory of Cell and Molecular Biology, University of Wisconsin, Madison, United States
| | | | - Marisa S Otegui
- Department of Botany, Laboratory of Cell and Molecular Biology, University of Wisconsin, Madison, United States.,Department of Genetics, University of Wisconsin, Madison, United States
| |
Collapse
|
81
|
Wesley CC, Mishra S, Levy DL. Organelle size scaling over embryonic development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 9:e376. [PMID: 32003549 DOI: 10.1002/wdev.376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/19/2019] [Accepted: 01/08/2020] [Indexed: 12/13/2022]
Abstract
Cell division without growth results in progressive cell size reductions during early embryonic development. How do the sizes of intracellular structures and organelles scale with cell size and what are the functional implications of such scaling relationships? Model organisms, in particular Caenorhabditis elegans worms, Drosophila melanogaster flies, Xenopus laevis frogs, and Mus musculus mice, have provided insights into developmental size scaling of the nucleus, mitotic spindle, and chromosomes. Nuclear size is regulated by nucleocytoplasmic transport, nuclear envelope proteins, and the cytoskeleton. Regulators of microtubule dynamics and chromatin compaction modulate spindle and mitotic chromosome size scaling, respectively. Developmental scaling relationships for membrane-bound organelles, like the endoplasmic reticulum, Golgi, mitochondria, and lysosomes, have been less studied, although new imaging approaches promise to rectify this deficiency. While models that invoke limiting components and dynamic regulation of assembly and disassembly can account for some size scaling relationships in early embryos, it will be exciting to investigate the contribution of newer concepts in cell biology such as phase separation and interorganellar contacts. With a growing understanding of the underlying mechanisms of organelle size scaling, future studies promise to uncover the significance of proper scaling for cell function and embryonic development, as well as how aberrant scaling contributes to disease. This article is categorized under: Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Early Embryonic Development > Fertilization to Gastrulation Comparative Development and Evolution > Model Systems.
Collapse
Affiliation(s)
- Chase C Wesley
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Sampada Mishra
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| |
Collapse
|
82
|
Abstract
Zika virus (ZIKV) belongs to the Flavivirus genus of the Flaviviridae family. It is an arbovirus that can cause congenital abnormalities and is sexually transmissible. A series of outbreaks accompanied by unexpected severe clinical complications have captured medical attention to further characterize the clinical features of congenital ZIKV syndrome and its underlying pathophysiological mechanisms. Endoplasmic reticulum (ER) and ER-related proteins are essential in ZIKV genome replication. This review highlights the subcellular localization of ZIKV to the ER and ZIKV modulation on the architecture of the ER. This review also discusses ZIKV interaction with ER proteins such as signal peptidase complex subunit 1 (SPCS1), ER membrane complex (EMC) subunits, and ER translocon for viral replication. Furthermore, the review covers several important resulting effects of ZIKV infection to the ER and cellular processes including ER stress, reticulophagy, and paraptosis-like death. Pharmacological targeting of ZIKV-affected ER-resident proteins and ER-associated components demonstrate promising signs of combating ZIKV infection and rescuing host organisms from severe neurologic sequelae.
Collapse
|
83
|
Schäfer JA, Schessner JP, Bircham PW, Tsuji T, Funaya C, Pajonk O, Schaeff K, Ruffini G, Papagiannidis D, Knop M, Fujimoto T, Schuck S. ESCRT machinery mediates selective microautophagy of endoplasmic reticulum in yeast. EMBO J 2020; 39:e102586. [PMID: 31802527 PMCID: PMC6960443 DOI: 10.15252/embj.2019102586] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 10/30/2019] [Accepted: 11/11/2019] [Indexed: 01/14/2023] Open
Abstract
ER-phagy, the selective autophagy of endoplasmic reticulum (ER), safeguards organelle homeostasis by eliminating misfolded proteins and regulating ER size. ER-phagy can occur by macroautophagic and microautophagic mechanisms. While dedicated machinery for macro-ER-phagy has been discovered, the molecules and mechanisms mediating micro-ER-phagy remain unknown. Here, we first show that micro-ER-phagy in yeast involves the conversion of stacked cisternal ER into multilamellar ER whorls during microautophagic uptake into lysosomes. Second, we identify the conserved Nem1-Spo7 phosphatase complex and the ESCRT machinery as key components for micro-ER-phagy. Third, we demonstrate that macro- and micro-ER-phagy are parallel pathways with distinct molecular requirements. Finally, we provide evidence that the ESCRT machinery directly functions in scission of the lysosomal membrane to complete the microautophagic uptake of ER. These findings establish a framework for a mechanistic understanding of micro-ER-phagy and, thus, a comprehensive appreciation of the role of autophagy in ER homeostasis.
Collapse
Affiliation(s)
- Jasmin A Schäfer
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
| | - Julia P Schessner
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
- Present address:
Department of Proteomics and Signal TransductionMax Planck Institute of BiochemistryMartinsriedGermany
| | - Peter W Bircham
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
- Present address:
Laboratory of Systems BiologyVIB Center for Microbiology/Laboratory of Genetics and GenomicsCMPGKU LeuvenLeuvenBelgium
| | - Takuma Tsuji
- Research Institute for Diseases of Old AgeJuntendo University Graduate School of MedicineTokyoJapan
| | - Charlotta Funaya
- Electron Microscopy Core FacilityHeidelberg UniversityHeidelbergGermany
| | - Oliver Pajonk
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
| | - Katharina Schaeff
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
| | - Giulia Ruffini
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
| | - Dimitrios Papagiannidis
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
| | - Michael Knop
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
| | - Toyoshi Fujimoto
- Research Institute for Diseases of Old AgeJuntendo University Graduate School of MedicineTokyoJapan
| | - Sebastian Schuck
- DKFZ‐ZMBH Alliance and CellNetworks Cluster of ExcellenceCenter for Molecular Biology of Heidelberg University (ZMBH)HeidelbergGermany
| |
Collapse
|
84
|
Wilkinson S. Emerging Principles of Selective ER Autophagy. J Mol Biol 2020; 432:185-205. [PMID: 31100386 PMCID: PMC6971691 DOI: 10.1016/j.jmb.2019.05.012] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/07/2019] [Accepted: 05/07/2019] [Indexed: 12/13/2022]
Abstract
The endoplasmic reticulum (ER) is a fundamental organelle in cellular metabolism and signal transduction. It is subject to complex, dynamic sculpting of morphology and composition. Degradation of ER content has an important role to play here. Indeed, a major emerging player in ER turnover is ER-phagy, the degradation of ER fragments by selective autophagy, particularly macroautophagy. This article proposes a number of unifying principles of ER-phagy mechanism and compares these with other selective autophagy pathways. A perspective on the likely roles of ER-phagy in determining cell fate is provided. Emerging related forms of intracellular catabolism of the ER or contents, including ER-phagy by microautophagy and selective ER protein removal via the lysosome, are outlined for comparison. Unresolved questions regarding the mechanism of ER-phagy and its significance in cellular and organismal health are put forward. This review concludes with a perspective on how this fundamental knowledge might inform future clinical developments.
Collapse
Affiliation(s)
- Simon Wilkinson
- Edinburgh Cancer Research UK Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, EH4 2XR, United Kingdom
| |
Collapse
|
85
|
NAKATOGAWA H. Autophagic degradation of the endoplasmic reticulum. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2020; 96:1-9. [PMID: 31932525 PMCID: PMC6974406 DOI: 10.2183/pjab.96.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
Autophagy is an intracellular degradation system that is present in most eukaryotes. In the process of autophagy, double membrane vesicles called autophagosomes sequester a wide variety of cellular constituents and deliver them to lytic organelles: lysosomes in mammals and vacuoles in yeast and plants. Although autophagy used to be considered a non-selective process in its target sequestration into autophagosomes, recent studies have revealed that autophagosomes can also selectively sequester certain proteins and organelles that have become unnecessary or harmful for the cell. We recently discovered that the endoplasmic reticulum (ER) is degraded by autophagy in a selective manner in the budding yeast Saccharomyces cerevisiae, and identified "receptor proteins" that play pivotal roles in this "ER-phagy" pathway. Moreover, several ER-phagy receptors in mammalian cells have also been reported. This report provides an overview of our current knowledge on ER-phagy and discuss their mechanisms, physiological roles, and possible links to human diseases.
Collapse
Affiliation(s)
- Hitoshi NAKATOGAWA
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
| |
Collapse
|
86
|
Daniele JR, Higuchi-Sanabria R, Durieux J, Monshietehadi S, Ramachandran V, Tronnes SU, Kelet N, Sanchez M, Metcalf MG, Garcia G, Frankino PA, Benitez C, Zeng M, Esping DJ, Joe L, Dillin A. UPR ER promotes lipophagy independent of chaperones to extend life span. SCIENCE ADVANCES 2020; 6:eaaz1441. [PMID: 31911951 PMCID: PMC6938708 DOI: 10.1126/sciadv.aaz1441] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 11/05/2019] [Indexed: 05/13/2023]
Abstract
Longevity is dictated by a combination of environmental and genetic factors. One of the key mechanisms to regulate life-span extension is the induction of protein chaperones for protein homeostasis. Ectopic activation of the unfolded protein response of the endoplasmic reticulum (UPRER) specifically in neurons is sufficient to enhance organismal stress resistance and extend life span. Here, we find that this activation not only promotes chaperones but also facilitates ER restructuring and ER function. This restructuring is concomitant with lipid depletion through lipophagy. Activation of lipophagy is distinct from chaperone induction and is required for the life-span extension found in this paradigm. Last, we find that overexpression of the lipophagy component, ehbp-1, is sufficient to deplete lipids, remodel ER, and promote life span. Therefore, UPR induction in neurons triggers two distinct programs in the periphery: the proteostasis arm through protein chaperones and metabolic changes through lipid depletion mediated by EH domain binding protein 1 (EHBP-1).
Collapse
Affiliation(s)
- Joseph R. Daniele
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Ryo Higuchi-Sanabria
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Jenni Durieux
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Samira Monshietehadi
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Vidhya Ramachandran
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
- Thermo Fisher Scientific, Genetic Sciences Division, Santa Clara, CA 95051, USA
| | - Sarah U. Tronnes
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Naame Kelet
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Melissa Sanchez
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Melissa G. Metcalf
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Gilberto Garcia
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Phillip A. Frankino
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Camila Benitez
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Mandy Zeng
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Daniel J. Esping
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Larry Joe
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
| | - Andrew Dillin
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA 94720-3370, USA
- Corresponding author.
| |
Collapse
|
87
|
Morshed S, Sharmin T, Ushimaru T. TORC1 regulates ESCRT-0 complex formation on the vacuolar membrane and microautophagy induction in yeast. Biochem Biophys Res Commun 2020; 522:88-94. [DOI: 10.1016/j.bbrc.2019.11.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 11/10/2019] [Indexed: 11/26/2022]
|
88
|
Liao Y, Duan B, Zhang Y, Zhang X, Xia B. Excessive ER-phagy mediated by the autophagy receptor FAM134B results in ER stress, the unfolded protein response, and cell death in HeLa cells. J Biol Chem 2019; 294:20009-20023. [PMID: 31748416 PMCID: PMC6937584 DOI: 10.1074/jbc.ra119.008709] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 11/07/2019] [Indexed: 12/19/2022] Open
Abstract
Autophagy is typically a prosurvival cellular process that promotes the turnover of long-lived proteins and damaged organelles, but it can also induce cell death. We have previously reported that the small molecule Z36 induces autophagy along with autophagic cell death in HeLa cells. In this study, we analyzed differential gene expression in Z36-treated HeLa cells and found that Z36-induced endoplasmic reticulum-specific autophagy (ER-phagy) results in ER stress and the unfolded protein response (UPR). This result is in contrast to the common notion that autophagy is generally activated in response to ER stress and the UPR. We demonstrate that Z36 up-regulates the expression levels of FAM134B, LC3, and Atg9, which together mediate excessive ER-phagy, characterized by forming increased numbers of autophagosomes with larger sizes. We noted that the excessive ER-phagy accelerates ER degradation and impairs ER homeostasis and thereby triggers ER stress and the UPR as well as ER-phagy-dependent cell death. Interestingly, overexpression of FAM134B alone in HeLa cells is sufficient to impair ER homeostasis and cause ER stress and cell death. These findings suggest a mechanism involving FAM134B activity for ER-phagy to promote cell death.
Collapse
Affiliation(s)
- Yangjie Liao
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Bo Duan
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yufei Zhang
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | | | - Bin Xia
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
89
|
Valionyte E, Yang Y, Roberts SL, Kelly J, Lu B, Luo S. Lowering Mutant Huntingtin Levels and Toxicity: Autophagy-Endolysosome Pathways in Huntington's Disease. J Mol Biol 2019; 432:2673-2691. [PMID: 31786267 DOI: 10.1016/j.jmb.2019.11.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 11/04/2019] [Accepted: 11/19/2019] [Indexed: 02/06/2023]
Abstract
Huntington's disease (HD) is a monogenetic neurodegenerative disease, which serves as a model of neurodegeneration with protein aggregation. Autophagy has been suggested to possess a great value to tackle protein aggregation toxicity and neurodegenerative diseases. Current studies suggest that autophagy-endolysosomal pathways are critical for HD pathology. Here we review recent advancement in the studies of autophagy and selective autophagy relating HD. Restoration of autophagy flux and enhancement of selective removal of mutant huntingtin/disease-causing protein would be effective approaches towards tackling HD as well as other similar neurodegenerative disorders.
Collapse
Affiliation(s)
- Evelina Valionyte
- Peninsula Schools of Medicine and Dentistry, Institute of Translational and Stratified Medicine, University of Plymouth, Research Way, Plymouth PL6 8BU, UK
| | - Yi Yang
- Peninsula Schools of Medicine and Dentistry, Institute of Translational and Stratified Medicine, University of Plymouth, Research Way, Plymouth PL6 8BU, UK
| | - Sheridan L Roberts
- Peninsula Schools of Medicine and Dentistry, Institute of Translational and Stratified Medicine, University of Plymouth, Research Way, Plymouth PL6 8BU, UK
| | - Jack Kelly
- Peninsula Schools of Medicine and Dentistry, Institute of Translational and Stratified Medicine, University of Plymouth, Research Way, Plymouth PL6 8BU, UK
| | - Boxun Lu
- State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Shouqing Luo
- Peninsula Schools of Medicine and Dentistry, Institute of Translational and Stratified Medicine, University of Plymouth, Research Way, Plymouth PL6 8BU, UK.
| |
Collapse
|
90
|
Buchanan BW, Mehrtash AB, Broshar CL, Runnebohm AM, Snow BJ, Scanameo LN, Hochstrasser M, Rubenstein EM. Endoplasmic reticulum stress differentially inhibits endoplasmic reticulum and inner nuclear membrane protein quality control degradation pathways. J Biol Chem 2019; 294:19814-19830. [PMID: 31723032 DOI: 10.1074/jbc.ra119.010295] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 11/04/2019] [Indexed: 12/29/2022] Open
Abstract
Endoplasmic reticulum (ER) stress occurs when the abundance of unfolded proteins in the ER exceeds the capacity of the folding machinery. Despite the expanding cadre of characterized cellular adaptations to ER stress, knowledge of the effects of ER stress on cellular physiology remains incomplete. We investigated the impact of ER stress on ER and inner nuclear membrane protein quality control mechanisms in Saccharomyces cerevisiae. We analyzed the turnover of substrates of four ubiquitin ligases (Doa10, Rkr1/Ltn1, Hrd1, and the Asi complex) and the metalloprotease Ste24 in induced models of ER stress. ER stress did not substantially impact Doa10 or Rkr1 substrates. However, Hrd1-mediated destruction of a protein that aberrantly engages the translocon (Deg1-Sec62) and substrates with luminal degradation signals was markedly impaired by ER stress; by contrast, Hrd1-dependent degradation of proteins with intramembrane degrons was largely unperturbed by ER stress. ER stress impaired the degradation of one of two Asi substrates analyzed and caused a translocon-clogging Ste24 substrate to accumulate in a form consistent with persistent translocon occupation. Degradation of Deg1-Sec62 in the absence of stress and stabilization during ER stress were independent of four ER stress-sensing pathways. Our results indicate ER stress differentially impacts degradation of protein quality control substrates, including those mediated by the same ubiquitin ligase. These observations suggest the existence of additional regulatory mechanisms dictating substrate selection during ER stress.
Collapse
Affiliation(s)
- Bryce W Buchanan
- Department of Biology, Ball State University, Muncie, Indiana 47306
| | - Adrian B Mehrtash
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | | | | | - Brian J Snow
- Department of Biology, Ball State University, Muncie, Indiana 47306
| | - Laura N Scanameo
- Department of Biology, Ball State University, Muncie, Indiana 47306
| | - Mark Hochstrasser
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | | |
Collapse
|
91
|
Loi M, Raimondi A, Morone D, Molinari M. ESCRT-III-driven piecemeal micro-ER-phagy remodels the ER during recovery from ER stress. Nat Commun 2019; 10:5058. [PMID: 31699981 PMCID: PMC6838186 DOI: 10.1038/s41467-019-12991-z] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/10/2019] [Indexed: 12/13/2022] Open
Abstract
The endoplasmic reticulum (ER) produces about 40% of the nucleated cell's proteome. ER size and content in molecular chaperones increase upon physiologic and pathologic stresses on activation of unfolded protein responses (UPR). On stress resolution, the mammalian ER is remodeled to pre-stress, physiologic size and function on activation of the LC3-binding activity of the translocon component SEC62. This elicits recov-ER-phagy, i.e., the delivery of the excess ER generated during the phase of stress to endolysosomes (EL) for clearance. Here, ultrastructural and genetic analyses reveal that recov-ER-phagy entails the LC3 lipidation machinery and proceeds via piecemeal micro-ER-phagy, where RAB7/LAMP1-positive EL directly engulf excess ER in processes that rely on the Endosomal Sorting Complex Required for Transport (ESCRT)-III component CHMP4B and the accessory AAA+ ATPase VPS4A. Thus, ESCRT-III-driven micro-ER-phagy emerges as a key catabolic pathway activated to remodel the mammalian ER on recovery from ER stress.
Collapse
Affiliation(s)
- Marisa Loi
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Bellinzona, Switzerland
- Department of Biology, Swiss Federal Institute of Technology, 8093, Zurich, Switzerland
| | - Andrea Raimondi
- Experimental Imaging Center, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Diego Morone
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Bellinzona, Switzerland
| | - Maurizio Molinari
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Bellinzona, Switzerland.
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland.
| |
Collapse
|
92
|
Tao T, Wang J, Wang X, Wang Y, Mao H, Liu X. The PERK/Nrf2 pathway mediates endoplasmic reticulum stress-induced injury by upregulating endoplasmic reticulophagy in H9c2 cardiomyoblasts. Life Sci 2019; 237:116944. [DOI: 10.1016/j.lfs.2019.116944] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/30/2019] [Accepted: 10/07/2019] [Indexed: 12/12/2022]
|
93
|
Karagöz GE, Acosta-Alvear D, Walter P. The Unfolded Protein Response: Detecting and Responding to Fluctuations in the Protein-Folding Capacity of the Endoplasmic Reticulum. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033886. [PMID: 30670466 DOI: 10.1101/cshperspect.a033886] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Most of the secreted and plasma membrane proteins are synthesized on membrane-bound ribosomes on the endoplasmic reticulum (ER). They require engagement of ER-resident chaperones and foldases that assist in their folding and maturation. Since protein homeostasis in the ER is crucial for cellular function, the protein-folding status in the organelle's lumen is continually surveyed by a network of signaling pathways, collectively called the unfolded protein response (UPR). Protein-folding imbalances, or "ER stress," are detected by highly conserved sensors that adjust the ER's protein-folding capacity according to the physiological needs of the cell. We review recent developments in the field that have provided new insights into the ER stress-sensing mechanisms used by UPR sensors and the mechanisms by which they integrate various cellular inputs to adjust the folding capacity of the organelle to accommodate to fluctuations in ER protein-folding demands.
Collapse
Affiliation(s)
- G Elif Karagöz
- Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
| | - Diego Acosta-Alvear
- Department of Molecular, Cellular, and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California 93106
| | - Peter Walter
- Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
| |
Collapse
|
94
|
Yazawa R, Nishida Y, Aoyama S, Tanida I, Miyatsuka T, Suzuki L, Himuro M, Haruna H, Takubo N, Shimizu T, Watada H. Establishment of a system for screening autophagic flux regulators using a modified fluorescent reporter and CRISPR/Cas9. Biochem Biophys Res Commun 2019; 516:686-692. [PMID: 31253397 DOI: 10.1016/j.bbrc.2019.06.129] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 06/22/2019] [Indexed: 10/26/2022]
Abstract
Autophagy is a mechanism of bulk protein degradation that plays an important role in regulating homeostasis in many organisms. Among several methods for evaluating its activity, a fluorescent reporter GFP-LC3-RFP-LC3ΔG, in which GFP-LC3 is cleaved by ATG4 following autophagic induction and degraded in lysosome, has been used for monitoring autophagic flux, which is the amount of lysosomal protein degradation. In this study, we modified this reporter by exchanging GFP for pHluorin, which is more sensitive to low pH, and RFP to mCherry, to construct pHluorin-LC3-mCherry reporter. Following starvation or mTOR inhibition, the increase of autophagic flux was detected by a decrease of the fluorescent ratio of pHluorin to mCherry; our reporter was also more sensitive to autophagy-inducing stimuli than the previous one. To establish monitoring cells for mouse genome-wide screening of regulators of autophagic flux based on CRISPR/Cas9 system, after evaluating knockout efficiency of clones of Cas9-expressing MEFs, we co-expressed our reporter and confirmed that autophagic flux was impaired in gRNA-mediated knockout of canonical autophagy genes. Finally, we performed genome-wide gRNA screening for genes inhibiting starvation-mediated autophagic flux and identified previously reported genes such as Atgs. Thus, we have successfully established a system for screening of genes regulating autophagic flux with our pHluorin-LC3-mCherry reporter in mice.
Collapse
Affiliation(s)
- Rieko Yazawa
- Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Yuya Nishida
- Department of Endocrinology and Metabolism, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan; Center for Therapeutic Innovations in Diabetes, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
| | - Shuhei Aoyama
- Department of Endocrinology and Metabolism, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Isei Tanida
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Takeshi Miyatsuka
- Department of Endocrinology and Metabolism, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan; Center for Identification of Diabetic Therapeutic Targets, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Luka Suzuki
- Department of Endocrinology and Metabolism, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan; Center for Identification of Diabetic Therapeutic Targets, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Miwa Himuro
- Department of Endocrinology and Metabolism, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Hidenori Haruna
- Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Noriyuki Takubo
- Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Toshiaki Shimizu
- Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Hirotaka Watada
- Department of Endocrinology and Metabolism, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan; Center for Therapeutic Innovations in Diabetes, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan; Center for Identification of Diabetic Therapeutic Targets, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| |
Collapse
|
95
|
Messias Sandes J, Nascimento Moura DM, Divina da Silva Santiago M, Barbosa de Lima G, Cabral Filho PE, da Cunha Gonçalves de Albuquerque S, de Paiva Cavalcanti M, Fontes A, Bressan Queiroz Figueiredo RC. The effects of endoplasmic reticulum stressors, tunicamycin and dithiothreitol on Trypanosoma cruzi. Exp Cell Res 2019; 383:111560. [PMID: 31437457 DOI: 10.1016/j.yexcr.2019.111560] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 08/14/2019] [Accepted: 08/17/2019] [Indexed: 12/12/2022]
Abstract
In higher eukaryotic cells, pertubations in ER environment, called ER stress, usually activate unfolded protein response (UPR) pathway in an attempt to re-stablish the ER homeostasis and prevent cell death. Because trypanosomatids appear to lack the classical UPR, it is not clear how these parasites respond to ER stress. Thus, the aim of this work was to evaluate the effects of ER stressors tunicamycin (TM) or dithiothreitol (DTT) on Trypanosoma cruzi. The TM treatment showed strong trypanostatic effect. At 2.5 μg/mL of TM, the mRNA levels of both binding protein (BiP) and calreticulin (CRT) increased significantly, whereas the protein levels of BiP remained stable. TM treatment induced ultrastructural changes compatible with an autophagic process. The DTT treatment inhibited the cell growth, induced drastic morphological changes, mitochondrial membrane depolarization and increased ROS production. The expression of BiP apparently was not affected by DTT, whereas the mRNA levels of BiP and CRT were significantly reduced. Our results suggest that TM induces autophagy/ER-phagy without causing substantial injury to the parasite. Conversely, the DTT treatment seems to rupture the mitochondrion homeostasis leading to parasite death. The comprehension of the mechanisms behind the susceptibility of T. cruzi to ER stress open perspectives for the development of chemotherapeutic agents addressed to these pathways.
Collapse
Affiliation(s)
- Jana Messias Sandes
- Departamento de Microbiologia, Instituto Aggeu Magalhães/FIOCRUZ, Recife, Pernambuco, Brazil; Laboratório de Imunopatologia Keizo Asami - LIKA, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
| | | | | | - Gustavo Barbosa de Lima
- Departamento de Microbiologia, Instituto Aggeu Magalhães/FIOCRUZ, Recife, Pernambuco, Brazil.
| | - Paulo Euzébio Cabral Filho
- Departamento de Biofísica e Radiobiologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
| | | | | | - Adriana Fontes
- Departamento de Biofísica e Radiobiologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
| | | |
Collapse
|
96
|
De Leonibus C, Cinque L, Settembre C. Emerging lysosomal pathways for quality control at the endoplasmic reticulum. FEBS Lett 2019; 593:2319-2329. [PMID: 31388984 DOI: 10.1002/1873-3468.13571] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 07/30/2019] [Accepted: 08/02/2019] [Indexed: 01/01/2023]
Abstract
Protein misfolding occurring in the endoplasmic reticulum (ER) might eventually lead to aggregation and cellular distress, and is a primary pathogenic mechanism in multiple human disorders. Mammals have developed evolutionary-conserved quality control mechanisms at the level of the ER. The best characterized is the ER-associated degradation (ERAD) pathway, through which misfolded proteins translocate from the ER to the cytosol and are subsequently proteasomally degraded. However, increasing evidence indicates that additional quality control mechanisms apply for misfolded ER clients that are not eligible for ERAD. This review focuses on the alternative, ERAD-independent, mechanisms of clearance of misfolded polypeptides from the ER. These processes, collectively referred to as ER-to-lysosome-associated degradation, involve ER-phagy, microautophagy or vesicular transport. The identification of the underlying molecular mechanisms is particularly important for developing new therapeutic approaches for human diseases associated with protein aggregate formation.
Collapse
Affiliation(s)
| | - Laura Cinque
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Carmine Settembre
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Medical and Translational Science, University of Naples "Federico II", Italy
| |
Collapse
|
97
|
Needham PG, Guerriero CJ, Brodsky JL. Chaperoning Endoplasmic Reticulum-Associated Degradation (ERAD) and Protein Conformational Diseases. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033928. [PMID: 30670468 DOI: 10.1101/cshperspect.a033928] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Misfolded proteins compromise cellular homeostasis. This is especially problematic in the endoplasmic reticulum (ER), which is a high-capacity protein-folding compartment and whose function requires stringent protein quality-control systems. Multiprotein complexes in the ER are able to identify, remove, ubiquitinate, and deliver misfolded proteins to the 26S proteasome for degradation in the cytosol, and these events are collectively termed ER-associated degradation, or ERAD. Several steps in the ERAD pathway are facilitated by molecular chaperone networks, and the importance of ERAD is highlighted by the fact that this pathway is linked to numerous protein conformational diseases. In this review, we discuss the factors that constitute the ERAD machinery and detail how each step in the pathway occurs. We then highlight the underlying pathophysiology of protein conformational diseases associated with ERAD.
Collapse
Affiliation(s)
- Patrick G Needham
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | | | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| |
Collapse
|
98
|
Increased autophagy in EphrinB2-deficient osteocytes is associated with elevated secondary mineralization and brittle bone. Nat Commun 2019; 10:3436. [PMID: 31366886 PMCID: PMC6668467 DOI: 10.1038/s41467-019-11373-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 07/10/2019] [Indexed: 12/30/2022] Open
Abstract
Mineralized bone forms when collagen-containing osteoid accrues mineral crystals. This is initiated rapidly (primary mineralization), and continues slowly (secondary mineralization) until bone is remodeled. The interconnected osteocyte network within the bone matrix differentiates from bone-forming osteoblasts; although osteoblast differentiation requires EphrinB2, osteocytes retain its expression. Here we report brittle bones in mice with osteocyte-targeted EphrinB2 deletion. This is not caused by low bone mass, but by defective bone material. While osteoid mineralization is initiated at normal rate, mineral accrual is accelerated, indicating that EphrinB2 in osteocytes limits mineral accumulation. No known regulators of mineralization are modified in the brittle cortical bone but a cluster of autophagy-associated genes are dysregulated. EphrinB2-deficient osteocytes displayed more autophagosomes in vivo and in vitro, and EphrinB2-Fc treatment suppresses autophagy in a RhoA-ROCK dependent manner. We conclude that secondary mineralization involves EphrinB2-RhoA-limited autophagy in osteocytes, and disruption leads to a bone fragility independent of bone mass. Osteoblasts mediate bone formation, and their differentiation requires expression of EphrinB2. Here, the authors show that EphrinB2 is also expressed by osteocytes, and that its genetic ablation in mice is associated with altered autophagy, elevated mineralization and brittle bone.
Collapse
|
99
|
Yin Z, Feng W, Chen C, Xu J, Li Y, Yang L, Wang J, Liu X, Wang W, Gao C, Zhang H, Zheng X, Wang P, Zhang Z. Shedding light on autophagy coordinating with cell wall integrity signaling to govern pathogenicity of Magnaporthe oryzae. Autophagy 2019; 16:900-916. [PMID: 31313634 DOI: 10.1080/15548627.2019.1644075] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cells are faced with various stresses during their growth and development, and autophagy is a degradative process in which cells can break down their own components to recycle macromolecules and provide energy under these stresses. For pathogenic fungi that utilize cell wall as the first barrier against external stress, the cell wall integrity (CWI) pathway also provides an essential role in responding to these stresses. However, the specific connection between autophagy and CWI remains elusive in either the model fungi including budding yeast Saccharomyces cerevisiae or the rice blast fungus Magnaporthe oryzae. Here, we provided evidence that the endoplasmic reticulum (ER) stress is highly induced during M. oryzae infection and that CWI MAP kinase kinase MoMkk1 (S. cerevisiae Mkk1/2 homolog) was subject to phosphorylation regulation by MoAtg1, the only identified kinase in the core autophagy machinery. We also identified MoMkk1 serine 115 as the MoAtg1-dependent phosphorylation site and this phosphorylation could activate CWI, similar to that by the conserved MAP kinase kinase kinase MoMck1 (S. cerevisiae Bck1 homolog). Together with the first report of MoMkk1 subjects to phosphorylation regulation by MoAtg1, we revealed a new mechanism by which autophagy coordinates with CWI signaling under ER stress, and this MoAtg1-dependent MoMkk1 phosphorylation is essential for the pathogenicity of M. oryzae.Abbreviations: A/Ala: alanine; Atg: autophagy-related; Bck1: bypass of C kinase 1; co-IP: co-immunoprecipitation; CWI: cell wall integrity;DTT: dithiothreitol; ER: endoplasmic reticulum; GFP: green fluorescent protein; Mo: Magnaporthe oryzae; MAPK: mitogen-activated protein kinase; Mkk1: mitogen-activated protein kinase-kinase 1; MS: mass spectrometry; PAS: phagophore assembly site; RFP: red fluorescent protein; RT: room temperature; S/Ser: serine; Slt2: suppressor of the lytic phenotype 2; T/Thr: threonine; UPR: unfolded protein response; Y2H: yeast two-hybrid screen.
Collapse
Affiliation(s)
- Ziyi Yin
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Wanzhen Feng
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Chen Chen
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Jiayun Xu
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Ying Li
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Lina Yang
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Jingzhen Wang
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Xinyu Liu
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Wenhao Wang
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Chuyun Gao
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Haifeng Zhang
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Xiaobo Zheng
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Ping Wang
- Departments of Pediatrics, and Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
100
|
Zhang Z, Gao W, Zhou L, Chen Y, Qin S, Zhang L, Liu J, He Y, Lei Y, Chen HN, Han J, Zhou ZG, Nice EC, Li C, Huang C, Wei X. Repurposing Brigatinib for the Treatment of Colorectal Cancer Based on Inhibition of ER-phagy. Am J Cancer Res 2019; 9:4878-4892. [PMID: 31410188 PMCID: PMC6691391 DOI: 10.7150/thno.36254] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/27/2019] [Indexed: 02/05/2023] Open
Abstract
Rationale: The sustained and severe endoplasmic reticulum (ER) stress in cancer cells may contribute to apoptotic cell death, thus representing a potential target for cancer therapy. Brigatinib is an anaplastic lymphoma kinase (ALK) inhibitor approved for the treatment of ALK-positive non-small-cell lung cancer (NSCLC). However, it remains unclear if brigatinib has alternative model of action to exert antitumor effect in ALK-negative cancers. Methods: ALK-positive NSCLC cells and various human ALK-negative cancer cells, especially human colorectal cancer (CRC) cells were used to examine the tumor suppression effect of brigatinib alone or in combination with autophagy inhibitors in vitro and in vivo. A variety of biochemical assays were conducted to elucidate the underlying mechanisms of brigatinib in CRC cells. Results: Here, we show the significant anti-cancer effect of brigatinib in CRC through induction of apoptosis by sustained ER stress. Mechanistically, brigatinib induces ER stress via promoting the interaction between ubiquitin-specific peptidase 5 (USP5), a deubiquitinase, and oxysterol-binding protein-related protein 8 (ORP8), leading to ORP8 deubiquitination, accumulation and growth inhibition. Furthermore, we find that brigatinib-mediated ER stress simultaneously induces autophagic response via ER-phagy that acts as a protective mechanism to relieve excessive ER stress. As such, combination of brigatinib with autophagy inhibitors significantly enhances the anti-CRC effect of brigatinib both in vitro and in vivo, supporting the repurposing of brigatinib in CRC, independently of ALK. Conclusion: The unearthed new molecular action of brigatinib suggests that therapeutic modulation of ER stress and autophagy might represent a valid strategy to treat CRC and perhaps other ALK-negative cancers.
Collapse
|