1
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Wei L, Gok MO, Svoboda JD, Kozul KL, Forny M, Friedman JR, Niemi NM. Dual-localized PPTC7 limits mitophagy through proximal and dynamic interactions with BNIP3 and NIX. Life Sci Alliance 2024; 7:e202402765. [PMID: 38991726 PMCID: PMC11239977 DOI: 10.26508/lsa.202402765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 07/13/2024] Open
Abstract
PPTC7 is a mitochondrial-localized phosphatase that suppresses BNIP3- and NIX-mediated mitophagy, but the mechanisms underlying this regulation remain ill-defined. Here, we demonstrate that loss of PPTC7 upregulates BNIP3 and NIX post-transcriptionally and independent of HIF-1α stabilization. Loss of PPTC7 prolongs the half-life of BNIP3 and NIX while blunting their accumulation in response to proteasomal inhibition, suggesting that PPTC7 promotes the ubiquitin-mediated turnover of BNIP3 and NIX. Consistently, overexpression of PPTC7 limits the accumulation of BNIP3 and NIX protein levels, which requires an intact catalytic motif but is surprisingly independent of its targeting to mitochondria. Consistently, we find that PPTC7 is dual-localized to the outer mitochondrial membrane and the matrix. Importantly, anchoring PPTC7 to the outer mitochondrial membrane is sufficient to blunt BNIP3 and NIX accumulation, and proximity labeling and fluorescence co-localization experiments demonstrate that PPTC7 dynamically associates with BNIP3 and NIX within the native cellular environment. Collectively, these data reveal that a fraction of PPTC7 localizes to the outer mitochondrial membrane to promote the proteasomal turnover of BNIP3 and NIX, limiting basal mitophagy.
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Affiliation(s)
- Lianjie Wei
- https://ror.org/04cf69335 Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Mehmet Oguz Gok
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jordyn D Svoboda
- https://ror.org/04cf69335 Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Keri-Lyn Kozul
- https://ror.org/04cf69335 Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Merima Forny
- https://ror.org/04cf69335 Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Jonathan R Friedman
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Natalie M Niemi
- https://ror.org/04cf69335 Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
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2
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Pareek G, Kundu M. Physiological functions of ULK1/2. J Mol Biol 2024; 436:168472. [PMID: 38311233 DOI: 10.1016/j.jmb.2024.168472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/10/2024]
Abstract
UNC-51-like kinases 1 and 2 (ULK1/2) are serine/threonine kinases that are best known for their evolutionarily conserved role in the autophagy pathway. Upon sensing the nutrient status of a cell, ULK1/2 integrate signals from upstream cellular energy sensors such as mTOR and AMPK and relay them to the downstream components of the autophagy machinery. ULK1/2 also play indispensable roles in the selective autophagy pathway, removing damaged mitochondria, invading pathogens, and toxic protein aggregates. Additional functions of ULK1/2 have emerged beyond autophagy, including roles in protein trafficking, RNP granule dynamics, and signaling events impacting innate immunity, axon guidance, cellular homeostasis, and cell fate. Therefore, it is no surprise that alterations in ULK1/2 expression and activity have been linked with pathophysiological processes, including cancer, neurological disorders, and cardiovascular diseases. Growing evidence suggests that ULK1/2 function as biological rheostats, tuning cellular functions to intra and extra-cellular cues. Given their broad physiological relevance, ULK1/2 are candidate targets for small molecule activators or inhibitors that may pave the way for the development of therapeutics for the treatment of diseases in humans.
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Affiliation(s)
- Gautam Pareek
- Cell and Molecular Biology Department, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Mondira Kundu
- Cell and Molecular Biology Department, St. Jude Children's Research Hospital, Memphis, TN, USA.
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3
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Nguyen-Dien GT, Townsend B, Kulkarni PG, Kozul KL, Ooi SS, Eldershaw DN, Weeratunga S, Liu M, Jones MJ, Millard SS, Ng DC, Pagano M, Bonfim-Melo A, Schneider T, Komander D, Lazarou M, Collins BM, Pagan JK. PPTC7 antagonizes mitophagy by promoting BNIP3 and NIX degradation via SCF FBXL4. EMBO Rep 2024; 25:3324-3347. [PMID: 38992176 PMCID: PMC11316107 DOI: 10.1038/s44319-024-00181-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 07/13/2024] Open
Abstract
Mitophagy must be carefully regulated to ensure that cells maintain appropriate numbers of functional mitochondria. The SCFFBXL4 ubiquitin ligase complex suppresses mitophagy by controlling the degradation of BNIP3 and NIX mitophagy receptors, and FBXL4 mutations result in mitochondrial disease as a consequence of elevated mitophagy. Here, we reveal that the mitochondrial phosphatase PPTC7 is an essential cofactor for SCFFBXL4-mediated destruction of BNIP3 and NIX, suppressing both steady-state and induced mitophagy. Disruption of the phosphatase activity of PPTC7 does not influence BNIP3 and NIX turnover. Rather, a pool of PPTC7 on the mitochondrial outer membrane acts as an adaptor linking BNIP3 and NIX to FBXL4, facilitating the turnover of these mitophagy receptors. PPTC7 accumulates on the outer mitochondrial membrane in response to mitophagy induction or the absence of FBXL4, suggesting a homoeostatic feedback mechanism that attenuates high levels of mitophagy. We mapped critical residues required for PPTC7-BNIP3/NIX and PPTC7-FBXL4 interactions and their disruption interferes with both BNIP3/NIX degradation and mitophagy suppression. Collectively, these findings delineate a complex regulatory mechanism that restricts BNIP3/NIX-induced mitophagy.
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Affiliation(s)
- Giang Thanh Nguyen-Dien
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
- Department of Biotechnology, School of Biotechnology, Viet Nam National University-International University, Ho Chi Minh City, Vietnam
| | - Brendan Townsend
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Prajakta Gosavi Kulkarni
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Keri-Lyn Kozul
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, MO, 63110, St Louis, USA
| | - Soo Siang Ooi
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Denaye N Eldershaw
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, QLD, 4072, Australia
| | - Saroja Weeratunga
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, QLD, 4072, Australia
| | - Meihan Liu
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, QLD, 4072, Australia
| | - Mathew Jk Jones
- The University of Queensland Frazer Institute, Faculty of Medicine, The University of Queensland, Brisbane, QLD, 4102, Australia
- School of Chemistry & Molecular Biosciences, University of Queensland, Brisbane, QLD, 4072, Australia
| | - S Sean Millard
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Dominic Ch Ng
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Michele Pagano
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
- Perlmutter Cancer Center, New York University Grossman School of Medicine, New York, NY, 10016, USA
- Howard Hughes Medical Institute, New York University Grossman School of Medicine, New York, NY, 10065, USA
| | - Alexis Bonfim-Melo
- The University of Queensland Frazer Institute, Faculty of Medicine, The University of Queensland, Brisbane, QLD, 4102, Australia
| | - Tobias Schneider
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, VIC, 3068, Australia
| | - David Komander
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, VIC, 3068, Australia
| | - Michael Lazarou
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3068, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, VIC, 3068, Australia
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Brett M Collins
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, QLD, 4072, Australia.
| | - Julia K Pagan
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia.
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4
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Pradeepkiran JA, Baig J, Seman A, Reddy PH. Mitochondria in Aging and Alzheimer's Disease: Focus on Mitophagy. Neuroscientist 2024; 30:440-457. [PMID: 36597577 DOI: 10.1177/10738584221139761] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Alzheimer's disease (AD) is characterized by the accumulation of amyloid β and phosphorylated τ protein aggregates in the brain, which leads to the loss of neurons. Under the microscope, the function of mitochondria is uniquely primed to play a pivotal role in neuronal cell survival, energy metabolism, and cell death. Research studies indicate that mitochondrial dysfunction, excessive oxidative damage, and defective mitophagy in neurons are early indicators of AD. This review article summarizes the latest development of mitochondria in AD: 1) disease mechanism pathways, 2) the importance of mitochondria in neuronal functions, 3) metabolic pathways and functions, 4) the link between mitochondrial dysfunction and mitophagy mechanisms in AD, and 5) the development of potential mitochondrial-targeted therapeutics and interventions to treat patients with AD.
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Affiliation(s)
| | - Javaria Baig
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Ashley Seman
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of Nutritional Sciences, College of Human Sciences, Texas Tech University, Lubbock, TX, USA
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of Neurology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of Public Health, Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of Speech, Language, and Hearing Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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5
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Restrepo LJ, Baehrecke EH. Regulation and Functions of Autophagy During Animal Development. J Mol Biol 2024; 436:168473. [PMID: 38311234 PMCID: PMC11260256 DOI: 10.1016/j.jmb.2024.168473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/10/2024]
Abstract
Autophagy is used to degrade cytoplasmic materials, and is critical to maintain cell and organismal health in diverse animals. Here we discuss the regulation, utilization and impact of autophagy on development, including roles in oogenesis, spermatogenesis and embryogenesis in animals. We also describe how autophagy influences postembryonic development in the context of neuronal and cardiac development, wound healing, and tissue regeneration. We describe recent studies of selective autophagy during development, including mitochondria-selective autophagy and endoplasmic reticulum (ER)-selective autophagy. Studies of developing model systems have also been used to discover novel regulators of autophagy, and we explain how studies of autophagy in these physiologically relevant systems are advancing our understanding of this important catabolic process.
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Affiliation(s)
- Lucas J Restrepo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605 USA
| | - Eric H Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605 USA.
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6
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Zenge C, Ordureau A. Ubiquitin system mutations in neurological diseases. Trends Biochem Sci 2024:S0968-0004(24)00154-3. [PMID: 38972780 DOI: 10.1016/j.tibs.2024.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/31/2024] [Accepted: 06/12/2024] [Indexed: 07/09/2024]
Abstract
Neuronal ubiquitin balance impacts the fate of countless cellular proteins, and its disruption is associated with various neurological disorders. The ubiquitin system is critical for proper neuronal cell state transitions and the clearance of misfolded or aggregated proteins that threaten cellular integrity. This article reviews the state of and recent advancements in our understanding of the disruptions to components of the ubiquitin system, in particular E3 ligases and deubiquitylases, in neurodevelopmental and neurodegenerative diseases. Specific focus is on enzymes with recent progress in their characterization, including identifying enzyme-substrate pairs, the use of stem cell and animal models, and the development of therapeutics for ubiquitin-related diseases.
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Affiliation(s)
- Colin Zenge
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Louis V. Gerstner, Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Alban Ordureau
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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7
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Yi SA, Sepic S, Schulman BA, Ordureau A, An H. mTORC1-CTLH E3 ligase regulates the degradation of HMG-CoA synthase 1 through the Pro/N-degron pathway. Mol Cell 2024; 84:2166-2184.e9. [PMID: 38788716 PMCID: PMC11186538 DOI: 10.1016/j.molcel.2024.04.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/15/2024] [Accepted: 04/30/2024] [Indexed: 05/26/2024]
Abstract
Mammalian target of rapamycin (mTOR) senses changes in nutrient status and stimulates the autophagic process to recycle amino acids. However, the impact of nutrient stress on protein degradation beyond autophagic turnover is incompletely understood. We report that several metabolic enzymes are proteasomal targets regulated by mTOR activity based on comparative proteome degradation analysis. In particular, 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A (CoA) synthase 1 (HMGCS1), the initial enzyme in the mevalonate pathway, exhibits the most significant half-life adaptation. Degradation of HMGCS1 is regulated by the C-terminal to LisH (CTLH) E3 ligase through the Pro/N-degron motif. HMGCS1 is ubiquitylated on two C-terminal lysines during mTORC1 inhibition, and efficient degradation of HMGCS1 in cells requires a muskelin adaptor. Importantly, modulating HMGCS1 abundance has a dose-dependent impact on cell proliferation, which is restored by adding a mevalonate intermediate. Overall, our unbiased degradomics study provides new insights into mTORC1 function in cellular metabolism: mTORC1 regulates the stability of limiting metabolic enzymes through the ubiquitin system.
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Affiliation(s)
- Sang Ah Yi
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Sara Sepic
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany; Technical University of Munich, School of Natural Sciences, Munich, Germany
| | - Brenda A Schulman
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany; Technical University of Munich, School of Natural Sciences, Munich, Germany; Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Alban Ordureau
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Heeseon An
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Tri-Institutional PhD Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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8
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Watzlawik JO, Fiesel FC, Fiorino G, Bustillos BA, Baninameh Z, Markham BN, Hou X, Hayes CS, Bredenberg JM, Kurchaba NW, Fričová D, Siuda J, Wszolek ZK, Noda S, Sato S, Hattori N, Prasad AA, Kirik D, Fox HS, Stauch KL, Goldberg MS, Springer W. Basal activity of PINK1 and PRKN in cell models and rodent brain. Autophagy 2024; 20:1147-1158. [PMID: 38041584 PMCID: PMC11135862 DOI: 10.1080/15548627.2023.2286414] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/15/2023] [Indexed: 12/03/2023] Open
Abstract
The ubiquitin kinase-ligase pair PINK1-PRKN recognizes and transiently labels damaged mitochondria with ubiquitin phosphorylated at Ser65 (p-S65-Ub) to mediate their selective degradation (mitophagy). Complete loss of PINK1 or PRKN function unequivocally leads to early-onset Parkinson disease, but it is debated whether impairments in mitophagy contribute to disease later in life. While the pathway has been extensively studied in cell culture upon acute and massive mitochondrial stress, basal levels of activation under endogenous conditions and especially in vivo in the brain remain undetermined. Using rodent samples, patient-derived cells, and isogenic neurons, we here identified age-dependent, brain region-, and cell type-specific effects and determined expression levels and extent of basal and maximal activation of PINK1 and PRKN. Our work highlights the importance of defining critical risk and therapeutically relevant levels of PINK1-PRKN signaling which will further improve diagnosis and prognosis and will lead to better stratification of patients for future clinical trials.
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Affiliation(s)
| | - Fabienne C. Fiesel
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience PhD Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Gabriella Fiorino
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience PhD Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | | | - Zahra Baninameh
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | | | - Xu Hou
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Caleb S. Hayes
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | | | | | | | - Joanna Siuda
- Department of Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | | | - Sachiko Noda
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Shigeto Sato
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Asheeta A. Prasad
- Faculty of Medicine and Health, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Deniz Kirik
- Faculty of Medicine and Health, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Howard S. Fox
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Kelly L. Stauch
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Matthew S. Goldberg
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wolfdieter Springer
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience PhD Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
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9
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Nam KH, Ordureau A. How does the neuronal proteostasis network react to cellular cues? Biochem Soc Trans 2024; 52:581-592. [PMID: 38488108 DOI: 10.1042/bst20230316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 04/25/2024]
Abstract
Even though neurons are post-mitotic cells, they still engage in protein synthesis to uphold their cellular content balance, including for organelles, such as the endoplasmic reticulum or mitochondria. Additionally, they expend significant energy on tasks like neurotransmitter production and maintaining redox homeostasis. This cellular homeostasis is upheld through a delicate interplay between mRNA transcription-translation and protein degradative pathways, such as autophagy and proteasome degradation. When faced with cues such as nutrient stress, neurons must adapt by altering their proteome to survive. However, in many neurodegenerative disorders, such as Parkinson's disease, the pathway and processes for coping with cellular stress are impaired. This review explores neuronal proteome adaptation in response to cellular stress, such as nutrient stress, with a focus on proteins associated with autophagy, stress response pathways, and neurotransmitters.
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Affiliation(s)
- Ki Hong Nam
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, U.S.A
| | - Alban Ordureau
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, U.S.A
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10
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Zhou X, Lee YK, Li X, Kim H, Sanchez-Priego C, Han X, Tan H, Zhou S, Fu Y, Purtell K, Wang Q, Holstein GR, Tang B, Peng J, Yang N, Yue Z. Integrated proteomics reveals autophagy landscape and an autophagy receptor controlling PKA-RI complex homeostasis in neurons. Nat Commun 2024; 15:3113. [PMID: 38600097 PMCID: PMC11006854 DOI: 10.1038/s41467-024-47440-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 04/02/2024] [Indexed: 04/12/2024] Open
Abstract
Autophagy is a conserved, catabolic process essential for maintaining cellular homeostasis. Malfunctional autophagy contributes to neurodevelopmental and neurodegenerative diseases. However, the exact role and targets of autophagy in human neurons remain elusive. Here we report a systematic investigation of neuronal autophagy targets through integrated proteomics. Deep proteomic profiling of multiple autophagy-deficient lines of human induced neurons, mouse brains, and brain LC3-interactome reveals roles of neuronal autophagy in targeting proteins of multiple cellular organelles/pathways, including endoplasmic reticulum (ER), mitochondria, endosome, Golgi apparatus, synaptic vesicle (SV) for degradation. By combining phosphoproteomics and functional analysis in human and mouse neurons, we uncovered a function of neuronal autophagy in controlling cAMP-PKA and c-FOS-mediated neuronal activity through selective degradation of the protein kinase A - cAMP-binding regulatory (R)-subunit I (PKA-RI) complex. Lack of AKAP11 causes accumulation of the PKA-RI complex in the soma and neurites, demonstrating a constant clearance of PKA-RI complex through AKAP11-mediated degradation in neurons. Our study thus reveals the landscape of autophagy degradation in human neurons and identifies a physiological function of autophagy in controlling homeostasis of PKA-RI complex and specific PKA activity in neurons.
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Affiliation(s)
- Xiaoting Zhou
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - You-Kyung Lee
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Xianting Li
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Henry Kim
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Carlos Sanchez-Priego
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Institute for Regenerative Medicine, Alper Center for Neural Development and Regeneration, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Xian Han
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Haiyan Tan
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Suiping Zhou
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Yingxue Fu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Kerry Purtell
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Qian Wang
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Gay R Holstein
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Junmin Peng
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
| | - Nan Yang
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Institute for Regenerative Medicine, Alper Center for Neural Development and Regeneration, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| | - Zhenyu Yue
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Center of Parkinson's Disease Neurobiology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY, 10029, USA.
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11
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Pigeon J, Hassan BA. Timing neurogenesis: a clock or an algorithm? Curr Opin Genet Dev 2024; 85:102156. [PMID: 38354530 DOI: 10.1016/j.gde.2024.102156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 02/16/2024]
Abstract
Emerging evidence supports the existence of dedicated molecular mechanisms under evolutionary selection to control time during neurogenesis. Here, we briefly review these mechanisms and discuss a potentially useful conceptual framework inspired by computer science to think about how these biological mechanisms operate during brain development and evolution.
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Affiliation(s)
- Julien Pigeon
- Institut du Cerveau-Paris Brain Institute (ICM), Sorbonne Université, Inserm, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Bassem A Hassan
- Institut du Cerveau-Paris Brain Institute (ICM), Sorbonne Université, Inserm, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.
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12
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Nagayach A, Wang C. Autophagy in neural stem cells and glia for brain health and diseases. Neural Regen Res 2024; 19:729-736. [PMID: 37843206 PMCID: PMC10664120 DOI: 10.4103/1673-5374.382227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/19/2023] [Accepted: 07/14/2023] [Indexed: 10/17/2023] Open
Abstract
Autophagy is a multifaceted cellular process that not only maintains the homeostatic and adaptive responses of the brain but is also dynamically involved in the regulation of neural cell generation, maturation, and survival. Autophagy facilities the utilization of energy and the microenvironment for developing neural stem cells. Autophagy arbitrates structural and functional remodeling during the cell differentiation process. Autophagy also plays an indispensable role in the maintenance of stemness and homeostasis in neural stem cells during essential brain physiology and also in the instigation and progression of diseases. Only recently, studies have begun to shed light on autophagy regulation in glia (microglia, astrocyte, and oligodendrocyte) in the brain. Glial cells have attained relatively less consideration despite their unquestioned influence on various aspects of neural development, synaptic function, brain metabolism, cellular debris clearing, and restoration of damaged or injured tissues. Thus, this review composes pertinent information regarding the involvement of autophagy in neural stem cells and glial regulation and the role of this connexion in normal brain functions, neurodevelopmental disorders, and neurodegenerative diseases. This review will provide insight into establishing a concrete strategic approach for investigating pathological mechanisms and developing therapies for brain diseases.
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Affiliation(s)
- Aarti Nagayach
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Chenran Wang
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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13
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Kraus F, He Y, Swarup S, Overmyer KA, Jiang Y, Brenner J, Capitanio C, Bieber A, Jen A, Nightingale NM, Anderson BJ, Lee C, Paulo JA, Smith IR, Plitzko JM, Schulman BA, Wilfling F, Coon JJ, Wade Harper J. Lysosomal storage disease proteo/lipidomic profiling using nMOST links ferritinophagy with mitochondrial iron deficiencies in cells lacking NPC2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586828. [PMID: 38585873 PMCID: PMC10996675 DOI: 10.1101/2024.03.26.586828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Lysosomal storage diseases (LSDs) comprised ~50 monogenic diseases characterized by the accumulation of cellular material in lysosomes and associated defects in lysosomal function, but systematic molecular phenotyping is lacking. Here, we develop a nanoflow-based multi-omic single-shot technology (nMOST) workflow allowing simultaneously quantify HeLa cell proteomes and lipidomes from more than two dozen LSD mutants, revealing diverse molecular phenotypes. Defects in delivery of ferritin and its autophagic receptor NCOA4 to lysosomes (ferritinophagy) were pronounced in NPC2-/- cells, which correlated with increased lyso-phosphatidylcholine species and multi-lamellar membrane structures visualized by cryo-electron-tomography. Ferritinophagy defects correlated with loss of mitochondrial cristae, MICOS-complex components, and electron transport chain complexes rich in iron-sulfur cluster proteins. Strikingly, mitochondrial defects were alleviated when iron was provided through the transferrin system. This resource reveals how defects in lysosomal function can impact mitochondrial homeostasis in trans and highlights nMOST as a discovery tool for illuminating molecular phenotypes across LSDs.
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Affiliation(s)
- Felix Kraus
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- equal contribution
| | - Yuchen He
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- equal contribution
| | - Sharan Swarup
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- equal contribution
| | - Katherine A Overmyer
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53715, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Yizhi Jiang
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Johann Brenner
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt, Germany
- CryoEM Technology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Cristina Capitanio
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Anna Bieber
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Annie Jen
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Nicole M Nightingale
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Benton J Anderson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Chan Lee
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Joao A Paulo
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ian R Smith
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jürgen M Plitzko
- CryoEM Technology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Brenda A Schulman
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Joshua J Coon
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53715, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - J Wade Harper
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
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14
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Hoyer MJ, Capitanio C, Smith IR, Paoli JC, Bieber A, Jiang Y, Paulo JA, Gonzalez-Lozano MA, Baumeister W, Wilfling F, Schulman BA, Harper JW. Combinatorial selective ER-phagy remodels the ER during neurogenesis. Nat Cell Biol 2024; 26:378-392. [PMID: 38429475 PMCID: PMC10940164 DOI: 10.1038/s41556-024-01356-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 01/11/2024] [Indexed: 03/03/2024]
Abstract
The endoplasmic reticulum (ER) employs a diverse proteome landscape to orchestrate many cellular functions, ranging from protein and lipid synthesis to calcium ion flux and inter-organelle communication. A case in point concerns the process of neurogenesis, where a refined tubular ER network is assembled via ER shaping proteins into the newly formed neuronal projections to create highly polarized dendrites and axons. Previous studies have suggested a role for autophagy in ER remodelling, as autophagy-deficient neurons in vivo display axonal ER accumulation within synaptic boutons, and the membrane-embedded ER-phagy receptor FAM134B has been genetically linked with human sensory and autonomic neuropathy. However, our understanding of the mechanisms underlying selective removal of the ER and the role of individual ER-phagy receptors is limited. Here we combine a genetically tractable induced neuron (iNeuron) system for monitoring ER remodelling during in vitro differentiation with proteomic and computational tools to create a quantitative landscape of ER proteome remodelling via selective autophagy. Through analysis of single and combinatorial ER-phagy receptor mutants, we delineate the extent to which each receptor contributes to both the magnitude and selectivity of ER protein clearance. We define specific subsets of ER membrane or lumenal proteins as preferred clients for distinct receptors. Using spatial sensors and flux reporters, we demonstrate receptor-specific autophagic capture of ER in axons, and directly visualize tubular ER membranes within autophagosomes in neuronal projections by cryo-electron tomography. This molecular inventory of ER proteome remodelling and versatile genetic toolkit provide a quantitative framework for understanding the contributions of individual ER-phagy receptors for reshaping ER during cell state transitions.
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Affiliation(s)
- Melissa J Hoyer
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Cristina Capitanio
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Ian R Smith
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Velia Therapeutics, San Diego, CA, USA
| | - Julia C Paoli
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Anna Bieber
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Yizhi Jiang
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Miguel A Gonzalez-Lozano
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Wolfgang Baumeister
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Wilfling
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Brenda A Schulman
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
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15
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Molinari M. ER remodelling by ER-phagy in neurogenesis. Nat Cell Biol 2024; 26:316-317. [PMID: 38429474 DOI: 10.1038/s41556-024-01362-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Affiliation(s)
- Maurizio Molinari
- Università della Svizzera italiana, Institute for Research in Biomedicine, Bellinzona, Switzerland.
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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16
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Magnati S, Alladio E, Bracco E. A Survey on the Expression of the Ubiquitin Proteasome System Components HECT- and RBR-E3 Ubiquitin Ligases and E2 Ubiquitin-Conjugating and E1 Ubiquitin-Activating Enzymes during Human Brain Development. Int J Mol Sci 2024; 25:2361. [PMID: 38397039 PMCID: PMC10889685 DOI: 10.3390/ijms25042361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
Human brain development involves a tightly regulated sequence of events that starts shortly after conception and continues up to adolescence. Before birth, neurogenesis occurs, implying an extensive differentiation process, sustained by changes in the gene expression profile alongside proteome remodeling, regulated by the ubiquitin proteasome system (UPS) and autophagy. The latter processes rely on the selective tagging with ubiquitin of the proteins that must be disposed of. E3 ubiquitin ligases accomplish the selective recognition of the target proteins. At the late stage of neurogenesis, the brain starts to take shape, and neurons migrate to their designated locations. After birth, neuronal myelination occurs, and, in parallel, neurons form connections among each other throughout the synaptogenesis process. Due to the malfunctioning of UPS components, aberrant brain development at the very early stages leads to neurodevelopmental disorders. Through deep data mining and analysis and by taking advantage of machine learning-based models, we mapped the transcriptomic profile of the genes encoding HECT- and ring-between-ring (RBR)-E3 ubiquitin ligases as well as E2 ubiquitin-conjugating and E1 ubiquitin-activating enzymes during human brain development, from early post-conception to adulthood. The inquiry outcomes unveiled some implications for neurodevelopment-related disorders.
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Affiliation(s)
- Stefano Magnati
- Centro Regionale Anti Doping—A. Bertinaria, Orbassano, 10043 Turin, Italy;
- Politecnico di Torino, 10129, Turin, Italy
| | - Eugenio Alladio
- Centro Regionale Anti Doping—A. Bertinaria, Orbassano, 10043 Turin, Italy;
- Department of Chemistry, University of Turin, 10125 Turin, Italy
| | - Enrico Bracco
- Department of Oncology, University of Turin, 10043 Orbassano, Italy
- Istituto Nazionale Ricerca Metrologica, 10135 Turin, Italy
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17
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Wei L, Oguz Gok M, Svoboda JD, Forny M, Friedman JR, Niemi NM. PPTC7 limits mitophagy through proximal and dynamic interactions with BNIP3 and NIX. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.24.576953. [PMID: 38328188 PMCID: PMC10849627 DOI: 10.1101/2024.01.24.576953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
PPTC7 is a mitochondrial-localized PP2C phosphatase that maintains mitochondrial protein content and metabolic homeostasis. We previously demonstrated that knockout of Pptc7 elevates mitophagy in a BNIP3- and NIX-dependent manner, but the mechanisms by which PPTC7 influences receptor-mediated mitophagy remain ill-defined. Here, we demonstrate that loss of PPTC7 upregulates BNIP3 and NIX post-transcriptionally and independent of HIF-1α stabilization. On a molecular level, loss of PPTC7 prolongs the half-life of BNIP3 and NIX while blunting their accumulation in response to proteasomal inhibition, suggesting that PPTC7 promotes the ubiquitin-mediated turnover of BNIP3 and NIX. Consistently, overexpression of PPTC7 limits the accumulation of BNIP3 and NIX protein levels in response to pseudohypoxia, a well-known inducer of mitophagy. This PPTC7-mediated suppression of BNIP3 and NIX protein expression requires an intact PP2C catalytic motif but is surprisingly independent of its mitochondrial targeting, indicating that PPTC7 influences mitophagy outside of the mitochondrial matrix. We find that PPTC7 exists in at least two distinct states in cells: a longer isoform, which likely represents full length protein, and a shorter isoform, which likely represents an imported, matrix-localized phosphatase pool. Importantly, anchoring PPTC7 to the outer mitochondrial membrane is sufficient to blunt BNIP3 and NIX accumulation, and proximity labeling and fluorescence co-localization experiments suggest that PPTC7 associates with BNIP3 and NIX within the native cellular environment. Importantly, these associations are enhanced in cellular conditions that promote BNIP3 and NIX turnover, demonstrating that PPTC7 is dynamically recruited to BNIP3 and NIX to facilitate their degradation. Collectively, these data reveal that a fraction of PPTC7 dynamically localizes to the outer mitochondrial membrane to promote the proteasomal turnover of BNIP3 and NIX.
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Affiliation(s)
- Lianjie Wei
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
| | - Mehmet Oguz Gok
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jordyn D. Svoboda
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
| | - Merima Forny
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
| | - Jonathan R. Friedman
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Natalie M. Niemi
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
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18
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König T, McBride HM. Mitochondrial-derived vesicles in metabolism, disease, and aging. Cell Metab 2024; 36:21-35. [PMID: 38171335 DOI: 10.1016/j.cmet.2023.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/16/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024]
Abstract
Mitochondria are central hubs of cellular metabolism and are tightly connected to signaling pathways. The dynamic plasticity of mitochondria to fuse, divide, and contact other organelles to flux metabolites is central to their function. To ensure bona fide functionality and signaling interconnectivity, diverse molecular mechanisms evolved. An ancient and long-overlooked mechanism is the generation of mitochondrial-derived vesicles (MDVs) that shuttle selected mitochondrial cargoes to target organelles. Just recently, we gained significant insight into the mechanisms and functions of MDV transport, ranging from their role in mitochondrial quality control to immune signaling, thus demonstrating unexpected and diverse physiological aspects of MDV transport. This review highlights the origin of MDVs, their biogenesis, and their cargo selection, with a specific focus on the contribution of MDV transport to signaling across cell and organ barriers. Additionally, the implications of MDVs in peroxisome biogenesis, neurodegeneration, metabolism, aging, and cancer are discussed.
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Affiliation(s)
- Tim König
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Heidi M McBride
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
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19
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Dai S, Feng Y, Lu C, Zhang H, Ma W, Xie W, Wu X, Luo P, Zhang L, Fei F, Fei Z, Li X. Impairment of Autophagic Flux After Hypobaric Hypoxia Potentiates Oxidative Stress and Cognitive Function Disturbances in Mice. Neurosci Bull 2024; 40:35-49. [PMID: 37608137 PMCID: PMC10774493 DOI: 10.1007/s12264-023-01099-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 06/01/2023] [Indexed: 08/24/2023] Open
Abstract
Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude sickness. Autophagy plays a critical role in ischemic brain injury, but its role in hypobaric hypoxia (HH) remains unknown. Here we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain, and is partially responsible for HH-induced oxidative stress, neuronal loss, and brain damage. The autophagic agonist rapamycin only promotes the initiation of autophagy. By proteome analysis, a screen showed that protein dynamin2 (DNM2) potentially regulates autophagic flux. Overexpression of DNM2 significantly increased the formation of autolysosomes, thus maintaining autophagic flux in combination with rapamycin. Furthermore, the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH exposure. These results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.
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Affiliation(s)
- Shuhui Dai
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
- National Translational Science Center for Molecular Medicine and Department of Cell Biology, Fourth Military Medical University, Xi'an, 710000, China
| | - Yuan Feng
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Chuanhao Lu
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Hongchen Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Wenke Ma
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
- Department of Neurosurgery, The Central Hospital of Baoji, Baoji, 721000, China
| | - Wenyu Xie
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Xiuquan Wu
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Lei Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Fei Fei
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Zhou Fei
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China.
| | - Xia Li
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China.
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20
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Delgado JM, Shepard LW, Lamson SW, Liu SL, Shoemaker CJ. The ER membrane protein complex restricts mitophagy by controlling BNIP3 turnover. EMBO J 2024; 43:32-60. [PMID: 38177312 PMCID: PMC10883272 DOI: 10.1038/s44318-023-00006-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 11/01/2023] [Accepted: 11/08/2023] [Indexed: 01/06/2024] Open
Abstract
Lysosomal degradation of autophagy receptors is a common proxy for selective autophagy. However, we find that two established mitophagy receptors, BNIP3 and BNIP3L/NIX, are constitutively delivered to lysosomes in an autophagy-independent manner. This alternative lysosomal delivery of BNIP3 accounts for nearly all its lysosome-mediated degradation, even upon mitophagy induction. To identify how BNIP3, a tail-anchored protein in the outer mitochondrial membrane, is delivered to lysosomes, we performed a genome-wide CRISPR screen for factors influencing BNIP3 flux. This screen revealed both known modifiers of BNIP3 stability as well as a pronounced reliance on endolysosomal components, including the ER membrane protein complex (EMC). Importantly, the endolysosomal system and the ubiquitin-proteosome system regulated BNIP3 independently. Perturbation of either mechanism is sufficient to modulate BNIP3-associated mitophagy and affect underlying cellular physiology. More broadly, these findings extend recent models for tail-anchored protein quality control and install endosomal trafficking and lysosomal degradation in the canon of pathways that tightly regulate endogenous tail-anchored protein localization.
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Affiliation(s)
- Jose M Delgado
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Logan Wallace Shepard
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Sarah W Lamson
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Samantha L Liu
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Christopher J Shoemaker
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA.
- Dartmouth Cancer Center, Lebanon, NH, USA.
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21
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Bunker EN, Le Guerroué F, Wang C, Strub M, Werner A, Tjandra N, Youle RJ. Nix interacts with WIPI2 to induce mitophagy. EMBO J 2023; 42:e113491. [PMID: 37621214 PMCID: PMC10646555 DOI: 10.15252/embj.2023113491] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 07/13/2023] [Accepted: 07/15/2023] [Indexed: 08/26/2023] Open
Abstract
Nix is a membrane-anchored outer mitochondrial protein that induces mitophagy. While Nix has an LC3-interacting (LIR) motif that binds to ATG8 proteins, it also contains a minimal essential region (MER) that induces mitophagy through an unknown mechanism. We used chemically induced dimerization (CID) to probe the mechanism of Nix-mediated mitophagy and found that both the LIR and MER are required for robust mitophagy. We find that the Nix MER interacts with the autophagy effector WIPI2 and recruits WIPI2 to mitochondria. The Nix LIR motif is also required for robust mitophagy and converts a homogeneous WIPI2 distribution on the surface of the mitochondria into puncta, even in the absence of ATG8s. Together, this work reveals unanticipated mechanisms in Nix-induced mitophagy and the elusive role of the MER, while also describing an interesting example of autophagy induction that acts downstream of the canonical initiation complexes.
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Affiliation(s)
- Eric N Bunker
- Surgical Neurology BranchNational Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaMDUSA
| | - François Le Guerroué
- Surgical Neurology BranchNational Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaMDUSA
| | - Chunxin Wang
- Surgical Neurology BranchNational Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaMDUSA
| | - Marie‐Paule Strub
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood Institute, National Institutes of HealthBethesdaMDUSA
| | - Achim Werner
- Stem Cell Biochemistry UnitNational Institute of Dental and Craniofacial Research, National Institutes of HealthBethesdaMDUSA
| | - Nico Tjandra
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood Institute, National Institutes of HealthBethesdaMDUSA
| | - Richard J Youle
- Surgical Neurology BranchNational Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaMDUSA
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22
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Hoyer MJ, Capitanio C, Smith IR, Paoli JC, Bieber A, Jiang Y, Paulo JA, Gonzalez-Lozano MA, Baumeister W, Wilfling F, Schulman BA, Harper JW. Combinatorial selective ER-phagy remodels the ER during neurogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546565. [PMID: 37425907 PMCID: PMC10326971 DOI: 10.1101/2023.06.26.546565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The endoplasmic reticulum (ER) employs a diverse proteome landscape to orchestrate many cellular functions ranging from protein and lipid synthesis to calcium ion flux and inter-organelle communication. A case in point concerns the process of neurogenesis: a refined tubular ER network is assembled via ER shaping proteins into the newly formed neuronal projections to create highly polarized dendrites and axons. Previous studies have suggested a role for autophagy in ER remodeling, as autophagy-deficient neurons in vivo display axonal ER accumulation within synaptic boutons, and the membrane-embedded ER-phagy receptor FAM134B has been genetically linked with human sensory and autonomic neuropathy. However, our understanding of the mechanisms underlying selective removal of ER and the role of individual ER-phagy receptors is limited. Here, we combine a genetically tractable induced neuron (iNeuron) system for monitoring ER remodeling during in vitro differentiation with proteomic and computational tools to create a quantitative landscape of ER proteome remodeling via selective autophagy. Through analysis of single and combinatorial ER-phagy receptor mutants, we delineate the extent to which each receptor contributes to both magnitude and selectivity of ER protein clearance. We define specific subsets of ER membrane or lumenal proteins as preferred clients for distinct receptors. Using spatial sensors and flux reporters, we demonstrate receptor-specific autophagic capture of ER in axons, and directly visualize tubular ER membranes within autophagosomes in neuronal projections by cryo-electron tomography. This molecular inventory of ER proteome remodeling and versatile genetic toolkit provides a quantitative framework for understanding contributions of individual ER-phagy receptors for reshaping ER during cell state transitions.
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23
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Hickey KL, Swarup S, Smith IR, Paoli JC, Miguel Whelan E, Paulo JA, Harper JW. Proteome census upon nutrient stress reveals Golgiphagy membrane receptors. Nature 2023; 623:167-174. [PMID: 37757899 PMCID: PMC10620096 DOI: 10.1038/s41586-023-06657-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 09/20/2023] [Indexed: 09/29/2023]
Abstract
During nutrient stress, macroautophagy degrades cellular macromolecules, thereby providing biosynthetic building blocks while simultaneously remodelling the proteome1,2. Although the machinery responsible for initiation of macroautophagy has been well characterized3,4, our understanding of the extent to which individual proteins, protein complexes and organelles are selected for autophagic degradation, and the underlying targeting mechanisms, is limited. Here we use orthogonal proteomic strategies to provide a spatial proteome census of autophagic cargo during nutrient stress in mammalian cells. We find that macroautophagy has selectivity for recycling membrane-bound organelles (principally Golgi and endoplasmic reticulum). Through autophagic cargo prioritization, we identify a complex of membrane-embedded proteins, YIPF3 and YIPF4, as receptors for Golgiphagy. During nutrient stress, YIPF3 and YIPF4 interact with ATG8 proteins through LIR motifs and are mobilized into autophagosomes that traffic to lysosomes in a process that requires the canonical autophagic machinery. Cells lacking YIPF3 or YIPF4 are selectively defective in elimination of a specific cohort of Golgi membrane proteins during nutrient stress. Moreover, YIPF3 and YIPF4 play an analogous role in Golgi remodelling during programmed conversion of stem cells to the neuronal lineage in vitro. Collectively, the findings of this study reveal prioritization of membrane protein cargo during nutrient-stress-dependent proteome remodelling and identify a Golgi remodelling pathway that requires membrane-embedded receptors.
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Affiliation(s)
- Kelsey L Hickey
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Sharan Swarup
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Casma Therapeutics, Cambridge, MA, USA
| | - Ian R Smith
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Velia Therapeutics, San Diego, CA, USA
| | - Julia C Paoli
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | | | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
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24
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Uoselis L, Nguyen TN, Lazarou M. Mitochondrial degradation: Mitophagy and beyond. Mol Cell 2023; 83:3404-3420. [PMID: 37708893 DOI: 10.1016/j.molcel.2023.08.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023]
Abstract
Mitochondria are central hubs of cellular metabolism that also play key roles in signaling and disease. It is therefore fundamentally important that mitochondrial quality and activity are tightly regulated. Mitochondrial degradation pathways contribute to quality control of mitochondrial networks and can also regulate the metabolic profile of mitochondria to ensure cellular homeostasis. Here, we cover the many and varied ways in which cells degrade or remove their unwanted mitochondria, ranging from mitophagy to mitochondrial extrusion. The molecular signals driving these varied pathways are discussed, including the cellular and physiological contexts under which the different degradation pathways are engaged.
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Affiliation(s)
- Louise Uoselis
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia; Aligning Science Across Parkinson's Collaborative Research Network, Chevy Chase, MD 20185, USA
| | - Thanh Ngoc Nguyen
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia; Aligning Science Across Parkinson's Collaborative Research Network, Chevy Chase, MD 20185, USA.
| | - Michael Lazarou
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia; Aligning Science Across Parkinson's Collaborative Research Network, Chevy Chase, MD 20185, USA.
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25
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Wang R, Fortier TM, Chai F, Miao G, Shen JL, Restrepo LJ, DiGiacomo JJ, Velentzas PD, Baehrecke EH. PINK1, Keap1, and Rtnl1 regulate selective clearance of endoplasmic reticulum during development. Cell 2023; 186:4172-4188.e18. [PMID: 37633267 PMCID: PMC10530463 DOI: 10.1016/j.cell.2023.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 04/27/2023] [Accepted: 08/07/2023] [Indexed: 08/28/2023]
Abstract
Selective clearance of organelles, including endoplasmic reticulum (ER) and mitochondria, by autophagy plays an important role in cell health. Here, we describe a developmentally programmed selective ER clearance by autophagy. We show that Parkinson's disease-associated PINK1, as well as Atl, Rtnl1, and Trp1 receptors, regulate ER clearance by autophagy. The E3 ubiquitin ligase Parkin functions downstream of PINK1 and is required for mitochondrial clearance while having the opposite function in ER clearance. By contrast, Keap1 and the E3 ubiquitin ligase Cullin3 function downstream of PINK1 to regulate ER clearance by influencing Rtnl1 and Atl. PINK1 regulates a change in Keap1 localization and Keap1-dependent ubiquitylation of the ER-phagy receptor Rtnl1 to facilitate ER clearance. Thus, PINK1 regulates the selective clearance of ER and mitochondria by influencing the balance of Keap1- and Parkin-dependent ubiquitylation of substrates that determine which organelle is removed by autophagy.
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Affiliation(s)
- Ruoxi Wang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Tina M Fortier
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Fei Chai
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Guangyan Miao
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - James L Shen
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Lucas J Restrepo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Jeromy J DiGiacomo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Panagiotis D Velentzas
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Eric H Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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26
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Elcocks H, Brazel AJ, McCarron KR, Kaulich M, Husnjak K, Mortiboys H, Clague MJ, Urbé S. FBXL4 ubiquitin ligase deficiency promotes mitophagy by elevating NIX levels. EMBO J 2023; 42:e112799. [PMID: 37102372 PMCID: PMC10308357 DOI: 10.15252/embj.2022112799] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/17/2023] [Accepted: 04/09/2023] [Indexed: 04/28/2023] Open
Abstract
Selective autophagy of mitochondria, mitophagy, is linked to mitochondrial quality control and as such is critical to a healthy organism. We have used a CRISPR/Cas9 approach to screen human E3 ubiquitin ligases for influence on mitophagy under both basal cell culture conditions and upon acute mitochondrial depolarization. We identify two cullin-RING ligase substrate receptors, VHL and FBXL4, as the most profound negative regulators of basal mitophagy. We show that these converge, albeit via different mechanisms, on control of the mitophagy adaptors BNIP3 and BNIP3L/NIX. FBXL4 restricts NIX and BNIP3 levels via direct interaction and protein destabilization, while VHL acts through suppression of HIF1α-mediated transcription of BNIP3 and NIX. Depletion of NIX but not BNIP3 is sufficient to restore mitophagy levels. Our study contributes to an understanding of the aetiology of early-onset mitochondrial encephalomyopathy that is supported by analysis of a disease-associated mutation. We further show that the compound MLN4924, which globally interferes with cullin-RING ligase activity, is a strong inducer of mitophagy, thus providing a research tool in this context and a candidate therapeutic agent for conditions linked to mitochondrial dysfunction.
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Affiliation(s)
- Hannah Elcocks
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative BiologyUniversity of LiverpoolLiverpoolUK
| | - Ailbhe J Brazel
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative BiologyUniversity of LiverpoolLiverpoolUK
- Present address:
Department of BiologyMaynooth UniversityMaynoothIreland
| | - Katy R McCarron
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative BiologyUniversity of LiverpoolLiverpoolUK
| | - Manuel Kaulich
- Institute of Biochemistry IIGoethe University, Medical Faculty, University HospitalFrankfurt am MainGermany
- Frankfurt Cancer InstituteFrankfurt am MainGermany
| | - Koraljka Husnjak
- Institute of Biochemistry IIGoethe University, Medical Faculty, University HospitalFrankfurt am MainGermany
| | - Heather Mortiboys
- Sheffield Institute for Translational Neuroscience (SITraN)University of SheffieldSheffieldUK
| | - Michael J Clague
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative BiologyUniversity of LiverpoolLiverpoolUK
| | - Sylvie Urbé
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative BiologyUniversity of LiverpoolLiverpoolUK
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27
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Kraus F, Goodall EA, Smith IR, Jiang Y, Paoli JC, Adolf F, Zhang J, Paulo JA, Schulman BA, Harper JW. PARK15/FBXO7 is dispensable for PINK1/Parkin mitophagy in iNeurons and HeLa cell systems. EMBO Rep 2023:e56399. [PMID: 37334901 PMCID: PMC10398645 DOI: 10.15252/embr.202256399] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 05/16/2023] [Accepted: 06/01/2023] [Indexed: 06/21/2023] Open
Abstract
The protein kinase PINK1 and ubiquitin ligase Parkin promote removal of damaged mitochondria via a feed-forward mechanism involving ubiquitin (Ub) phosphorylation (pUb), Parkin activation, and ubiquitylation of mitochondrial outer membrane proteins to support the recruitment of mitophagy receptors. The ubiquitin ligase substrate receptor FBXO7/PARK15 is mutated in an early-onset parkinsonian-pyramidal syndrome. Previous studies have proposed a role for FBXO7 in promoting Parkin-dependent mitophagy. Here, we systematically examine the involvement of FBXO7 in depolarization and mt UPR-dependent mitophagy in the well-established HeLa and induced-neurons cell systems. We find that FBXO7-/- cells have no demonstrable defect in: (i) kinetics of pUb accumulation, (ii) pUb puncta on mitochondria by super-resolution imaging, (iii) recruitment of Parkin and autophagy machinery to damaged mitochondria, (iv) mitophagic flux, and (v) mitochondrial clearance as quantified by global proteomics. Moreover, global proteomics of neurogenesis in the absence of FBXO7 reveals no obvious alterations in mitochondria or other organelles. These results argue against a general role for FBXO7 in Parkin-dependent mitophagy and point to the need for additional studies to define how FBXO7 mutations promote parkinsonian-pyramidal syndrome.
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Affiliation(s)
- Felix Kraus
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Ellen A Goodall
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Ian R Smith
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Yizhi Jiang
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Julia C Paoli
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Frank Adolf
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jiuchun Zhang
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Joao A Paulo
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Brenda A Schulman
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - J Wade Harper
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
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28
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Kallergi E, Siva Sankar D, Matera A, Kolaxi A, Paolicelli RC, Dengjel J, Nikoletopoulou V. Profiling of purified autophagic vesicle degradome in the maturing and aging brain. Neuron 2023:S0896-6273(23)00384-7. [PMID: 37279748 DOI: 10.1016/j.neuron.2023.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 03/19/2023] [Accepted: 05/11/2023] [Indexed: 06/08/2023]
Abstract
Autophagy disorders prominently affect the brain, entailing neurodevelopmental and neurodegenerative phenotypes in adolescence or aging, respectively. Synaptic and behavioral deficits are largely recapitulated in mouse models with ablation of autophagy genes in brain cells. Yet, the nature and temporal dynamics of brain autophagic substrates remain insufficiently characterized. Here, we immunopurified LC3-positive autophagic vesicles (LC3-pAVs) from the mouse brain and proteomically profiled their content. Moreover, we characterized the LC3-pAV content that accumulates after macroautophagy impairment, validating a brain autophagic degradome. We reveal selective pathways for aggrephagy, mitophagy, and ER-phagy via selective autophagy receptors, and the turnover of numerous synaptic substrates, under basal conditions. To gain insight into the temporal dynamics of autophagic protein turnover, we quantitatively compared adolescent, adult, and aged brains, revealing critical periods of enhanced mitophagy or degradation of synaptic substrates. Overall, this resource unbiasedly characterizes the contribution of autophagy to proteostasis in the maturing, adult, and aged brain.
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Affiliation(s)
- Emmanouela Kallergi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | | | - Alessandro Matera
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Angeliki Kolaxi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | | | - Joern Dengjel
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland.
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29
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Themistokleous C, Bagnoli E, Parulekar R, M K Muqit M. Role of autophagy pathway in Parkinson's disease and related Genetic Neurological disorders. J Mol Biol 2023:168144. [PMID: 37182812 DOI: 10.1016/j.jmb.2023.168144] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023]
Abstract
The elucidation of the function of the PINK1 protein kinase and Parkin ubiquitin E3 ligase in the elimination of damaged mitochondria by autophagy (mitophagy) has provided unprecedented understanding of the mechanistic pathways underlying Parkinson's disease (PD). We provide a comprehensive overview of the general importance of autophagy in Parkinson's disease and related disorders of the central nervous system. This reveals a critical link between autophagy and neurodegenerative and neurodevelopmental disorders and suggests that strategies to modulate mitophagy may have greater relevance in the CNS beyond PD.
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Affiliation(s)
- Christos Themistokleous
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK of Dundee, Dundee, DD1 5EH, UK; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Enrico Bagnoli
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK of Dundee, Dundee, DD1 5EH, UK; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Ramaa Parulekar
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK of Dundee, Dundee, DD1 5EH, UK
| | - Miratul M K Muqit
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK of Dundee, Dundee, DD1 5EH, UK; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA.
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30
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Barone FG, Urbé S, Clague MJ. Segregation of pathways leading to pexophagy. Life Sci Alliance 2023; 6:e202201825. [PMID: 36810161 PMCID: PMC9944197 DOI: 10.26508/lsa.202201825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/12/2023] [Accepted: 02/13/2023] [Indexed: 02/24/2023] Open
Abstract
Peroxisomes are organelles with key roles in metabolism including long-chain fatty acid production. Their metabolic functions overlap and interconnect with those of mitochondria, with which they share an overlapping but distinct proteome. Both organelles are degraded by selective autophagy processes termed pexophagy and mitophagy. Although mitophagy has received intense attention, the pathways linked to pexophagy and associated tools are less well developed. We have identified the neddylation inhibitor MLN4924 as a potent activator of pexophagy and show that this is mediated by the HIF1α-dependent up-regulation of BNIP3L/NIX, a known adaptor for mitophagy. We show that this pathway is distinct from pexophagy induced by the USP30 deubiquitylase inhibitor CMPD-39, for which we identify the adaptor NBR1 as a central player. Our work suggests a level of complexity to the regulation of peroxisome turnover that includes the capacity to coordinate with mitophagy, via NIX, which acts as a rheostat for both processes.
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Affiliation(s)
- Francesco G Barone
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Sylvie Urbé
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Michael J Clague
- Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
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31
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Mauri S, Bernardo G, Martinez A, Favaro M, Trevisan M, Cobraiville G, Fillet M, Caicci F, Whitworth AJ, Ziviani E. USP8 Down-Regulation Promotes Parkin-Independent Mitophagy in the Drosophila Brain and in Human Neurons. Cells 2023; 12:cells12081143. [PMID: 37190052 DOI: 10.3390/cells12081143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 05/17/2023] Open
Abstract
Stress-induced mitophagy, a tightly regulated process that targets dysfunctional mitochondria for autophagy-dependent degradation, mainly relies on two proteins, PINK1 and Parkin, which genes are mutated in some forms of familiar Parkinson's Disease (PD). Upon mitochondrial damage, the protein kinase PINK1 accumulates on the organelle surface where it controls the recruitment of the E3-ubiquitin ligase Parkin. On mitochondria, Parkin ubiquitinates a subset of mitochondrial-resident proteins located on the outer mitochondrial membrane, leading to the recruitment of downstream cytosolic autophagic adaptors and subsequent autophagosome formation. Importantly, PINK1/Parkin-independent mitophagy pathways also exist that can be counteracted by specific deubiquitinating enzymes (DUBs). Down-regulation of these specific DUBs can presumably enhance basal mitophagy and be beneficial in models in which the accumulation of defective mitochondria is implicated. Among these DUBs, USP8 is an interesting target because of its role in the endosomal pathway and autophagy and its beneficial effects, when inhibited, in models of neurodegeneration. Based on this, we evaluated autophagy and mitophagy levels when USP8 activity is altered. We used genetic approaches in D. melanogaster to measure autophagy and mitophagy in vivo and complementary in vitro approaches to investigate the molecular pathway that regulates mitophagy via USP8. We found an inverse correlation between basal mitophagy and USP8 levels, in that down-regulation of USP8 correlates with increased Parkin-independent mitophagy. These results suggest the existence of a yet uncharacterized mitophagic pathway that is inhibited by USP8.
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Affiliation(s)
- Sofia Mauri
- Department of Biology, University of Padova, 35121 Padova, Italy
| | - Greta Bernardo
- Department of Biology, University of Padova, 35121 Padova, Italy
| | - Aitor Martinez
- MRC Mitochondrial Biology Unit, Cambridge Biomedical Campus, University of Cambridge, Cambridge CB2 0XY, UK
| | | | - Marta Trevisan
- Department of Molecular Medicine (DMM), University of Padova, 35121 Padova, Italy
| | - Gael Cobraiville
- Laboratory for the Analysis of Medicines, Center for Interdisciplinary Research on Medicines (CIRM), Quartier Hopital, University of Liege, Avenue Hippocrate 15, 4000 Liege, Belgium
| | - Marianne Fillet
- Laboratory for the Analysis of Medicines, Center for Interdisciplinary Research on Medicines (CIRM), Quartier Hopital, University of Liege, Avenue Hippocrate 15, 4000 Liege, Belgium
| | - Federico Caicci
- Department of Biology, University of Padova, 35121 Padova, Italy
| | - Alexander J Whitworth
- MRC Mitochondrial Biology Unit, Cambridge Biomedical Campus, University of Cambridge, Cambridge CB2 0XY, UK
| | - Elena Ziviani
- Department of Biology, University of Padova, 35121 Padova, Italy
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32
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Gok MO, Connor OM, Wang X, Menezes CJ, Llamas CB, Mishra P, Friedman JR. The outer mitochondrial membrane protein TMEM11 demarcates spatially restricted BNIP3/BNIP3L-mediated mitophagy. J Cell Biol 2023; 222:e202204021. [PMID: 36795401 PMCID: PMC9960330 DOI: 10.1083/jcb.202204021] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 11/30/2022] [Accepted: 01/16/2023] [Indexed: 02/17/2023] Open
Abstract
Mitochondria play critical roles in cellular metabolism and to maintain their integrity, they are regulated by several quality control pathways, including mitophagy. During BNIP3/BNIP3L-dependent receptor-mediated mitophagy, mitochondria are selectively targeted for degradation by the direct recruitment of the autophagy protein LC3. BNIP3 and/or BNIP3L are upregulated situationally, for example during hypoxia and developmentally during erythrocyte maturation. However, it is not well understood how they are spatially regulated within the mitochondrial network to locally trigger mitophagy. Here, we find that the poorly characterized mitochondrial protein TMEM11 forms a complex with BNIP3 and BNIP3L and co-enriches at sites of mitophagosome formation. We find that mitophagy is hyper-active in the absence of TMEM11 during both normoxia and hypoxia-mimetic conditions due to an increase in BNIP3/BNIP3L mitophagy sites, supporting a model that TMEM11 spatially restricts mitophagosome formation.
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Affiliation(s)
- Mehmet Oguz Gok
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Olivia M. Connor
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xun Wang
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Cameron J. Menezes
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Claire B. Llamas
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Prashant Mishra
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jonathan R. Friedman
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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33
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Delgado JM, Wallace Shepard L, Lamson SW, Liu SL, Shoemaker CJ. The ER membrane protein complex governs lysosomal turnover of a mitochondrial tail-anchored protein, BNIP3, to restrict mitophagy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.22.533681. [PMID: 36993512 PMCID: PMC10055395 DOI: 10.1101/2023.03.22.533681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Lysosomal degradation of autophagy receptors is a common proxy for selective autophagy. However, we find that two established mitophagy receptors, BNIP3 and BNIP3L/NIX, violate this assumption. Rather, BNIP3 and NIX are constitutively delivered to lysosomes in an autophagy-independent manner. This alternative lysosomal delivery of BNIP3 accounts for nearly all of its lysosome-mediated degradation, even upon mitophagy induction. To identify how BNIP3, a tail-anchored protein in the outer mitochondrial membrane, is delivered to lysosomes, we performed a genome-wide CRISPR screen for factors influencing BNIP3 flux. By this approach, we revealed both known modifiers of BNIP3 stability as well as a pronounced reliance on endolysosomal components, including the ER membrane protein complex (EMC). Importantly, the endolysosomal system regulates BNIP3 alongside, but independent of, the ubiquitin-proteosome system (UPS). Perturbation of either mechanism is sufficient to modulate BNIP3-associated mitophagy and affect underlying cellular physiology. In short, while BNIP3 can be cleared by parallel and partially compensatory quality control pathways, non-autophagic lysosomal degradation of BNIP3 is a strong post-translational modifier of BNIP3 function. More broadly, these data reveal an unanticipated connection between mitophagy and TA protein quality control, wherein the endolysosomal system provides a critical axis for regulating cellular metabolism. Moreover, these findings extend recent models for tail-anchored protein quality control and install endosomal trafficking and lysosomal degradation in the canon of pathways that ensure tight regulation of endogenous TA protein localization.
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Affiliation(s)
- Jose M Delgado
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Logan Wallace Shepard
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Sarah W Lamson
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Samantha L Liu
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Christopher J Shoemaker
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
- Dartmouth Cancer Center, Lebanon, NH, USA
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34
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Collier JJ, Oláhová M, McWilliams TG, Taylor RW. Mitochondrial signalling and homeostasis: from cell biology to neurological disease. Trends Neurosci 2023; 46:137-152. [PMID: 36635110 DOI: 10.1016/j.tins.2022.12.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/18/2022] [Accepted: 12/05/2022] [Indexed: 01/11/2023]
Abstract
Efforts to understand how mitochondrial dysfunction contributes to neurodegeneration have primarily focussed on the role of mitochondria in neuronal energy metabolism. However, progress in understanding the etiological nature of emerging mitochondrial functions has yielded new ideas about the mitochondrial basis of neurological disease. Studies aimed at deciphering how mitochondria signal through interorganellar contacts, vesicular trafficking, and metabolic transmission have revealed that mitochondrial regulation of immunometabolism, cell death, organelle dynamics, and neuroimmune interplay are critical determinants of neural health. Moreover, the homeostatic mechanisms that exist to protect mitochondrial health through turnover via nanoscale proteostasis and lysosomal degradation have become integrated within mitochondrial signalling pathways to support metabolic plasticity and stress responses in the nervous system. This review highlights how these distinct mitochondrial pathways converge to influence neurological health and contribute to disease pathology.
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Affiliation(s)
- Jack J Collier
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Thomas G McWilliams
- Translational Stem Cell Biology & Metabolism Program, Research Programs Unit, University of Helsinki, Helsinki, Finland; Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders of Adults and Children, Newcastle University, Newcastle upon Tyne, UK.
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35
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Mitochondrial remodelling is essential for female germ cell differentiation and survival. PLoS Genet 2023; 19:e1010610. [PMID: 36696418 PMCID: PMC9901744 DOI: 10.1371/journal.pgen.1010610] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 02/06/2023] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
Stem cells often possess immature mitochondria with few inner membrane invaginations, which increase as stem cells differentiate. Despite this being a conserved feature across many stem cell types in numerous organisms, how and why mitochondria undergo such remodelling during stem cell differentiation has remained unclear. Here, using Drosophila germline stem cells (GSCs), we show that Complex V drives mitochondrial remodelling during the early stages of GSC differentiation, prior to terminal differentiation. This endows germline mitochondria with the capacity to generate large amounts of ATP required for later egg growth and development. Interestingly, impairing mitochondrial remodelling prior to terminal differentiation results in endoplasmic reticulum (ER) lipid bilayer stress, Protein kinase R-like ER kinase (PERK)-mediated activation of the Integrated Stress Response (ISR) and germ cell death. Taken together, our data suggest that mitochondrial remodelling is an essential and tightly integrated aspect of stem cell differentiation. This work sheds light on the potential impact of mitochondrial dysfunction on stem and germ cell function, highlighting ER lipid bilayer stress as a potential major driver of phenotypes caused by mitochondrial dysfunction.
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36
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Sherpa D, Mueller J, Karayel Ö, Xu P, Yao Y, Chrustowicz J, Gottemukkala KV, Baumann C, Gross A, Czarnecki O, Zhang W, Gu J, Nilvebrant J, Sidhu SS, Murray PJ, Mann M, Weiss MJ, Schulman BA, Alpi AF. Modular UBE2H-CTLH E2-E3 complexes regulate erythroid maturation. eLife 2022; 11:77937. [PMID: 36459484 PMCID: PMC9718529 DOI: 10.7554/elife.77937] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 11/24/2022] [Indexed: 12/05/2022] Open
Abstract
The development of haematopoietic stem cells into mature erythrocytes - erythropoiesis - is a controlled process characterized by cellular reorganization and drastic reshaping of the proteome landscape. Failure of ordered erythropoiesis is associated with anaemias and haematological malignancies. Although the ubiquitin system is a known crucial post-translational regulator in erythropoiesis, how the erythrocyte is reshaped by the ubiquitin system is poorly understood. By measuring the proteomic landscape of in vitro human erythropoiesis models, we found dynamic differential expression of subunits of the CTLH E3 ubiquitin ligase complex that formed maturation stage-dependent assemblies of topologically homologous RANBP9- and RANBP10-CTLH complexes. Moreover, protein abundance of CTLH's cognate E2 ubiquitin conjugating enzyme UBE2H increased during terminal differentiation, and UBE2H expression depended on catalytically active CTLH E3 complexes. CRISPR-Cas9-mediated inactivation of CTLH E3 assemblies or UBE2H in erythroid progenitors revealed defects, including spontaneous and accelerated erythroid maturation as well as inefficient enucleation. Thus, we propose that dynamic maturation stage-specific changes of UBE2H-CTLH E2-E3 modules control the orderly progression of human erythropoiesis.
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Affiliation(s)
- Dawafuti Sherpa
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Judith Mueller
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Özge Karayel
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Peng Xu
- Cyrus Tang Medical Institute, National Clinical Research Centre for Hematologic Diseases, Collaborative Innovation Centre of Hematology, State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Department of Hematology, St. Jude Children's Research Hospital, Memphis, United States
| | - Yu Yao
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, United States
| | - Jakub Chrustowicz
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Karthik V Gottemukkala
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Christine Baumann
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Annette Gross
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany.,Department of Immunoregulation, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Oliver Czarnecki
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Wei Zhang
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | - Jun Gu
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Johan Nilvebrant
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Sachdev S Sidhu
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Peter J Murray
- Department of Immunoregulation, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Mitchell J Weiss
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, United States
| | - Brenda A Schulman
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Arno F Alpi
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
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37
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Liang JR, Corn JE. A CRISPR view on autophagy. Trends Cell Biol 2022; 32:1008-1022. [PMID: 35581059 DOI: 10.1016/j.tcb.2022.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 01/21/2023]
Abstract
Autophagy is a fundamental pathway for the degradation of cytoplasmic content in response to pleiotropic extracellular and intracellular stimuli. Recent advances in the autophagy field have demonstrated that different organelles can also be specifically targeted for autophagy with broad implications on cellular and organismal health. This opens new dimensions in the autophagy field and more unanswered questions on the rationale and underlying mechanisms to degrade different organelles. Functional genomics via clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9-based screening has gained popularity in the autophagy field to understand the common and unique factors that are implicated in the signaling, recognition, and execution of different cargo-specific autophagies. We focus on recent applications of CRISPR-based screens in the autophagy field, their discoveries, and the future directions of autophagy screens.
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Affiliation(s)
- Jin Rui Liang
- Department of Biology, Institute of Molecular Health Sciences, ETH Zürich, 8093, Zürich, Switzerland; Medical Research Council, Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
| | - Jacob E Corn
- Department of Biology, Institute of Molecular Health Sciences, ETH Zürich, 8093, Zürich, Switzerland.
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38
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Physiological functions of Mitophagy. CURRENT OPINION IN PHYSIOLOGY 2022. [DOI: 10.1016/j.cophys.2022.100612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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39
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Palozzi JM, Jeedigunta SP, Minenkova AV, Monteiro VL, Thompson ZS, Lieber T, Hurd TR. Mitochondrial DNA quality control in the female germline requires a unique programmed mitophagy. Cell Metab 2022; 34:1809-1823.e6. [PMID: 36323236 DOI: 10.1016/j.cmet.2022.10.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/22/2022] [Accepted: 10/06/2022] [Indexed: 11/07/2022]
Abstract
Mitochondria have their own DNA (mtDNA), which is susceptible to the accumulation of disease-causing mutations. To prevent deleterious mutations from being inherited, the female germline has evolved a conserved quality control mechanism that remains poorly understood. Here, through a large-scale screen, we uncover a unique programmed germline mitophagy (PGM) that is essential for mtDNA quality control. We find that PGM is developmentally triggered as germ cells enter meiosis by inhibition of the target of rapamycin complex 1 (TORC1). We identify a role for the RNA-binding protein Ataxin-2 (Atx2) in coordinating the timing of PGM with meiosis. We show that PGM requires the mitophagy receptor BNIP3, mitochondrial fission and translation factors, and members of the Atg1 complex, but not the mitophagy factors PINK1 and Parkin. Additionally, we report several factors that are critical for germline mtDNA quality control and show that pharmacological manipulation of one of these factors promotes mtDNA quality control.
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Affiliation(s)
- Jonathan M Palozzi
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Swathi P Jeedigunta
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Anastasia V Minenkova
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Vernon L Monteiro
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Zoe S Thompson
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Toby Lieber
- HHMI and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Thomas R Hurd
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada.
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40
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Rappe A, McWilliams TG. Mitophagy in the aging nervous system. Front Cell Dev Biol 2022; 10:978142. [PMID: 36303604 PMCID: PMC9593040 DOI: 10.3389/fcell.2022.978142] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 09/07/2022] [Indexed: 02/01/2024] Open
Abstract
Aging is characterised by the progressive accumulation of cellular dysfunction, stress, and inflammation. A large body of evidence implicates mitochondrial dysfunction as a cause or consequence of age-related diseases including metabolic disorders, neuropathies, various forms of cancer and neurodegenerative diseases. Because neurons have high metabolic demands and cannot divide, they are especially vulnerable to mitochondrial dysfunction which promotes cell dysfunction and cytotoxicity. Mitophagy neutralises mitochondrial dysfunction, providing an adaptive quality control strategy that sustains metabolic homeostasis. Mitophagy has been extensively studied as an inducible stress response in cultured cells and short-lived model organisms. In contrast, our understanding of physiological mitophagy in mammalian aging remains extremely limited, particularly in the nervous system. The recent profiling of mitophagy reporter mice has revealed variegated vistas of steady-state mitochondrial destruction across different tissues. The discovery of patients with congenital autophagy deficiency provokes further intrigue into the mechanisms that underpin neural integrity. These dimensions have considerable implications for targeting mitophagy and other degradative pathways in age-related neurological disease.
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Affiliation(s)
- Anna Rappe
- Translational Stem Cell Biology and Metabolism Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Thomas G. McWilliams
- Translational Stem Cell Biology and Metabolism Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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41
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Elder N, Fattahi F, McDevitt TC, Zholudeva LV. Diseased, differentiated and difficult: Strategies for improved engineering of in vitro neurological systems. Front Cell Neurosci 2022; 16:962103. [PMID: 36238834 PMCID: PMC9550918 DOI: 10.3389/fncel.2022.962103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 08/22/2022] [Indexed: 12/01/2022] Open
Abstract
The rapidly growing field of cellular engineering is enabling scientists to more effectively create in vitro models of disease and develop specific cell types that can be used to repair damaged tissue. In particular, the engineering of neurons and other components of the nervous system is at the forefront of this field. The methods used to engineer neural cells can be largely divided into systems that undergo directed differentiation through exogenous stimulation (i.e., via small molecules, arguably following developmental pathways) and those that undergo induced differentiation via protein overexpression (i.e., genetically induced and activated; arguably bypassing developmental pathways). Here, we highlight the differences between directed differentiation and induced differentiation strategies, how they can complement one another to generate specific cell phenotypes, and impacts of each strategy on downstream applications. Continued research in this nascent field will lead to the development of improved models of neurological circuits and novel treatments for those living with neurological injury and disease.
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Affiliation(s)
- Nicholas Elder
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, United States
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, United States
- Gladstone Institutes, San Francisco, CA, United States
| | - Faranak Fattahi
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, United States
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, United States
| | - Todd C. McDevitt
- Gladstone Institutes, San Francisco, CA, United States
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, United States
- Sana Biotechnology, Inc., South San Francisco, CA, United States
| | - Lyandysha V. Zholudeva
- Gladstone Institutes, San Francisco, CA, United States
- *Correspondence: Lyandysha V. Zholudeva,
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42
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Mauri S, Favaro M, Bernardo G, Mazzotta GM, Ziviani E. Mitochondrial autophagy in the sleeping brain. Front Cell Dev Biol 2022; 10:956394. [PMID: 36092697 PMCID: PMC9449320 DOI: 10.3389/fcell.2022.956394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
A significant percentage of the mitochondrial mass is replaced on a daily basis via mechanisms of mitochondrial quality control. Through mitophagy (a selective type of autophagy that promotes mitochondrial proteostasis) cells keep a healthy pool of mitochondria, and prevent oxidative stress and inflammation. Furthermore, mitophagy helps adapting to the metabolic demand of the cells, which changes on a daily basis.Core components of the mitophagy process are PINK1 and Parkin, which mutations are linked to Parkinson’s Disease. The crucial role of PINK1/Parkin pathway during stress-induced mitophagy has been extensively studied in vitro in different cell types. However, recent advances in the field allowed discovering that mitophagy seems to be only slightly affected in PINK1 KO mice and flies, putting into question the physiological relevance of this pathway in vivo in the whole organism. Indeed, several cell-specific PINK1/Parkin-independent mitophagy pathways have been recently discovered, which appear to be activated under physiological conditions such as those that promote mitochondrial proteome remodeling during differentiation or in response to specific physiological stimuli.In this Mini Review we want to summarize the recent advances in the field, and add another level of complexity by focusing attention on a potentially important aspect of mitophagy regulation: the implication of the circadian clock. Recent works showed that the circadian clock controls many aspects of mitochondrial physiology, including mitochondrial morphology and dynamic, respiratory activity, and ATP synthesis. Furthermore, one of the essential functions of sleep, which is controlled by the clock, is the clearance of toxic metabolic compounds from the brain, including ROS, via mechanisms of proteostasis. Very little is known about a potential role of the clock in the quality control mechanisms that maintain the mitochondrial repertoire healthy during sleep/wake cycles. More importantly, it remains completely unexplored whether (dys)function of mitochondrial proteostasis feedbacks to the circadian clockwork.
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Affiliation(s)
| | | | | | | | - Elena Ziviani
- *Correspondence: Gabriella M. Mazzotta, Elena Ziviani,
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43
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Systematic Functional Analysis of PINK1 and PRKN Coding Variants. Cells 2022; 11:cells11152426. [PMID: 35954270 PMCID: PMC9367835 DOI: 10.3390/cells11152426] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/22/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
Loss of either PINK1 or PRKN causes an early onset Parkinson’s disease (PD) phenotype. Functionally, PINK1 and PRKN work together to mediate stress-activated mitochondrial quality control. Upon mitochondrial damage, PINK1, a ubiquitin kinase and PRKN, a ubiquitin ligase, decorate damaged organelles with phosphorylated ubiquitin for sequestration and degradation in lysosomes, a process known as mitophagy. While several genetic mutations are established to result in loss of mitophagy function, many others have not been extensively characterized and are of unknown significance. Here, we analyzed a set of twenty variants, ten in each gene, focusing on understudied variants mostly from the Parkinson’s progressive marker initiative, with sensitive assays to define potential functional deficits. Our results nominate specific rare genetic PINK1 and PRKN variants that cause loss of enzymatic function in line with a potential causative role for PD. Additionally, we identify several variants with intermediate phenotypes and follow up on two of them by gene editing midbrain-derived neuronal precursor cells. Thereof derived isogenic neurons show a stability defect of the rare PINK1 D525N mutation, while the common PINK1 Q115L substitution results in reduced kinase activity. Our strategy to analyze variants with sensitive functional readouts will help aid diagnostics and disease treatment in line with current genomic and therapeutic advances.
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44
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Nam KH, Ordureau A. Quantitative proteome remodeling characterization of two human reference pluripotent stem cell lines during neurogenesis and cardiomyogenesis. Proteomics 2022; 22:e2100246. [PMID: 35871287 PMCID: PMC10389174 DOI: 10.1002/pmic.202100246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 07/05/2022] [Accepted: 07/18/2022] [Indexed: 11/08/2022]
Abstract
Human pluripotent stem cells (PSCs) have become popular tools within the research community to study developmental and model diseases. While many induced-PSCs (iPSCs) from various genetic background sources are currently available, scientific advancement has been hampered by the considerable phenotypic variations observed between different iPSC lines. A recent collaborative effort selected a novel iPSC line to address this and encourage the adoption of a standardized iPSC line termed KOLF2.1J. Here, leveraging the multiplexing power of isobaric labeling, we systematically investigate, at the 10k proteome level, the relative protein abundance profiles of the KOLF2.1J reference iPSC line upon two distinct cell state differentiation trajectories. In addition, we side-by-side systematically compare this line with the H9 line, an established embryonically derived PSC line that we previously characterized. We noticed differences in the basal proteome of the two cell lines and highlighted the differentially expressed proteins. While the difference between the cell line's proteome subsisted upon differentiation, the global proteome remodeling trajectory was highly similar during the tested differentiation routes. We thus conclude that the KOLF2.1J line performs well at the proteome level upon the neuro and cardiomyogenesis differentiation protocol used. We believe this dataset will serve as a resource of value for the research community.
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Affiliation(s)
- Ki Hong Nam
- Cell Biology Program Sloan Kettering Institute Memorial Sloan Kettering Cancer Center New York New York 10065 USA
| | - Alban Ordureau
- Cell Biology Program Sloan Kettering Institute Memorial Sloan Kettering Cancer Center New York New York 10065 USA
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45
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Goodall EA, Kraus F, Harper JW. Mechanisms underlying ubiquitin-driven selective mitochondrial and bacterial autophagy. Mol Cell 2022; 82:1501-1513. [PMID: 35364016 PMCID: PMC9254164 DOI: 10.1016/j.molcel.2022.03.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/01/2022] [Accepted: 03/04/2022] [Indexed: 01/23/2023]
Abstract
Selective autophagy specifically eliminates damaged or superfluous organelles, maintaining cellular health. In this process, a double membrane structure termed an autophagosome captures target organelles or proteins and delivers this cargo to the lysosome for degradation. The attachment of the small protein ubiquitin to cargo has emerged as a common mechanism for initiating organelle or protein capture by the autophagy machinery. In this process, a suite of ubiquitin-binding cargo receptors function to initiate autophagosome assembly in situ on the target cargo, thereby providing selectivity in cargo capture. Here, we review recent efforts to understand the biochemical mechanisms and principles by which cargo are marked with ubiquitin and how ubiquitin-binding cargo receptors use conserved structural modules to recruit the autophagosome initiation machinery, with a particular focus on mitochondria and intracellular bacteria as cargo. These emerging mechanisms provide answers to long-standing questions in the field concerning how selectivity in cargo degradation is achieved.
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Affiliation(s)
- Ellen A. Goodall
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Felix Kraus
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA,Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - J. Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA,Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
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46
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Goldsmith J, Ordureau A, Harper JW, Holzbaur ELF. Brain-derived autophagosome profiling reveals the engulfment of nucleoid-enriched mitochondrial fragments by basal autophagy in neurons. Neuron 2022; 110:967-976.e8. [PMID: 35051374 PMCID: PMC8930448 DOI: 10.1016/j.neuron.2021.12.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/18/2021] [Accepted: 12/16/2021] [Indexed: 12/20/2022]
Abstract
Neurons depend on autophagy to maintain cellular homeostasis, and defects in autophagy are pathological hallmarks of neurodegenerative disease. To probe the role of basal autophagy in the maintenance of neuronal health, we isolated autophagic vesicles from mouse brain tissue and used proteomics to identify the major cargos engulfed within autophagosomes, validating our findings in rodent primary and human iPSC-derived neurons. Mitochondrial proteins were identified as a major cargo in the absence of mitophagy adaptors such as OPTN. We found that nucleoid-associated proteins are enriched compared with other mitochondrial components. In the axon, autophagic engulfment of nucleoid-enriched mitochondrial fragments requires the mitochondrial fission machinery Drp1. We proposed that localized Drp1-dependent fission of nucleoid-enriched fragments in proximity to the sites of autophagosome biogenesis enhances their capture. The resulting efficient autophagic turnover of nucleoids may prevent accumulation of mitochondrial DNA in the neuron, thus mitigating activation of proinflammatory pathways that contribute to neurodegeneration.
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Affiliation(s)
- Juliet Goldsmith
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Alban Ordureau
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - J Wade Harper
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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47
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Lazarou M. Programmed autophagy prevents excess organelle baggage during neurogenesis. Mol Cell 2021; 81:4960-4961. [PMID: 34919817 DOI: 10.1016/j.molcel.2021.11.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
By putting a proteomic spin on the analysis of neurogenesis, Ordureau et al. (2021) produce a vast resource of information and reveal a program of mitophagy and organelle remodeling, which may play a key role in adapting organelles to a neuronal lineage.
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Affiliation(s)
- Michael Lazarou
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, 3800, Australia.
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