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Kumar A, Waingankar TP, D'Silva P. Seahorse assay for the analysis of mitochondrial respiration using Saccharomyces cerevisiae as a model system. Methods Enzymol 2024; 707:673-683. [PMID: 39488396 DOI: 10.1016/bs.mie.2024.07.061] [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] [Indexed: 11/04/2024]
Abstract
Eukaryotic cells require energy to perform diverse cellular functions critical for survival. Mitochondria are multifunctional organelles that generate energy in the form of Adenosine triphosphate by oxidative phosphorylation, emphasizing their importance to eukaryotic cell viability. The ability of mitochondria to consume oxygen for respiration is a key parameter in assessing mitochondrial health. Therefore, developing new techniques to monitor mitochondrial respiration are crucial for advancing our understanding of organelle functioning. Recently, Seahorse technology has emerged as a valuable tool to analyze various aspects of mitochondrial bioenergetics. Although the Seahorse assay is well established in adherent cell lines and other model organisms, it remains challenging to employ it efficiently in yeast, a powerful genetic system for studying mitochondrial biology. In this chapter, we provide a comprehensive methodology for assessing oxygen consumption rate in baker's yeast using Seahorse.
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Affiliation(s)
- Abhishek Kumar
- Department of Biochemistry, New Biological Sciences Building, Indian Institute of Science, Bangalore, Karnataka, India; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Tejashree Pradip Waingankar
- Department of Biochemistry, New Biological Sciences Building, Indian Institute of Science, Bangalore, Karnataka, India; Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States
| | - Patrick D'Silva
- Department of Biochemistry, New Biological Sciences Building, Indian Institute of Science, Bangalore, Karnataka, India.
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den Brave F, Schulte U, Fakler B, Pfanner N, Becker T. Mitochondrial complexome and import network. Trends Cell Biol 2024; 34:578-594. [PMID: 37914576 DOI: 10.1016/j.tcb.2023.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/02/2023] [Accepted: 10/04/2023] [Indexed: 11/03/2023]
Abstract
Mitochondria perform crucial functions in cellular metabolism, protein and lipid biogenesis, quality control, and signaling. The systematic analysis of protein complexes and interaction networks provided exciting insights into the structural and functional organization of mitochondria. Most mitochondrial proteins do not act as independent units, but are interconnected by stable or dynamic protein-protein interactions. Protein translocases are responsible for importing precursor proteins into mitochondria and form central elements of several protein interaction networks. These networks include molecular chaperones and quality control factors, metabolite channels and respiratory chain complexes, and membrane and organellar contact sites. Protein translocases link the distinct networks into an overarching network, the mitochondrial import network (MitimNet), to coordinate biogenesis, membrane organization and function of mitochondria.
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Affiliation(s)
- Fabian den Brave
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, 53115 Bonn, Germany
| | - Uwe Schulte
- Institute of Physiology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Nikolaus Pfanner
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, 53115 Bonn, Germany.
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Kan KT, Wilcock J, Lu H. Role of Yme1 in mitochondrial protein homeostasis: from regulation of protein import, OXPHOS function to lipid synthesis and mitochondrial dynamics. Biochem Soc Trans 2024; 52:1539-1548. [PMID: 38864432 PMCID: PMC11346431 DOI: 10.1042/bst20240450] [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: 04/16/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/13/2024]
Abstract
Mitochondria are essential organelles of eukaryotic cells and thus mitochondrial proteome is under constant quality control and remodelling. Yme1 is a multi-functional protein and subunit of the homo-hexametric complex i-AAA proteinase. Yme1 plays vital roles in the regulation of mitochondrial protein homeostasis and mitochondrial plasticity, ranging from substrate degradation to the regulation of protein functions involved in mitochondrial protein biosynthesis, energy production, mitochondrial dynamics, and lipid biosynthesis and signalling. In this mini review, we focus on discussing the current understanding of the roles of Yme1 in mitochondrial protein import via TIM22 and TIM23 pathways, oxidative phosphorylation complex function, as well as mitochondrial lipid biosynthesis and signalling, as well as a brief discussion of the role of Yme1 in modulating mitochondrial dynamics.
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Affiliation(s)
- Kwan Ting Kan
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, U.K
| | - Joel Wilcock
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, U.K
| | - Hui Lu
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, U.K
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Disha B, Mathew RP, Dalal AB, Mahato AK, Satyamoorthy K, Singh KK, Thangaraj K, Govindaraj P. Mitochondria in biology and medicine - 2023. Mitochondrion 2024; 76:101853. [PMID: 38423268 DOI: 10.1016/j.mito.2024.101853] [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: 11/27/2023] [Revised: 02/07/2024] [Accepted: 02/14/2024] [Indexed: 03/02/2024]
Abstract
Mitochondria are an indispensable part of the cell that plays a crucial role in regulating various signaling pathways, energy metabolism, cell differentiation, proliferation, and cell death. Since mitochondria have their own genetic material, they differ from their nuclear counterparts, and dysregulation is responsible for a broad spectrum of diseases. Mitochondrial dysfunction is associated with several disorders, including neuro-muscular disorders, cancer, and premature aging, among others. The intricacy of the field is due to the cross-talk between nuclear and mitochondrial genes, which has also improved our knowledge of mitochondrial functions and their pathogenesis. Therefore, interdisciplinary research and communication are crucial for mitochondrial biology and medicine due to the challenges they pose for diagnosis and treatment. The ninth annual conference of the Society for Mitochondria Research and Medicine (SMRM)- India, titled "Mitochondria in Biology and Medicine" was organized at the Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, India, on June 21-23, 2023. The latest advancements in the field of mitochondrial biology and medicine were discussed at the conference. In this article, we summarize the entire event for the benefit of researchers working in the field of mitochondrial biology and medicine.
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Affiliation(s)
- B Disha
- Centre for DNA Fingerprinting and Diagnostics, Uppal, Hyderabad 500039, India; Regional Centre for Biotechnology, Faridabad, Haryana 121001, India
| | - Rohan Peter Mathew
- Centre for DNA Fingerprinting and Diagnostics, Uppal, Hyderabad 500039, India; Manipal Academy of Higher Education, Manipal 576104, India
| | - Ashwin B Dalal
- Centre for DNA Fingerprinting and Diagnostics, Uppal, Hyderabad 500039, India
| | - Ajay K Mahato
- Centre for DNA Fingerprinting and Diagnostics, Uppal, Hyderabad 500039, India
| | - Kapaettu Satyamoorthy
- Shri Dharmasthala Manjunatheshwara (SDM) University, SDM College of Medical Sciences and Hospital, Manjushree Nagar, Sattur, Dharwad 580009, India
| | - Keshav K Singh
- Department of Genetics, School of Medicine, The University of Alabama at Birmingham, Kaul Genetics Building, Rm. 620, 720 20th St. South, Birmingham, AL, 35294, USA
| | - Kumarasamy Thangaraj
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India
| | - Periyasamy Govindaraj
- Centre for DNA Fingerprinting and Diagnostics, Uppal, Hyderabad 500039, India; Department of Neuropathology, National Institute of Mental Health and Neurosciences, Hosur Road, Bengaluru 560029, India.
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Coyne LP, Wang X, Song J, de Jong E, Schneider K, Massa PT, Middleton FA, Becker T, Chen XJ. Mitochondrial protein import clogging as a mechanism of disease. eLife 2023; 12:e84330. [PMID: 37129366 PMCID: PMC10208645 DOI: 10.7554/elife.84330] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 04/17/2023] [Indexed: 05/03/2023] Open
Abstract
Mitochondrial biogenesis requires the import of >1,000 mitochondrial preproteins from the cytosol. Most studies on mitochondrial protein import are focused on the core import machinery. Whether and how the biophysical properties of substrate preproteins affect overall import efficiency is underexplored. Here, we show that protein traffic into mitochondria can be disrupted by amino acid substitutions in a single substrate preprotein. Pathogenic missense mutations in ADP/ATP translocase 1 (ANT1), and its yeast homolog ADP/ATP carrier 2 (Aac2), cause the protein to accumulate along the protein import pathway, thereby obstructing general protein translocation into mitochondria. This impairs mitochondrial respiration, cytosolic proteostasis, and cell viability independent of ANT1's nucleotide transport activity. The mutations act synergistically, as double mutant Aac2/ANT1 causes severe clogging primarily at the translocase of the outer membrane (TOM) complex. This confers extreme toxicity in yeast. In mice, expression of a super-clogger ANT1 variant led to neurodegeneration and an age-dependent dominant myopathy that phenocopy ANT1-induced human disease, suggesting clogging as a mechanism of disease. More broadly, this work implies the existence of uncharacterized amino acid requirements for mitochondrial carrier proteins to avoid clogging and subsequent disease.
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Affiliation(s)
- Liam P Coyne
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical UniversitySyracuseUnited States
| | - Xiaowen Wang
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical UniversitySyracuseUnited States
| | - Jiyao Song
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of FreiburgFreiburgGermany
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of BonnBonnGermany
| | - Ebbing de Jong
- Proteomics and Mass Spectrometry Core Facility, State University of New York Upstate Medical UniversitySyracuseUnited States
| | - Karin Schneider
- Department of Microbiology and Immunology, State University of New York Upstate Medical UniversitySyracuseUnited States
| | - Paul T Massa
- Department of Microbiology and Immunology, State University of New York Upstate Medical UniversitySyracuseUnited States
- Department of Neurology, State University of New York Upstate Medical UniversitySyracuseUnited States
| | - Frank A Middleton
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical UniversitySyracuseUnited States
- Department of Neuroscience and Physiology, State University of New York Upstate Medical UniversitySyracuseUnited States
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of BonnBonnGermany
| | - Xin Jie Chen
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical UniversitySyracuseUnited States
- Department of Neuroscience and Physiology, State University of New York Upstate Medical UniversitySyracuseUnited States
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