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Wu Y, Ren X, Shi P, Wu C. Regulation of mitochondrial structure by the actin cytoskeleton. Cytoskeleton (Hoboken) 2024; 81:206-214. [PMID: 37929797 DOI: 10.1002/cm.21804] [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: 07/18/2023] [Revised: 10/16/2023] [Accepted: 10/22/2023] [Indexed: 11/07/2023]
Abstract
Mitochondria are the powerhouse of the cell and play important roles in multiple cellular processes including cell metabolism, proliferation, and programmed cell death. Mitochondria are double-membrane organelles with the inner membrane folding inward to form cristae. Mitochondria networks undergo dynamic fission and fusion. Deregulation of mitochondrial structure has been linked to perturbed mitochondrial membrane potential and disrupted metabolism, as evidenced in tumorigenesis, neurodegenerative diseases, etc. Actin and its motors-myosins have long been known to generate mechanical forces and participate in short-distance cargo transport. Accumulating knowledge from biochemistry and live cell/electron microscope imaging has demonstrated the role of actin filaments in pre-constricting the mitochondria during fission. Recent studies have suggested the involvement of myosins in cristae maintenance and mitochondria quality control. Here, we review current findings and discuss future directions in the emerging fields of cytoskeletal regulation in cristae formation, mitochondrial dynamics, intracellular transport, and mitocytosis, with focus on the actin cytoskeleton and its motor proteins.
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Affiliation(s)
- Yihe Wu
- Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Xiaoyu Ren
- Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Peng Shi
- Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- International Cancer Institute, Peking University, Beijing, China
| | - Congying Wu
- Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- International Cancer Institute, Peking University, Beijing, China
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2
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Kučerová J, Zdrha A, Shinde A, Harant K, Hrdý I, Tachezy J. The divergent ER-mitochondria encounter structures (ERMES) are conserved in parabasalids but lost in several anaerobic lineages with hydrogenosomes. BMC Biol 2023; 21:259. [PMID: 37968591 PMCID: PMC10648710 DOI: 10.1186/s12915-023-01765-1] [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: 08/25/2023] [Accepted: 11/09/2023] [Indexed: 11/17/2023] Open
Abstract
BACKGROUND The endoplasmic reticulum (ER)-mitochondria membrane contact sites (MCS) are extensively studied in aerobic eukaryotes; however, little is known about MCS in anaerobes with reduced forms of mitochondria named hydrogenosomes. In several eukaryotic lineages, the direct physical tether between ER and the outer mitochondrial membrane is formed by ER-mitochondria encounter structure (ERMES). The complex consists of four core proteins (Mmm1, Mmm2, Mdm12, and Mdm10) which are involved in phospholipid trafficking. Here we investigated ERMES distribution in organisms bearing hydrogenosomes and employed Trichomonas vaginalis as a model to estimate ERMES cellular localization, structure, and function. RESULTS Homology searches revealed that Parabasalia-Anaeramoebae, anaerobic jakobids, and anaerobic fungi are lineages with hydrogenosomes that retain ERMES, while ERMES components were gradually lost in Fornicata, and are absent in Preaxostyla and Archamoebae. In T. vaginalis and other parabasalids, three ERMES components were found with the expansion of Mmm1. Immunofluorescence microscopy confirmed that Mmm1 localized in ER, while Mdm12 and Mmm2 were partially localized in hydrogenosomes. Pull-down assays and mass spectrometry of the ERMES components identified a parabasalid-specific Porin2 as a substitute for the Mdm10. ERMES modeling predicted a formation of a continuous hydrophobic tunnel of TvMmm1-TvMdm12-TvMmm2 that is anchored via Porin2 to the hydrogenosomal outer membrane. Phospholipid-ERMES docking and Mdm12-phospholipid dot-blot indicated that ERMES is involved in the transport of phosphatidylinositol phosphates. The absence of enzymes involved in hydrogenosomal phospholipid metabolism implies that ERMES is not involved in the exchange of substrates between ER and hydrogenosomes but in the unidirectional import of phospholipids into hydrogenosomal membranes. CONCLUSIONS Our investigation demonstrated that ERMES mediates ER-hydrogenosome interactions in parabasalid T. vaginalis, while the complex was lost in several other lineages with hydrogenosomes.
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Affiliation(s)
- Jitka Kučerová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242, Vestec, Czech Republic
| | - Alois Zdrha
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242, Vestec, Czech Republic
| | - Abhishek Shinde
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242, Vestec, Czech Republic
| | - Karel Harant
- OMICS Proteomics Laboratory, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242, Vestec, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242, Vestec, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242, Vestec, Czech Republic.
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Okamoto M, Nakano K, Takahashi-Nakaguchi A, Sasamoto K, Yamaguchi M, Teixeira MC, Chibana H. In Candida glabrata, ERMES Component GEM1 Controls Mitochondrial Morphology, mtROS, and Drug Efflux Pump Expression, Resulting in Azole Susceptibility. J Fungi (Basel) 2023; 9:jof9020240. [PMID: 36836353 PMCID: PMC9965728 DOI: 10.3390/jof9020240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/05/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
Mitochondrial dysfunction or morphological abnormalities in human pathogenic fungi are known to contribute to azole resistance; however, the underlying molecular mechanisms are unknown. In this study, we investigated the link between mitochondrial morphology and azole resistance in Candida glabrata, which is the second most common cause of human candidiasis worldwide. The ER-mitochondrial encounter structure (ERMES) complex is thought to play an important role in the mitochondrial dynamics necessary for mitochondria to maintain their function. Of the five components of the ERMES complex, deletion of GEM1 increased azole resistance. Gem1 is a GTPase that regulates the ERMES complex activity. Point mutations in GEM1 GTPase domains were sufficient to confer azole resistance. The cells lacking GEM1 displayed abnormalities in mitochondrial morphology, increased mtROS levels, and increased expression of azole drug efflux pumps encoded by CDR1 and CDR2. Interestingly, treatment with N-acetylcysteine (NAC), an antioxidant, reduced ROS production and the expression of CDR1 in Δgem1 cells. Altogether, the absence of Gem1 activity caused an increase in mitochondrial ROS concentration, leading to Pdr1-dependent upregulation of the drug efflux pump Cdr1, resulting in azole resistance.
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Affiliation(s)
- Michiyo Okamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Keiko Nakano
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | | | - Kaname Sasamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Masashi Yamaguchi
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Miguel Cacho Teixeira
- iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
- Correspondence:
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Kakimoto-Takeda Y, Kojima R, Shiino H, Shinmyo M, Kurokawa K, Nakano A, Endo T, Tamura Y. Dissociation of ERMES clusters plays a key role in attenuating the endoplasmic reticulum stress. iScience 2022; 25:105362. [PMID: 36339260 PMCID: PMC9626684 DOI: 10.1016/j.isci.2022.105362] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/24/2022] [Accepted: 10/12/2022] [Indexed: 11/27/2022] Open
Abstract
In yeast, ERMES, which mediates phospholipid transport between the ER and mitochondria, forms a limited number of oligomeric clusters at ER-mitochondria contact sites in a cell. Although the number of the ERMES clusters appears to be regulated to maintain proper inter-organelle phospholipid trafficking, its underlying mechanism and physiological relevance remain poorly understood. Here, we show that mitochondrial dynamics control the number of ERMES clusters. Moreover, we find that ER stress causes dissociation of the ERMES clusters independently of Ire1 and Hac1, canonical ER-stress response pathway components, leading to a delay in the phospholipid transport from the ER to mitochondria. Our biochemical and genetic analyses strongly suggest that the impaired phospholipid transport contributes to phospholipid accumulation in the ER, expanding the ER for ER stress attenuation. We thus propose that the ERMES dissociation constitutes an overlooked pathway of the ER stress response that operates in addition to the canonical Ire1/Hac1-dependent pathway. Mitochondrial fusion and division regulate the clustering of the ERMES complex ER stress leads to dissociation of the ERMES clusters independently of Ire1 and Hac1 The dissociated ERMES complexes have less activity in transporting phospholipids The defective phospholipid transport may cause the ER expansion to relieve ER stress
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Affiliation(s)
- Yuriko Kakimoto-Takeda
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Rieko Kojima
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
| | - Hiroya Shiino
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
| | - Manatsu Shinmyo
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
| | - Kazuo Kurokawa
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akihiko Nakano
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Yasushi Tamura
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
- Corresponding author
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5
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ER-misfolded proteins become sequestered with mitochondria and impair mitochondrial function. Commun Biol 2021; 4:1350. [PMID: 34857875 PMCID: PMC8640021 DOI: 10.1038/s42003-021-02873-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 11/08/2021] [Indexed: 01/23/2023] Open
Abstract
Proteostasis is a challenge for cellular organisms, as all known protein synthesis machineries are error-prone. Here we show by cell fractionation and microscopy studies that misfolded proteins formed in the endoplasmic reticulum can become associated with and partly transported into mitochondria, resulting in impaired mitochondrial function. Blocking the endoplasmic reticulum-mitochondria encounter structure (ERMES), but not the mitochondrial sorting and assembly machinery (SAM) or the mitochondrial surveillance pathway components Msp1 and Vms1, abrogated mitochondrial sequestration of ER-misfolded proteins. We term this mitochondria-associated proteostatic mechanism for ER-misfolded proteins ERAMS (ER-associated mitochondrial sequestration). We testify to the relevance of this pathway by using mutant α-1-antitrypsin as an example of a human disease-related misfolded ER protein, and we hypothesize that ERAMS plays a role in pathological features such as mitochondrial dysfunction.
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6
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Koch C, Schuldiner M, Herrmann JM. ER-SURF: Riding the Endoplasmic Reticulum Surface to Mitochondria. Int J Mol Sci 2021; 22:9655. [PMID: 34502567 PMCID: PMC8432098 DOI: 10.3390/ijms22179655] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 08/29/2021] [Indexed: 02/08/2023] Open
Abstract
Most mitochondrial proteins are synthesized in the cytosol and targeted to the mitochondrial surface in a post-translational manner. The surface of the endoplasmic reticulum (ER) plays an active role in this targeting reaction. ER-associated chaperones interact with certain mitochondrial membrane protein precursors and transfer them onto receptor proteins of the mitochondrial surface in a process termed ER-SURF. ATP-driven proteins in the membranes of mitochondria (Msp1, ATAD1) and the ER (Spf1, P5A-ATPase) serve as extractors for the removal of mislocalized proteins. If the re-routing to mitochondria fails, precursors can be degraded by ER or mitochondria-associated degradation (ERAD or MAD respectively) in a proteasome-mediated reaction. This review summarizes the current knowledge about the cooperation of the ER and mitochondria in the targeting and quality control of mitochondrial precursor proteins.
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Affiliation(s)
- Christian Koch
- Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany;
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel;
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7
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Acoba MG, Senoo N, Claypool SM. Phospholipid ebb and flow makes mitochondria go. J Cell Biol 2021; 219:151918. [PMID: 32614384 PMCID: PMC7401802 DOI: 10.1083/jcb.202003131] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 01/19/2023] Open
Abstract
Mitochondria, so much more than just being energy factories, also have the capacity to synthesize macromolecules including phospholipids, particularly cardiolipin (CL) and phosphatidylethanolamine (PE). Phospholipids are vital constituents of mitochondrial membranes, impacting the plethora of functions performed by this organelle. Hence, the orchestrated movement of phospholipids to and from the mitochondrion is essential for cellular integrity. In this review, we capture recent advances in the field of mitochondrial phospholipid biosynthesis and trafficking, highlighting the significance of interorganellar communication, intramitochondrial contact sites, and lipid transfer proteins in maintaining membrane homeostasis. We then discuss the physiological functions of CL and PE, specifically how they associate with protein complexes in mitochondrial membranes to support bioenergetics and maintain mitochondrial architecture.
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Affiliation(s)
- Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nanami Senoo
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
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8
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Rasul F, Zheng F, Dong F, He J, Liu L, Liu W, Cheema JY, Wei W, Fu C. Emr1 regulates the number of foci of the endoplasmic reticulum-mitochondria encounter structure complex. Nat Commun 2021; 12:521. [PMID: 33483504 PMCID: PMC7822926 DOI: 10.1038/s41467-020-20866-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 12/16/2020] [Indexed: 11/21/2022] Open
Abstract
The endoplasmic reticulum-mitochondria encounter structure (ERMES) complex creates contact sites between the endoplasmic reticulum and mitochondria, playing crucial roles in interorganelle communication, mitochondrial fission, mtDNA inheritance, lipid transfer, and autophagy. The mechanism regulating the number of ERMES foci within the cell remains unclear. Here, we demonstrate that the mitochondrial membrane protein Emr1 contributes to regulating the number of ERMES foci. We show that the absence of Emr1 significantly decreases the number of ERMES foci. Moreover, we find that Emr1 interacts with the ERMES core component Mdm12 and colocalizes with Mdm12 on mitochondria. Similar to ERMES mutant cells, cells lacking Emr1 display defective mitochondrial morphology and impaired mitochondrial segregation, which can be rescued by an artificial tether capable of linking the endoplasmic reticulum and mitochondria. We further demonstrate that the cytoplasmic region of Emr1 is required for regulating the number of ERMES foci. This work thus reveals a crucial regulatory protein necessary for ERMES functions and provides mechanistic insights into understanding the dynamic regulation of endoplasmic reticulum-mitochondria communication. Interorganelle membrane contact sites between the endoplasmic reticulum and mitochondria can be mediated with the ER-mitochondria encounter structure (ERMES) complex, though precise regulation is unclear. Here, the authors report that the number of ERMES foci is regulated by the previously uncharacterized mitochondrial membrane protein Emr1.
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Affiliation(s)
- Faiz Rasul
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Fan Zheng
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Fenfen Dong
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Jiajia He
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Ling Liu
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Wenyue Liu
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Javairia Yousuf Cheema
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Wenfan Wei
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China.
| | - Chuanhai Fu
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China.
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Cheema JY, He J, Wei W, Fu C. The Endoplasmic Reticulum-Mitochondria Encounter Structure and its Regulatory Proteins. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211064491. [PMID: 37366373 PMCID: PMC10243566 DOI: 10.1177/25152564211064491] [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: 06/28/2023]
Abstract
In fungi, the endoplasmic reticulum-mitochondria encounter structure (ERMES) is present between the endoplasmic reticulon (ER) and mitochondria to promote the formation of the ER-mitochondria contact sites. Four constitutive components (Mmm1, Mdm12, Mdm34, and Mdm10) assemble to form the ERMES complex while regulator proteins are required for regulating the organization and function of the ERMES complex. Multiple regulator proteins, including Gem1, Lam6, Tom7, and Emr1, of the ERMES complex, have been identified recently. In this review, we discuss the organization of the ERMES complex and the roles of the regulator proteins of the ERMES complex.
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Affiliation(s)
- Javairia Y. Cheema
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
| | - Jiajia He
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
| | - Wenfan Wei
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
| | - Chuanhai Fu
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
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10
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English AM, Schuler MH, Xiao T, Kornmann B, Shaw JM, Hughes AL. ER-mitochondria contacts promote mitochondrial-derived compartment biogenesis. J Biophys Biochem Cytol 2020; 219:211482. [PMID: 33090183 PMCID: PMC7588143 DOI: 10.1083/jcb.202002144] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/25/2020] [Accepted: 10/01/2020] [Indexed: 01/04/2023] Open
Abstract
Mitochondria are dynamic organelles with essential roles in signaling and metabolism. We recently identified a cellular structure called the mitochondrial-derived compartment (MDC) that is generated from mitochondria in response to amino acid overabundance stress. How cells form MDCs is unclear. Here, we show that MDCs are dynamic structures that form and stably persist at sites of contact between the ER and mitochondria. MDC biogenesis requires the ER-mitochondria encounter structure (ERMES) and the conserved GTPase Gem1, factors previously implicated in lipid exchange and membrane tethering at ER-mitochondria contacts. Interestingly, common genetic suppressors of abnormalities displayed by ERMES mutants exhibit distinct abilities to rescue MDC formation in ERMES-depleted strains and are incapable of rescuing MDC formation in cells lacking Gem1. Thus, the function of ERMES and Gem1 in MDC biogenesis may extend beyond their conventional role in maintaining mitochondrial phospholipid homeostasis. Overall, this study identifies an important function for ER-mitochondria contacts in the biogenesis of MDCs.
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Affiliation(s)
- Alyssa M. English
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT
| | - Max-Hinderk Schuler
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT
| | - Tianyao Xiao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT
| | - Benoît Kornmann
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Janet M. Shaw
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT
| | - Adam L. Hughes
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT,Correspondence to Adam L. Hughes:
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11
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Kornmann B. The endoplasmic reticulum-mitochondria encounter structure: coordinating lipid metabolism across membranes. Biol Chem 2020; 401:811-820. [DOI: 10.1515/hsz-2020-0102] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/05/2020] [Indexed: 02/06/2023]
Abstract
AbstractEndosymbiosis, the beginning of a collaboration between an archaeon and a bacterium and a founding step in the evolution of eukaryotes, owes its success to the establishment of communication routes between the host and the symbiont to allow the exchange of metabolites. As far as lipids are concerned, it is the host that has learnt the symbiont’s language, as eukaryote lipids appear to have been borrowed from the bacterial symbiont. Mitochondria exchange lipids with the rest of the cell at membrane contact sites. In fungi, the endoplasmic reticulum-mitochondria encounter structure (ERMES) is one of the best understood membrane tethering complexes. Its discovery has yielded crucial insight into the mechanisms of intracellular lipid trafficking. Despite a wealth of data, our understanding of ERMES formation and its exact role(s) remains incomplete. Here, I endeavour to summarise our knowledge on the ERMES complex and to identify lingering gaps.
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Affiliation(s)
- Benoît Kornmann
- Department of Biochemistry, University of Oxford, South Parks Rd, Oxford OX1 3QU, UK
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12
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Kundu D, Pasrija R. The ERMES (Endoplasmic Reticulum and Mitochondria Encounter Structures) mediated functions in fungi. Mitochondrion 2020; 52:89-99. [PMID: 32105794 DOI: 10.1016/j.mito.2020.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 12/21/2019] [Accepted: 02/21/2020] [Indexed: 01/01/2023]
Abstract
Cellular organelles are membrane-bound and provide a microenvironment for specific functions. A mitochondrion is a double membranous and dynamic organelle that undergoes numerous fusion/fission events, which depends on various cellular factors. However, it is still dependent on other organelles and requires both communications as well as the movement of physical metabolites between them. Mitochondria interact with different organelles counting lipid droplets (LD), peroxisomes, vacuoles, endoplasmic reticulum (ER) and plasma membrane (PM), etc. Apart from them, mitochondria maintain multiple interactions with ER including ERMES (Endoplasmic Reticulum and Mitochondria encounter structures). ERMES is actually a multi-protein complex, and imperative in the maintenance of mitochondrial morphology and its functions. Its disruption also compromises phospholipid exchange, drug resistance and pathogenicity. This assembly is reportedly unique to fungal systems and proposed as a target for development of new antifungal. In the light of separate reports across diverse fungal systems, we have summarised the information about its distribution and effect on mitochondrial fitness.
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Affiliation(s)
- Deepika Kundu
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Ritu Pasrija
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, India.
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13
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Kuznetsov AV, Javadov S, Grimm M, Margreiter R, Ausserlechner MJ, Hagenbuchner J. Crosstalk between Mitochondria and Cytoskeleton in Cardiac Cells. Cells 2020; 9:cells9010222. [PMID: 31963121 PMCID: PMC7017221 DOI: 10.3390/cells9010222] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/10/2020] [Accepted: 01/13/2020] [Indexed: 12/28/2022] Open
Abstract
Elucidation of the mitochondrial regulatory mechanisms for the understanding of muscle bioenergetics and the role of mitochondria is a fundamental problem in cellular physiology and pathophysiology. The cytoskeleton (microtubules, intermediate filaments, microfilaments) plays a central role in the maintenance of mitochondrial shape, location, and motility. In addition, numerous interactions between cytoskeletal proteins and mitochondria can actively participate in the regulation of mitochondrial respiration and oxidative phosphorylation. In cardiac and skeletal muscles, mitochondrial positions are tightly fixed, providing their regular arrangement and numerous interactions with other cellular structures such as sarcoplasmic reticulum and cytoskeleton. This can involve association of cytoskeletal proteins with voltage-dependent anion channel (VDAC), thereby, governing the permeability of the outer mitochondrial membrane (OMM) to metabolites, and regulating cell energy metabolism. Cardiomyocytes and myocardial fibers demonstrate regular arrangement of tubulin beta-II isoform entirely co-localized with mitochondria, in contrast to other isoforms of tubulin. This observation suggests the participation of tubulin beta-II in the regulation of OMM permeability through interaction with VDAC. The OMM permeability is also regulated by the specific isoform of cytolinker protein plectin. This review summarizes and discusses previous studies on the role of cytoskeletal proteins in the regulation of energy metabolism and mitochondrial function, adenosine triphosphate (ATP) production, and energy transfer.
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Affiliation(s)
- Andrey V. Kuznetsov
- Cardiac Surgery Research Laboratory, Department of Cardiac Surgery, Innsbruck Medical University, 6020 Innsbruck, Austria;
- Department of Paediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria;
- Correspondence: (A.V.K.); (J.H.); Tel.: +43-512-504-27815 (A.V.K.); +43-512-504-81578 (J.H.)
| | - Sabzali Javadov
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR 00936-5067, USA;
| | - Michael Grimm
- Cardiac Surgery Research Laboratory, Department of Cardiac Surgery, Innsbruck Medical University, 6020 Innsbruck, Austria;
| | - Raimund Margreiter
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | | | - Judith Hagenbuchner
- Department of Paediatrics II, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Correspondence: (A.V.K.); (J.H.); Tel.: +43-512-504-27815 (A.V.K.); +43-512-504-81578 (J.H.)
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14
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Odendall F, Backes S, Tatsuta T, Weill U, Schuldiner M, Langer T, Herrmann JM, Rapaport D, Dimmer KS. The mitochondrial intermembrane space-facing proteins Mcp2 and Tgl2 are involved in yeast lipid metabolism. Mol Biol Cell 2019; 30:2681-2694. [PMID: 31483742 PMCID: PMC6761770 DOI: 10.1091/mbc.e19-03-0166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are unique organelles harboring two distinct membranes, the mitochondrial inner and outer membrane (MIM and MOM, respectively). Mitochondria comprise only a subset of metabolic pathways for the synthesis of membrane lipids; therefore most lipid species and their precursors have to be imported from other cellular compartments. One such import process is mediated by the ER mitochondria encounter structure (ERMES) complex. Both mitochondrial membranes surround the hydrophilic intermembrane space (IMS). Therefore, additional systems are required that shuttle lipids between the MIM and MOM. Recently, we identified the IMS protein Mcp2 as a high-copy suppressor for cells that lack a functional ERMES complex. To understand better how mitochondria facilitate transport and biogenesis of lipids, we searched for genetic interactions of this suppressor. We found that MCP2 has a negative genetic interaction with the gene TGL2 encoding a neutral lipid hydrolase. We show that this lipase is located in the intermembrane space of the mitochondrion and is imported via the Mia40 disulfide relay system. Furthermore, we show a positive genetic interaction of double deletion of MCP2 and PSD1, the gene encoding the enzyme that synthesizes the major amount of cellular phosphatidylethanolamine. Finally, we demonstrate that the nucleotide-binding motifs of the predicted atypical kinase Mcp2 are required for its proper function. Taken together, our data suggest that Mcp2 is involved in mitochondrial lipid metabolism and an increase of this involvement by overexpression suppresses loss of ERMES.
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Affiliation(s)
- Fenja Odendall
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Sandra Backes
- Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Takashi Tatsuta
- Max Planck Institute for Biology of Ageing, 50931 Köln, Germany
| | - Uri Weill
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Thomas Langer
- Max Planck Institute for Biology of Ageing, 50931 Köln, Germany
| | | | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Kai Stefan Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
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15
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Ong SB, Kwek XY, Katwadi K, Hernandez-Resendiz S, Crespo-Avilan GE, Ismail NI, Lin YH, Yap EP, Lim SY, Ja KPMM, Ramachandra CJA, Tee N, Toh JJ, Shim W, Wong P, Cabrera-Fuentes HA, Hausenloy DJ. Targeting Mitochondrial Fission Using Mdivi-1 in A Clinically Relevant Large Animal Model of Acute Myocardial Infarction: A Pilot Study. Int J Mol Sci 2019; 20:E3972. [PMID: 31443187 PMCID: PMC6720595 DOI: 10.3390/ijms20163972] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/09/2019] [Accepted: 08/14/2019] [Indexed: 12/19/2022] Open
Abstract
Background: New treatments are needed to reduce myocardial infarct size (MI) and prevent heart failure (HF) following acute myocardial infarction (AMI), which are the leading causes of death and disability worldwide. Studies in rodent AMI models showed that genetic and pharmacological inhibition of mitochondrial fission, induced by acute ischemia and reperfusion, reduced MI size. Whether targeting mitochondrial fission at the onset of reperfusion is also cardioprotective in a clinically-relevant large animal AMI model remains to be determined. Methods: Adult pigs (30-40 kg) were subjected to closed-chest 90-min left anterior descending artery ischemia followed by 72 h of reperfusion and were randomized to receive an intracoronary bolus of either mdivi-1 (1.2 mg/kg, a small molecule inhibitor of the mitochondrial fission protein, Drp1) or vehicle control, 10-min prior to reperfusion. The left ventricular (LV) size and function were both assessed by transthoracic echocardiography prior to AMI and after 72 h of reperfusion. MI size and the area-at-risk (AAR) were determined using dual staining with Tetrazolium and Evans blue. Heart samples were collected for histological determination of fibrosis and for electron microscopic analysis of mitochondrial morphology. Results: A total of 14 pigs underwent the treatment protocols (eight control and six mdivi-1). Administration of mdivi-1 immediately prior to the onset of reperfusion did not reduce MI size (MI size as % of AAR: Control 49.2 ± 8.6 vs. mdivi-1 50.5 ± 11.4; p = 0.815) or preserve LV systolic function (LV ejection fraction %: Control 67.5 ± 0.4 vs. mdivi-1 59.6 ± 0.6; p = 0.420), when compared to vehicle control. Similarly, there were no differences in mitochondrial morphology or myocardial fibrosis between mdivi-1 and vehicle control groups. Conclusion: Our pilot study has shown that treatment with mdivi-1 (1.2 mg/kg) at the onset of reperfusion did not reduce MI size or preserve LV function in the clinically-relevant closed-chest pig AMI model. A larger study, testing different doses of mdivi-1 or using a more specific Drp1 inhibitor are required to confirm these findings.
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Affiliation(s)
- Sang-Bing Ong
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore.
- Department of Cardiovascular, Renal and Metabolic Medicine, School of Medicine, Sapporo Medical University, Hokkaido 060-8543, Japan.
| | - Xiu-Yi Kwek
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | - Khairunnisa Katwadi
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | - Sauri Hernandez-Resendiz
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | - Gustavo E Crespo-Avilan
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
- Institute of Biochemistry, Medical School, Justus-Liebig University, 35392 Giessen, Germany
| | - Nur Izzah Ismail
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
| | - Ying-Hsi Lin
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | - En Ping Yap
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | - Song-Yi Lim
- Innoheart Pte Ltd., Singapore 119844, Singapore
| | - K P Myu Mai Ja
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | - Chrishan J A Ramachandra
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | - Nicole Tee
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
| | | | - Winston Shim
- Innoheart Pte Ltd., Singapore 119844, Singapore
- Health and Social Sciences Cluster, Singapore Institute of Technology, Singapore 138683, Singapore
| | - Philip Wong
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
- Innoheart Pte Ltd., Singapore 119844, Singapore
| | - Hector A Cabrera-Fuentes
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore.
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore.
- Institute of Biochemistry, Medical School, Justus-Liebig University, 35392 Giessen, Germany.
- Tecnologico de Monterrey, Centro de Biotecnologia-FEMSA, Monterrey, NL 64849, Mexico.
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russian.
| | - Derek J Hausenloy
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
- National Heart Research Institute Singapore, National Heart Centre, Singapore 169609, Singapore
- Tecnologico de Monterrey, Centro de Biotecnologia-FEMSA, Monterrey, NL 64849, Mexico
- Yong Loo Lin School of Medicine, National University Singapore, Singapore 119228, Singapore
- The Hatter Cardiovascular Institute, Institute of Cardiovascular Science, University College London, London WC1E 6HX, UK
- The National Institute of Health Research University College London Hospitals Biomedical Research Centre, London W1T 7DN, UK
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16
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Esposito M, Hermann-Le Denmat S, Delahodde A. Contribution of ERMES subunits to mature peroxisome abundance. PLoS One 2019; 14:e0214287. [PMID: 30908556 PMCID: PMC6433259 DOI: 10.1371/journal.pone.0214287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/11/2019] [Indexed: 11/26/2022] Open
Abstract
Eukaryotic organelles share different components and establish physical contacts to communicate throughout the cell. One of the best-recognized examples of such interplay is the metabolic cooperation and crosstalk between mitochondria and peroxisomes, both organelles being functionally and physically connected and linked to the endoplasmic reticulum (ER). In Saccharomyces cerevisiae, mitochondria are linked to the ER by the ERMES complex that facilitates inter-organelle calcium and phospholipid exchanges. Recently, peroxisome-mitochondria contact sites (PerMit) have been reported and among Permit tethers, one component of the ERMES complex (Mdm34) was shown to interact with the peroxin Pex11, suggesting that the ERMES complex or part of it may be involved in two membrane contact sites (ER-mitochondria and peroxisome- mitochondria). This opens the possibility of exchanges between these three membrane compartments. Here, we investigated in details the role of each ERMES subunit on peroxisome abundance. First, we confirmed previous studies from other groups showing that absence of Mdm10 or Mdm12 leads to an increased number of mature peroxisomes. Secondly, we showed that this is not simply due to respiratory function defect, mitochondrial DNA (mtDNA) loss or mitochondrial network alteration. Finally, we present evidence that the contribution of ERMES subunits Mdm10 and Mdm12 to peroxisome number involves two different mechanisms.
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Affiliation(s)
- Michela Esposito
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
| | - Sylvie Hermann-Le Denmat
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
- Ecole Normale Supérieure, PSL Research University, Paris, France
| | - Agnès Delahodde
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
- * E-mail:
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17
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Légiot A, Céré C, Dupoiron T, Kaabouni M, Camougrand N, Manon S. Mitochondria-Associated Membranes (MAMs) are involved in Bax mitochondrial localization and cytochrome c release. MICROBIAL CELL 2019; 6:257-266. [PMID: 31114795 PMCID: PMC6506693 DOI: 10.15698/mic2019.05.678] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The distribution of the pro-apoptotic protein Bax in the outer mi-tochondrial membrane (OMM) is a central point of regulation of apoptosis. It is now widely recognized that parts of the endoplasmic reticulum (ER) are closely associated to the OMM, and are actively involved in different signaling processes. We addressed a possible role of these domains, called Mitochon-dria-Associated Membranes (MAMs) in Bax localization and function, by ex-pressing the human protein in a yeast mutant deleted of MDM34, a ERMES (ER-Mitochondria Encounter Structure) component. By affecting MAMs stabil-ity, the deletion of MDM34 altered Bax mitochondrial localization, and de-creased its capacity to release cytochrome c. Furthermore, the deletion of MDM34 decreased the size of an incompletely released, MAMs-associated pool of cytochrome c.
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Affiliation(s)
- Alexandre Légiot
- Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS & Université de Bordeaux, Campus Carreire, CS61390, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
| | - Claire Céré
- Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS & Université de Bordeaux, Campus Carreire, CS61390, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
| | - Thibaud Dupoiron
- Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS & Université de Bordeaux, Campus Carreire, CS61390, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
| | - Mohamed Kaabouni
- Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS & Université de Bordeaux, Campus Carreire, CS61390, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
| | - Nadine Camougrand
- Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS & Université de Bordeaux, Campus Carreire, CS61390, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
| | - Stéphen Manon
- Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS & Université de Bordeaux, Campus Carreire, CS61390, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
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18
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Tamura Y, Kawano S, Endo T. Organelle contact zones as sites for lipid transfer. J Biochem 2019; 165:115-123. [PMID: 30371789 DOI: 10.1093/jb/mvy088] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/26/2018] [Indexed: 01/06/2023] Open
Abstract
Since the 1950s, electron microscopic observations have suggested the existence of special regions where the distinct organelle membranes are closely apposed to each other, yet their molecular basis and functions have not been examined for a long time. Recent studies using yeast as a model organism identified multiple organelle-membrane tethering sites/factors, such as ERMES (ER-mitochondria encounter structure), NVJ (Nuclear-vacuole junction), vCLAMP (Vacuole and mitochondria patch) and MICOS (Mitochondrial contact site). Among them, ERMES is the best-characterized contact-site protein complex, which was found to function as not only an organelle-tethering factor but also a phospholipid transfer protein complex. In this review, we will discuss recent advances in the characterization of ERMES and other organelle contact zones, vCLAMP, NVJ and MICOS in yeast.
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Affiliation(s)
- Yasushi Tamura
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Japan
| | - Shin Kawano
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan.,Research Center for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan.,Research Center for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan
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19
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Eisenberg-Bord M, Tsui HS, Antunes D, Fernández-Del-Río L, Bradley MC, Dunn CD, Nguyen TPT, Rapaport D, Clarke CF, Schuldiner M. The Endoplasmic Reticulum-Mitochondria Encounter Structure Complex Coordinates Coenzyme Q Biosynthesis. ACTA ACUST UNITED AC 2019; 2:2515256418825409. [PMID: 30937424 PMCID: PMC6441334 DOI: 10.1177/2515256418825409] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Loss of the endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) complex that resides in contact sites between the yeast ER and mitochondria leads to impaired respiration; however, the reason for that is not clear. We find that in ERMES null mutants, there is an increase in the level of mRNAs encoding for biosynthetic enzymes of coenzyme Q6 (CoQ6), an essential electron carrier of the mitochondrial respiratory chain. We show that the mega complexes involved in CoQ6 biosynthesis (CoQ synthomes) are destabilized in ERMES mutants. This, in turn, affects the level and distribution of CoQ6 within the cell, resulting in reduced mitochondrial CoQ6. We suggest that these outcomes contribute to the reduced respiration observed in ERMES mutants. Fluorescence microscopy experiments demonstrate close proximity between the CoQ synthome and ERMES, suggesting a spatial coordination. The involvement of the ER-mitochondria contact site in regulation of CoQ6 biogenesis highlights an additional level of communication between these two organelles.
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Affiliation(s)
| | - Hui S Tsui
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA, USA
| | - Diana Antunes
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Lucía Fernández-Del-Río
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA, USA
| | - Michelle C Bradley
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA, USA
| | - Cory D Dunn
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.,Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | | | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Catherine F Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA, USA
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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20
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Sinzel M, Zeitler A, Dimmer KS. Interaction network of the mitochondrial outer membrane protein Mcp3. FEBS Lett 2018; 592:3210-3220. [PMID: 30192984 DOI: 10.1002/1873-3468.13243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/30/2018] [Accepted: 09/03/2018] [Indexed: 02/04/2023]
Abstract
Mitochondria are organelles containing two membranes that are distinct in composition and function. A role of the mitochondrial outer membrane (MOM) is to mediate contact of the organelle with the rest of the cell. In yeast, the MOM contains about 40 different integral proteins. Recently, we described the MOM protein Mcp3, which can serve as a multicopy suppressor of loss of ERMES complex that mediates mitochondria-endoplasmic reticulum contacts. To shed further light on the role of Mcp3 in the MOM, we analyzed its physical interaction with other proteins. We show that Mcp3 interacts with the MOM protein Om45 and the inner membrane protein Aim19. Our observations hint toward a potential involvement of Mcp3 in a structural and/or functional link between both mitochondrial membranes.
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Affiliation(s)
- Monika Sinzel
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
| | - Andreas Zeitler
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
| | - Kai S Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
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21
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Kakimoto Y, Tashiro S, Kojima R, Morozumi Y, Endo T, Tamura Y. Visualizing multiple inter-organelle contact sites using the organelle-targeted split-GFP system. Sci Rep 2018; 8:6175. [PMID: 29670150 PMCID: PMC5906596 DOI: 10.1038/s41598-018-24466-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/04/2018] [Indexed: 12/18/2022] Open
Abstract
Functional integrity of eukaryotic organelles relies on direct physical contacts between distinct organelles. However, the entity of organelle-tethering factors is not well understood due to lack of means to analyze inter-organelle interactions in living cells. Here we evaluate the split-GFP system for visualizing organelle contact sites in vivo and show its advantages and disadvantages. We observed punctate GFP signals from the split-GFP fragments targeted to any pairs of organelles among the ER, mitochondria, peroxisomes, vacuole and lipid droplets in yeast cells, which suggests that these organelles form contact sites with multiple organelles simultaneously although it is difficult to rule out the possibilities that these organelle contacts sites are artificially formed by the irreversible associations of the split-GFP probes. Importantly, split-GFP signals in the overlapped regions of the ER and mitochondria were mainly co-localized with ERMES, an authentic ER-mitochondria tethering structure, suggesting that split-GFP assembly depends on the preexisting inter-organelle contact sites. We also confirmed that the split-GFP system can be applied to detection of the ER-mitochondria contact sites in HeLa cells. We thus propose that the split-GFP system is a potential tool to observe and analyze inter-organelle contact sites in living yeast and mammalian cells.
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Affiliation(s)
- Yuriko Kakimoto
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Shinya Tashiro
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Rieko Kojima
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Yuki Morozumi
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Yasushi Tamura
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan.
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22
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Kawano S, Tamura Y, Kojima R, Bala S, Asai E, Michel AH, Kornmann B, Riezman I, Riezman H, Sakae Y, Okamoto Y, Endo T. Structure-function insights into direct lipid transfer between membranes by Mmm1-Mdm12 of ERMES. J Cell Biol 2017; 217:959-974. [PMID: 29279306 PMCID: PMC5839780 DOI: 10.1083/jcb.201704119] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 11/06/2017] [Accepted: 12/01/2017] [Indexed: 12/26/2022] Open
Abstract
The ER–mitochondrial encounter structure (ERMES) physically links ER and mitochondrial membranes in yeast, but it is unclear whether ERMES directly facilitates lipid exchange between these organelles. Kawano et al. reveal by reconstitution experiments that a complex of Mmm1–Mdm12, two core subunits of ERMES, functions as a minimal unit for lipid transfer between membranes. The endoplasmic reticulum (ER)–mitochondrial encounter structure (ERMES) physically links the membranes of the ER and mitochondria in yeast. Although the ER and mitochondria cooperate to synthesize glycerophospholipids, whether ERMES directly facilitates the lipid exchange between the two organelles remains controversial. Here, we compared the x-ray structures of an ERMES subunit Mdm12 from Kluyveromyces lactis with that of Mdm12 from Saccharomyces cerevisiae and found that both Mdm12 proteins possess a hydrophobic pocket for phospholipid binding. However in vitro lipid transfer assays showed that Mdm12 alone or an Mmm1 (another ERMES subunit) fusion protein exhibited only a weak lipid transfer activity between liposomes. In contrast, Mdm12 in a complex with Mmm1 mediated efficient lipid transfer between liposomes. Mutations in Mmm1 or Mdm12 impaired the lipid transfer activities of the Mdm12–Mmm1 complex and furthermore caused defective phosphatidylserine transport from the ER to mitochondrial membranes via ERMES in vitro. Therefore, the Mmm1–Mdm12 complex functions as a minimal unit that mediates lipid transfer between membranes.
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Affiliation(s)
- Shin Kawano
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan.,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Kyoto Sangyo University, Kyoto, Japan.,Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan.,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Nagoya University, Nagoya, Japan
| | - Yasushi Tamura
- Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Nagoya University, Nagoya, Japan.,Research Center for Materials Science, Nagoya University, Nagoya, Japan.,Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata, Japan
| | - Rieko Kojima
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata, Japan
| | - Siqin Bala
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Eri Asai
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Agnès H Michel
- Institute of Biochemistry, ETH Zürich, Zürich, Switzerland
| | | | - Isabelle Riezman
- Department of Biochemistry, National Centre of Competence in Research Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Howard Riezman
- Department of Biochemistry, National Centre of Competence in Research Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Yoshitake Sakae
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Yuko Okamoto
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan .,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Kyoto Sangyo University, Kyoto, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan.,Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan.,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Nagoya University, Nagoya, Japan
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23
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Koch B, Tucey TM, Lo TL, Novakovic S, Boag P, Traven A. The Mitochondrial GTPase Gem1 Contributes to the Cell Wall Stress Response and Invasive Growth of Candida albicans. Front Microbiol 2017; 8:2555. [PMID: 29326680 PMCID: PMC5742345 DOI: 10.3389/fmicb.2017.02555] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/08/2017] [Indexed: 01/27/2023] Open
Abstract
The interactions of mitochondria with the endoplasmic reticulum (ER) are crucial for maintaining proper mitochondrial morphology, function and dynamics. This enables cells to utilize their mitochondria optimally for energy production and anabolism, and it further provides for metabolic control over developmental decisions. In fungi, a key mechanism by which ER and mitochondria interact is via a membrane tether, the protein complex ERMES (ER-Mitochondria Encounter Structure). In the model yeast Saccharomyces cerevisiae, the mitochondrial GTPase Gem1 interacts with ERMES, and it has been proposed to regulate its activity. Here we report on the first characterization of Gem1 in a human fungal pathogen. We show that in Candida albicans Gem1 has a dominant role in ensuring proper mitochondrial morphology, and our data is consistent with Gem1 working with ERMES in this role. Mitochondrial respiration and steady state cellular phospholipid homeostasis are not impacted by inactivation of GEM1 in C. albicans. There are two major virulence-related consequences of disrupting mitochondrial morphology by GEM1 inactivation: C. albicans becomes hypersusceptible to cell wall stress, and is unable to grow invasively. In the gem1Δ/Δ mutant, it is specifically the invasive capacity of hyphae that is compromised, not the ability to transition from yeast to hyphal morphology, and this phenotype is shared with ERMES mutants. As a consequence of the hyphal invasion defect, the gem1Δ/Δ mutant is drastically hypovirulent in the worm infection model. Activation of the mitogen activated protein (MAP) kinase Cek1 is reduced in the gem1Δ/Δ mutant, and this function could explain both the susceptibility to cell wall stress and lack of invasive growth. This result establishes a new, respiration-independent mechanism of mitochondrial control over stress signaling and hyphal functions in C. albicans. We propose that ER-mitochondria interactions and the ER-Mitochondria Organizing Network (ERMIONE) play important roles in adaptive responses in fungi, in particular cell surface-related mechanisms that drive invasive growth and stress responsive behaviors that support fungal pathogenicity.
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Affiliation(s)
- Barbara Koch
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Timothy M Tucey
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Tricia L Lo
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Stevan Novakovic
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Peter Boag
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
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24
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Crystal structures of Mmm1 and Mdm12-Mmm1 reveal mechanistic insight into phospholipid trafficking at ER-mitochondria contact sites. Proc Natl Acad Sci U S A 2017; 114:E9502-E9511. [PMID: 29078410 DOI: 10.1073/pnas.1715592114] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) comprises mitochondrial distribution and morphology 12 (Mdm12), maintenance of mitochondrial morphology 1 (Mmm1), Mdm34, and Mdm10 and mediates physical membrane contact sites and nonvesicular lipid trafficking between the ER and mitochondria in yeast. Herein, we report two crystal structures of the synaptotagmin-like mitochondrial lipid-binding protein (SMP) domain of Mmm1 and the Mdm12-Mmm1 complex at 2.8 Å and 3.8 Å resolution, respectively. Mmm1 adopts a dimeric SMP structure augmented with two extra structural elements at the N and C termini that are involved in tight self-association and phospholipid coordination. Mmm1 binds two phospholipids inside the hydrophobic cavity, and the phosphate ion of the distal phospholipid is specifically recognized through extensive H-bonds. A positively charged concave surface on the SMP domain not only mediates ER membrane docking but also results in preferential binding to glycerophospholipids such as phosphatidylcholine (PC), phosphatidic acid (PA), phosphatidylglycerol (PG), and phosphatidylserine (PS), some of which are substrates for lipid-modifying enzymes in mitochondria. The Mdm12-Mmm1 structure reveals two Mdm12s binding to the SMP domains of the Mmm1 dimer in a pairwise head-to-tail manner. Direct association of Mmm1 and Mdm12 generates a 210-Å-long continuous hydrophobic tunnel that facilitates phospholipid transport. The Mdm12-Mmm1 complex binds all glycerophospholipids except for phosphatidylethanolamine (PE) in vitro.
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25
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Court DA, Khetoo S, Shuvo SR, Reitmeier SD, Hausner G. In silico analysis of coevolution among ERMES proteins, Pex11, and Lam6. Can J Microbiol 2017; 63:984-997. [PMID: 28985476 DOI: 10.1139/cjm-2017-0460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In eukaryotic cells, communication and dynamic interactions among different organelles are important for maintaining cellular homeostasis. The endoplasmic reticulum (ER) mitochondria encounter structure (ERMES) complex establishes membrane contact sites between ER and mitochondria and is essential for phospholipid transport, protein import, and mitochondrial dynamics and inheritance. In this work, in silico analyses were used to probe the intramolecular interactions in ERMES proteins and the interactions that support the ERMES complex. Based on mutual information (MI), sites of intramolecular coevolution are predicted in the core proteins Mmm1, Mdm10, Mdm12, Mdm34, the peroxisomal protein Pex11, and cytoplasmic Lam6; these sites are linked to structural features of the proteins. Intermolecular coevolution is predicted among the synaptotagmin-like mitochondrial lipid-binding protein (SMP) domains of Mmm1, Mdm12, and Mdm34. Segments of Pex11 and Lam6 also share MI with the SMP domains of Mmm1 and Mdm12 and with the N terminus of Mdm34, implicating Mdm34 as part of a hub for interactions between ERMES and other complexes. In contrast, evidence of limited intermolecular coevolution involving the outer membrane protein Mdm10 was detected only with Mmm1 and Pex11. The results support models for the organization of these interacting proteins and suggest roles for Pex11 and Lam6 in regulating complex formation.
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Affiliation(s)
- Deborah A Court
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Shivani Khetoo
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Sabbir R Shuvo
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Shayne D Reitmeier
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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26
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Straub SP, Stiller SB, Wiedemann N, Pfanner N. Dynamic organization of the mitochondrial protein import machinery. Biol Chem 2017; 397:1097-1114. [PMID: 27289000 DOI: 10.1515/hsz-2016-0145] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 05/17/2016] [Indexed: 01/12/2023]
Abstract
Mitochondria contain elaborate machineries for the import of precursor proteins from the cytosol. The translocase of the outer mitochondrial membrane (TOM) performs the initial import of precursor proteins and transfers the precursors to downstream translocases, including the presequence translocase and the carrier translocase of the inner membrane, the mitochondrial import and assembly machinery of the intermembrane space, and the sorting and assembly machinery of the outer membrane. Although the protein translocases can function as separate entities in vitro, recent studies revealed a close and dynamic cooperation of the protein import machineries to facilitate efficient transfer of precursor proteins in vivo. In addition, protein translocases were found to transiently interact with distinct machineries that function in the respiratory chain or in the maintenance of mitochondrial membrane architecture. Mitochondrial protein import is embedded in a regulatory network that ensures protein biogenesis, membrane dynamics, bioenergetic activity and quality control.
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27
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Ellenrieder L, Rampelt H, Becker T. Connection of Protein Transport and Organelle Contact Sites in Mitochondria. J Mol Biol 2017; 429:2148-2160. [DOI: 10.1016/j.jmb.2017.05.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/19/2017] [Accepted: 05/23/2017] [Indexed: 12/31/2022]
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28
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Xue Y, Schmollinger S, Attar N, Campos OA, Vogelauer M, Carey MF, Merchant SS, Kurdistani SK. Endoplasmic reticulum-mitochondria junction is required for iron homeostasis. J Biol Chem 2017. [PMID: 28637866 DOI: 10.1074/jbc.m117.784249] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) is a protein complex that physically tethers the two organelles to each other and creates the physical basis for communication between them. ERMES functions in lipid exchange between the ER and mitochondria, protein import into mitochondria, and maintenance of mitochondrial morphology and genome. Here, we report that ERMES is also required for iron homeostasis. Loss of ERMES components activates an Aft1-dependent iron deficiency response even in iron-replete conditions, leading to accumulation of excess iron inside the cell. This function is independent of known ERMES roles in calcium regulation, phospholipid biosynthesis, or effects on mitochondrial morphology. A mutation in the vacuolar protein sorting 13 (VPS13) gene that rescues the glycolytic phenotype of ERMES mutants suppresses the iron deficiency response and iron accumulation. Our findings reveal that proper communication between the ER and mitochondria is required for appropriate maintenance of cellular iron levels.
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Affiliation(s)
- Yong Xue
- From the Department of Biological Chemistry.,Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Huaihai Institute of Technology, Lianyungang 222005, China
| | - Stefan Schmollinger
- Institute for Genomics and Proteomics, Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095 and
| | - Narsis Attar
- From the Department of Biological Chemistry.,Molecular Biology Institute, and
| | - Oscar A Campos
- From the Department of Biological Chemistry.,Molecular Biology Institute, and
| | | | - Michael F Carey
- From the Department of Biological Chemistry.,Molecular Biology Institute, and
| | - Sabeeha S Merchant
- Institute for Genomics and Proteomics, Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095 and
| | - Siavash K Kurdistani
- From the Department of Biological Chemistry, .,Molecular Biology Institute, and.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, and
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29
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Mitochondria-organelle contact sites: the plot thickens. Biochem Soc Trans 2017; 45:477-488. [PMID: 28408488 DOI: 10.1042/bst20160130] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 02/07/2017] [Accepted: 02/13/2017] [Indexed: 01/30/2023]
Abstract
Membrane contact sites (MCSs) are areas of close apposition between the membranes of two different organelles that enable non-vesicular transfer of ions and lipids. Recent studies reveal that mitochondria maintain contact sites with organelles other than the endoplasmic reticulum such as the vacuole, plasma membrane and peroxisomes. This review focuses on novel findings achieved mainly in yeast regarding tethers, function and regulation of mitochondria-organelle contact sites. The emerging network of MCSs linking virtually all cellular organelles is highly dynamic and integrated with cellular metabolism.
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30
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Geißel B, Penka M, Neubauer M, Wagener J. The ER-mitochondria encounter structure contributes to hyphal growth, mitochondrial morphology and virulence of the pathogenic mold Aspergillus fumigatus. Int J Med Microbiol 2017; 307:37-43. [DOI: 10.1016/j.ijmm.2016.11.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 11/10/2016] [Accepted: 11/20/2016] [Indexed: 11/15/2022] Open
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31
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Tamura Y, Endo T. Role of Intra- and Inter-mitochondrial Membrane Contact Sites in Yeast Phospholipid Biogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 997:121-133. [PMID: 28815526 DOI: 10.1007/978-981-10-4567-7_9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Eukaryotic cells exhibit intracellular compartments called organelles wherein various specialized enzymatic reactions occur. Despite the specificity of the characteristic functions of organelles, recent studies have shown that distinct organelles physically connect and communicate with each other to maintain the integrity of their functions. In yeast, multiple inter- and intramitochondrial membrane contact sites (MCSs) were identified to date and were proposed to be involved in phospholipid biogenesis. In the present article, we focus on inter- and intra-organellar MCSs involving mitochondria and their tethering factors, such as the ERMES (endoplasmic reticulum (ER)-mitochondria encounter structure) complex and EMC (conserved ER membrane protein complex) between mitochondria and the ER, vCLAMP (vacuole and mitochondria patch) between mitochondria and vacuoles, and the MICOS (mitochondrial contact site) complex between the mitochondrial outer and inner membranes (MOM and MIM). All of these membrane-tethering factors were proposed to be involved in phospholipid biogenesis. Furthermore, the existence of functional interconnections among multiple organelle contact sites is suggested. In the present article, we summarize the latest discoveries in regard to MCSs and MCS-forming factors involving mitochondria and discuss their molecular functions, with particular focus on phospholipid metabolism in yeast.
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Affiliation(s)
- Yasushi Tamura
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata, 990-8560, Japan.
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan
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32
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Belgareh-Touzé N, Cavellini L, Cohen MM. Ubiquitination of ERMES components by the E3 ligase Rsp5 is involved in mitophagy. Autophagy 2016; 13:114-132. [PMID: 27846375 PMCID: PMC5240830 DOI: 10.1080/15548627.2016.1252889] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Mitochondria are dynamic organelles that undergo permanent fission and fusion events. These processes play an essential role in maintaining normal cellular function. In the yeast Saccharomyces cerevisiae, the endoplasmic reticulum-mitochondrial encounter structure (ERMES) is a marker of sites of mitochondrial division, but it is also involved in a plethora of other mitochondrial functions. However, it remains unclear how these different functions are regulated. We show here that Mdm34 and Mdm12, 2 components of ERMES, are ubiquitinated by the E3 ligase Rsp5. This ubiquitination is not involved in mitochondrial dynamics or in the distribution and turnover of ERMES. Nevertheless, the ubiquitination of Mdm34 and Mdm12 was required for efficient mitophagy. We thus report here the first identification of ubiquitinated substrates participating in yeast mitophagy.
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Affiliation(s)
- Naïma Belgareh-Touzé
- a UMR8226, CNRS/UPMC, Sorbonne Université, Institut de Biologie Physico-Chimique , Paris , France
| | - Laetitia Cavellini
- a UMR8226, CNRS/UPMC, Sorbonne Université, Institut de Biologie Physico-Chimique , Paris , France
| | - Mickael M Cohen
- a UMR8226, CNRS/UPMC, Sorbonne Université, Institut de Biologie Physico-Chimique , Paris , France
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33
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Ellenrieder L, Opaliński Ł, Becker L, Krüger V, Mirus O, Straub SP, Ebell K, Flinner N, Stiller SB, Guiard B, Meisinger C, Wiedemann N, Schleiff E, Wagner R, Pfanner N, Becker T. Separating mitochondrial protein assembly and endoplasmic reticulum tethering by selective coupling of Mdm10. Nat Commun 2016; 7:13021. [PMID: 27721450 PMCID: PMC5476798 DOI: 10.1038/ncomms13021] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 08/25/2016] [Indexed: 01/19/2023] Open
Abstract
The endoplasmic reticulum–mitochondria encounter structure (ERMES) connects the mitochondrial outer membrane with the ER. Multiple functions have been linked to ERMES, including maintenance of mitochondrial morphology, protein assembly and phospholipid homeostasis. Since the mitochondrial distribution and morphology protein Mdm10 is present in both ERMES and the mitochondrial sorting and assembly machinery (SAM), it is unknown how the ERMES functions are connected on a molecular level. Here we report that conserved surface areas on opposite sides of the Mdm10 β-barrel interact with SAM and ERMES, respectively. We generated point mutants to separate protein assembly (SAM) from morphology and phospholipid homeostasis (ERMES). Our study reveals that the β-barrel channel of Mdm10 serves different functions. Mdm10 promotes the biogenesis of α-helical and β-barrel proteins at SAM and functions as integral membrane anchor of ERMES, demonstrating that SAM-mediated protein assembly is distinct from ER-mitochondria contact sites. The protein Mdm10 is known to be present in the endoplasmic reticulum-mitochondria encounter structure (ERMES) and in mitochondrial sorting and assembly machinery (SAM). Here, the authors examine how this protein interacts with SAM and EMRES, showing that the SAM-mediated protein machinery is independent of ERMES.
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Affiliation(s)
- Lars Ellenrieder
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,Faculty of Biology, University of Freiburg, Freiburg D-79104, Germany
| | - Łukasz Opaliński
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany
| | - Lars Becker
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany
| | - Vivien Krüger
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany
| | - Oliver Mirus
- Molecular Cell Biology of Plants, University of Frankfurt, Frankfurt D-60438, Germany
| | - Sebastian P Straub
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,Faculty of Biology, University of Freiburg, Freiburg D-79104, Germany
| | - Katharina Ebell
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany
| | - Nadine Flinner
- Molecular Cell Biology of Plants, University of Frankfurt, Frankfurt D-60438, Germany
| | - Sebastian B Stiller
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany
| | - Bernard Guiard
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, Gif-sur-Yvette 91190, France
| | - Chris Meisinger
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
| | - Enrico Schleiff
- Molecular Cell Biology of Plants, University of Frankfurt, Frankfurt D-60438, Germany.,Buchmann Institute of Molecular Life Sciences, Cluster of Excellence Macromolecular Complexes, University of Frankfurt, Frankfurt D-60438, Germany
| | - Richard Wagner
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany.,Life Sciences &Chemistry, Focus Area Health, Jacobs University Bremen, Bremen D-28759, Germany
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
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34
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Kojima R, Kajiura S, Sesaki H, Endo T, Tamura Y. Identification of multi-copy suppressors for endoplasmic reticulum-mitochondria tethering proteins in Saccharomyces cerevisiae. FEBS Lett 2016; 590:3061-70. [PMID: 27531107 DOI: 10.1002/1873-3468.12358] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/16/2016] [Accepted: 08/09/2016] [Indexed: 11/08/2022]
Abstract
In yeast, the endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) tethers the ER to mitochondria, but its primary function remains unclear. To gain insight into ERMES functions, we screened multi-copy suppressors of the growth-defective phenotype of mmm1∆ cells, which lack a core component of ERMES, and identified MCP1, MGA2, SPT23, and YGR250C (termed RIE1). Spt23 and Mga2 are homologous transcription factors known to activate transcription of the OLE1 gene, which encodes the fatty acid ∆9 desaturase. We found that Ole1 partially relieves the growth defects of ERMES-lacking cells, thus uncovering a relationship between fatty acid metabolism and ERMES functions.
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Affiliation(s)
- Rieko Kojima
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan.,Department of Material and Biological Science, Faculty of Science, Yamagata University, Japan
| | - Shu Kajiura
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan
| | - Hiromi Sesaki
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Toshiya Endo
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan. .,Faculty of Life Sciences, Kyoto Sangyo University, Japan. .,JST/CREST, Kyoto Sangyo University, Japan.
| | - Yasushi Tamura
- Department of Material and Biological Science, Faculty of Science, Yamagata University, Japan. .,Research Center for Materials Science, Nagoya University, Japan.
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35
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Fernández-Murray JP, McMaster CR. Lipid synthesis and membrane contact sites: a crossroads for cellular physiology. J Lipid Res 2016; 57:1789-1805. [PMID: 27521373 DOI: 10.1194/jlr.r070920] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Indexed: 12/17/2022] Open
Abstract
Membrane contact sites (MCSs) are regions of close apposition between different organelles that contribute to the functional integration of compartmentalized cellular processes. In recent years, we have gained insight into the molecular architecture of several contact sites, as well as into the regulatory mechanisms that underlie their roles in cell physiology. We provide an overview of two selected topics where lipid metabolism intersects with MCSs and organelle dynamics. First, the role of phosphatidic acid phosphatase, Pah1, the yeast homolog of metazoan lipin, toward the synthesis of triacylglycerol is outlined in connection with the seipin complex, Fld1/Ldb16, and lipid droplet formation. Second, we recapitulate the different contact sites connecting mitochondria and the endomembrane system and emphasize their contribution to phospholipid synthesis and their coordinated regulation. A comprehensive view is emerging where the multiplicity of contact sites connecting different cellular compartments together with lipid transfer proteins functioning at more than one MCS allow for functional redundancy and cross-regulation.
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36
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Smethurst DGJ, Cooper KF. ER fatalities-The role of ER-mitochondrial contact sites in yeast life and death decisions. Mech Ageing Dev 2016; 161:225-233. [PMID: 27507669 DOI: 10.1016/j.mad.2016.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/22/2016] [Accepted: 07/19/2016] [Indexed: 12/22/2022]
Abstract
Following extracellular stress signals, all eukaryotic cells choose whether to elicit a pro-survival or pro-death response. The decision over which path to take is governed by the severity and duration of the damage. In response to mild stress, pro-survival programs are initiated (unfolded protein response, autophagy, mitophagy) whereas severe or chronic stress forces the cell to abandon these adaptive programs and shift towards regulated cell death to remove irreversibly damaged cells. Both pro-survival and pro-death programs involve regulated communication between the endoplasmic reticulum (ER) and mitochondria. In yeast, recent data suggest this inter-organelle contact is facilitated by the endoplasmic reticulum mitochondria encounter structure (ERMES). These membrane contacts are not only important for the exchange of cellular signals, but also play a role in mitochondrial tethering during mitophagy, mitochondrial fission and mitochondrial inheritance. This review focuses on recent findings in yeast that shed light on how ER-mitochondrial communication mediates critical cell fate decisions.
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Affiliation(s)
- Daniel G J Smethurst
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, NJ, 08055 USA
| | - Katrina F Cooper
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, NJ, 08055 USA.
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37
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Dimmer KS, Rapaport D. Mitochondrial contact sites as platforms for phospholipid exchange. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:69-80. [PMID: 27477677 DOI: 10.1016/j.bbalip.2016.07.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/21/2016] [Accepted: 07/22/2016] [Indexed: 12/15/2022]
Abstract
Mitochondria are unique organelles that contain their own - although strongly reduced - genome, and are surrounded by two membranes. While most cellular phospholipid biosynthesis takes place in the ER, mitochondria harbor the whole spectrum of glycerophospholipids common to biological membranes. Mitochondria also contribute to overall phospholipid biosynthesis in cells by producing phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. Considering these features, it is not surprising that mitochondria maintain highly active exchange of phospholipids with other cellular compartments. In this contribution we describe the transport of phospholipids between mitochondria and other organelles, and discuss recent developments in our understanding of the molecular functions of the protein complexes that mediate these processes. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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Affiliation(s)
- Kai Stefan Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany.
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
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The Endoplasmic Reticulum-Mitochondrion Tether ERMES Orchestrates Fungal Immune Evasion, Illuminating Inflammasome Responses to Hyphal Signals. mSphere 2016; 1:mSphere00074-16. [PMID: 27303738 PMCID: PMC4888881 DOI: 10.1128/msphere.00074-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/26/2016] [Indexed: 01/01/2023] Open
Abstract
The pathogenic yeast Candida albicans escapes macrophages by triggering NLRP3 inflammasome-dependent host cell death (pyroptosis). Pyroptosis is inflammatory and must be tightly regulated by host and microbe, but the mechanism is incompletely defined. We characterized the C. albicans endoplasmic reticulum (ER)-mitochondrion tether ERMES and show that the ERMES mmm1 mutant is severely crippled in killing macrophages despite hyphal formation and normal phagocytosis and survival. To understand dynamic inflammasome responses to Candida with high spatiotemporal resolution, we established live-cell imaging for parallel detection of inflammasome activation and pyroptosis at the single-cell level. This showed that the inflammasome response to mmm1 mutant hyphae is delayed by 10 h, after which an exacerbated activation occurs. The NLRP3 inhibitor MCC950 inhibited inflammasome activation and pyroptosis by C. albicans, including exacerbated inflammasome activation by the mmm1 mutant. At the cell biology level, inactivation of ERMES led to a rapid collapse of mitochondrial tubular morphology, slow growth and hyphal elongation at host temperature, and reduced exposed 1,3-β-glucan in hyphal populations. Our data suggest that inflammasome activation by C. albicans requires a signal threshold dependent on hyphal elongation and cell wall remodeling, which could fine-tune the response relative to the level of danger posed by C. albicans. The phenotypes of the ERMES mutant and the lack of conservation in animals suggest that ERMES is a promising antifungal drug target. Our data further indicate that NLRP3 inhibition by MCC950 could modulate C. albicans-induced inflammation. IMPORTANCE The yeast Candida albicans causes human infections that have mortality rates approaching 50%. The key to developing improved therapeutics is to understand the host-pathogen interface. A critical interaction is that with macrophages: intracellular Candida triggers the NLRP3/caspase-1 inflammasome for escape through lytic host cell death, but this also activates antifungal responses. To better understand how the inflammasome response to Candida is fine-tuned, we established live-cell imaging of inflammasome activation at single-cell resolution, coupled with analysis of the fungal ERMES complex, a mitochondrial regulator that lacks human homologs. We show that ERMES mediates Candida escape via inflammasome-dependent processes, and our data suggest that inflammasome activation is controlled by the level of hyphal growth and exposure of cell wall components as a proxy for severity of danger. Our study provides the most detailed dynamic analysis of inflammasome responses to a fungal pathogen so far and establishes promising pathogen- and host-derived therapeutic strategies.
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Sinzel M, Tan T, Wendling P, Kalbacher H, Özbalci C, Chelius X, Westermann B, Brügger B, Rapaport D, Dimmer KS. Mcp3 is a novel mitochondrial outer membrane protein that follows a unique IMP-dependent biogenesis pathway. EMBO Rep 2016; 17:965-81. [PMID: 27226123 DOI: 10.15252/embr.201541273] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 04/26/2016] [Indexed: 11/09/2022] Open
Abstract
Mitochondria are separated from the remainder of the eukaryotic cell by the mitochondrial outer membrane (MOM). The MOM plays an important role in different transport processes like lipid trafficking and protein import. In yeast, the ER-mitochondria encounter structure (ERMES) has a central, but poorly defined role in both activities. To understand the functions of the ERMES, we searched for suppressors of the deficiency of one of its components, Mdm10, and identified a novel mitochondrial protein that we named Mdm10 complementing protein 3 (Mcp3). Mcp3 partially rescues a variety of ERMES-related phenotypes. We further demonstrate that Mcp3 is an integral protein of the MOM that follows a unique import pathway. It is recognized initially by the import receptor Tom70 and then crosses the MOM via the translocase of the outer membrane. Mcp3 is next relayed to the TIM23 translocase at the inner membrane, gets processed by the inner membrane peptidase (IMP) and finally integrates into the MOM. Hence, Mcp3 follows a novel biogenesis route where a MOM protein is processed by a peptidase of the inner membrane.
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Affiliation(s)
- Monika Sinzel
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Tao Tan
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Philipp Wendling
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Hubert Kalbacher
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Cagakan Özbalci
- Heidelberg University Biochemistry Center, Heidelberg, Germany
| | - Xenia Chelius
- Cell Biology, University of Bayreuth, Bayreuth, Germany
| | | | - Britta Brügger
- Heidelberg University Biochemistry Center, Heidelberg, Germany
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Kai Stefan Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
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TAC102 Is a Novel Component of the Mitochondrial Genome Segregation Machinery in Trypanosomes. PLoS Pathog 2016; 12:e1005586. [PMID: 27168148 PMCID: PMC4864229 DOI: 10.1371/journal.ppat.1005586] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/30/2016] [Indexed: 11/19/2022] Open
Abstract
Trypanosomes show an intriguing organization of their mitochondrial DNA into a catenated network, the kinetoplast DNA (kDNA). While more than 30 proteins involved in kDNA replication have been described, only few components of kDNA segregation machinery are currently known. Electron microscopy studies identified a high-order structure, the tripartite attachment complex (TAC), linking the basal body of the flagellum via the mitochondrial membranes to the kDNA. Here we describe TAC102, a novel core component of the TAC, which is essential for proper kDNA segregation during cell division. Loss of TAC102 leads to mitochondrial genome missegregation but has no impact on proper organelle biogenesis and segregation. The protein is present throughout the cell cycle and is assembled into the newly developing TAC only after the pro-basal body has matured indicating a hierarchy in the assembly process. Furthermore, we provide evidence that the TAC is replicated de novo rather than using a semi-conservative mechanism. Lastly, we demonstrate that TAC102 lacks an N-terminal mitochondrial targeting sequence and requires sequences in the C-terminal part of the protein for its proper localization. Proper segregation of the mitochondrial genome during cell division is a prerequisite of healthy eukaryotic cells. However, the mechanism underlying the segregation process is only poorly understood. We use the single celled parasite Trypanosoma brucei, which, unlike most model organisms, harbors a single large mitochondrion with a single mitochondrial genome, also called kinetoplast DNA (kDNA), to study this question. In trypanosomes, kDNA replication and segregation are tightly integrated into the cell cycle and thus can be studied alongside cell cycle markers. Furthermore, previous studies using electron microscopy have characterized the tripartite attachment complex (TAC) as a structural element of the mitochondrial genome segregation machinery. Here, we characterize TAC102, a novel trypanosome protein localized to the TAC. The protein is essential for proper kDNA segregation and cell growth. We analyze the presence of this protein using super resolution microscopy and show that TAC102 is a mitochondrial protein localized between the kDNA and the basal body of the cell’s flagellum. In addition, we characterize different parts of the protein and show that the C-terminus of TAC102 is important for its proper localization. The data and resources presented will allow a more detailed characterization of the dynamics and hierarchy of the TAC in the future and might open new avenues for drug discovery targeting this structure.
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Wideman JG, Muñoz-Gómez SA. The evolution of ERMIONE in mitochondrial biogenesis and lipid homeostasis: An evolutionary view from comparative cell biology. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:900-912. [PMID: 26825688 DOI: 10.1016/j.bbalip.2016.01.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/19/2016] [Accepted: 01/25/2016] [Indexed: 12/17/2022]
Abstract
The ER-mitochondria organizing network (ERMIONE) in Saccharomyces cerevisiae is involved in maintaining mitochondrial morphology and lipid homeostasis. ERMES and MICOS are two scaffolding complexes of ERMIONE that contribute to these processes. ERMES is ancient but has been lost in several lineages including animals, plants, and SAR (stramenopiles, alveolates and rhizaria). On the other hand, MICOS is ancient and has remained present in all organisms bearing mitochondrial cristae. The ERMIONE precursor evolved in the α-proteobacterial ancestor of mitochondria which had the central subunit of MICOS, Mic60. The subsequent evolution of ERMIONE and its interactors in eukaryotes reflects the integrative co-evolution of mitochondria and their hosts and the adaptive paths that some lineages have followed in their specialization to certain environments. By approaching the ERMIONE from a perspective of comparative evolutionary cell biology, we hope to shed light on not only its evolutionary history, but also how ERMIONE components may function in organisms other than S. cerevisiae. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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Affiliation(s)
| | - Sergio A Muñoz-Gómez
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
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42
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Lang AB, John Peter AT, Walter P, Kornmann B. ER-mitochondrial junctions can be bypassed by dominant mutations in the endosomal protein Vps13. J Cell Biol 2015; 210:883-90. [PMID: 26370498 PMCID: PMC4576869 DOI: 10.1083/jcb.201502105] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Substitutions in Vps13 suppress all measured phenotypic consequences of ERMES deficiency, and Vps13 dynamically localizes to vacuole–mitochondria and to vacuole–nucleus contact sites depending on growth conditions, suggesting that ERMES function can be bypassed by the activity of other contact sites, and that contact sites establish a growth condition–regulated organelle network. The endoplasmic reticulum–mitochondria encounter structure (ERMES) complex tethers the endoplasmic reticulum and the mitochondria. It is thought to facilitate interorganelle lipid exchange and influence mitochondrial dynamics and mitochondrial DNA maintenance. Despite this important role, ERMES is not found in metazoans. Here, we identified single amino acid substitutions in Vps13 (vacuolar protein sorting 13), a large universally conserved eukaryotic protein, which suppress all measured phenotypic consequences of ERMES deficiency. Combined loss of VPS13 and ERMES is lethal, indicating that Vps13 and ERMES function in redundant pathways. Vps13 dynamically localizes to vacuole–mitochondria and to vacuole–nucleus contact sites depending on growth conditions, suggesting that ERMES function can be bypassed by the activity of other contact sites, and that contact sites establish a growth condition–regulated organelle network.
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Affiliation(s)
| | | | - Peter Walter
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158 Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| | - Benoît Kornmann
- ETH Zürich, Institute of Biochemistry, 8093 Zürich, Switzerland
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43
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Calzada E, Onguka O, Claypool SM. Phosphatidylethanolamine Metabolism in Health and Disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 321:29-88. [PMID: 26811286 DOI: 10.1016/bs.ircmb.2015.10.001] [Citation(s) in RCA: 251] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Phosphatidylethanolamine (PE) is the second most abundant glycerophospholipid in eukaryotic cells. The existence of four only partially redundant biochemical pathways that produce PE, highlights the importance of this essential phospholipid. The CDP-ethanolamine and phosphatidylserine decarboxylase pathways occur in different subcellular compartments and are the main sources of PE in cells. Mammalian development fails upon ablation of either pathway. Once made, PE has diverse cellular functions that include serving as a precursor for phosphatidylcholine and a substrate for important posttranslational modifications, influencing membrane topology, and promoting cell and organelle membrane fusion, oxidative phosphorylation, mitochondrial biogenesis, and autophagy. The importance of PE metabolism in mammalian health has recently emerged following its association with Alzheimer's disease, Parkinson's disease, nonalcoholic liver disease, and the virulence of certain pathogenic organisms.
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Affiliation(s)
- Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ouma Onguka
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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44
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Mic60/Mitofilin determines MICOS assembly essential for mitochondrial dynamics and mtDNA nucleoid organization. Cell Death Differ 2015; 23:380-92. [PMID: 26250910 DOI: 10.1038/cdd.2015.102] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 05/14/2015] [Accepted: 06/22/2015] [Indexed: 01/23/2023] Open
Abstract
The MICOS complex (mitochondrial contact site and cristae organizing system) is essential for mitochondrial inner membrane organization and mitochondrial membrane contacts, however, the molecular regulation of MICOS assembly and the physiological functions of MICOS in mammals remain obscure. Here, we report that Mic60/Mitofilin has a critical role in the MICOS assembly, which determines the mitochondrial morphology and mitochondrial DNA (mtDNA) organization. The downregulation of Mic60/Mitofilin or Mic19/CHCHD3 results in instability of other MICOS components, disassembly of MICOS complex and disorganized mitochondrial cristae. We show that there exists direct interaction between Mic60/Mitofilin and Mic19/CHCHD3, which is crucial for their stabilization in mammals. Importantly, we identified that the mitochondrial i-AAA protease Yme1L regulates Mic60/Mitofilin homeostasis. Impaired MICOS assembly causes the formation of 'giant mitochondria' because of dysregulated mitochondrial fusion and fission. Also, mtDNA nucleoids are disorganized and clustered in these giant mitochondria in which mtDNA transcription is attenuated because of remarkable downregulation of some key mtDNA nucleoid-associated proteins. Together, these findings demonstrate that Mic60/Mitofilin homeostasis regulated by Yme1L is central to the MICOS assembly, which is required for maintenance of mitochondrial morphology and organization of mtDNA nucleoids.
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45
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Lang A, John Peter AT, Kornmann B. ER-mitochondria contact sites in yeast: beyond the myths of ERMES. Curr Opin Cell Biol 2015; 35:7-12. [PMID: 25836730 DOI: 10.1016/j.ceb.2015.03.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/10/2015] [Accepted: 03/10/2015] [Indexed: 10/23/2022]
Abstract
A standout feature of eukaryotic cells is the presence of organelles with distinct chemical compositions and physical properties, which aid in the accomplishment of specialized metabolic tasks. This complex topology, however, makes a permanent crosstalk between the organelles a necessity for the coordination of cellular function. While molecule exchange between organelles via the vesicular transport system has been extensively studied, communication via direct connections has only recently become a new matter of interest. These direct connections termed membrane contact sites (MCSs) represent zones of close proximity (10-30nm) between two organelles. Research in the past years has revealed a number of MCSs especially between the ER and almost every other organelle [1(•)]. In particular, the MCSs between the ER and the mitochondria have undergone intense investigation. While the quest for ER-mitochondria MCS components in human cells has led to the revelation of an ever growing number of potential factors, studies in the simpler eukaryote Saccharomyces cerevisiae revealed the actual existence of a molecular tether between the two organelles [2(••)].
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Affiliation(s)
- Alexander Lang
- Institute of Biochemistry, ETH Zurich, 8093 Zürich, Switzerland
| | | | - Benoît Kornmann
- Institute of Biochemistry, ETH Zurich, 8093 Zürich, Switzerland.
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46
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Kannan M, Riekhof WR, Voelker DR. Transport of Phosphatidylserine from the Endoplasmic Reticulum to the Site of Phosphatidylserine Decarboxylase2 in Yeast. Traffic 2014; 16:123-34. [DOI: 10.1111/tra.12236] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 10/17/2014] [Accepted: 10/28/2014] [Indexed: 02/03/2023]
Affiliation(s)
- Muthukumar Kannan
- Department of Medicine and Program in Cell Biology; National Jewish Health; Denver CO 80206 USA
| | - Wayne R. Riekhof
- School of Biological Sciences; University of Nebraska; Lincoln NE 68588 USA
| | - Dennis R. Voelker
- Department of Medicine and Program in Cell Biology; National Jewish Health; Denver CO 80206 USA
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47
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Murcha MW, Kmiec B, Kubiszewski-Jakubiak S, Teixeira PF, Glaser E, Whelan J. Protein import into plant mitochondria: signals, machinery, processing, and regulation. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6301-35. [PMID: 25324401 DOI: 10.1093/jxb/eru399] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The majority of more than 1000 proteins present in mitochondria are imported from nuclear-encoded, cytosolically synthesized precursor proteins. This impressive feat of transport and sorting is achieved by the combined action of targeting signals on mitochondrial proteins and the mitochondrial protein import apparatus. The mitochondrial protein import apparatus is composed of a number of multi-subunit protein complexes that recognize, translocate, and assemble mitochondrial proteins into functional complexes. While the core subunits involved in mitochondrial protein import are well conserved across wide phylogenetic gaps, the accessory subunits of these complexes differ in identity and/or function when plants are compared with Saccharomyces cerevisiae (yeast), the model system for mitochondrial protein import. These differences include distinct protein import receptors in plants, different mechanistic operation of the intermembrane protein import system, the location and activity of peptidases, the function of inner-membrane translocases in linking the outer and inner membrane, and the association/regulation of mitochondrial protein import complexes with components of the respiratory chain. Additionally, plant mitochondria share proteins with plastids, i.e. dual-targeted proteins. Also, the developmental and cell-specific nature of mitochondrial biogenesis is an aspect not observed in single-celled systems that is readily apparent in studies in plants. This means that plants provide a valuable model system to study the various regulatory processes associated with protein import and mitochondrial biogenesis.
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Affiliation(s)
- Monika W Murcha
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Beata Kmiec
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, SE-10691 Stockholm, Sweden
| | - Szymon Kubiszewski-Jakubiak
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Pedro F Teixeira
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, SE-10691 Stockholm, Sweden
| | - Elzbieta Glaser
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, SE-10691 Stockholm, Sweden
| | - James Whelan
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria, 3086, Australia
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48
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Höhr AIC, Straub SP, Warscheid B, Becker T, Wiedemann N. Assembly of β-barrel proteins in the mitochondrial outer membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:74-88. [PMID: 25305573 DOI: 10.1016/j.bbamcr.2014.10.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 09/25/2014] [Accepted: 10/01/2014] [Indexed: 12/15/2022]
Abstract
Mitochondria evolved through endosymbiosis of a Gram-negative progenitor with a host cell to generate eukaryotes. Therefore, the outer membrane of mitochondria and Gram-negative bacteria contain pore proteins with β-barrel topology. After synthesis in the cytosol, β-barrel precursor proteins are first transported into the mitochondrial intermembrane space. Folding and membrane integration of β-barrel proteins depend on the mitochondrial sorting and assembly machinery (SAM) located in the outer membrane, which is related to the β-barrel assembly machinery (BAM) in bacteria. The SAM complex recognizes β-barrel proteins by a β-signal in the C-terminal β-strand that is required to initiate β-barrel protein insertion into the outer membrane. In addition, the SAM complex is crucial to form membrane contacts with the inner mitochondrial membrane by interacting with the mitochondrial contact site and cristae organizing system (MICOS) and shares a subunit with the endoplasmic reticulum-mitochondria encounter structure (ERMES) that links the outer mitochondrial membrane to the endoplasmic reticulum (ER).
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Affiliation(s)
- Alexandra I C Höhr
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany; Fakultät für Biologie, Universität Freiburg, 79104 Freiburg, Germany
| | - Sebastian P Straub
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany; Fakultät für Biologie, Universität Freiburg, 79104 Freiburg, Germany
| | - Bettina Warscheid
- BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany; Abteilung Biochemie und Funktionelle Proteomik, Institut für Biologie II, Fakultät für Biologie, Universität Freiburg, 79104 Freiburg, Germany
| | - Thomas Becker
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany
| | - Nils Wiedemann
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany.
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49
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Mishra P, Chan DC. Mitochondrial dynamics and inheritance during cell division, development and disease. Nat Rev Mol Cell Biol 2014; 15:634-46. [PMID: 25237825 DOI: 10.1038/nrm3877] [Citation(s) in RCA: 716] [Impact Index Per Article: 71.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During cell division, it is critical to properly partition functional sets of organelles to each daughter cell. The partitioning of mitochondria shares some common features with that of other organelles, particularly in the use of interactions with cytoskeletal elements to facilitate delivery to the daughter cells. However, mitochondria have unique features - including their own genome and a maternal mode of germline transmission - that place additional demands on this process. Consequently, mechanisms have evolved to regulate mitochondrial segregation during cell division, oogenesis, fertilization and tissue development, as well as to ensure the integrity of these organelles and their DNA, including fusion-fission dynamics, organelle transport, mitophagy and genetic selection of functional genomes. Defects in these processes can lead to cell and tissue pathologies.
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Affiliation(s)
- Prashant Mishra
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - David C Chan
- 1] Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA. [2] Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125, USA
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50
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Tamura Y, Sesaki H, Endo T. Phospholipid transport via mitochondria. Traffic 2014; 15:933-45. [PMID: 24954234 DOI: 10.1111/tra.12188] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 06/16/2014] [Accepted: 06/16/2014] [Indexed: 12/27/2022]
Abstract
In eukaryotic cells, complex membrane structures called organelles are highly developed to exert specialized functions. Mitochondria are one of such organelles consisting of the outer and inner membranes (OM and IM) with characteristic protein and phospholipid compositions. Maintaining proper phospholipid compositions of the membranes is crucial for mitochondrial integrity, thereby contributing to normal cell activities. As cellular locations for phospholipid synthesis are restricted to specific compartments such as the endoplasmic reticulum (ER) membrane and the mitochondrial inner membrane, newly synthesized phospholipids have to be transported and distributed properly from the ER or mitochondria to other cellular membranes. Although understanding of molecular mechanisms of phospholipid transport are much behind those of protein transport, recent studies using yeast as a model system began to provide intriguing insights into phospholipid exchange between the ER and mitochondria as well as between the mitochondrial OM and IM. In this review, we summarize the latest findings of phospholipid transport via mitochondria and discuss the implicated molecular mechanisms.
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Affiliation(s)
- Yasushi Tamura
- Research Center for Materials Science, Nagoya University, Nagoya, 464-8602, Japan
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