1
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Mariani JN, Mansky B, Madsen PM, Salinas D, Kesmen D, Huynh NPT, Kuypers NJ, Kesel ER, Bates J, Payne C, Chandler-Militello D, Benraiss A, Goldman SA. Repression of developmental transcription factor networks triggers aging-associated gene expression in human glial progenitor cells. Nat Commun 2024; 15:3873. [PMID: 38719882 PMCID: PMC11079006 DOI: 10.1038/s41467-024-48118-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 04/18/2024] [Indexed: 05/12/2024] Open
Abstract
Human glial progenitor cells (hGPCs) exhibit diminished expansion competence with age, as well as after recurrent demyelination. Using RNA-sequencing to compare the gene expression of fetal and adult hGPCs, we identify age-related changes in transcription consistent with the repression of genes enabling mitotic expansion, concurrent with the onset of aging-associated transcriptional programs. Adult hGPCs develop a repressive transcription factor network centered on MYC, and regulated by ZNF274, MAX, IKZF3, and E2F6. Individual over-expression of these factors in iPSC-derived hGPCs lead to a loss of proliferative gene expression and an induction of mitotic senescence, replicating the transcriptional changes incurred during glial aging. miRNA profiling identifies the appearance of an adult-selective miRNA signature, imposing further constraints on the expansion competence of aged GPCs. hGPC aging is thus associated with acquisition of a MYC-repressive environment, suggesting that suppression of these repressors of glial expansion may permit the rejuvenation of aged hGPCs.
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Affiliation(s)
- John N Mariani
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA.
| | - Benjamin Mansky
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Pernille M Madsen
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health, Copenhagen, 2200, Denmark
| | - Dennis Salinas
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Deniz Kesmen
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Nguyen P T Huynh
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health, Copenhagen, 2200, Denmark
| | - Nicholas J Kuypers
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Erin R Kesel
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Janna Bates
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Casey Payne
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Devin Chandler-Militello
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Abdellatif Benraiss
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Steven A Goldman
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA.
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health, Copenhagen, 2200, Denmark.
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2
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Azbarova AV, Knorre DA. Role of Mitochondrial DNA in Yeast Replicative Aging. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1997-2006. [PMID: 38462446 DOI: 10.1134/s0006297923120040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 03/12/2024]
Abstract
Despite the diverse manifestations of aging across different species, some common aging features and underlying mechanisms are shared. In particular, mitochondria appear to be among the most vulnerable systems in both metazoa and fungi. In this review, we discuss how mitochondrial dysfunction is related to replicative aging in the simplest eukaryotic model, the baker's yeast Saccharomyces cerevisiae. We discuss a chain of events that starts from asymmetric distribution of mitochondria between mother and daughter cells. With age, yeast mother cells start to experience a decrease in mitochondrial transmembrane potential and, consequently, a decrease in mitochondrial protein import efficiency. This induces mitochondrial protein precursors in the cytoplasm, the loss of mitochondrial DNA (mtDNA), and at the later stages - cell death. Interestingly, yeast strains without mtDNA can have either increased or decreased lifespan compared to the parental strains with mtDNA. The direction of the effect depends on their ability to activate compensatory mechanisms preventing or mitigating negative consequences of mitochondrial dysfunction. The central role of mitochondria in yeast aging and death indicates that it is one of the most complex and, therefore, deregulation-prone systems in eukaryotic cells.
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Affiliation(s)
- Aglaia V Azbarova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Dmitry A Knorre
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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3
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Phua CZJ, Zhao X, Turcios-Hernandez L, McKernan M, Abyadeh M, Ma S, Promislow D, Kaeberlein M, Kaya A. Genetic perturbation of mitochondrial function reveals functional role for specific mitonuclear genes, metabolites, and pathways that regulate lifespan. GeroScience 2023; 45:2161-2178. [PMID: 37086368 PMCID: PMC10651825 DOI: 10.1007/s11357-023-00796-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/08/2023] [Indexed: 04/23/2023] Open
Abstract
Altered mitochondrial function is tightly linked to lifespan regulation, but underlying mechanisms remain unclear. Here, we report the chronological and replicative lifespan variation across 167 yeast knock-out strains, each lacking a single nuclear-coded mitochondrial gene, including 144 genes with human homologs, many associated with diseases. We dissected the signatures of observed lifespan differences by analyzing profiles of each strain's proteome, lipidome, and metabolome under fermentative and respiratory culture conditions, which correspond to the metabolic states of replicative and chronologically aging cells, respectively. Examination of the relationships among extended longevity phenotypes, protein, and metabolite levels revealed that although many of these nuclear-encoded mitochondrial genes carry out different functions, their inhibition attenuates a common mechanism that controls cytosolic ribosomal protein abundance, actin dynamics, and proteasome function to regulate lifespan. The principles of lifespan control learned through this work may be applicable to the regulation of lifespan in more complex organisms, since many aspects of mitochondrial function are highly conserved among eukaryotes.
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Affiliation(s)
- Cheryl Zi Jin Phua
- Genome Institute of Singapore, Agency for Science, Technology, and Research (A* STAR), Singapore, Singapore
| | - Xiaqing Zhao
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
| | - Lesly Turcios-Hernandez
- Department of Biology, Virginia Commonwealth University, Room 126, 1000 West Cary St. , Richmond, VA, 23284, USA
| | - Morrigan McKernan
- Department of Biology, Virginia Commonwealth University, Room 126, 1000 West Cary St. , Richmond, VA, 23284, USA
| | - Morteza Abyadeh
- Department of Biology, Virginia Commonwealth University, Room 126, 1000 West Cary St. , Richmond, VA, 23284, USA
| | - Siming Ma
- Genome Institute of Singapore, Agency for Science, Technology, and Research (A* STAR), Singapore, Singapore
| | - Daniel Promislow
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Department of Biology, University of Washington, Seattle, WA, 98195, USA
| | - Matt Kaeberlein
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
| | - Alaattin Kaya
- Department of Biology, Virginia Commonwealth University, Room 126, 1000 West Cary St. , Richmond, VA, 23284, USA.
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4
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Staneva D, Vasileva B, Podlesniy P, Miloshev G, Georgieva M. Yeast Chromatin Mutants Reveal Altered mtDNA Copy Number and Impaired Mitochondrial Membrane Potential. J Fungi (Basel) 2023; 9:jof9030329. [PMID: 36983497 PMCID: PMC10058930 DOI: 10.3390/jof9030329] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/02/2023] [Accepted: 03/04/2023] [Indexed: 03/30/2023] Open
Abstract
Mitochondria are multifunctional, dynamic organelles important for stress response, cell longevity, ageing and death. Although the mitochondrion has its genome, nuclear-encoded proteins are essential in regulating mitochondria biogenesis, morphology, dynamics and function. Moreover, chromatin structure and epigenetic mechanisms govern the accessibility to DNA and control gene transcription, indirectly influencing nucleo-mitochondrial communications. Thus, they exert crucial functions in maintaining proper chromatin structure, cell morphology, gene expression, stress resistance and ageing. Here, we present our studies on the mtDNA copy number in Saccharomyces cerevisiae chromatin mutants and investigate the mitochondrial membrane potential throughout their lifespan. The mutants are arp4 (with a point mutation in the ARP4 gene, coding for actin-related protein 4-Arp4p), hho1Δ (lacking the HHO1 gene, coding for the linker histone H1), and the double mutant arp4 hho1Δ cells with the two mutations. Our findings showed that the three chromatin mutants acquired strain-specific changes in the mtDNA copy number. Furthermore, we detected the disrupted mitochondrial membrane potential in their chronological lifespan. In addition, the expression of nuclear genes responsible for regulating mitochondria biogenesis and turnover was changed. The most pronounced were the alterations found in the double mutant arp4 hho1Δ strain, which appeared as the only petite colony-forming mutant, unable to grow on respiratory substrates and with partial depletion of the mitochondrial genome. The results suggest that in the studied chromatin mutants, hho1Δ, arp4 and arp4 hho1Δ, the nucleus-mitochondria communication was disrupted, leading to impaired mitochondrial function and premature ageing phenotype in these mutants, especially in the double mutant.
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Affiliation(s)
- Dessislava Staneva
- Laboratory of Molecular Genetics, Epigenetics and Longevity, Institute of Molecular Biology "RoumenTsanev", Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Bela Vasileva
- Laboratory of Molecular Genetics, Epigenetics and Longevity, Institute of Molecular Biology "RoumenTsanev", Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Petar Podlesniy
- CiberNed (Centro Investigacion Biomedica en Red Enfermedades Neurodegenerativas), 28029 Barcelona, Spain
| | - George Miloshev
- Laboratory of Molecular Genetics, Epigenetics and Longevity, Institute of Molecular Biology "RoumenTsanev", Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Milena Georgieva
- Laboratory of Molecular Genetics, Epigenetics and Longevity, Institute of Molecular Biology "RoumenTsanev", Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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5
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Guo J, Chiang WC. Mitophagy in aging and longevity. IUBMB Life 2021; 74:296-316. [PMID: 34889504 DOI: 10.1002/iub.2585] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 11/21/2021] [Indexed: 12/22/2022]
Abstract
The clearance of damaged or unwanted mitochondria by autophagy (also known as mitophagy) is a mitochondrial quality control mechanism postulated to play an essential role in cellular homeostasis, metabolism, and development and confers protection against a wide range of diseases. Proper removal of damaged or unwanted mitochondria is essential for organismal health. Defects in mitophagy are associated with Parkinson's, Alzheimer's disease, cancer, and other degenerative disorders. Mitochondria regulate organismal fitness and longevity via multiple pathways, including cellular senescence, stem cell function, inflammation, mitochondrial unfolded protein response (mtUPR), and bioenergetics. Thus, mitophagy is postulated to be pivotal for maintaining organismal healthspan and lifespan and the protection against aged-related degeneration. In this review, we will summarize recent understanding of the mechanism of mitophagy and aspects of mitochondrial functions. We will focus on mitochondria-related cellular processes that are linked to aging and examine current genetic evidence that supports the hypothesis that mitophagy is a pro-longevity mechanism.
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Affiliation(s)
- Jing Guo
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Wei-Chung Chiang
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
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6
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The SPFH Protein Superfamily in Fungi: Impact on Mitochondrial Function and Implications in Virulence. Microorganisms 2021; 9:microorganisms9112287. [PMID: 34835412 PMCID: PMC8624314 DOI: 10.3390/microorganisms9112287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 11/01/2021] [Indexed: 11/17/2022] Open
Abstract
Integral membrane proteins from the ancient SPFH (stomatin, prohibitin, flotillin, HflK/HflC) protein superfamily are found in nearly all living organisms. Mammalian SPFH proteins are primarily associated with mitochondrial functions but also coordinate key processes such as ion transport, signaling, and mechanosensation. In addition, SPFH proteins are required for virulence in parasites. While mitochondrial functions of SPFH proteins are conserved in fungi, recent evidence has uncovered additional roles for SPFH proteins in filamentation and stress signaling. Inhibitors that target SPFH proteins have been successfully used in cancer and inflammation treatment. Thus, SPFH proteins may serve as a potential target for novel antifungal drug development. This review article surveys SPFH function in various fungal species with a special focus on the most common human fungal pathogen, Candida albicans.
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7
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Belser M, Walker DW. Role of Prohibitins in Aging and Therapeutic Potential Against Age-Related Diseases. Front Genet 2021; 12:714228. [PMID: 34868199 PMCID: PMC8636131 DOI: 10.3389/fgene.2021.714228] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/21/2021] [Indexed: 12/16/2022] Open
Abstract
A decline in mitochondrial function has long been associated with age-related health decline. Several lines of evidence suggest that interventions that stimulate mitochondrial autophagy (mitophagy) can slow aging and prolong healthy lifespan. Prohibitins (PHB1 and PHB2) assemble at the mitochondrial inner membrane and are critical for mitochondrial homeostasis. In addition, prohibitins (PHBs) have diverse roles in cell and organismal biology. Here, we will discuss the role of PHBs in mitophagy, oxidative phosphorylation, cellular senescence, and apoptosis. We will also discuss the role of PHBs in modulating lifespan. In addition, we will review the links between PHBs and diseases of aging. Finally, we will discuss the emerging concept that PHBs may represent an attractive therapeutic target to counteract aging and age-onset disease.
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Affiliation(s)
- Misa Belser
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - David W. Walker
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
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8
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Telini BDP, Menoncin M, Bonatto D. Does Inter-Organellar Proteostasis Impact Yeast Quality and Performance During Beer Fermentation? Front Genet 2020; 11:2. [PMID: 32076433 PMCID: PMC7006503 DOI: 10.3389/fgene.2020.00002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/06/2020] [Indexed: 02/02/2023] Open
Abstract
During beer production, yeast generate ethanol that is exported to the extracellular environment where it accumulates. Depending on the initial carbohydrate concentration in the wort, the amount of yeast biomass inoculated, the fermentation temperature, and the yeast attenuation capacity, a high concentration of ethanol can be achieved in beer. The increase in ethanol concentration as a consequence of the fermentation of high gravity (HG) or very high gravity (VHG) worts promotes deleterious pleiotropic effects on the yeast cells. Moderate concentrations of ethanol (5% v/v) change the enzymatic kinetics of proteins and affect biological processes, such as the cell cycle and metabolism, impacting the reuse of yeast for subsequent fermentation. However, high concentrations of ethanol (> 5% v/v) dramatically alter protein structure, leading to unfolded proteins as well as amorphous protein aggregates. It is noteworthy that the effects of elevated ethanol concentrations generated during beer fermentation resemble those of heat shock stress, with similar responses observed in both situations, such as the activation of proteostasis and protein quality control mechanisms in different cell compartments, including endoplasmic reticulum (ER), mitochondria, and cytosol. Despite the extensive published molecular and biochemical data regarding the roles of proteostasis in different organelles of yeast cells, little is known about how this mechanism impacts beer fermentation and how different proteostasis mechanisms found in ER, mitochondria, and cytosol communicate with each other during ethanol/fermentative stress. Supporting this integrative view, transcriptome data analysis was applied using publicly available information for a lager yeast strain grown under beer production conditions. The transcriptome data indicated upregulation of genes that encode chaperones, co-chaperones, unfolded protein response elements in ER and mitochondria, ubiquitin ligases, proteasome components, N-glycosylation quality control pathway proteins, and components of processing bodies (p-bodies) and stress granules (SGs) during lager beer fermentation. Thus, the main purpose of this hypothesis and theory manuscript is to provide a concise picture of how inter-organellar proteostasis mechanisms are connected with one another and with biological processes that may modulate the viability and/or vitality of yeast populations during HG/VHG beer fermentation and serial repitching.
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Affiliation(s)
- Bianca de Paula Telini
- Brewing Yeast Research Group, Centro de Biotecnologia da UFRGS, Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Marcelo Menoncin
- Brewing Yeast Research Group, Centro de Biotecnologia da UFRGS, Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Diego Bonatto
- Brewing Yeast Research Group, Centro de Biotecnologia da UFRGS, Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
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9
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van Gastel J, Leysen H, Santos-Otte P, Hendrickx JO, Azmi A, Martin B, Maudsley S. The RXFP3 receptor is functionally associated with cellular responses to oxidative stress and DNA damage. Aging (Albany NY) 2019; 11:11268-11313. [PMID: 31794429 PMCID: PMC6932917 DOI: 10.18632/aging.102528] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 11/18/2019] [Indexed: 12/19/2022]
Abstract
DNA damage response (DDR) processes, often caused by oxidative stress, are important in aging and -related disorders. We recently showed that G protein-coupled receptor (GPCR) kinase interacting protein 2 (GIT2) plays a key role in both DNA damage and oxidative stress. Multiple tissue analyses in GIT2KO mice demonstrated that GIT2 expression affects the GPCR relaxin family peptide 3 receptor (RXFP3), and is thus a therapeutically-targetable system. RXFP3 and GIT2 play similar roles in metabolic aging processes. Gaining a detailed understanding of the RXFP3-GIT2 functional relationship could aid the development of novel anti-aging therapies. We determined the connection between RXFP3 and GIT2 by investigating the role of RXFP3 in oxidative stress and DDR. Analyzing the effects of oxidizing (H2O2) and DNA-damaging (camptothecin) stressors on the interacting partners of RXFP3 using Affinity Purification-Mass Spectrometry, we found multiple proteins linked to DDR and cell cycle control. RXFP3 expression increased in response to DNA damage, overexpression, and Relaxin 3-mediated stimulation of RXFP3 reduced phosphorylation of DNA damage marker H2AX, and repair protein BRCA1, moderating DNA damage. Our data suggests an RXFP3-GIT2 system that could regulate cellular degradation after DNA damage, and could be a novel mechanism for mitigating the rate of age-related damage accumulation.
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Affiliation(s)
- Jaana van Gastel
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Translational Neurobiology Group, Centre for Molecular Neuroscience, VIB, Antwerp, Belgium
| | - Hanne Leysen
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Translational Neurobiology Group, Centre for Molecular Neuroscience, VIB, Antwerp, Belgium
| | - Paula Santos-Otte
- Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Jhana O Hendrickx
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Translational Neurobiology Group, Centre for Molecular Neuroscience, VIB, Antwerp, Belgium
| | - Abdelkrim Azmi
- Translational Neurobiology Group, Centre for Molecular Neuroscience, VIB, Antwerp, Belgium
| | - Bronwen Martin
- Faculty of Pharmaceutical, Veterinary and Biomedical Science, University of Antwerp, Antwerp, Belgium
| | - Stuart Maudsley
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Translational Neurobiology Group, Centre for Molecular Neuroscience, VIB, Antwerp, Belgium
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10
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Qiu X, Yang H, Ren Z, Han S, Mu C, Li R, Ye Y, Song W, Shi C, Liu L, Wang H, Wang C. Characterization of PHB in the gonadal development of the swimming crab Portunus trituberculatus. Comp Biochem Physiol B Biochem Mol Biol 2019; 240:110338. [PMID: 31629811 DOI: 10.1016/j.cbpb.2019.110338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/19/2019] [Accepted: 09/03/2019] [Indexed: 01/18/2023]
Abstract
Prohibitin (PHB) is an evolutionarily conserved multifunctional protein with ubiquitous expression. In this study, we cloned the PHB gene from the testis of the swimming crab Portunus trituberculatus (PtPHB) and analyzed the deduced amino acid sequence. The expression level of phb mRNA in larvae was analyzed using qRT-PCR. The expression level of phb mRNA and PHB protein in different tissues were analyzed using qRT-PCR and Western blot respectively. Enzyme-linked immunosorbent assay analyses of the PHB protein were conducted with the testis and ovaries from P. trituberculatus specimens at different developmental stages. PHB was localized with mitochondria and ubiquitin in the testis and ovaries. The PtPHB gene was found to contain an open reading frame of 825 bp, encoding a predicted peptide with 275 amino acids, sharing between 65.9% and 96.7% similarity with that of other species. The qRT-PCR and Western blot results showed that the phb gene and PHB protein both expressed less in the testis and ovary than in other tissues, and the phb gene presented the lowest expression in the Z1 stage. Furthermore, the phb gene and PHB protein expression were different in the testis and ovaries at different developmental stages. PHB was mainly found to be co-localized with mitochondria and ubiquitin in cytoplasm and acrosome complex during spermatogenesis and in follicular cells during oogenesis. Interestingly, PHB-mitochondria signals and ubiquitin signal were also found in oocytes. These results indicated that PHB might play important roles during spermatogenesis and oogenesis by regulating mitochondrial activities.
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Affiliation(s)
- Xueni Qiu
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo 315211, China
| | - Hua Yang
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo 315211, China
| | - Zhiming Ren
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo 315211, China
| | - Shengming Han
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China
| | - Changkao Mu
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China.
| | - Ronghua Li
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China
| | - Yangfang Ye
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China
| | - Weiwei Song
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China
| | - Ce Shi
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China
| | - Lei Liu
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China
| | - Huan Wang
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China
| | - Chunlin Wang
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China.
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11
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Matz JM, Goosmann C, Matuschewski K, Kooij TWA. An Unusual Prohibitin Regulates Malaria Parasite Mitochondrial Membrane Potential. Cell Rep 2019; 23:756-767. [PMID: 29669282 DOI: 10.1016/j.celrep.2018.03.088] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/16/2018] [Accepted: 03/20/2018] [Indexed: 11/26/2022] Open
Abstract
Proteins of the stomatin/prohibitin/flotillin/HfIK/C (SPFH) family are membrane-anchored and perform diverse cellular functions in different organelles. Here, we investigate the SPFH proteins of the murine malaria model parasite Plasmodium berghei, the conserved prohibitin 1, prohibitin 2, and stomatin-like protein and an unusual prohibitin-like protein (PHBL). The SPFH proteins localize to the parasite mitochondrion. While the conserved family members could not be deleted from the Plasmodium genome, PHBL was successfully ablated, resulting in impaired parasite fitness and attenuated virulence in the mammalian host. Strikingly, PHBL-deficient parasites fail to colonize the Anopheles vector because of complete arrest during ookinete development in vivo. We show that this arrest correlates with depolarization of the mitochondrial membrane potential (ΔΨmt). Our results underline the importance of SPFH proteins in the regulation of core mitochondrial functions and suggest that fine-tuning of ΔΨmt in malarial parasites is critical for colonization of the definitive host.
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Affiliation(s)
- Joachim Michael Matz
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Philippstraße 13, 10115 Berlin, Germany; Parasitology Unit, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany; Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands.
| | - Christian Goosmann
- Microscopy Core Facility, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Philippstraße 13, 10115 Berlin, Germany; Parasitology Unit, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany
| | - Taco Wilhelmus Antonius Kooij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands; Center for Molecular and Biomolecular Informatics and Radboud Center for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands.
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12
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Hernando-Rodríguez B, Artal-Sanz M. Mitochondrial Quality Control Mechanisms and the PHB (Prohibitin) Complex. Cells 2018; 7:cells7120238. [PMID: 30501123 PMCID: PMC6315423 DOI: 10.3390/cells7120238] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial functions are essential for life, critical for development, maintenance of stem cells, adaptation to physiological changes, responses to stress, and aging. The complexity of mitochondrial biogenesis requires coordinated nuclear and mitochondrial gene expression, owing to the need of stoichiometrically assemble the oxidative phosphorylation (OXPHOS) system for ATP production. It requires, in addition, the import of a large number of proteins from the cytosol to keep optimal mitochondrial function and metabolism. Moreover, mitochondria require lipid supply for membrane biogenesis, while it is itself essential for the synthesis of membrane lipids. To achieve mitochondrial homeostasis, multiple mechanisms of quality control have evolved to ensure that mitochondrial function meets cell, tissue, and organismal demands. Herein, we give an overview of mitochondrial mechanisms that are activated in response to stress, including mitochondrial dynamics, mitophagy and the mitochondrial unfolded protein response (UPRmt). We then discuss the role of these stress responses in aging, with particular focus on Caenorhabditis elegans. Finally, we review observations that point to the mitochondrial prohibitin (PHB) complex as a key player in mitochondrial homeostasis, being essential for mitochondrial biogenesis and degradation, and responding to mitochondrial stress. Understanding how mitochondria responds to stress and how such responses are regulated is pivotal to combat aging and disease.
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Affiliation(s)
- Blanca Hernando-Rodríguez
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas, Junta de Andalucía, Universidad Pablo de Olavide, 41013 Seville, Spain.
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain.
| | - Marta Artal-Sanz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas, Junta de Andalucía, Universidad Pablo de Olavide, 41013 Seville, Spain.
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain.
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Dual roles of mitochondrial fusion gene FZO1 in yeast age asymmetry and in longevity mediated by a novel ATG32-dependent retrograde response. Biogerontology 2018; 20:93-107. [PMID: 30298458 DOI: 10.1007/s10522-018-9779-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/04/2018] [Indexed: 12/27/2022]
Abstract
The replicative lifespan of the yeast Saccharomyces cerevisiae models the aging of stem cells. Age asymmetry between the mother and daughter cells is established during each cell division, such that the daughter retains the capacity for self-renewal while this ability is diminished in the mother. The segregation of fully-functional mitochondria to daughter cells is one mechanism that underlies this age asymmetry. In this study, we have examined the role of mitochondrial dynamics in this phenomenon. Mitochondrial dynamics involve the processes of fission and fusion. Out of the three fusion and three fission genes tested, we have found that only FZO1 is required for the segregation of fully-functional mitochondria to daughter cells and in the maintenance of age asymmetry as manifested in the potential of daughters for a full replicative lifespan despite its deterioration in their mothers. The quality of mitochondria is determined by their turnover, and we have also discovered that deletion of FZO1 reduces mitophagy. Mitochondrial dysfunction elicits a compensatory retrograde response that extends replicative lifespan. Typically, the dysfunction that triggers this response encompasses energy production. The disruption of mitochondrial dynamics by deletion of FZO1 also activates the retrograde response to extend replicative lifespan. We call this novel pathway the mitochondrial dynamics-associated retrograde response (MDARR) because it is distinct in the signal proximal to the mitochondrion that initiates it. Furthermore, the MDARR engages the mitophagy receptor Atg32 on the mitochondrial surface, and we propose that this is due to the accumulation of Atg32-Atg11-Dnm1 complexes on the mitochondrion in the absence of Fzo1 activity. MDARR can be masked by the operation of the 'classic' retrograde response.
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Xiong Z, Zhang H, Huang B, Liu Q, Wang Y, Shi D, Li X. Expression pattern of prohibitin, capping actin protein of muscle Z-line beta subunit and tektin-2 gene in Murrah buffalo sperm and its relationship with sperm motility. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2018; 31:1729-1737. [PMID: 29642674 PMCID: PMC6212766 DOI: 10.5713/ajas.18.0025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 03/19/2018] [Indexed: 01/13/2023]
Abstract
Objective The aim of the current study is to investigate the relationship between prohibitin (PHB), capping actin protein of muscle Z-line beta subunit (CAPZB), and tektin-2 (TEKT2) and sperm motility in Murrah buffalo. Methods We collected the high-motility and low-motility semen samples, testis, ovary, muscle, kidney, liver, brain and pituitary from Murrah buffalo, and analysed the expression of PHB, CAPZB, and TEKT2 in mRNA (message RNA) and protein level. Results Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) result showed that the expression of PHB was higher and CAPZB, TEKT2 were specifically expressed in testis as compared to the other 6 tissues, and that in testis, the expression of TEKT2 was higher than that of CAPZB and PHB. Immunohistochemistry test revealed that all three genes were located on the convoluted seminiferous tubule and enriched in spermatogenic cells. Both qRT-PCR and Western Blot results showed that the expression levels of PHB, CAPZB, and TEKT2 were significantly lower in the low-motility semen group compared to the high-motility semen group (p<0.05). Conclusion The expression levels of PHB, CAPZB, and TEKT2 in Murrah buffalo sperm have a high positive correlation with sperm motility. And the three genes may be potential molecular markers for the decline of buffalo sperm motility.
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Affiliation(s)
- Zhaocheng Xiong
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning 530004, China
| | - Haihang Zhang
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning 530004, China
| | - Ben Huang
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning 530004, China
| | - Qingyou Liu
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning 530004, China
| | - Yingqun Wang
- Guangxi Livestock and Poultry Variety Reforming Station, Nanning 530001, China
| | - Deshun Shi
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning 530004, China
| | - Xiangping Li
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning 530004, China
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Hou CC, Wei CG, Lu CP, Gao XM, Yang WX, Zhu JQ. Prohibitin-mediated mitochondrial ubiquitination during spermiogenesis in Chinese mitten crab Eriocheir sinensis. Oncotarget 2017; 8:98782-98797. [PMID: 29228727 PMCID: PMC5716767 DOI: 10.18632/oncotarget.21961] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 09/23/2017] [Indexed: 12/21/2022] Open
Abstract
The sperm of Eriocheir sinensis has a cup-shaped nucleus that contains several mitochondria embedded at the opening of the cup. The acrosome vesicle also contains derivants of mitochondria. The mitochondria distribution pattern involves a decrease in the number and changes in the structure and transportation of these organelles. The decreased number of sperm mitochondria is achieved through autophagy or the ubiquitination pathway. Prohibitin (PHB), the mitochondria inner membrane protein, is an evolutionarily highly conserved protein, is closely associated with spermatogenesis and sperm quality control and is also a potential substrate of ubiquitination. However, whether PHB protein mediates the ubiquitination pathway of sperm mitochondria in crustacean animals remains poorly understood. In the present study, we revealed that PHB, a substrate of ubiquitin, participates in the ubiquitination and degradation of mitochondria during spermiogenesis in E. sinensis. To confirm this finding, we used shRNA interference to reduce PHB expression and an overexpression technique to increase PHB expression in vitro. The interference experiment showed that the reduced PHB expression directly affected the polyubiquitination level and mitochondria status, whereas PHB overexpression markedly increased the polyubiquitination level. In vitro experiments also showed that PHB and its ubiquitination decide the fate of mitochondria.
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Affiliation(s)
- Cong-Cong Hou
- Key Laboratory of Applied Marine Biotechnology of Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Chao-Guang Wei
- Key Laboratory of Applied Marine Biotechnology of Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Cheng-Peng Lu
- Key Laboratory of Applied Marine Biotechnology of Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Xin-Ming Gao
- Key Laboratory of Applied Marine Biotechnology of Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jun-Quan Zhu
- Key Laboratory of Applied Marine Biotechnology of Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo 315211, China
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Kaneko K, Sasaki M, Kuribayashi N, Suzuki H, Sasuga Y, Shiraya T, Inomata T, Itoh K, Baslam M, Mitsui T. Proteomic and Glycomic Characterization of Rice Chalky Grains Produced Under Moderate and High-temperature Conditions in Field System. RICE (NEW YORK, N.Y.) 2016; 9:26. [PMID: 27246013 PMCID: PMC4887401 DOI: 10.1186/s12284-016-0100-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/11/2016] [Indexed: 05/03/2023]
Abstract
BACKGROUND Global climate models predict an increase in global mean temperature and a higher frequency of intense heat spikes during this century. Cereals such as rice (Oryza sativa L.) are more susceptible to heat stress, mainly during the gametogenesis and flowering stages. During periods of high temperatures, grain filling often causes serious damage to the grain quality of rice and, therefore, yield losses. While the genes encoding enzymes involved in carbohydrate metabolism of chalky grains have been established, a significant knowledge gap exists in the proteomic and glycomic responses to warm temperatures in situ. Here, we studied the translucent and opaque characters of high temperature stressed chalky grains of 2009 and 2010 (ripening temperatures: 24.4 and 28.0 °C, respectively). RESULTS Appearance of chalky grains of both years showed some resemblance, and the high-temperature stress of 2010 remarkably extended the chalking of grain. Scanning electron microscopic observation showed that round-shaped starch granules with numerous small pits were loosely packed in the opaque part of the chalky grains. Proteomic analyzes of rice chalky grains revealed deregulations in the expression of multiple proteins implicated in diverse metabolic and physiological functions, such as protein synthesis, redox homeostasis, lipid metabolism, and starch biosynthesis and degradation. The glycomic profiling has shown slight differences in chain-length distributions of starches in the grains of 2009-to-2010. However, no significant changes were observed in the chain-length distributions between the translucent and opaque parts of perfect and chalky grains in both years. The glucose and soluble starch contents in opaque parts were increased by the high-temperature stress of 2010, though those in perfect grains were not different regardless of the environmental changes of 2009-to-2010. CONCLUSION Together with previous findings on the increased expression of α-amylases in the endosperm, these results suggested that unusual starch degradation rather than starch synthesis is involved in occurring of chalky grains of rice under the high-temperature stress during grain filling period.
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Affiliation(s)
- Kentaro Kaneko
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Maiko Sasaki
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Nanako Kuribayashi
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Hiromu Suzuki
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Yukiko Sasuga
- Department of Applied Biological Chemistry, Niigata University, Niigata, 950-218, Japan
| | - Takeshi Shiraya
- Department of Applied Biological Chemistry, Niigata University, Niigata, 950-218, Japan
- Present address: Niigata Crop Research Center, Niigata Agricultural Research Institute, Nagaoka, 940-0826, Japan
| | - Takuya Inomata
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Kimiko Itoh
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Marouane Baslam
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Toshiaki Mitsui
- Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan.
- Department of Applied Biological Chemistry, Niigata University, Niigata, 950-218, Japan.
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Jazwinski S. Mitochondria to nucleus signaling and the role of ceramide in its integration into the suite of cell quality control processes during aging. Ageing Res Rev 2015; 23:67-74. [PMID: 25555678 DOI: 10.1016/j.arr.2014.12.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/15/2014] [Accepted: 12/22/2014] [Indexed: 12/26/2022]
Abstract
Mitochondria to nucleus signaling has been the most extensively studied mode of inter-organelle communication. The first signaling pathway in this category of information transfer to be discovered was the retrograde response, with its own set of signal transduction proteins. The finding that this pathway compensates for mitochondrial dysfunction to extend the replicative lifespan of yeast cells has generated additional impetus for its study. This research has demonstrated crosstalk between the retrograde response and the target of rapamycin (TOR), small GTPase RAS, and high-osmolarity glycerol (HOG) pathways in yeast, all of which are key players in replicative lifespan. More recently, the retrograde response has been implicated in the diauxic shift and survival in stationary phase, extending its operation to the yeast chronological lifespan as well. In this capacity, the retrograde response may cooperate with other, related mitochondria to nucleus signaling pathways. Counterparts of the retrograde response are found in the roundworm, the fruit fly, the mouse, and even in human cells in tissue culture. The exciting realization that the retrograde response is embedded in the network of cellular quality control processes has emerged over the past few years. Most strikingly, it is closely integrated with autophagy and the selective brand of this quality control process, mitophagy. This coordination depends on TOR, and it engages ceramide/sphingolipid signaling. The yeast LAG1 ceramide synthase gene was the first longevity gene cloned as such, and its orthologs hyl-1 and hyl-2 determine worm lifespan. Thus, the involvement of ceramide signaling in quality control gives these findings cellular context. The retrograde response and ceramide are essential components of a lifespan maintenance process that likely evolved as a cytoprotective mechanism to defend the organism from diverse stressors.
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Rossi L, Bonuccelli L, Iacopetti P, Evangelista M, Ghezzani C, Tana L, Salvetti A. Prohibitin 2 regulates cell proliferation and mitochondrial cristae morphogenesis in planarian stem cells. Stem Cell Rev Rep 2015; 10:871-87. [PMID: 24974103 DOI: 10.1007/s12015-014-9540-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Prohibitins are pleiotropic proteins, whose multiple roles are emerging as key elements in the regulation of cell survival and proliferation. Indeed, prohibitins interact with several intracellular proteins strategically involved in the regulation of cell cycle progression in response to extracellular growth signals. Prohibitins also have regulatory functions in mitochondrial fusion and cristae morphogenesis, phenomena related to the ability of self-renewing embryonic stem cells to undergo differentiation, during which mitochondria develop numerous cristae, increase in number, and generate an extensive reticular network. We recently identified a Prohibitin 2 homolog (DjPhb2) that is expressed in adult stem cells (neoblasts) of planarians, a well-known model system for in vivo studies on stem cells and tissue regeneration. Here, we show that in DjPhb2 silenced planarians, most proliferating cells disappear, with the exception of a subpopulation of neoblasts localized along the dorsal body midline. Neoblast depletion impairs regeneration and, finally, leads animals to death. Our in vivo findings demonstrate that prohibitin 2 plays an important role in regulating stem cell biology, being involved in both the control of cell cycle progression and mitochondrial cristae morphogenesis.
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Affiliation(s)
- Leonardo Rossi
- Unit of Experimental Biology and Genetics, Department of Clinical and Experimental Medicine, University of Pisa, Via Volta 4, 56126, Pisa, Italy
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Farlora R, Nuñez-Acuña G, Gallardo-Escárate C. Prohibitin-2 gene reveals sex-related differences in the salmon louse Caligus rogercresseyi. Gene 2015; 564:73-80. [DOI: 10.1016/j.gene.2015.03.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 03/18/2015] [Accepted: 03/20/2015] [Indexed: 12/16/2022]
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Dong WL, Hou CC, Yang WX. Mitochondrial prohibitin and its ubiquitination during crayfish Procambarus clarkii spermiogenesis. Cell Tissue Res 2014; 359:679-692. [PMID: 25418137 DOI: 10.1007/s00441-014-2044-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/16/2014] [Indexed: 12/11/2022]
Abstract
Prohibitin (PHB), an evolutionarily conserved mitochondrial membrane protein, is associated with spermatogenesis and sperm quality control in mammals. It is identified as a substrate of ubiquitin and thus may function via a mitochondrial ubiquitin-proteasome pathway. In this study, we examined the localization of PHB during spermiogenesis of the macrura crustacean Procambarus clarkii. We traced phb mRNA's temporal and spatial expression pattern in spermiogenesis, and found its localization highly coherent with acrosome formation and nuclear shaping, two key events during crustacean spermiogenesis. We further detected the associations of PHB with mitochondria and ubiquitin using immunofluorescent staining. PHB was co-localized with mitochondria through spermiogenesis. PHB as well as mitochondria were co-localized with ubiquitin from the late stage of spermiogenesis, and the co-signals reached their peak in the mature sperm. The results raise the hypothesis that PHB is likely to function in nuclear shaping and acrosome formation in the spermiogenesis of P. clarkii. In addition, it might possess a more profound role in mediating mitochondrial ubiquitination. For the first time this study uncovers the role of PHB in the spermiogenesis of macrura crustacean species.
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Affiliation(s)
- Wei-Lai Dong
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Cong-Cong Hou
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China.
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Denoth Lippuner A, Julou T, Barral Y. Budding yeast as a model organism to study the effects of age. FEMS Microbiol Rev 2014; 38:300-25. [PMID: 24484434 DOI: 10.1111/1574-6976.12060] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 12/13/2013] [Accepted: 01/06/2014] [Indexed: 12/20/2022] Open
Abstract
Although a budding yeast culture can be propagated eternally, individual yeast cells age and eventually die. The detailed knowledge of this unicellular eukaryotic species as well as the powerful tools developed to study its physiology makes budding yeast an ideal model organism to study the mechanisms involved in aging. Considering both detrimental and positive aspects of age, we review changes occurring during aging both at the whole-cell level and at the intracellular level. The possible mechanisms allowing old cells to produce rejuvenated progeny are described in terms of accumulation and inheritance of aging factors. Based on the dynamic changes associated with age, we distinguish different stages of age: early age, during which changes do not impair cell growth; intermediate age, during which aging factors start to accumulate; and late age, which corresponds to the last divisions before death. For each aging factor, we examine its asymmetric segregation and whether it plays a causal role in aging. Using the example of caloric restriction, we describe how the aging process can be modulated at different levels and how changes in different organelles might interplay with each other. Finally, we discuss the beneficial aspects that might be associated with age.
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The mitochondrial unfolded protein response and increased longevity: cause, consequence, or correlation? Exp Gerontol 2014; 56:142-6. [PMID: 24518875 DOI: 10.1016/j.exger.2014.02.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/30/2014] [Accepted: 02/01/2014] [Indexed: 12/31/2022]
Abstract
The mitochondrial unfolded protein response is a conserved pathway that allows mitochondrial chaperones and other factors to be induced in response to mitochondrial dysfunction. Activation of this pathway has been proposed to underlie lifespan extension from knockdown or mutation of several nuclear encoded mitochondrial genes in Caenorhabditis elegans. In some cases, however, induction of the mitochondrial unfolded protein response is associated with a reduction of lifespan in both yeast and C. elegans. It also has yet to be demonstrated that induction of the mitochondrial unfolded protein response is sufficient to increase lifespan in the absence of overt mitochondrial dysfunction. In this perspective, we briefly review the evidence for and against a direct pro-longevity role of the mitochondrial unfolded protein response and suggest important areas of investigation for experimentally addressing this question.
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Fang DA, Wang Y, Wang J, Liu LH, Wang Q. Characterization of Cherax quadricarinatus prohibitin and its potential role in spermatogenesis. Gene 2013; 519:318-25. [PMID: 23485620 DOI: 10.1016/j.gene.2013.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 02/01/2013] [Accepted: 02/06/2013] [Indexed: 01/10/2023]
Abstract
Prohibitin (PHB) proteins have diverse functions, such as cellular signaling, transcriptional control and mitochondrial biogenesis. In this study, we characterized PHB gene and its protein expression in Cherax quadricarinatus. PHB cDNA comprises 1472 nucleotides with an open reading frame of 828bp, which encodes 275 amino acid residues. The highest transcript levels were found during the spermatogonial developmental phase, with the lowest levels detected during the resting phase in the reproductive cycle. Western blot analysis revealed that PHB is an approximately 30kDa protein, and occurs in a number of unexpected isoforms, ranging from 30kDa to greater than 180kDa in the testes of different developmental phases, which may be the ubiquitinated substrates. The strongest immunolabeling signal was found in spermatogonia, with lower levels of staining in secondary spermatocytes, and weak or absent expression in mature sperm. Immunogold electron microscopy results confirmed the localization of PHB in the inner mitochondrial membranes. The results showed that PHB is a substrate protein for spermatogenesis, with a potential reproductive function involving sperm ubiquitination in invertebrates.
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Affiliation(s)
- Di-An Fang
- Scientific Observing and Experimental Station of Fishery Resources and Environment in the Changjiang River, Freshwater Fisheries Research Center, Wuxi, Shanshui Road 9, 214081, China
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Wright J, Dungrawala H, Bright RK, Schneider BL. A growing role for hypertrophy in senescence. FEMS Yeast Res 2012; 13:2-6. [PMID: 23107076 DOI: 10.1111/1567-1364.12015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Lv Z, Zhang X, Liu L, Chen J, Nie Z, Sheng Q, Zhang W, Jiang C, Yu W, Wang D, Wu X, Zhang S, Li J, Zhang Y. Characterization of a gene encoding prohibitin in silkworm, Bombyx mori. Gene 2012; 502:118-24. [PMID: 22450364 DOI: 10.1016/j.gene.2012.03.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 02/23/2012] [Accepted: 03/04/2012] [Indexed: 12/11/2022]
Abstract
BACKGROUND Prohibitin (PHB) is an evolutionarily conserved multifunctional protein with ubiquitous expression. However, its molecular roles are largely unknown. METHODS To better understand the function of prohibitin protein in silkworm (BmPHB), its coding sequence was isolated from a cDNA library of silkworm pupae. An His-tagged BmPHB fusion protein was expressed in Escherichia coli Rosetta (DE3) and purified with affinity and reversed-phase chromatography. Purified rBmPHB was used to generate anti-BmPHB polyclonal antibody. The subcellular localization of BmPHB was analysed by immunohistochemistry. RESULTS BmPHB gene has an ORF of 825 bp, encoding a predicted peptide with 274 amino acid residues. Immunostaining indicate that prohibitin is expressed in nucleus and predominately in cytoplasm. Western blot analyses indicated that, in the fifth instar larva, BmPHB was expressed descendingly in gonad, malpighian tubule, trachea, fatty body, intestine, and head. However, no expression was detected in larva's silk gland and epidermis. In addition, BmPHB was expressed in the nascent egg, larva and pupa, but not in the moth. CONCLUSIONS The expression of BmPHB gene presents differential characteristic in different stage and tissues. It may play important roles in the development of silkworm. GENERAL SIGNIFICANCE Studies on prohibitin have been still restricted to a few specific insects and insect cell lines such as Drosophila, Acyrthosiphon pisum and mosquito cell lines, not yet in silkworm. This is a first characterization of prohibitin in silkworm, B. mori.
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Affiliation(s)
- Zhengbing Lv
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018, China
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Mao HT, Wang DH, Lan Z, Zhou H, Yang WX. Gene expression profiles of prohibitin in testes of Octopus tankahkeei (ot-phb) revealing its possible role during spermiogenesis. Mol Biol Rep 2011; 39:5519-28. [DOI: 10.1007/s11033-011-1355-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Accepted: 12/12/2011] [Indexed: 10/14/2022]
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McFaline-Figueroa JR, Vevea J, Swayne TC, Zhou C, Liu C, Leung G, Boldogh IR, Pon LA. Mitochondrial quality control during inheritance is associated with lifespan and mother-daughter age asymmetry in budding yeast. Aging Cell 2011; 10:885-95. [PMID: 21726403 DOI: 10.1111/j.1474-9726.2011.00731.x] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Fluorescence loss in photobleaching experiments and analysis of mitochondrial function using superoxide and redox potential biosensors revealed that mitochondria within individual yeast cells are physically and functionally distinct. Mitochondria that are retained in mother cells during yeast cell division have a significantly more oxidizing redox potential and higher superoxide levels compared to mitochondria in buds. Retention of mitochondria with more oxidizing redox potential in mother cells occurs to the same extent in young and older cells and can account for the age-associated decline in total cellular mitochondrial redox potential in yeast as they age from 0 to 5 generations. Deletion of Mmr1p, a member of the DSL1 family of tethering proteins that localizes to mitochondria at the bud tip and is required for normal mitochondrial inheritance, produces defects in mitochondrial quality control and heterogeneity in replicative lifespan (RLS). Long-lived mmr1Δ cells exhibit prolonged RLS, reduced mean generation times, more reducing mitochondrial redox potential and lower mitochondrial superoxide levels compared to wild-type cells. Short-lived mmr1Δ cells exhibit the opposite phenotypes. Moreover, short-lived cells give rise exclusively to short-lived cells, while the majority of daughters of long-lived cells are long lived. These findings support the model that the mitochondrial inheritance machinery promotes retention of lower-functioning mitochondria in mother cells and that this process contributes to both mother-daughter age asymmetry and age-associated declines in cellular fitness.
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Affiliation(s)
- José Ricardo McFaline-Figueroa
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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Abstract
While specific signalling cascades involved in aging, such as the insulin/IGF-1 pathway, are well-described, the actual metabolic changes they elicit to prolong lifespan remain obscure. Nevertheless, the tuning of cellular metabolism towards maximal survival is the molecular basis of longevity. The eukaryotic mitochondrial prohibitin complex is a macromolecular structure at the inner mitochondrial membrane, implicated in several important cellular processes such as mitochondrial biogenesis and function, molecular signalling, replicative senescence, and cell death. Recent studies in C. elegans have revealed that prohibitin differentially influences aging by moderating fat metabolism and energy production, in response to both intrinsic signalling events and extrinsic cues. These findings indicate that prohibitin is a context-dependent modulator of longevity. The tight evolutionary conservation and ubiquitous expression of prohibitin proteins suggest a similar role for the mitochondrial prohibitin complex during aging in other organisms.
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Affiliation(s)
- Marta Artal-Sanz
- Laboratory for Bioinformatics and Molecular Genetics, Bio III, Albert-Ludwigs-University of Freiburg, D-79104 Freiburg, Germany. ‐freiburg.de
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29
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The retrograde response retrograde response and other pathways of interorganelle communication interorganelle communication in yeast replicative aging. Subcell Biochem 2011; 57:79-100. [PMID: 22094418 DOI: 10.1007/978-94-007-2561-4_4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A form of mitochondria-to-nucleus signaling mitochondria-to-nucleus signaling is known to play a role in determining replicative life span in yeast. This retrograde response is triggered by experimentally-induced mitochondrial dysfunction mitochondrial dysfunction, but it also is activated during the course of normal replicative aging, allowing yeast to have as long a replicative life span as they do. The components of the retrograde signaling pathway participate in diverse cellular processes such as mitophagy, which appear to be involved in mitochondrial quality control mitochondrial quality control. This plethora of mitochondrial surveillance mitochondrial surveillance mechanisms points to the central importance of this organelle organelle in yeast replicative aging. Additional pathways pathways that monitor mitochondrial status mitochondrial status that do not apparently involve the retrograde response machinery also play a role. A unifying theme is the involvement of the target of rapamycin target of rapamycin (TOR) in both these additional pathways and in the retrograde response. The involvement of TOR brings another large family of signaling events into juxtaposition. Ceramide synthesis is regulated by TOR opening up the potential for coordination of mitochondrial status with a wide array of additional cellular processes. The retrograde response lies at the nexus of metabolic regulation metabolic regulation, stress resistance stress resistance, chromatin-dependent gene regulation chromatin-dependent gene regulation, and genome stability genome stability. In its metabolic outputs, it is related to calorie restriction,calorie restriction, which may be the result of the involvement of TOR. Retrograde response-like processes have been identified in systems other than yeast, including mammalian cells mammalian cells. The retrograde response is a prototypical pathway of interorganelle communication. Other such phenomena are emerging, such as the cross-talk cross-talk between mitochondria mitochondria and the vacuole vacuole, which involves components of the retrograde signaling pathway. The impact of these varied physiological responses on yeast replicative aging remains to be assessed.
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Sievers C, Billig G, Gottschalk K, Rudel T. Prohibitins are required for cancer cell proliferation and adhesion. PLoS One 2010; 5:e12735. [PMID: 20856874 PMCID: PMC2939069 DOI: 10.1371/journal.pone.0012735] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 08/06/2010] [Indexed: 12/25/2022] Open
Abstract
Prohibitin 1 (PHB1) is a highly conserved protein that together with its homologue prohibitin 2 (PHB2) mainly localizes to the inner mitochondrial membrane. Although it was originally identified by its ability to inhibit G1/S progression in human fibroblasts, its role as tumor suppressor is debated. To determine the function of prohibitins in maintaining cell homeostasis, we generated cancer cell lines expressing prohibitin-directed shRNAs. We show that prohibitin proteins are necessary for the proliferation of cancer cells. Down-regulation of prohibitin expression drastically reduced the rate of cell division. Furthermore, mitochondrial morphology was not affected, but loss of prohibitins did lead to the degradation of the fusion protein OPA1 and, in certain cancer cell lines, to a reduced capability to exhibit anchorage-independent growth. These cancer cells also exhibited reduced adhesion to the extracellular matrix. Taken together, these observations suggest prohibitins play a crucial role in adhesion processes in the cell and thereby sustaining cancer cell propagation and survival.
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Affiliation(s)
- Claudia Sievers
- Research Group for Molecular Infection and Cancer Biology, Department of Molecular Biology, Max-Planck Institute for Infection Biology, Berlin, Germany
- Department of Biochemistry, Free University Berlin, Berlin, Germany
| | - Gwendolyn Billig
- Research Group for Molecular Infection and Cancer Biology, Department of Molecular Biology, Max-Planck Institute for Infection Biology, Berlin, Germany
- Department of Biochemistry, Free University Berlin, Berlin, Germany
| | - Kathleen Gottschalk
- Research Group for Molecular Infection and Cancer Biology, Department of Molecular Biology, Max-Planck Institute for Infection Biology, Berlin, Germany
| | - Thomas Rudel
- Research Group for Molecular Infection and Cancer Biology, Department of Molecular Biology, Max-Planck Institute for Infection Biology, Berlin, Germany
- Biocenter, University of Würzburg, Würzburg, Germany
- * E-mail:
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31
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Barros MH, da Cunha FM, Oliveira GA, Tahara EB, Kowaltowski AJ. Yeast as a model to study mitochondrial mechanisms in ageing. Mech Ageing Dev 2010; 131:494-502. [DOI: 10.1016/j.mad.2010.04.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 04/19/2010] [Accepted: 04/27/2010] [Indexed: 01/08/2023]
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32
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Shi SL, Li QF, Liu QR, Xu DH, Tang J, Liang Y, Zhao ZL, Yang LM. Nuclear matrix protein, prohibitin, was down-regulated and translocated from nucleus to cytoplasm during the differentiation of osteosarcoma MG-63 cells induced by ginsenoside Rg1, cinnamic acid, and tanshinone IIA (RCT). J Cell Biochem 2010; 108:926-34. [PMID: 19725052 DOI: 10.1002/jcb.22324] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Ginsenoside Rg1, cinnamic acid, and tanshinone IIA (RCT) are effective anticancer and antioxidant constituents of traditional Chinese herbal medicines of Ginseng, Xuanseng, and Danseng. The molecular mechanisms of anticancer effects of those constituents and their targets are unknown. Prohibitin, an inner membrane-bound chaperone in mitochondrion involved in the regulation of cell growth, proliferation, differentiation, aging, and apoptosis, was chosen as a candidate molecular target because of its frequent up-regulation in various cancer cells. We demonstrated that prohibitin existed in the filaments of the nuclear matrix of the MG-63 cell and its expression was down-regulated by the treatment of RCT using proteomic methodologies and Western blot analysis. Immunogold electro-microscopy also found that prohibitin was localized on nuclear matrix intermediate filaments (NM-IF) that had undergone restorational changes after RCT treatment. Prohibitin may function as a molecular chaperone that might interact with multiple oncogenes and tumor suppressor genes. We found that oncogenes c-myc and c-fos and tumor suppressor genes P53 and Rb were regulated by RCT as well and that these gene products co-localized with prohibitin. Our study identified prohibitin as a molecular target of the effective anticancer constituents of Ginseng, Xuanseng, and Danseng that down-regulated prohibitin in nuclear matrix, changed prohibtin trafficking from nucleolus to cytoplasm, and regulated several oncogenes and tumor suppressor genes. Prohibitin downregulation and cellular trafficking from nucleolus to cytoplasm indicated RCT protective roles in cancer prevention and treatment.
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Affiliation(s)
- Song-Lin Shi
- The Key Laboratory of Ministry of Education for Cell Biology & Tumor Cell Engineering, School of Life Science, Xiamen University, Xiamen 361005, P.R. China
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Lee JH, Nguyen KH, Mishra S, Nyomba BLG. Prohibitin is expressed in pancreatic beta-cells and protects against oxidative and proapoptotic effects of ethanol. FEBS J 2009; 277:488-500. [PMID: 20030709 DOI: 10.1111/j.1742-4658.2009.07505.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Pancreatic beta-cell dysfunction is a prerequisite for the development of type 2 diabetes. Alcoholism is a diabetes risk factor and ethanol increases oxidative stress in beta-cells, whereas the mitochondrial chaperone prohibitin (PHB) has antioxidant effects in several cell types. In the present study we investigated whether PHB is expressed in beta-cells and protects these cells against deleterious effects of ethanol, using INS-1E and RINm5F beta-cell lines. Endogenous PHB was detected by western blot and immunocytochemistry. Reactive oxygen species were determined by 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate fluorescence assay, and mitochondrial activity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) reduction, uncoupling protein 2 expression and ATP production. Cell death was determined by Hoechst 33342 staining, cleaved caspase-3 levels and flow cytometry. PHB was expressed in beta-cells under normal conditions and colocalized with Hoechst 33342 in the nucleus and with the mitochondrial probe Mitofluor in the perinuclear area. In ethanol-treated cells, MTT reduction and ATP production decreased, whereas reactive oxygen species, uncoupling protein 2 and cleaved caspase-3 levels increased. In addition, flow cytometry analysis showed an increase of apoptotic cells. Ethanol treatment increased PHB expression and induced PHB translocation from the nucleus to the mitochondria. PHB overexpression decreased the apoptotic effects of ethanol, whereas PHB knockdown enhanced these effects. The protective effects of endogenous PHB were recapitulated by incubation of the cells with recombinant human PHB. Thus, PHB is expressed in beta-cells, increases with oxidative stress and protects the cells against deleterious effects of ethanol.
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Affiliation(s)
- Jong Han Lee
- Department of Physiology, Diabetes Research Group, University of Manitoba, Winnipeg, Canada
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34
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Artal-Sanz M, Tavernarakis N. Prohibitin and mitochondrial biology. Trends Endocrinol Metab 2009; 20:394-401. [PMID: 19733482 DOI: 10.1016/j.tem.2009.04.004] [Citation(s) in RCA: 215] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2009] [Revised: 04/12/2009] [Accepted: 04/14/2009] [Indexed: 12/15/2022]
Abstract
Prohibitins are ubiquitous, evolutionarily conserved proteins that are mainly localized in mitochondria. The mitochondrial prohibitin complex comprises two subunits, PHB1 and PHB2. These two proteins assemble into a ring-like macromolecular structure at the inner mitochondrial membrane and are implicated in diverse cellular processes: from mitochondrial biogenesis and function to cell death and replicative senescence. In humans, prohibitins have been associated with various types of cancer. While their biochemical function remains poorly understood, studies in organisms ranging from yeast to mammals have provided significant insights into the role of the prohibitin complex in mitochondrial biogenesis and metabolism. Here we review recent studies and discuss their implications for deciphering the function of prohibitins in mitochondria.
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Affiliation(s)
- Marta Artal-Sanz
- Instituto de Biomedicina de Valencia, CSIC, 46010 Valencia, Spain
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35
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Yeast prion [PSI+] lowers the levels of mitochondrial prohibitins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1703-9. [PMID: 19695293 DOI: 10.1016/j.bbamcr.2009.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 08/07/2009] [Accepted: 08/07/2009] [Indexed: 12/11/2022]
Abstract
We report proteomic analyses that establish the effect of cytoplasmic prion [PSI(+)] on the protein complement of yeast mitochondria. A set of 44 yeast mitochondrial proteins whose levels were affected by [PSI(+)] was identified by two methods of gel-free and label-free differential proteomics. From this set we focused on prohibitins, Phb1 and Phb2, and the mitochondrially synthesized Cox2 subunit of cytochrome oxidase. By immunoblotting we confirmed the decreased level of Cox2 and reduced mitochondrial localization of the prohibitins in [PSI(+)] cells, which both became partially restored by [PSI(+)] curing. The presence of the [PSI(+)] prion also caused premature fragmentation of mitochondria, a phenomenon linked to prohibitin depletion in mammalian cells. By fractionation of cellular extracts we demonstrated a [PSI(+)]-dependent increase of the proportion of prohibitins in the high molecular weight fraction of aggregated proteins. We propose that the presence of the yeast prion causes newly synthesized prohibitins to aggregate in the cytosol, and therefore reduces their levels in mitochondria, which in turn reduces the stability of Cox2 and possibly of other proteins, not investigated here in detail.
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36
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Gómez LA, Monette JS, Chavez JD, Maier CS, Hagen TM. Supercomplexes of the mitochondrial electron transport chain decline in the aging rat heart. Arch Biochem Biophys 2009; 490:30-5. [PMID: 19679098 DOI: 10.1016/j.abb.2009.08.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 08/03/2009] [Accepted: 08/04/2009] [Indexed: 01/06/2023]
Abstract
Accumulation of mitochondrial electron transport chain (ETC) defects is a recognized hallmark of the age-associated decline in cardiac bioenergetics; however, the molecular events involved are only poorly understood. In the present work, we hypothesized that age-related ETC deterioration stemmed partly from disassociation of large solid-state macromolecular assemblies termed "supercomplexes". Mitochondrial proteins from young and old rat hearts were separated by blue native-PAGE, protein bands analyzed by LC-MALDI-MS/MS, and protein levels quantified by densitometry. Results showed that supercomplexes comprised of various stoichiometries of complexes I, III and IV were observed, and declined significantly (p<0.05, n=4) with age. Supercomplexes displaying the highest molecular masses were the most severely affected. Considering that certain diseases (e.g. Barth Syndrome) display similar supercomplex destabilization as our results for aging, the deterioration in ETC supercomplexes may be an important underlying factor for both impaired mitochondrial function and loss of cardiac bioenergetics with age.
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Affiliation(s)
- Luis A Gómez
- Linus Pauling Institute and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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37
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Woo DK, Poyton RO. The absence of a mitochondrial genome in rho0 yeast cells extends lifespan independently of retrograde regulation. Exp Gerontol 2009; 44:390-7. [PMID: 19285548 DOI: 10.1016/j.exger.2009.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 02/26/2009] [Accepted: 03/03/2009] [Indexed: 10/21/2022]
Abstract
The absence of mtDNA in rho0 yeast cells affects both respiration and mitochondrial-nuclear communication (e.g., retrograde regulation, intergenomic signaling, or pleiotropic drug resistance). Previously, it has been reported that some rho0 strains have increased replicative lifespans, attributable to the lack of respiration and retrograde regulation. Here, we have been able to confirm that rho0 cells exhibit increased replicative lifespans but have found that this is not associated with the lack of respiration or reduced oxidative stress but instead, is related to the lack of mtDNA per se in rho0 cells. Also, we find no correlation between the strength of retrograde regulation and lifespan. Furthermore, we find that pdr3- or rtg2- mutations are not responsible for lifespan extension in rho0 cells, ruling out a specific role for PDR3-pleiotropic drug resistance or RGT2-retrograde regulation pathways in the extended lifespans of rho0 cells. Surprisingly, Rtg3p, which acts downstream of Rtg2p, is required for lifespan increase in rho0 cells. Together, these findings indicate that the loss of mtDNA per se and not the lack of respiration lead to extended longevity in rho0 cells. They also suggest that Rtg3p, acting independently of retrograde regulation, mediates this effect, possibly via intergenomic signaling.
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Affiliation(s)
- Dong Kyun Woo
- The Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
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38
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Zadrag-Tecza R, Kwolek-Mirek M, Bartosz G, Bilinski T. Cell volume as a factor limiting the replicative lifespan of the yeast Saccharomyces cerevisiae. Biogerontology 2008; 10:481-8. [DOI: 10.1007/s10522-008-9192-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2008] [Accepted: 10/16/2008] [Indexed: 10/21/2022]
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39
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Qin H, Lu M, Goldfarb DS. Genomic instability is associated with natural life span variation in Saccharomyces cerevisiae. PLoS One 2008; 3:e2670. [PMID: 18628831 PMCID: PMC2441830 DOI: 10.1371/journal.pone.0002670] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 06/13/2008] [Indexed: 12/13/2022] Open
Abstract
Increasing genomic instability is associated with aging in eukaryotes, but the connection between genomic instability and natural variation in life span is unknown. We have quantified chronological life span and loss-of-heterozygosity (LOH) in 11 natural isolates of Saccharomyces cerevisiae. We show that genomic instability increases and mitotic asymmetry breaks down during chronological aging. The age-dependent increase of genomic instability generally lags behind the drop of viability and this delay accounts for approximately 50% of the observed natural variation of replicative life span in these yeast isolates. We conclude that the abilities of yeast strains to tolerate genomic instability co-vary with their replicative life spans. To the best of our knowledge, this is the first quantitative evidence that demonstrates a link between genomic instability and natural variation in life span.
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Affiliation(s)
- Hong Qin
- Center for Aging and Development Biology, Department of Biology, University of Rochester, Rochester, New York, United States of America.
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40
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Merkwirth C, Langer T. Prohibitin function within mitochondria: essential roles for cell proliferation and cristae morphogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:27-32. [PMID: 18558096 DOI: 10.1016/j.bbamcr.2008.05.013] [Citation(s) in RCA: 292] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 05/14/2008] [Accepted: 05/16/2008] [Indexed: 12/23/2022]
Abstract
Prohibitins comprise an evolutionary conserved and ubiquitously expressed family of membrane proteins. Various roles in different cellular compartments have been proposed for prohibitin proteins. Recent experiments, however, identify large assemblies of two homologous prohibitin subunits, PHB1 and PHB2, in the inner membrane of mitochondria as the physiologically active structure. Mitochondrial prohibitin complexes control cell proliferation, cristae morphogenesis and the functional integrity of mitochondria. The processing of the dynamin-like GTPase OPA1, a core component of the mitochondrial fusion machinery, has been defined as a key process affected by prohibitins. The molecular mechanism of prohibitin function, however, remained elusive. The ring-like assembly of prohibitins and their sequence similarity with lipid raft-associated SPFH-family members suggests a scaffolding function of prohibitins, which may lead to functional compartmentalization in the inner membrane of mitochondria.
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Affiliation(s)
- Carsten Merkwirth
- Institute for Genetics, Centre for Molecular Medicine (CMMC), University of Cologne, 50674 Cologne, Germany
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41
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Schleicher M, Shepherd BR, Suarez Y, Fernandez-Hernando C, Yu J, Pan Y, Acevedo LM, Shadel GS, Sessa WC. Prohibitin-1 maintains the angiogenic capacity of endothelial cells by regulating mitochondrial function and senescence. J Cell Biol 2008; 180:101-12. [PMID: 18195103 PMCID: PMC2213620 DOI: 10.1083/jcb.200706072] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Accepted: 12/10/2007] [Indexed: 12/21/2022] Open
Abstract
Prohibitin 1 (PHB1) is a highly conserved protein that is mainly localized to the inner mitochondrial membrane and has been implicated in regulating mitochondrial function in yeast. Because mitochondria are emerging as an important regulator of vascular homeostasis, we examined PHB1 function in endothelial cells. PHB1 is highly expressed in the vascular system and knockdown of PHB1 in endothelial cells increases mitochondrial production of reactive oxygen species via inhibition of complex I, which results in cellular senescence. As a direct consequence, both Akt and Rac1 are hyperactivated, leading to cytoskeletal rearrangements and decreased endothelial cell motility, e.g., migration and tube formation. This is also reflected in an in vivo angiogenesis assay, where silencing of PHB1 blocks the formation of functional blood vessels. Collectively, our results provide evidence that PHB1 is important for mitochondrial function and prevents reactive oxygen species-induced senescence and thereby maintains the angiogenic capacity of endothelial cells.
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Affiliation(s)
- Michael Schleicher
- Department of Pharmacology, and Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06536, USA
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42
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Abstract
The size of cells, tissues and organisms is a fundamental yet poorly understood attribute of biological systems. Traditional difficulties in interrogating the basis for size regulation have been surmounted by recent systematic phenotypic analyses. Genome-wide size screens in yeast suggest that ribosome biogenesis rate dictates cell size thresholds, whereas analogous RNAi-based size screens in metazoans cells reveal further connections between cell size and translation, as well as myriad other pathways. Sophisticated genetic screens in flies have delineated the new Hippo-signalling pathway that controls tissue and organ size. While the plethora of genes that alter size phenotypes at present defies a unified model, systems-level analysis suggests many new inroads into the longstanding enigma of size control.
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Affiliation(s)
- Mike Cook
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5
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43
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Ferrer I, Perez E, Dalfó E, Barrachina M. Abnormal levels of prohibitin and ATP synthase in the substantia nigra and frontal cortex in Parkinson's disease. Neurosci Lett 2007; 415:205-9. [PMID: 17284347 DOI: 10.1016/j.neulet.2007.01.026] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2006] [Revised: 12/25/2006] [Accepted: 01/11/2007] [Indexed: 11/29/2022]
Abstract
Prohibitin and ATP synthase protein levels were examined in the substantia nigra and frontal cortex (area 8) in five cases of Parkinson's disease (PD), five cases of dementia with Lewy bodies pure form (pDLB), five cases of early Alzheimer's disease (AD stage IIA, B), nine cases with advanced AD (stages V/VIC), and nine controls. A significant reduction of prohibitin and ATP synthase was observed in the substantia nigra in PD cases. In contrast, increased prohibitin and ATP synthase levels were found in the frontal cortex in PD, and increased prohibitin but not ATP synthase in the frontal cortex in pDLB. Superoxide dismutase 2 (SOD2) expression levels were also increased in the frontal cortex in PD and pDLB. No modifications in prohibitin and ATP synthase levels were found in the frontal cortex in sporadic AD. These findings demonstrate disease-specific modifications in the expression of mitochondrial-related proteins in the frontal cortex at stages of PD in which there is no alpha-synuclein aggregation in the form of Lewy bodies and Lewy neurites in this area. These findings emphasize the presence of mitochondrial modifications before the appearance of histological hallmarks of PD, and point to the possibility of a more extended molecular pathology in PD than currently accepted.
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Affiliation(s)
- I Ferrer
- Institut de Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Facultad de Medicina, Universitat de Barcelona, carrer Feixa Llarga s/n, 08907 Hospitalet de Llobregat, Spain.
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44
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Kirchman PA, Botta G. Copper supplementation increases yeast life span under conditions requiring respiratory metabolism. Mech Ageing Dev 2007; 128:187-95. [PMID: 17129597 PMCID: PMC1850965 DOI: 10.1016/j.mad.2006.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 10/22/2006] [Indexed: 10/23/2022]
Abstract
To further exploit yeast as a model for cellular aging we have modified the replicative life span assay to force respiration, by replacing glucose with the non-fermentable carbon source glycerol. The growth rates of several different strains varied greatly, with doubling times ranging from 2.7 to 7 h. Life spans of all strains were lower on media containing glycerol than on media containing glucose. However, supplementation of glycerol-containing media with copper resulted in increases in life span of between 17 and 72%; life spans equivalent to or beyond those obtained on glucose media. Addition of copper to glucose medium had no effect on life span. Microarray analysis showed that genes responsible for high affinity import of copper display reduced expression upon addition of copper, while most genes showed no change in expression. No differences in growth rate, oxygen uptake, or the levels of subunit II of the copper-containing cytochrome c oxidase were found between cultures of yeast grown with or without copper supplementation. Copper supplementation greatly extended the life span of sod1 and sod2 strains, suggesting that addition of copper may reduce the generation of superoxide. Forcing yeast to respire places an emphasis on mitochondrial function and may aid in the identification of factors involved in aging in other respiratory-dependent organisms.
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Affiliation(s)
- Paul A Kirchman
- Harriet L. Wilkes Honors College, Florida Atlantic University, 5353 Parkside Dr., Jupiter, FL 33458, United States.
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45
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Passos JF, von Zglinicki T, Kirkwood TBL. Mitochondria and ageing: winning and losing in the numbers game. Bioessays 2007; 29:908-17. [PMID: 17688237 DOI: 10.1002/bies.20634] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mitochondrial dysfunction has long been considered a key mechanism in the ageing process but surprisingly little attention has been paid to the impact of mitochondrial number or density within cells. Recent reports suggest a positive association between mitochondrial density, energy homeostasis and longevity. However, mitochondrial number also determines the number of sites generating reactive oxygen species (ROS) and we suggest that the links between mitochondrial density and ageing are more complex, potentially acting in both directions. The idea that increased density, especially when combined with mitochondrial dysfunction, might accelerate ageing is supported by a negative correlation between mitochondrial density and maximum longevity in an interspecies comparison in mammals, and by evidence for an intimate interconnection between cellular ROS levels, mitochondrial density and cellular ageing. Recent data suggest that retrograde response, which activates mitochondrial biogenesis, accompanies cellular ageing processes. We hypothesise that increased mitochondrial biogenesis, and possibly also impaired degradation and segregation of mitochondria, if occurring as adaptation to pre-existing mitochondrial dysfunction, might aggravate ROS production and thus actively contribute to ageing.
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Affiliation(s)
- João F Passos
- Centre for Integrated Systems Biology of Ageing and Nutrition, Henry Wellcome Laboratory for Biogerontology Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
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46
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Theiss AL, Idell RD, Srinivasan S, Klapproth JM, Jones DP, Merlin D, Sitaraman SV. Prohibitin protects against oxidative stress in intestinal epithelial cells. FASEB J 2006; 21:197-206. [PMID: 17135366 DOI: 10.1096/fj.06-6801com] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Prohibitin (PHB) is an evolutionarily conserved and ubiquitously expressed protein whose expression or function in intestinal diseases is not known. In this study, we examined the expression and role of PHB in oxidative stress associated with inflammatory bowel disease. Our results show that PHB primarily localizes to the mitochondria in intestinal epithelial cells. Its expression is down-regulated during active human Crohn's disease, experimental colitis in vivo, and oxidative stress in vitro. PHB overexpression increases the expression of glutathione-S-transferase pi and protects from oxidant-induced depletion of glutathione. Finally, PHB overexpression decreases accumulation of reactive oxygen metabolites, as well as increased permeability induced by oxidative stress in intestinal epithelial cells. Together, these results suggest that PHB constitutes a previously unrecognized cellular defense against oxidant injury. Thus, strategies to modulate PHB levels may constitute a novel therapeutic approach for intestinal inflammatory diseases, wherein oxidative stress plays a critical role in tissue injury and inflammation.
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Affiliation(s)
- Arianne L Theiss
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, Georgia 30322, USA.
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Hájek P, Chomyn A, Attardi G. Identification of a novel mitochondrial complex containing mitofusin 2 and stomatin-like protein 2. J Biol Chem 2006; 282:5670-81. [PMID: 17121834 DOI: 10.1074/jbc.m608168200] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A reverse genetics approach was utilized to discover new proteins that interact with the mitochondrial fusion mediator mitofusin 2 (Mfn2) and that may participate in mitochondrial fusion. In particular, in vivo formaldehyde cross-linking of whole HeLa cells and immunoprecipitation with purified Mfn2 antibodies of SDS cell lysates were used to detect an approximately 42-kDa protein. This protein was identified by liquid chromatography and tandem mass spectrometry as stomatin-like protein 2 (Stoml2), previously described as a peripheral plasma membrane protein of unknown function associated with the cytoskeleton of erythrocytes (Wang, Y., and Morrow, J. S. (2000) J. Biol. Chem. 275, 8062-8071). Immunoblot analysis with anti-Stoml2 antibodies showed that Stoml2 could be immunoprecipitated specifically with Mfn2 antibody either from formaldehyde-cross-linked and SDS-lysed cells or from cells lysed with digitonin. Subsequent immunocytochemistry and cell fractionation experiments fully supported the conclusion that Stoml2 is indeed a mitochondrial protein. Furthermore, demonstration of mitochondrial membrane potential-dependent import of Stoml2 accompanied by proteolytic processing, together with the results of sublocalization experiments, suggested that Stoml2 is associated with the inner mitochondrial membrane and faces the intermembrane space. Notably, formaldehyde cross-linking revealed a "ladder" of high molecular weight protein species, indicating the presence of high molecular weight Stoml2-Mfn2 hetero-oligomers. Knockdown of Stoml2 by the short interfering RNA approach showed a reduction of the mitochondrial membrane potential, without, however, any obvious changes in mitochondrial morphology.
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Affiliation(s)
- Petr Hájek
- Division of Biology, California Institute of Technology, Pasadena, California 91125, USA
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Kasashima K, Ohta E, Kagawa Y, Endo H. Mitochondrial Functions and Estrogen Receptor-dependent Nuclear Translocation of Pleiotropic Human Prohibitin 2. J Biol Chem 2006; 281:36401-10. [PMID: 17008324 DOI: 10.1074/jbc.m605260200] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proteins with multiple cellular functions provide biological diversity to eukaryotic cells. In the current studies, we identified the mitochondrial functions of human prohibitin 2 (PHB2), which was initially identified as a repressor of estrogen-dependent transcriptional activity. The mitochondrial complex of PHB2 consists of PHB1, voltage-dependent anion channel 2, adenine nucleotide translocator 2, and the anti-apoptotic Hax-1, which is a novel binding partner for PHB2. RNA interference-mediated knockdown of PHB2 in HeLa cells resulted in caspase-dependent apoptosis through down-regulation of Hax-1 and fragmentation of mitochondria. We also found that, although PHB2 is predominantly expressed in the mitochondria of HeLa cells, it translocates to nucleus in the presence of estrogen receptor alpha and estradiol. Here, we first demonstrated the roles of mammalian PHB2 in mitochondria and the molecular mechanism of its nuclear targeting and showed that PHB2 is a possible molecule directly coupling nuclear-mitochondrial interaction.
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Affiliation(s)
- Katsumi Kasashima
- Department of Biochemistry, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
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Ahn CS, Lee JH, Reum Hwang A, Kim WT, Pai HS. Prohibitin is involved in mitochondrial biogenesis in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 46:658-67. [PMID: 16640602 DOI: 10.1111/j.1365-313x.2006.02726.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Prohibitin, which consists of two subunits PHB1 and PHB2, plays a role in cell-cycle progression, senescence, apoptosis, and maintenance of mitochondrial function in mammals and yeast. In this study, we examined the role of prohibitins in plants by using virus-induced gene silencing (VIGS) of two prohibitin subunit genes of Nicotiana benthamiana, designated NbPHB1 and NbPHB2. NbPHB1 and NbPHB2 were targeted to the mitochondria, and their gene expression was suppressed during senescence. VIGS of NbPHB2 caused severe growth inhibition, leaf yellowing and symptoms of cell death, whereas VIGS of NbPHB1 resulted in a milder phenotype. At the cellular level, depletion of these subunits affected mitochondria by severely reducing their number and/or mass, and by causing morphological and physiological abnormalities. Suppression of prohibitin function resulted in a 10- to 20-fold higher production of reactive oxygen species and induced premature leaf senescence. Finally, disruption of prohibitin function rendered the plants more susceptible to various oxidative stress-inducing reagents, including H(2)O(2), paraquat, antimycin A and salicylic acid. These results suggest that prohibitins play a crucial role in mitochondrial biogenesis and protection against stress and senescence in plant cells.
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Affiliation(s)
- Chang Sook Ahn
- Department of Biology, Yonsei University, Seoul 120-749, Korea
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Liu F, Jamieson DJ. Isolation of mutations synthetic-lethal to prohibitin 2 null mutants of Saccharomyces cerevisiae. Antonie van Leeuwenhoek 2006; 89:281-92. [PMID: 16710639 DOI: 10.1007/s10482-005-9029-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Accepted: 12/21/2005] [Indexed: 11/28/2022]
Abstract
Prohibitins are ubiquitous, abundant proteins found in a wide range of organisms and that have a high degree of sequence conservation. In yeast it has previously been demonstrated that prohibitin proteins form a complex and are involved in maintaining the morphological and functional integrity of mitochondria. We have used a colony-sectoring assay as a screen for mutants that are dependent upon the presence of functional Phb2p in the cell. Two classes of prohibitin dependent mutation (pbd1 and pbd2) were isolated and characterised. The effect of these mutations on replicative lifespan was determined, demonstrating that the pbd1 mutant slightly extended lifespan, whereas in contrast, the pbd2 mutation resulted in a shortening in both the mean- and the maximum-lifespan. The pbd1 mutation was also found to reduce chronological lifespan. Reducing the expression of the PHB2 gene in the pbd mutants was found to retard the rate of growth and to affect replicative lifespan. As the two mutants behave in a different manner they probably affect different aspects of prohibitin function.
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Affiliation(s)
- Feng Liu
- School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK
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