1
|
Xhonneux I, Marei WFA, Meulders B, Slootmans J, Pintelon I, Leroy JLMR. The impact of offspring and maternal obesogenic diets on adult offspring oocyte mitochondrial morphology in primordial and preantral follicles. PLoS One 2024; 19:e0305912. [PMID: 38935642 PMCID: PMC11210809 DOI: 10.1371/journal.pone.0305912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/05/2024] [Indexed: 06/29/2024] Open
Abstract
Diet-induced obesity reduces oocyte quality mainly by impacting oocyte mitochondrial functions. Moreover, maternal obesity is associated with mitochondrial dysfunction in oocytes of their adult offspring. However, these effects were reported only in fully grown oocytes, mainly in the form of abnormal mitochondrial ultrastructure. It is unknown if obesogenic (OB) diets or maternal obesity already impact the primordial and preantral follicles. Considering the long duration and dynamics of folliculogenesis, determining the stage at which oocytes are affected and the extent of the damage is crucial for optimal reproductive management of obese patients and their daughters. Potential interaction between maternal and offspring diet effects are also not described, yet pivotal in our contemporary society. Therefore, here we examined the impact of OB diets on oocyte mitochondrial ultrastructure in primordial and activated preantral follicles in offspring from diet-induced obese or lean mothers. We used an outbred Swiss mouse model to increase the pathophysiological relevance to humans. Female mice were fed control or OB diets for 7 weeks, then mated with control males. Their female offspring were fed control or OB diets after weaning for 7 weeks (2-by-2 factorial design). Adult offspring ovarian sections were examined using transmission electron microscopy. We characterised and classified unique features of oocyte mitochondrial ultrastructure in the preantral follicles. An increase in mitochondrial matrix density was the most predominant change during follicle activation in secondary follicles, a feature that is linked with a higher mitochondrial activity. Maternal obesity increased mitochondrial density already in the primordial follicles suggesting an earlier increase in bioenergetic capacity. Maternal obesity did not induce abberant ultrastructure (abnormalities and defects) in primordial or preantral follicles. In contrast, offspring OB diet increased mitochondrial abnormalities in the primordial follicles. Further investigation of the consequences of these changes on oocyte metabolic regulation and stress levels during folliculogenesis is needed.
Collapse
Affiliation(s)
- Inne Xhonneux
- Department of Veterinary Sciences, Laboratory of Veterinary Physiology and Biochemistry, Gamete Research Centre, University of Antwerp, Wilrijk, Belgium
| | - Waleed F. A. Marei
- Department of Veterinary Sciences, Laboratory of Veterinary Physiology and Biochemistry, Gamete Research Centre, University of Antwerp, Wilrijk, Belgium
- Faculty of Veterinary Medicine, Department of Theriogenology, Cairo University, Giza, Egypt
| | - Ben Meulders
- Department of Veterinary Sciences, Laboratory of Veterinary Physiology and Biochemistry, Gamete Research Centre, University of Antwerp, Wilrijk, Belgium
| | - Jens Slootmans
- Department of Biosystems, University of Louvain, Louvain, Belgium
- Flanders Research Institute for Agriculture, Fisheries and Food, Merelbeke, Belgium
| | - Isabel Pintelon
- Department of Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Wilrijk, Belgium
- Antwerp Centre for Advanced Microscopy (ACAM), University of Antwerp, Wilrijk, Belgium
| | - Jo L. M. R. Leroy
- Department of Veterinary Sciences, Laboratory of Veterinary Physiology and Biochemistry, Gamete Research Centre, University of Antwerp, Wilrijk, Belgium
| |
Collapse
|
2
|
Sarkar D, Bhunia A. Delineating the Role of GxxxG Motif in Amyloidogenesis: A New Perspective in Targeting Amyloid-Beta Mediated AD Pathogenesis. ACS BIO & MED CHEM AU 2024; 4:4-19. [PMID: 38404748 PMCID: PMC10885112 DOI: 10.1021/acsbiomedchemau.3c00055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 02/27/2024]
Abstract
The pursuit of a novel structural motif that can shed light on the key functional attributes is a primary focus in the study of protein folding disorders. Decades of research on Alzheimer's disease (AD) have centered on the Amyloid β (Aβ) pathway, highlighting its significance in understanding the disorder. The diversity in the Aβ pathway and the possible silent tracks which are yet to discover, makes it exceedingly intimidating to the interdisciplinary scientific community. Over the course of AD research, Aβ has consistently been at the forefront of scientific inquiry and discussion. In this review, we epitomize the role of a potential structural motif (GxxxG motif) that may provide a new horizon to the Aβ conflict. We emphasize on how comprehensive understanding of this motif from a structure-function perspective may pave the way for designing novel therapeutics intervention in AD and related diseases.
Collapse
Affiliation(s)
- Dibakar Sarkar
- Department of Chemical Sciences, Bose Institute, Unified Academic Campus, Sector V, Salt Lake EN
80, Kolkata 700 091, India
| | - Anirban Bhunia
- Department of Chemical Sciences, Bose Institute, Unified Academic Campus, Sector V, Salt Lake EN
80, Kolkata 700 091, India
| |
Collapse
|
3
|
Chu Y, Li M, Sun M, Wang J, Xin W, Xu L. Gene crosstalk between COVID-19 and preeclampsia revealed by blood transcriptome analysis. Front Immunol 2024; 14:1243450. [PMID: 38259479 PMCID: PMC10800816 DOI: 10.3389/fimmu.2023.1243450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 12/14/2023] [Indexed: 01/24/2024] Open
Abstract
Background The extensive spread of coronavirus disease 2019 (COVID-19) has led to a rapid increase in global mortality. Preeclampsia is a commonly observed pregnancy ailment characterized by high maternal morbidity and mortality rates, in addition to the restriction of fetal growth within the uterine environment. Pregnant individuals afflicted with vascular disorders, including preeclampsia, exhibit an increased susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection via mechanisms that have not been fully delineated. Additionally, the intricate molecular mechanisms underlying preeclampsia and COVID-19 have not been fully elucidated. This study aimed to discern commonalities in gene expression, regulators, and pathways shared between COVID-19 and preeclampsia. The objective was to uncover potential insights that could contribute to novel treatment strategies for both COVID-19 and preeclampsia. Method Transcriptomic datasets for COVID-19 peripheral blood (GSE152418) and preeclampsia blood (GSE48424) were initially sourced from the Gene Expression Omnibus (GEO) database. Subsequent to that, we conducted a subanalysis by selecting females from the GSE152418 dataset and employed the "Deseq2" package to identify genes that exhibited differential expression. Simultaneously, the "limma" package was applied to identify differentially expressed genes (DEGs) in the preeclampsia dataset (GSE48424). Following that, an intersection analysis was conducted to identify the common DEGs obtained from both the COVID-19 and preeclampsia datasets. The identified shared DEGs were subsequently utilized for functional enrichment analysis, transcription factor (TF) and microRNAs (miRNA) prediction, pathway analysis, and identification of potential candidate drugs. Finally, to validate the bioinformatics findings, we collected peripheral blood mononuclear cell (PBMC) samples from healthy individuals, COVID-19 patients, and Preeclampsia patients. The abundance of the top 10 Hub genes in both diseases was assessed using real-time quantitative polymerase chain reaction (RT-qPCR). Result A total of 355 overlapping DEGs were identified in both preeclampsia and COVID-19 datasets. Subsequent ontological analysis, encompassing Gene Ontology (GO) functional assessment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, revealed a significant association between the two conditions. Protein-protein interactions (PPIs) were constructed using the STRING database. Additionally, the top 10 hub genes (MRPL11, MRPS12, UQCRH, ATP5I, UQCRQ, ATP5D, COX6B1, ATP5O, ATP5H, NDUFA6) were selected based on their ranking scores using the degree algorithm, which considered the shared DEGs. Moreover, transcription factor-gene interactions, protein-drug interactions, co-regulatory networks of DEGs and miRNAs, and protein-drug interactions involving the shared DEGs were also identified in the datasets. Finally, RT-PCR results confirmed that 10 hub genes do exhibit distinct expression profiles in the two diseases. Conclusion This study successfully identified overlapping DEGs, functional pathways, and regulatory elements between COVID-19 and preeclampsia. The findings provide valuable insights into the shared molecular mechanisms and potential therapeutic targets for both diseases. The validation through RT-qPCR further supports the distinct expression profiles of the identified hub genes in COVID-19 and preeclampsia, emphasizing their potential roles as biomarkers or therapeutic targets in these conditions.
Collapse
Affiliation(s)
| | | | | | | | | | - Lin Xu
- Department of Obstetrics, the Affiliated Hospital of Qingdao University, Qingdao, China
| |
Collapse
|
4
|
Miranda-Astudillo H, Ostolga-Chavarría M, Cardol P, González-Halphen D. Beyond being an energy supplier, ATP synthase is a sculptor of mitochondrial cristae. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148569. [PMID: 35577152 DOI: 10.1016/j.bbabio.2022.148569] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Mitochondrial F1FO-ATP synthase plays a key role in cellular bioenergetics; this enzyme is present in all eukaryotic linages except in amitochondriate organisms. Despite its ancestral origin, traceable to the alpha proteobacterial endosymbiotic event, the actual structural diversity of these complexes, due to large differences in their polypeptide composition, reflects an important evolutionary divergence between eukaryotic lineages. We discuss the effect of these structural differences on the oligomerization of the complex and the shape of mitochondrial cristae.
Collapse
Affiliation(s)
- Héctor Miranda-Astudillo
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Marcos Ostolga-Chavarría
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Pierre Cardol
- InBios/Phytosystems, Institut de Botanique, Université de Liège, Liège, Belgium
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico.
| |
Collapse
|
5
|
Mendoza-Hoffmann F, Zarco-Zavala M, Ortega R, Celis-Sandoval H, Torres-Larios A, García-Trejo JJ. Evolution of the Inhibitory and Non-Inhibitory ε, ζ, and IF 1 Subunits of the F 1F O-ATPase as Related to the Endosymbiotic Origin of Mitochondria. Microorganisms 2022; 10:microorganisms10071372. [PMID: 35889091 PMCID: PMC9317440 DOI: 10.3390/microorganisms10071372] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/03/2022] [Accepted: 07/03/2022] [Indexed: 12/10/2022] Open
Abstract
The F1FO-ATP synthase nanomotor synthesizes >90% of the cellular ATP of almost all living beings by rotating in the “forward” direction, but it can also consume the same ATP pools by rotating in “reverse.” To prevent futile F1FO-ATPase activity, several different inhibitory proteins or domains in bacteria (ε and ζ subunits), mitochondria (IF1), and chloroplasts (ε and γ disulfide) emerged to block the F1FO-ATPase activity selectively. In this study, we analyze how these F1FO-ATPase inhibitory proteins have evolved. The phylogeny of the α-proteobacterial ε showed that it diverged in its C-terminal side, thus losing both the inhibitory function and the ATP-binding/sensor motif that controls this inhibition. The losses of inhibitory function and the ATP-binding site correlate with an evolutionary divergence of non-inhibitory α-proteobacterial ε and mitochondrial δ subunits from inhibitory bacterial and chloroplastidic ε subunits. Here, we confirm the lack of inhibitory function of wild-type and C-terminal truncated ε subunits of P. denitrificans. Taken together, the data show that ζ evolved to replace ε as the primary inhibitor of the F1FO-ATPase of free-living α-proteobacteria. However, the ζ inhibitory function was also partially lost in some symbiotic α-proteobacteria and totally lost in some strictly parasitic α-proteobacteria such as the Rickettsiales order. Finally, we found that ζ and IF1 likely evolved independently via convergent evolution before and after the endosymbiotic origin mitochondria, respectively. This led us to propose the ε and ζ subunits as tracer genes of the pre-endosymbiont that evolved into the actual mitochondria.
Collapse
Affiliation(s)
- Francisco Mendoza-Hoffmann
- Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California (UABC)—Campus Tijuana, Tijuana C.P. 22390, Baja California, Mexico
- Correspondence: (F.M.-H.); (J.J.G.-T.)
| | - Mariel Zarco-Zavala
- Departamento de Biología, Facultad de Química, Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Ciudad de Mexico C.P. 04510, Coyoacan, Mexico
| | - Raquel Ortega
- Departamento de Biología, Facultad de Química, Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Ciudad de Mexico C.P. 04510, Coyoacan, Mexico
| | - Heliodoro Celis-Sandoval
- Instituto de Fisiología Celular (IFC), Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Ciudad de Mexico C.P. 04510, Coyoacan, Mexico
| | - Alfredo Torres-Larios
- Instituto de Fisiología Celular (IFC), Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Ciudad de Mexico C.P. 04510, Coyoacan, Mexico
| | - José J. García-Trejo
- Departamento de Biología, Facultad de Química, Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Ciudad de Mexico C.P. 04510, Coyoacan, Mexico
- Correspondence: (F.M.-H.); (J.J.G.-T.)
| |
Collapse
|
6
|
Hou Z, Gangjee A, Matherly LH. The evolving biology of the proton‐coupled folate transporter: New insights into regulation, structure, and mechanism. FASEB J 2022; 36:e22164. [PMID: 35061292 PMCID: PMC8978580 DOI: 10.1096/fj.202101704r] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/15/2021] [Accepted: 01/03/2022] [Indexed: 01/19/2023]
Abstract
The human proton‐coupled folate transporter (PCFT; SLC46A1) or hPCFT was identified in 2006 as the principal folate transporter involved in the intestinal absorption of dietary folates. A rare autosomal recessive hereditary folate malabsorption syndrome is attributable to human SLC46A1 variants. The recognition that hPCFT was highly expressed in many tumors stimulated substantial interest in its potential for cytotoxic drug targeting, taking advantage of its high‐level transport activity under acidic pH conditions that characterize many tumors and its modest expression in most normal tissues. To better understand the basis for variations in hPCFT levels between tissues including human tumors, studies have examined the transcriptional regulation of hPCFT including the roles of CpG hypermethylation and critical transcription factors and cis elements. Additional focus involved identifying key structural and functional determinants of hPCFT transport that, combined with homology models based on structural homologies to the bacterial transporters GlpT and LacY, have enabled new structural and mechanistic insights. Recently, cryo‐electron microscopy structures of chicken PCFT in a substrate‐free state and in complex with the antifolate pemetrexed were reported, providing further structural insights into determinants of (anti)folate recognition and the mechanism of pH‐regulated (anti)folate transport by PCFT. Like many major facilitator proteins, hPCFT exists as a homo‐oligomer, and evidence suggests that homo‐oligomerization of hPCFT monomeric proteins may be important for its intracellular trafficking and/or transport function. Better understanding of the structure, function and regulation of hPCFT should facilitate the rational development of new therapeutic strategies for conditions associated with folate deficiency, as well as cancer.
Collapse
Affiliation(s)
- Zhanjun Hou
- Molecular Therapeutics Program Barbara Ann Karmanos Cancer Institute Detroit Michigan USA
- Department of Oncology Wayne State University School of Medicine Detroit Michigan USA
| | - Aleem Gangjee
- Division of Medicinal Chemistry Graduate School of Pharmaceutical Sciences Duquesne University Pittsburgh Pennsylvania USA
| | - Larry H. Matherly
- Molecular Therapeutics Program Barbara Ann Karmanos Cancer Institute Detroit Michigan USA
- Department of Oncology Wayne State University School of Medicine Detroit Michigan USA
- Department of Pharmacology Wayne State University School of Medicine Detroit Michigan USA
| |
Collapse
|
7
|
Rampelt H, Wollweber F, Licheva M, de Boer R, Perschil I, Steidle L, Becker T, Bohnert M, van der Klei I, Kraft C, van der Laan M, Pfanner N. Dual role of Mic10 in mitochondrial cristae organization and ATP synthase-linked metabolic adaptation and respiratory growth. Cell Rep 2022; 38:110290. [PMID: 35081352 PMCID: PMC8810396 DOI: 10.1016/j.celrep.2021.110290] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/01/2021] [Accepted: 12/29/2021] [Indexed: 12/15/2022] Open
Abstract
Invaginations of the mitochondrial inner membrane, termed cristae, are hubs for oxidative phosphorylation. The mitochondrial contact site and cristae organizing system (MICOS) and the dimeric F1Fo-ATP synthase play important roles in controlling cristae architecture. A fraction of the MICOS core subunit Mic10 is found in association with the ATP synthase, yet it is unknown whether this interaction is of relevance for mitochondrial or cellular functions. Here, we established conditions to selectively study the role of Mic10 at the ATP synthase. Mic10 variants impaired in MICOS functions stimulate ATP synthase oligomerization like wild-type Mic10 and promote efficient inner membrane energization, adaptation to non-fermentable carbon sources, and respiratory growth. Mic10's functions in respiratory growth largely depend on Mic10ATPsynthase, not on Mic10MICOS. We conclude that Mic10 plays a dual role as core subunit of MICOS and as partner of the F1Fo-ATP synthase, serving distinct functions in cristae shaping and respiratory adaptation and growth. Dual role of Mic10 of mitochondrial contact site and cristae organizing system (MICOS) Mic10 binds to mitochondrial ATP synthase and stabilizes higher order assemblies Oligomerization of Mic10 is required for its function in MICOS, not at ATP synthase Mic10 binding to ATP synthase supports metabolic adaptation and respiratory growth
Collapse
Affiliation(s)
- Heike Rampelt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
| | - Florian Wollweber
- Medical Biochemistry & Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine, Saarland University, 66421 Homburg, Germany
| | - Mariya Licheva
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Rinse de Boer
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700 Groningen, the Netherlands
| | - Inge Perschil
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Liesa Steidle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, 53115 Bonn, Germany
| | - Maria Bohnert
- Institute of Cell Dynamics and Imaging, Cells in Motion Interfaculty Centre (CiM), University of Münster, 48149 Münster, Germany
| | - Ida van der Klei
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700 Groningen, the Netherlands
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Martin van der Laan
- Medical Biochemistry & Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine, Saarland University, 66421 Homburg, Germany.
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
| |
Collapse
|
8
|
Abstract
Mitochondria are complex organelles with two membranes. Their architecture is determined by characteristic folds of the inner membrane, termed cristae. Recent studies in yeast and other organisms led to the identification of four major pathways that cooperate to shape cristae membranes. These include dimer formation of the mitochondrial ATP synthase, assembly of the mitochondrial contact site and cristae organizing system (MICOS), inner membrane remodelling by a dynamin-related GTPase (Mgm1/OPA1), and modulation of the mitochondrial lipid composition. In this review, we describe the function of the evolutionarily conserved machineries involved in mitochondrial cristae biogenesis with a focus on yeast and present current models to explain how their coordinated activities establish mitochondrial membrane architecture.
Collapse
Affiliation(s)
- Till Klecker
- Institut für Zellbiologie, Universität Bayreuth, 95440 Bayreuth, Germany
| | | |
Collapse
|
9
|
Urbach J, Kondadi AK, David C, Naha R, Deinert K, Reichert AS, Anand R. Conserved GxxxG and WN motifs of MIC13 are essential for bridging two MICOS subcomplexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183683. [PMID: 34271005 DOI: 10.1016/j.bbamem.2021.183683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 10/20/2022]
Abstract
Mitochondrial ultrastructure is highly adaptable and undergoes dynamic changes upon physiological and energetic cues. MICOS (mitochondrial contact site and cristae organizing system), a large oligomeric protein complex, maintains mitochondrial ultrastructure as it is required for formation of crista junctions (CJs) and contact sites. MIC13 acts as a critical bridge between two MICOS subcomplexes. Deletion of MIC13 causes loss of CJs resulting in cristae accumulating as concentric rings and specific destabilization of the MIC10-subcomplex. Mutations in MIC13 are associated with infantile lethal mitochondrial hepato-encephalopathy, yet functional regions within MIC13 were not known. To identify and characterize such regions, we systemically generated 20 amino-acids deletion variants across the length of MIC13. While deletion of many of these regions of MIC13 is dispensable for its stability, the N-terminal region and a stretch between amino acid residues 84 and 103 are necessary for the stability and functionality of MIC13. We could further locate conserved motifs within these regions and found that a GxxxG motif in the N-terminal transmembrane segment and an internal WN motif are essential for stability of MIC13, formation of the MIC10-subcomplex, interaction with MIC10- and MIC60-subcomplexes and maintenance of cristae morphology. The GxxxG motif is required for membrane insertion of MIC13. Overall, we systematically found important conserved residues of MIC13 that are required to perform the bridging between the two MICOS subcomplexes. The study improves our understanding of the basic molecular function of MIC13 and has implications for its role in the pathogenesis of a severe mitochondrial disease.
Collapse
Affiliation(s)
- Jennifer Urbach
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Düsseldorf, Germany.
| | - Arun Kumar Kondadi
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Düsseldorf, Germany.
| | - Céline David
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Düsseldorf, Germany.
| | - Ritam Naha
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Düsseldorf, Germany.
| | - Kim Deinert
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Düsseldorf, Germany.
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Düsseldorf, Germany.
| | - Ruchika Anand
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Düsseldorf, Germany.
| |
Collapse
|
10
|
Emerging Roles of the MICOS Complex in Cristae Dynamics and Biogenesis. BIOLOGY 2021; 10:biology10070600. [PMID: 34209580 PMCID: PMC8301002 DOI: 10.3390/biology10070600] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/19/2022]
Abstract
Simple Summary Mitochondria possess an outer and inner membrane. The part of the inner membrane parallel to the outer membrane is termed the inner boundary membrane, while the cristae membrane folds towards the mitochondrial matrix and houses the respiratory chain complexes. Crista junctions are located at the interface of the inner boundary membrane and the cristae membrane and contain the important ‘mitochondrial contact site and cristae organizing system’ complex. Despite the growing evidence that the mitochondrial inner membrane could remodel, cristae membranes were largely considered static for nearly seventy years, as the observations were mostly based on electron microscopy and tomography. Recently, using fluorescence super-resolution techniques, several studies showed that cristae membranes undergo dynamic remodeling in living cells, and probably even fission and fusion of the inner membrane. In this review, we discuss the important recent literature conveying the emerging role of the MICOS complex in cristae dynamics and its relation to cristae biogenesis. As the aberrant inner membrane architecture is connected to various pathologies such as cardiomyopathies, neurodegeneration and diabetes, understanding the roles of various molecules connected with cristae biogenesis and dynamics would shed light on the pathophysiology, probably leading to therapeutics in the near future. Abstract Mitochondria are double membrane-enclosed organelles performing important cellular and metabolic functions such as ATP generation, heme biogenesis, apoptosis, ROS production and calcium buffering. The mitochondrial inner membrane (IM) is folded into cristae membranes (CMs) of variable shapes using molecular players including the ‘mitochondrial contact site and cristae organizing system’ (MICOS) complex, the dynamin-like GTPase OPA1, the F1FO ATP synthase and cardiolipin. Aberrant cristae structures are associated with different disorders such as diabetes, neurodegeneration, cancer and hepato-encephalopathy. In this review, we provide an updated view on cristae biogenesis by focusing on novel roles of the MICOS complex in cristae dynamics and shaping of cristae. For over seven decades, cristae were considered as static structures. It was recently shown that cristae constantly undergo rapid dynamic remodeling events. Several studies have re-oriented our perception on the dynamic internal ambience of mitochondrial compartments. In addition, we discuss the recent literature which sheds light on the still poorly understood aspect of cristae biogenesis, focusing on the role of MICOS and its subunits. Overall, we provide an integrated and updated view on the relation between the biogenesis of cristae and the novel aspect of cristae dynamics.
Collapse
|
11
|
Cadena LR, Gahura O, Panicucci B, Zíková A, Hashimi H. Mitochondrial Contact Site and Cristae Organization System and F 1F O-ATP Synthase Crosstalk Is a Fundamental Property of Mitochondrial Cristae. mSphere 2021; 6:e0032721. [PMID: 34133204 PMCID: PMC8265648 DOI: 10.1128/msphere.00327-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/02/2021] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial cristae are polymorphic invaginations of the inner membrane that are the fabric of cellular respiration. Both the mitochondrial contact site and cristae organization system (MICOS) and the F1FO-ATP synthase are vital for sculpting cristae by opposing membrane-bending forces. While MICOS promotes negative curvature at crista junctions, dimeric F1FO-ATP synthase is crucial for positive curvature at crista rims. Crosstalk between these two complexes has been observed in baker's yeast, the model organism of the Opisthokonta supergroup. Here, we report that this property is conserved in Trypanosoma brucei, a member of the Discoba clade that separated from the Opisthokonta ∼2 billion years ago. Specifically, one of the paralogs of the core MICOS subunit Mic10 interacts with dimeric F1FO-ATP synthase, whereas the other core Mic60 subunit has a counteractive effect on F1FO-ATP synthase oligomerization. This is evocative of the nature of MICOS-F1FO-ATP synthase crosstalk in yeast, which is remarkable given the diversification that these two complexes have undergone during almost 2 eons of independent evolution. Furthermore, we identified a highly diverged, putative homolog of subunit e, which is essential for the stability of F1FO-ATP synthase dimers in yeast. Just like subunit e, it is preferentially associated with dimers and interacts with Mic10, and its silencing results in severe defects to cristae and the disintegration of F1FO-ATP synthase dimers. Our findings indicate that crosstalk between MICOS and dimeric F1FO-ATP synthase is a fundamental property impacting crista shape throughout eukaryotes. IMPORTANCE Mitochondria have undergone profound diversification in separate lineages that have radiated since the last common ancestor of eukaryotes some eons ago. Most eukaryotes are unicellular protists, including etiological agents of infectious diseases, like Trypanosoma brucei. Thus, the study of a broad range of protists can reveal fundamental features shared by all eukaryotes and lineage-specific innovations. Here, we report that two different protein complexes, MICOS and F1FO-ATP synthase, known to affect mitochondrial architecture, undergo crosstalk in T. brucei, just as in baker's yeast. This is remarkable considering that these complexes have otherwise undergone many changes during their almost 2 billion years of independent evolution. Thus, this crosstalk is a fundamental property needed to maintain proper mitochondrial structure even if the constituent players considerably diverged.
Collapse
Affiliation(s)
- Lawrence Rudy Cadena
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Ondřej Gahura
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Brian Panicucci
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Alena Zíková
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Hassan Hashimi
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| |
Collapse
|
12
|
Franco LVR, Su CH, Tzagoloff A. Modular assembly of yeast mitochondrial ATP synthase and cytochrome oxidase. Biol Chem 2021; 401:835-853. [PMID: 32142477 DOI: 10.1515/hsz-2020-0112] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/24/2020] [Indexed: 12/27/2022]
Abstract
The respiratory pathway of mitochondria is composed of four electron transfer complexes and the ATP synthase. In this article, we review evidence from studies of Saccharomyces cerevisiae that both ATP synthase and cytochrome oxidase (COX) are assembled from independent modules that correspond to structurally and functionally identifiable components of each complex. Biogenesis of the respiratory chain requires a coordinate and balanced expression of gene products that become partner subunits of the same complex, but are encoded in the two physically separated genomes. Current evidence indicates that synthesis of two key mitochondrial encoded subunits of ATP synthase is regulated by the F1 module. Expression of COX1 that codes for a subunit of the COX catalytic core is also regulated by a mechanism that restricts synthesis of this subunit to the availability of a nuclear-encoded translational activator. The respiratory chain must maintain a fixed stoichiometry of the component enzyme complexes during cell growth. We propose that high-molecular-weight complexes composed of Cox6, a subunit of COX, and of the Atp9 subunit of ATP synthase play a key role in establishing the ratio of the two complexes during their assembly.
Collapse
Affiliation(s)
- Leticia Veloso Ribeiro Franco
- Department of Biological Sciences, Columbia University, New York City, NY 10027, USA.,Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, 05508-000, Brasil
| | - Chen Hsien Su
- Department of Biological Sciences, Columbia University, New York City, NY 10027, USA
| | - Alexander Tzagoloff
- Department of Biological Sciences, Columbia University, New York City, NY 10027, USA
| |
Collapse
|
13
|
Nesci S, Trombetti F, Pagliarani A, Ventrella V, Algieri C, Tioli G, Lenaz G. Molecular and Supramolecular Structure of the Mitochondrial Oxidative Phosphorylation System: Implications for Pathology. Life (Basel) 2021; 11:242. [PMID: 33804034 PMCID: PMC7999509 DOI: 10.3390/life11030242] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 02/07/2023] Open
Abstract
Under aerobic conditions, mitochondrial oxidative phosphorylation (OXPHOS) converts the energy released by nutrient oxidation into ATP, the currency of living organisms. The whole biochemical machinery is hosted by the inner mitochondrial membrane (mtIM) where the protonmotive force built by respiratory complexes, dynamically assembled as super-complexes, allows the F1FO-ATP synthase to make ATP from ADP + Pi. Recently mitochondria emerged not only as cell powerhouses, but also as signaling hubs by way of reactive oxygen species (ROS) production. However, when ROS removal systems and/or OXPHOS constituents are defective, the physiological ROS generation can cause ROS imbalance and oxidative stress, which in turn damages cell components. Moreover, the morphology of mitochondria rules cell fate and the formation of the mitochondrial permeability transition pore in the mtIM, which, most likely with the F1FO-ATP synthase contribution, permeabilizes mitochondria and leads to cell death. As the multiple mitochondrial functions are mutually interconnected, changes in protein composition by mutations or in supercomplex assembly and/or in membrane structures often generate a dysfunctional cascade and lead to life-incompatible diseases or severe syndromes. The known structural/functional changes in mitochondrial proteins and structures, which impact mitochondrial bioenergetics because of an impaired or defective energy transduction system, here reviewed, constitute the main biochemical damage in a variety of genetic and age-related diseases.
Collapse
Affiliation(s)
- Salvatore Nesci
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40064 Ozzano Emilia, Italy; (F.T.); (V.V.); (C.A.)
| | - Fabiana Trombetti
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40064 Ozzano Emilia, Italy; (F.T.); (V.V.); (C.A.)
| | - Alessandra Pagliarani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40064 Ozzano Emilia, Italy; (F.T.); (V.V.); (C.A.)
| | - Vittoria Ventrella
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40064 Ozzano Emilia, Italy; (F.T.); (V.V.); (C.A.)
| | - Cristina Algieri
- Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, 40064 Ozzano Emilia, Italy; (F.T.); (V.V.); (C.A.)
| | - Gaia Tioli
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum University of Bologna, 40138 Bologna, Italy;
| | - Giorgio Lenaz
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum University of Bologna, 40138 Bologna, Italy;
| |
Collapse
|
14
|
Tarasenko D, Meinecke M. Protein-dependent membrane remodeling in mitochondrial morphology and clathrin-mediated endocytosis. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:295-306. [PMID: 33527201 PMCID: PMC8071792 DOI: 10.1007/s00249-021-01501-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/04/2021] [Accepted: 01/13/2021] [Indexed: 11/30/2022]
Abstract
Cellular membranes can adopt a plethora of complex and beautiful shapes, most of which are believed to have evolved for a particular physiological reason. The closely entangled relationship between membrane morphology and cellular physiology is strikingly seen in membrane trafficking pathways. During clathrin-mediated endocytosis, for example, over the course of a minute, a patch of the more or less flat plasma membrane is remodeled into a highly curved clathrin-coated vesicle. Such vesicles are internalized by the cell to degrade or recycle plasma membrane receptors or to take up extracellular ligands. Other, steadier, membrane morphologies can be observed in organellar membranes like the endoplasmic reticulum or mitochondria. In the case of mitochondria, which are double membrane-bound, ubiquitous organelles of eukaryotic cells, especially the mitochondrial inner membrane displays an intricated ultrastructure. It is highly folded and consequently has a much larger surface than the mitochondrial outer membrane. It can adopt different shapes in response to cellular demands and changes of the inner membrane morphology often accompany severe diseases, including neurodegenerative- and metabolic diseases and cancer. In recent years, progress was made in the identification of molecules that are important for the aforementioned membrane remodeling events. In this review, we will sum up recent results and discuss the main players of membrane remodeling processes that lead to the mitochondrial inner membrane ultrastructure and in clathrin-mediated endocytosis. We will compare differences and similarities between the molecular mechanisms that peripheral and integral membrane proteins use to deform membranes.
Collapse
Affiliation(s)
- Daryna Tarasenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
| |
Collapse
|
15
|
Nesci S, Pagliarani A, Algieri C, Trombetti F. Mitochondrial F-type ATP synthase: multiple enzyme functions revealed by the membrane-embedded F O structure. Crit Rev Biochem Mol Biol 2020; 55:309-321. [PMID: 32580582 DOI: 10.1080/10409238.2020.1784084] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Of the two main sectors of the F-type ATP synthase, the membrane-intrinsic FO domain is the one which, during evolution, has undergone the highest structural variations and changes in subunit composition. The FO complexity in mitochondria is apparently related to additional enzyme functions that lack in bacterial and thylakoid complexes. Indeed, the F-type ATP synthase has the main bioenergetic role to synthesize ATP by exploiting the electrochemical gradient built by respiratory complexes. The FO membrane domain, essential in the enzyme machinery, also participates in the bioenergetic cost of synthesizing ATP and in the formation of the cristae, thus contributing to mitochondrial morphology. The recent enzyme involvement in a high-conductance channel, which forms in the inner mitochondrial membrane and promotes the mitochondrial permeability transition, highlights a new F-type ATP synthase role. Point mutations which cause amino acid substitutions in FO subunits produce mitochondrial dysfunctions and lead to severe pathologies. The FO variability in different species, pointed out by cryo-EM analysis, mirrors the multiple enzyme functions and opens a new scenario in mitochondrial biology.
Collapse
Affiliation(s)
- Salvatore Nesci
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | | | - Cristina Algieri
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Fabiana Trombetti
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| |
Collapse
|
16
|
Cobley J, Noble A, Bessell R, Guille M, Husi H. Reversible Thiol Oxidation Inhibits the Mitochondrial ATP Synthase in Xenopus Laevis Oocytes. Antioxidants (Basel) 2020; 9:antiox9030215. [PMID: 32150908 PMCID: PMC7139892 DOI: 10.3390/antiox9030215] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/15/2022] Open
Abstract
Oocytes are postulated to repress the proton pumps (e.g., complex IV) and ATP synthase to safeguard mitochondrial DNA homoplasmy by curtailing superoxide production. Whether the ATP synthase is inhibited is, however, unknown. Here we show that: oligomycin sensitive ATP synthase activity is significantly greater (~170 vs. 20 nmol/min-1/mg-1) in testes compared to oocytes in Xenopus laevis (X. laevis). Since ATP synthase activity is redox regulated, we explored a regulatory role for reversible thiol oxidation. If a protein thiol inhibits the ATP synthase, then constituent subunits must be reversibly oxidised. Catalyst-free trans-cyclooctene 6-methyltetrazine (TCO-Tz) immunocapture coupled to redox affinity blotting reveals several subunits in F1 (e.g., ATP-α-F1) and Fo (e.g., subunit c) are reversibly oxidised. Catalyst-free TCO-Tz Click PEGylation reveals significant (~60%) reversible ATP-α-F1 oxidation at two evolutionary conserved cysteine residues (C244 and C294) in oocytes. TCO-Tz Click PEGylation reveals ~20% of the total thiols in the ATP synthase are substantially oxidised. Chemically reversing thiol oxidation significantly increased oligomycin sensitive ATP synthase activity from ~12 to 100 nmol/min-1/mg-1 in oocytes. We conclude that reversible thiol oxidation inhibits the mitochondrial ATP synthase in X. laevis oocytes.
Collapse
Affiliation(s)
- James Cobley
- Centre for Health Sciences, University of the Highlands and Islands, Inverness IV2 3JH, UK; (R.B.); (H.H.)
- Correspondence:
| | - Anna Noble
- School of Biological Sciences, European Xenopus Resource Centre, University of Portsmouth, King Henry Building, Portsmouth PO1 2DY, UK; (A.N.); (M.G.)
| | - Rachel Bessell
- Centre for Health Sciences, University of the Highlands and Islands, Inverness IV2 3JH, UK; (R.B.); (H.H.)
| | - Matthew Guille
- School of Biological Sciences, European Xenopus Resource Centre, University of Portsmouth, King Henry Building, Portsmouth PO1 2DY, UK; (A.N.); (M.G.)
| | - Holger Husi
- Centre for Health Sciences, University of the Highlands and Islands, Inverness IV2 3JH, UK; (R.B.); (H.H.)
| |
Collapse
|
17
|
Huddleston ME, Xiao N, Both AP, Gordon DM. Single amino acid mutations in the Saccharomyces cerevisiae rhomboid peptidase, Pcp1p, alter mitochondrial morphology. Cell Biol Int 2020; 44:200-215. [PMID: 31441130 PMCID: PMC6972574 DOI: 10.1002/cbin.11219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/18/2019] [Indexed: 01/24/2023]
Abstract
Key to mitochondrial activities is the maintenance of mitochondrial morphology, specifically cristae structures formed by the invagination of the inner membrane that are enriched in proteins of the electron transport chain. In Saccharomyces cerevisiae , these cristae folds are a result of the membrane fusion activities of Mgm1p and the membrane-bending properties of adenosine triphosphate (ATP) synthase oligomerization. An additional protein linked to mitochondrial morphology is Pcp1p, a serine protease responsible for the proteolytic processing of Mgm1p. Here, we have used hydroxylamine-based random mutagenesis to identify amino acids important for Pcp1p peptidase activity. Using this approach we have isolated five single amino acid mutants that exhibit respiratory growth defects that correlate with loss of mitochondrial genome stability. Reduced Pcp1p protease activity was confirmed by immunoblotting with the accumulation of improperly processed Mgm1p. Ultra-structural analysis of mitochondrial morphology in these mutants found a varying degree of defects in cristae organization. However, not all of the mutants presented with decreased ATP synthase complex assembly as determined by blue native polyacrylamide gel electrophoresis. Together, these data suggest that there is a threshold level of processed Mgm1p required to maintain ATP synthase super-complex assembly and mitochondrial cristae organization.
Collapse
Affiliation(s)
| | - Ningyu Xiao
- Department of Biological SciencesMississippi State UniversityMississippi StateMississippi39762USA
| | - Andries Pieter Both
- Department of Biological SciencesMississippi State UniversityMississippi StateMississippi39762USA
| | - Donna M. Gordon
- Department of Biological SciencesMississippi State UniversityMississippi StateMississippi39762USA
| |
Collapse
|
18
|
Mitochondrial Dysfunctions: A Thread Sewing Together Alzheimer's Disease, Diabetes, and Obesity. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7210892. [PMID: 31316720 PMCID: PMC6604285 DOI: 10.1155/2019/7210892] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/20/2019] [Accepted: 05/21/2019] [Indexed: 02/03/2023]
Abstract
Metabolic disorders are severe and chronic impairments of the health of many people and represent a challenge for the society as a whole that has to deal with an ever-increasing number of affected individuals. Among common metabolic disorders are Alzheimer's disease, obesity, and type 2 diabetes. These disorders do not have a univocal genetic cause but rather can result from the interaction of multiple genes, lifestyle, and environmental factors. Mitochondrial alterations have emerged as a feature common to all these disorders, underlining perhaps an impaired coordination between cellular needs and mitochondrial responses that could contribute to their development and/or progression.
Collapse
|
19
|
Guo L, Carraro M, Carrer A, Minervini G, Urbani A, Masgras I, Tosatto SCE, Szabò I, Bernardi P, Lippe G. Arg-8 of yeast subunit e contributes to the stability of F-ATP synthase dimers and to the generation of the full-conductance mitochondrial megachannel. J Biol Chem 2019; 294:10987-10997. [PMID: 31160339 DOI: 10.1074/jbc.ra119.008775] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/29/2019] [Indexed: 01/08/2023] Open
Abstract
The mitochondrial F-ATP synthase is a complex molecular motor arranged in V-shaped dimers that is responsible for most cellular ATP synthesis in aerobic conditions. In the yeast F-ATP synthase, subunits e and g of the FO sector constitute a lateral domain, which is required for dimer stability and cristae formation. Here, by using site-directed mutagenesis, we identified Arg-8 of subunit e as a critical residue in mediating interactions between subunits e and g, most likely through an interaction with Glu-83 of subunit g. Consistent with this hypothesis, (i) the substitution of Arg-8 in subunit e (eArg-8) with Ala or Glu or of Glu-83 in subunit g (gGlu-83) with Ala or Lys destabilized the digitonin-extracted F-ATP synthase, resulting in decreased dimer formation as revealed by blue-native electrophoresis; and (ii) simultaneous substitution of eArg-8 with Glu and of gGlu-83 with Lys rescued digitonin-stable F-ATP synthase dimers. When tested in lipid bilayers for generation of Ca2+-dependent channels, WT dimers displayed the high-conductance channel activity expected for the mitochondrial megachannel/permeability transition pore, whereas dimers obtained at low digitonin concentrations from the Arg-8 variants displayed currents of strikingly small conductance. Remarkably, double replacement of eArg-8 with Glu and of gGlu-83 with Lys restored high-conductance channels indistinguishable from those seen in WT enzymes. These findings suggest that the interaction of subunit e with subunit g is important for generation of the full-conductance megachannel from F-ATP synthase.
Collapse
Affiliation(s)
- Lishu Guo
- Departments of Biomedical Sciences and
| | | | | | | | | | | | - Silvio C E Tosatto
- Departments of Biomedical Sciences and; Consiglio Nazionale delle Ricerche Institute of Neuroscience, 35131 Padova, Italy, and
| | - Ildikò Szabò
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, 35131 Padova, Italy, and; Biology, University of Padova, 35131 Padova, Italy
| | - Paolo Bernardi
- Departments of Biomedical Sciences and; Consiglio Nazionale delle Ricerche Institute of Neuroscience, 35131 Padova, Italy, and.
| | - Giovanna Lippe
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, 33100 Udine, Italy.
| |
Collapse
|
20
|
Mendoza-Hoffmann F, Zarco-Zavala M, Ortega R, García-Trejo JJ. Control of rotation of the F1FO-ATP synthase nanomotor by an inhibitory α-helix from unfolded ε or intrinsically disordered ζ and IF1 proteins. J Bioenerg Biomembr 2018; 50:403-424. [DOI: 10.1007/s10863-018-9773-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 09/13/2018] [Indexed: 12/14/2022]
|
21
|
Quintana-Cabrera R, Quirin C, Glytsou C, Corrado M, Urbani A, Pellattiero A, Calvo E, Vázquez J, Enríquez JA, Gerle C, Soriano ME, Bernardi P, Scorrano L. The cristae modulator Optic atrophy 1 requires mitochondrial ATP synthase oligomers to safeguard mitochondrial function. Nat Commun 2018; 9:3399. [PMID: 30143614 PMCID: PMC6109181 DOI: 10.1038/s41467-018-05655-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/18/2018] [Indexed: 12/16/2022] Open
Abstract
It is unclear how the mitochondrial fusion protein Optic atrophy 1 (OPA1), which inhibits cristae remodeling, protects from mitochondrial dysfunction. Here we identify the mitochondrial F1Fo-ATP synthase as the effector of OPA1 in mitochondrial protection. In OPA1 overexpressing cells, the loss of proton electrochemical gradient caused by respiratory chain complex III inhibition is blunted and this protection is abolished by the ATP synthase inhibitor oligomycin. Mechanistically, OPA1 and ATP synthase can interact, but recombinant OPA1 fails to promote oligomerization of purified ATP synthase reconstituted in liposomes, suggesting that OPA1 favors ATP synthase oligomerization and reversal activity by modulating cristae shape. When ATP synthase oligomers are genetically destabilized by silencing the key dimerization subunit e, OPA1 is no longer able to preserve mitochondrial function and cell viability upon complex III inhibition. Thus, OPA1 protects mitochondria from respiratory chain inhibition by stabilizing cristae shape and favoring ATP synthase oligomerization. Mitochondrial cristae shape influences apoptosis and respiration. Here the authors show that the mitochondrial fusion protein OPA1 protects mitochondria from dysfunction by promoting ATP synthase oligomerization and reversal activity.
Collapse
Affiliation(s)
- Rubén Quintana-Cabrera
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,University of Salamanca, Consejo Superior de Investigaciones Científicas CSIC, Institute of Functional Biology and Genomics, Salamanca, 37007, Spain.,Institute of Biomedical Research of Salamanca, University Hospital of Salamanca, University of Salamanca, CSIC, 37007, Salamanca, Spain.,CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Charlotte Quirin
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy
| | - Christina Glytsou
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,Department of Pathology, NYU School of Medicine, 10016, New York, NY, USA
| | - Mauro Corrado
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,Max Planck Institute of Immunology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Andrea Urbani
- Department of Biomedical Sciences, University of Padua, Padua, 35121, Italy
| | - Anna Pellattiero
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy
| | - Enrique Calvo
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain
| | - Jesús Vázquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain
| | - José Antonio Enríquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain.,CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Christoph Gerle
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan
| | | | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padua, Padua, 35121, Italy.,Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Padua, Italy
| | - Luca Scorrano
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy. .,Department of Biology, University of Padua, 35121, Padua, Italy.
| |
Collapse
|
22
|
Guo L, Carraro M, Sartori G, Minervini G, Eriksson O, Petronilli V, Bernardi P. Arginine 107 of yeast ATP synthase subunit g mediates sensitivity of the mitochondrial permeability transition to phenylglyoxal. J Biol Chem 2018; 293:14632-14645. [PMID: 30093404 DOI: 10.1074/jbc.ra118.004495] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 07/27/2018] [Indexed: 12/18/2022] Open
Abstract
Modification with arginine-specific glyoxals modulates the permeability transition (PT) of rat liver mitochondria, with inhibitory or inducing effects that depend on the net charge of the adduct(s). Here, we show that phenylglyoxal (PGO) affects the PT in a species-specific manner (inhibition in mouse and yeast, induction in human and Drosophila mitochondria). Following the hypotheses (i) that the effects are mediated by conserved arginine(s) and (ii) that the PT is mediated by the F-ATP synthase, we have narrowed the search to 60 arginines. Most of these residues are located in subunits α, β, γ, ϵ, a, and c and were excluded because PGO modification did not significantly affect enzyme catalysis. On the other hand, yeast mitochondria lacking subunit g or bearing a subunit g R107A mutation were totally resistant to PT inhibition by PGO. Thus, the effect of PGO on the PT is specifically mediated by Arg-107, the only subunit g arginine that has been conserved across species. These findings are evidence that the PT is mediated by F-ATP synthase.
Collapse
Affiliation(s)
- Lishu Guo
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Michela Carraro
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Geppo Sartori
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Giovanni Minervini
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Ove Eriksson
- the Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Valeria Petronilli
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Paolo Bernardi
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| |
Collapse
|
23
|
Nesci S, Trombetti F, Ventrella V, Pagliarani A. From the Ca 2+-activated F 1F O-ATPase to the mitochondrial permeability transition pore: an overview. Biochimie 2018; 152:85-93. [PMID: 29964086 DOI: 10.1016/j.biochi.2018.06.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/26/2018] [Indexed: 01/02/2023]
Abstract
Based on recent advances on the Ca2+-activated F1FO-ATPase features, a novel multistep mechanism involving the mitochondrial F1FO complex in the formation and opening of the still enigmatic mitochondrial permeability transition pore (MPTP), is proposed. MPTP opening makes the inner mitochondrial membrane (IMM) permeable to ions and solutes and, through cascade events, addresses cell fate to death. Since MPTP forms when matrix Ca2+ concentration rises and ATP is hydrolyzed by the F1FO-ATPase, conformational changes, triggered by Ca2+ insertion in F1, may be transmitted to FO and locally modify the IMM curvature. These events would cause F1FO-ATPase dimer dissociation and MPTP opening.
Collapse
Affiliation(s)
- Salvatore Nesci
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Fabiana Trombetti
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Vittoria Ventrella
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Alessandra Pagliarani
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy.
| |
Collapse
|
24
|
Abstract
Mitochondria are the power stations of the eukaryotic cell, using the energy released by the oxidation of glucose and other sugars to produce ATP. Electrons are transferred from NADH, produced in the citric acid cycle in the mitochondrial matrix, to oxygen by a series of large protein complexes in the inner mitochondrial membrane, which create a transmembrane electrochemical gradient by pumping protons across the membrane. The flow of protons back into the matrix via a proton channel in the ATP synthase leads to conformational changes in the nucleotide binding pockets and the formation of ATP. The three proton pumping complexes of the electron transfer chain are NADH-ubiquinone oxidoreductase or complex I, ubiquinone-cytochrome c oxidoreductase or complex III, and cytochrome c oxidase or complex IV. Succinate dehydrogenase or complex II does not pump protons, but contributes reduced ubiquinone. The structures of complex II, III and IV were determined by x-ray crystallography several decades ago, but complex I and ATP synthase have only recently started to reveal their secrets by advances in x-ray crystallography and cryo-electron microscopy. The complexes I, III and IV occur to a certain extent as supercomplexes in the membrane, the so-called respirasomes. Several hypotheses exist about their function. Recent cryo-electron microscopy structures show the architecture of the respirasome with near-atomic detail. ATP synthase occurs as dimers in the inner mitochondrial membrane, which by their curvature are responsible for the folding of the membrane into cristae and thus for the huge increase in available surface that makes mitochondria the efficient energy plants of the eukaryotic cell.
Collapse
Affiliation(s)
- Joana S Sousa
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Edoardo D'Imprima
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| |
Collapse
|
25
|
Guo H, Bueler SA, Rubinstein JL. Atomic model for the dimeric F O region of mitochondrial ATP synthase. Science 2017; 358:936-940. [PMID: 29074581 DOI: 10.1126/science.aao4815] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/11/2017] [Indexed: 01/01/2023]
Abstract
Mitochondrial adenosine triphosphate (ATP) synthase produces the majority of ATP in eukaryotic cells, and its dimerization is necessary to create the inner membrane folds, or cristae, characteristic of mitochondria. Proton translocation through the membrane-embedded FO region turns the rotor that drives ATP synthesis in the soluble F1 region. Although crystal structures of the F1 region have illustrated how this rotation leads to ATP synthesis, understanding how proton translocation produces the rotation has been impeded by the lack of an experimental atomic model for the FO region. Using cryo-electron microscopy, we determined the structure of the dimeric FO complex from Saccharomyces cerevisiae at a resolution of 3.6 angstroms. The structure clarifies how the protons travel through the complex, how the complex dimerizes, and how the dimers bend the membrane to produce cristae.
Collapse
Affiliation(s)
- Hui Guo
- Hospital for Sick Children Research Institute, Toronto, Ontario M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Stephanie A Bueler
- Hospital for Sick Children Research Institute, Toronto, Ontario M5G 0A4, Canada
| | - John L Rubinstein
- Hospital for Sick Children Research Institute, Toronto, Ontario M5G 0A4, Canada. .,Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| |
Collapse
|
26
|
Al-Zaidan L, El Ruz RA, Malki AM. Screening Novel Molecular Targets of Metformin in Breast Cancer by Proteomic Approach. Front Public Health 2017; 5:277. [PMID: 29085821 PMCID: PMC5650619 DOI: 10.3389/fpubh.2017.00277] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/27/2017] [Indexed: 01/09/2023] Open
Abstract
Metformin is a commonly prescribed antihyperglycemic drug, and has been investigated in vivo and in vitro for its effect to improve the comorbidity of diabetes and various types of cancers. Several studies investigated the therapeutic mechanisms of metformin on cancer cells, but the exact mechanism of metformin’s effect on the proteomic pathways of cancer cells is yet to be further investigated. The main objective of our research line is to discover safe and alternative therapeutic options for breast cancer, we aimed in this study to design a novel “bottom up proteomics workflow” in which proteins were first broken into peptides to reveal their identity, then the proteomes were precisely evaluated using spectrometry analysis. In our study, metformin suppressed cell proliferation and induced apoptosis in human breast carcinoma cell line MCF-7 with minimal toxicity to normal breast epithelial cells MCF-10. Metformin induced apoptosis by arresting cells in G1 phase as evaluated by flow cytometric analysis. Moreover, The G1 phase arrest for the MCF-7 has been confirmed by increased expression levels of p21 and reduction in cyclin D1 level. Additionally, metformin increased the expression levels of p53, Bax, Bad while it reduced expression levels of Akt, Bcl-2, and Mdm2. The study employed a serviceable strategy that investigates metformin-dependent changes in the proteome using a literature-derived network. The protein extracts of the treated and untreated cell lines were analyzed employing proteomic approaches; the findings conveyed a proposed mechanism of the effectual tactics of metformin on breast cancer cells. Metformin proposed an antibreast cancer effect through the examination of the proteomic pathways upon the MCF-7 and MCF-10A exposure to the drug. Our findings proposed prolific proteomic changes that revealed the therapeutic mechanisms of metformin on breast cancer cells upon their exposure. In conclusion, the reported proteomic pathways lead to increase the understanding of breast cancer prognosis and permit future studies to examine the effect of metformin on the proteomic pathways against other types of cancers. Finally, it suggests the possibility to develop further therapeutic generations of metformin with increased anticancer effect through targeting specific proteomes.
Collapse
Affiliation(s)
- Lobna Al-Zaidan
- Biomedical Sciences Department, College of Health Sciences, Qatar University, Doha, Qatar
| | - Rasha Abu El Ruz
- Biomedical Sciences Department, College of Health Sciences, Qatar University, Doha, Qatar
| | - Ahmed M Malki
- Biomedical Sciences Department, College of Health Sciences, Qatar University, Doha, Qatar
| |
Collapse
|
27
|
Esparza-Perusquía M, Olvera-Sánchez S, Pardo JP, Mendoza-Hernández G, Martínez F, Flores-Herrera O. Structural and kinetics characterization of the F 1F 0-ATP synthase dimer. New repercussion of monomer-monomer contact. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:975-981. [PMID: 28919501 DOI: 10.1016/j.bbabio.2017.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/24/2017] [Accepted: 09/12/2017] [Indexed: 12/20/2022]
Abstract
Ustilago maydis is an aerobic basidiomycete that fully depends on oxidative phosphorylation for its supply of ATP, pointing to mitochondria as a key player in the energy metabolism of this organism. Mitochondrial F1F0-ATP synthase occurs in supramolecular structures. In this work, we isolated the monomer (640kDa) and the dimer (1280kDa) and characterized their subunit composition and kinetics of ATP hydrolysis. Mass spectrometry revealed that dimerizing subunits e and g were present in the dimer but not in the monomer. Analysis of the ATPase activity showed that both oligomers had Michaelis-Menten kinetics, but the dimer was 7 times more active than the monomer, while affinities were similar. The dimer was more sensitive to oligomycin inhibition, with a Ki of 24nM, while the monomer had a Ki of 169nM. The results suggest that the interphase between the monomers in the dimer state affects the catalytic efficiency of the enzyme and its sensitivity to inhibitors.
Collapse
Affiliation(s)
- Mercedes Esparza-Perusquía
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México City, México
| | - Sofía Olvera-Sánchez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México City, México
| | - Juan Pablo Pardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México City, México
| | - Guillermo Mendoza-Hernández
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México City, México
| | - Federico Martínez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México City, México
| | - Oscar Flores-Herrera
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México City, México.
| |
Collapse
|
28
|
Transporter oligomerization: form and function. Biochem Soc Trans 2017; 44:1737-1744. [PMID: 27913684 PMCID: PMC5134999 DOI: 10.1042/bst20160217] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/16/2016] [Accepted: 09/19/2016] [Indexed: 12/22/2022]
Abstract
Transporters are integral membrane proteins with central roles in the efficient movement of molecules across biological membranes. Many transporters exist as oligomers in the membrane. Depending on the individual transport protein, oligomerization can have roles in membrane trafficking, function, regulation and turnover. For example, our recent studies on UapA, a nucleobase ascorbate transporter, from Aspergillus nidulans, have revealed both that dimerization of this protein is essential for correct trafficking to the membrane and the structural basis of how one UapA protomer can affect the function of the closely associated adjacent protomer. Here, we review the roles of oligomerization in many particularly well-studied transporters and transporter families.
Collapse
|
29
|
Sánchez-Vásquez L, Vázquez-Acevedo M, de la Mora J, Vega-deLuna F, Cardol P, Remacle C, Dreyfus G, González-Halphen D. Near-neighbor interactions of the membrane-embedded subunits of the mitochondrial ATP synthase of a chlorophycean alga. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:497-509. [DOI: 10.1016/j.bbabio.2017.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/25/2017] [Accepted: 04/29/2017] [Indexed: 12/24/2022]
|
30
|
Sánchez-Vásquez L, González-Halphen D. TOPOLOGÍA Y FUNCIÓN DE LAS SUBUNIDADES INTRÍNSECAS DE LA MEMBRANA DE LAS F 1 F O -ATP SINTASA MITOCONDRIALES. TIP REVISTA ESPECIALIZADA EN CIENCIAS QUÍMICO-BIOLÓGICAS 2017. [DOI: 10.1016/j.recqb.2017.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
31
|
Bonora M, Morganti C, Morciano G, Pedriali G, Lebiedzinska-Arciszewska M, Aquila G, Giorgi C, Rizzo P, Campo G, Ferrari R, Kroemer G, Wieckowski MR, Galluzzi L, Pinton P. Mitochondrial permeability transition involves dissociation of F 1F O ATP synthase dimers and C-ring conformation. EMBO Rep 2017; 18:1077-1089. [PMID: 28566520 DOI: 10.15252/embr.201643602] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 04/22/2017] [Accepted: 04/25/2017] [Indexed: 11/09/2022] Open
Abstract
The impact of the mitochondrial permeability transition (MPT) on cellular physiology is well characterized. In contrast, the composition and mode of action of the permeability transition pore complex (PTPC), the supramolecular entity that initiates MPT, remain to be elucidated. Specifically, the precise contribution of the mitochondrial F1FO ATP synthase (or subunits thereof) to MPT is a matter of debate. We demonstrate that F1FO ATP synthase dimers dissociate as the PTPC opens upon MPT induction. Stabilizing F1FO ATP synthase dimers by genetic approaches inhibits PTPC opening and MPT Specific mutations in the F1FO ATP synthase c subunit that alter C-ring conformation sensitize cells to MPT induction, which can be reverted by stabilizing F1FO ATP synthase dimers. Destabilizing F1FO ATP synthase dimers fails to trigger PTPC opening in the presence of mutants of the c subunit that inhibit MPT The current study does not provide direct evidence that the C-ring is the long-sought pore-forming subunit of the PTPC, but reveals that PTPC opening requires the dissociation of F1FO ATP synthase dimers and involves the C-ring.
Collapse
Affiliation(s)
- Massimo Bonora
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Claudia Morganti
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Giampaolo Morciano
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Gaia Pedriali
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | | | - Giorgio Aquila
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Carlotta Giorgi
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Paola Rizzo
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Gianluca Campo
- Cardiovascular Institute, University of Ferrara, Ferrara, Italy
| | - Roberto Ferrari
- Cardiovascular Institute, University of Ferrara, Ferrara, Italy
| | - Guido Kroemer
- Université Paris Descartes/Paris V, Paris, France.,Université Pierre et Marie Curie/Paris VI, Paris, France.,INSERM, U1138, Paris, France.,Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France.,Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.,Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France.,Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden
| | - Mariusz R Wieckowski
- Department of Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Lorenzo Galluzzi
- Université Paris Descartes/Paris V, Paris, France .,Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
| | - Paolo Pinton
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy .,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| |
Collapse
|
32
|
Quintana-Cabrera R, Mehrotra A, Rigoni G, Soriano ME. Who and how in the regulation of mitochondrial cristae shape and function. Biochem Biophys Res Commun 2017; 500:94-101. [PMID: 28438601 DOI: 10.1016/j.bbrc.2017.04.088] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 04/17/2017] [Indexed: 12/19/2022]
Abstract
Mitochondrial adaptation to different physiological conditions highly relies on the regulation of mitochondrial ultrastructure, particularly at the level of cristae compartment. Cristae represent the membrane hub where most of the respiratory complexes embed to account for OXPHOS and energy production in the form of adenosine triphosphate (ATP). Changes in cristae number and shape define the respiratory capacity as well as cell viability. The identification of key regulators of cristae morphology and the understanding of their contribution to the mitochondrial ultrastructure and function have become an strategic goal to understand mitochondrial disorders and to exploit as therapeutic targets. This review summarizes the known regulators of cristae ultrastructure and discusses their contribution and implications for mitochondrial dysfunction.
Collapse
Affiliation(s)
- R Quintana-Cabrera
- Department of Biology, University of Padova, Padova, 35121, Italy; Venetian Institute of Molecular Medicine, Padova 35129, Italy
| | - A Mehrotra
- Department of Biology, University of Padova, Padova, 35121, Italy
| | - G Rigoni
- Department of Biology, University of Padova, Padova, 35121, Italy
| | - M E Soriano
- Department of Biology, University of Padova, Padova, 35121, Italy.
| |
Collapse
|
33
|
Structure of the mitochondrial ATP synthase from Pichia angusta determined by electron cryo-microscopy. Proc Natl Acad Sci U S A 2016; 113:12709-12714. [PMID: 27791192 DOI: 10.1073/pnas.1615902113] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The structure of the intact monomeric ATP synthase from the fungus, Pichia angusta, has been solved by electron cryo-microscopy. The structure provides insights into the mechanical coupling of the transmembrane proton motive force across mitochondrial membranes in the synthesis of ATP. This mechanism requires a strong and integral stator, consisting of the catalytic α3β3-domain, peripheral stalk, and, in the membrane domain, subunit a and associated supernumerary subunits, kept in contact with the rotor turning at speeds up to 350 Hz. The stator's integrity is ensured by robust attachment of both the oligomycin sensitivity conferral protein (OSCP) to the catalytic domain and the membrane domain of subunit b to subunit a. The ATP8 subunit provides an additional brace between the peripheral stalk and subunit a. At the junction between the OSCP and the apparently stiff, elongated α-helical b-subunit and associated d- and h-subunits, an elbow or joint allows the stator to bend to accommodate lateral movements during the activity of the catalytic domain. The stator may also apply lateral force to help keep the static a-subunit and rotating c10-ring together. The interface between the c10-ring and the a-subunit contains the transmembrane pathway for protons, and their passage across the membrane generates the turning of the rotor. The pathway has two half-channels containing conserved polar residues provided by a bundle of four α-helices inclined at ∼30° to the plane of the membrane, similar to those described in other species. The structure provides more insights into the workings of this amazing machine.
Collapse
|
34
|
Barbot M, Meinecke M. Reconstitutions of mitochondrial inner membrane remodeling. J Struct Biol 2016; 196:20-28. [DOI: 10.1016/j.jsb.2016.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 02/03/2023]
|
35
|
Hahn A, Parey K, Bublitz M, Mills DJ, Zickermann V, Vonck J, Kühlbrandt W, Meier T. Structure of a Complete ATP Synthase Dimer Reveals the Molecular Basis of Inner Mitochondrial Membrane Morphology. Mol Cell 2016; 63:445-56. [PMID: 27373333 PMCID: PMC4980432 DOI: 10.1016/j.molcel.2016.05.037] [Citation(s) in RCA: 208] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 04/21/2016] [Accepted: 05/26/2016] [Indexed: 11/28/2022]
Abstract
We determined the structure of a complete, dimeric F1Fo-ATP synthase from yeast Yarrowia lipolytica mitochondria by a combination of cryo-EM and X-ray crystallography. The final structure resolves 58 of the 60 dimer subunits. Horizontal helices of subunit a in Fo wrap around the c-ring rotor, and a total of six vertical helices assigned to subunits a, b, f, i, and 8 span the membrane. Subunit 8 (A6L in human) is an evolutionary derivative of the bacterial b subunit. On the lumenal membrane surface, subunit f establishes direct contact between the two monomers. Comparison with a cryo-EM map of the F1Fo monomer identifies subunits e and g at the lateral dimer interface. They do not form dimer contacts but enable dimer formation by inducing a strong membrane curvature of ∼100°. Our structure explains the structural basis of cristae formation in mitochondria, a landmark signature of eukaryotic cell morphology. Cryo-EM structure of a yeast F1Fo-ATP synthase dimer Inhibitor-free X-ray structure of the F1 head and rotor complex Mechanism of ATP generation by rotary catalysis Structural basis of cristae formation in the inner mitochondrial membrane
Collapse
Affiliation(s)
- Alexander Hahn
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany
| | - Kristian Parey
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany
| | - Maike Bublitz
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Deryck J Mills
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany
| | - Volker Zickermann
- Institute of Biochemistry II, Medical School, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany.
| | - Thomas Meier
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany.
| |
Collapse
|
36
|
Papadopoulos M, Tran ENH, Murray GL, Morona R. Conserved transmembrane glycine residues in the Shigella flexneri polysaccharide co-polymerase protein WzzB influence protein-protein interactions. MICROBIOLOGY-SGM 2016; 162:921-929. [PMID: 27028755 DOI: 10.1099/mic.0.000282] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The O antigen (Oag) component of lipopolysaccharides (LPS) is crucial for virulence and Oag chain-length regulation is controlled by the polysaccharide co-polymerase class 1 (PCP1) proteins. Crystal structure analyses indicate that structural conservation among PCP1 proteins is highly maintained, however the mechanism of Oag modal-chain-length control remains to be fully elucidated. Shigella flexneri PCP1 protein WzzBSF confers a modal-chain length of 10-17 Oag repeat units (RUs), whereas the Salmonella enterica Typhimurium PCP1 protein WzzBST confers a modal-chain length of ~16-28 Oag RUs. Both proteins share >70 % overall sequence identity and contain two transmembrane (TM1 and TM2) regions, whereby a conserved proline-glycine-rich motif overlapping the TM2 region is identical in both proteins. Conserved glycine residues within TM2 are functionally important, as glycine to alanine substitutions at positions 305 and 311 confer very short Oag modal-chain length (~2-6 Oag RUs). In this study, WzzBSF was co-expressed with WzzBST in S. flexneri and a single intermediate modal-chain length of ~11-21 Oag RUs was observed, suggesting the presence of Wzz:Wzz interactions. Interestingly, co-expression of WzzBSF with WzzBG305A/G311A conferred a bimodal LPS Oag chain length (despite over 99 % protein sequence identity), and we hypothesized that the proteins fail to interact. Co-purification assays detected His6-WzzBSF co-purifying with FLAG-tagged WzzBST but not with FLAG-tagged WzzBG305A/G311A, supporting our hypothesis. These data indicate that the conserved glycine residues in TM2 are involved in Wzz:Wzz interactions, and provide insight into key interactions that drive Oag modal length control.
Collapse
Affiliation(s)
- Magdalene Papadopoulos
- School of Biological Sciences, Department of Molecular & Cellular Biology, Research Centre for Infectious Diseases, University of Adelaide, Adelaide 5005, Australia
| | - Elizabeth Ngoc Hoa Tran
- School of Biological Sciences, Department of Molecular & Cellular Biology, Research Centre for Infectious Diseases, University of Adelaide, Adelaide 5005, Australia
| | - Gerald Laurence Murray
- School of Biological Sciences, Department of Molecular & Cellular Biology, Research Centre for Infectious Diseases, University of Adelaide, Adelaide 5005, Australia
| | - Renato Morona
- School of Biological Sciences, Department of Molecular & Cellular Biology, Research Centre for Infectious Diseases, University of Adelaide, Adelaide 5005, Australia
| |
Collapse
|
37
|
The Dual Function of Reactive Oxygen/Nitrogen Species in Bioenergetics and Cell Death: The Role of ATP Synthase. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3869610. [PMID: 27034734 PMCID: PMC4806282 DOI: 10.1155/2016/3869610] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/15/2016] [Indexed: 01/11/2023]
Abstract
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) targeting mitochondria are major causative factors in disease pathogenesis. The mitochondrial permeability transition pore (PTP) is a mega-channel modulated by calcium and ROS/RNS modifications and it has been described to play a crucial role in many pathophysiological events since prolonged channel opening causes cell death. The recent identification that dimers of ATP synthase form the PTP and the fact that posttranslational modifications caused by ROS/RNS also affect cellular bioenergetics through the modulation of ATP synthase catalysis reveal a dual function of these modifications in the cells. Here, we describe mitochondria as a major site of production and as a target of ROS/RNS and discuss the pathophysiological conditions in which oxidative and nitrosative modifications modulate the catalytic and pore-forming activities of ATP synthase.
Collapse
|
38
|
Vázquez-Acevedo M, Vega-deLuna F, Sánchez-Vásquez L, Colina-Tenorio L, Remacle C, Cardol P, Miranda-Astudillo H, González-Halphen D. Dissecting the peripheral stalk of the mitochondrial ATP synthase of chlorophycean algae. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1183-1190. [PMID: 26873638 DOI: 10.1016/j.bbabio.2016.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/25/2016] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
Abstract
The algae Chlamydomonas reinhardtii and Polytomella sp., a green and a colorless member of the chlorophycean lineage respectively, exhibit a highly-stable dimeric mitochondrial F1Fo-ATP synthase (complex V), with a molecular mass of 1600 kDa. Polytomella, lacking both chloroplasts and a cell wall, has greatly facilitated the purification of the algal ATP-synthase. Each monomer of the enzyme has 17 polypeptides, eight of which are the conserved, main functional components, and nine polypeptides (Asa1 to Asa9) unique to chlorophycean algae. These atypical subunits form the two robust peripheral stalks observed in the highly-stable dimer of the algal ATP synthase in several electron-microscopy studies. The topological disposition of the components of the enzyme has been addressed with cross-linking experiments in the isolated complex; generation of subcomplexes by limited dissociation of complex V; detection of subunit-subunit interactions using recombinant subunits; in vitro reconstitution of subcomplexes; silencing of the expression of Asa subunits; and modeling of the overall structural features of the complex by EM image reconstruction. Here, we report that the amphipathic polymer Amphipol A8-35 partially dissociates the enzyme, giving rise to two discrete dimeric subcomplexes, whose compositions were characterized. An updated model for the topological disposition of the 17 polypeptides that constitute the algal enzyme is suggested. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
Collapse
Affiliation(s)
- Miriam Vázquez-Acevedo
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Félix Vega-deLuna
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Lorenzo Sánchez-Vásquez
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Lilia Colina-Tenorio
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Claire Remacle
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Pierre Cardol
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Héctor Miranda-Astudillo
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Diego González-Halphen
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico.
| |
Collapse
|
39
|
Turakhiya U, von der Malsburg K, Gold VAM, Guiard B, Chacinska A, van der Laan M, Ieva R. Protein Import by the Mitochondrial Presequence Translocase in the Absence of a Membrane Potential. J Mol Biol 2016; 428:1041-1052. [PMID: 26827728 DOI: 10.1016/j.jmb.2016.01.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/15/2015] [Accepted: 01/01/2016] [Indexed: 11/17/2022]
Abstract
The highly organized mitochondrial inner membrane harbors enzymes that produce the bulk of cellular ATP via oxidative phosphorylation. The majority of inner membrane protein precursors are synthesized in the cytosol. Precursors with a cleavable presequence are imported by the presequence translocase (TIM23 complex), while other precursors containing internal targeting signals are imported by the carrier translocase (TIM22 complex). Both TIM23 and TIM22 are activated by the transmembrane electrochemical potential. Many small inner membrane proteins, however, do not resemble canonical TIM23 or TIM22 substrates and their mechanism of import is unknown. We report that subunit e of the F1Fo-ATP synthase, a small single-spanning inner membrane protein that is critical for inner membrane organization, is imported by TIM23 in a process that does not require activation by the membrane potential. Absence of positively charged residues at the matrix-facing amino-terminus of subunit e facilitates membrane potential-independent import. Instead, engineered positive charges establish a dependence of the import reaction on the electrochemical potential. Our results have two major implications. First, they reveal an unprecedented pathway of protein import into the mitochondrial inner membrane, which is mediated by TIM23. Second, they directly demonstrate the role of the membrane potential in driving the electrophoretic transport of positively charged protein segments across the inner membrane.
Collapse
Affiliation(s)
- Uma Turakhiya
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Spemann Graduate School for Biology and Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Karina von der Malsburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Vicki A M Gold
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Bernard Guiard
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France
| | - Agnieszka Chacinska
- International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Martin van der Laan
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; Medical Biochemistry and Molecular Biology, Saarland University, 66421 Homburg, Germany
| | - Raffaele Ieva
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Laboratoire de Microbiologie et Génétique Moléculaire, Centre National de la Recherche Scientifique, Université Paul Sabatier, 31077 Toulouse, France.
| |
Collapse
|
40
|
Boudoures AL, Chi M, Thompson A, Zhang W, Moley KH. The effects of voluntary exercise on oocyte quality in a diet-induced obese murine model. Reproduction 2015; 151:261-70. [PMID: 26700938 DOI: 10.1530/rep-15-0419] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/22/2015] [Indexed: 12/31/2022]
Abstract
Obesity negatively affects many aspects of the human body including reproductive function. In females, the root of the decline in fertility is linked to problems in the oocyte. Problems seen in oocytes that positively correlate with increasing BMI include changes to the metabolism, lipid accumulation, meiosis, and metaphase II (MII) spindle structure. Studies in mice indicate that dietary interventions fail to reverse these problems. How exercise affects the oocytes has not been addressed. Therefore, we hypothesized an exercise intervention would improve oocyte quality. Here we show that in a mouse model of an exercise, intervention can improve lipid metabolism in germinal vesicle (GV) stage oocytes. Oocytes significantly increased activity and transcription of the β-oxidation enzyme hydroxyacyl-coenzyme A dehydrogenase in response to exercise training only if the mice had been fed a high-fat diet (HFD). An exercise intervention also reversed the lipid accumulation seen in GV stage oocytes of HFD females. However, delays in meiosis and disorganized MII spindles remained present. Therefore, exercise is able to improve, but not reverse, damage imparted on oocytes as a result of an HFD and obesity. By utilizing an exercise intervention on an HFD, we determined only lipid content, and lipid metabolism is changed in GV oocytes. Moving forward, interventions to improve oocyte quality may need to be more targeted to the oocyte specifically. Because of the HFD-induced deficiency in β-oxidation, dietary supplementation with substrates to improve lipid utilization may be more beneficial.
Collapse
Affiliation(s)
- Anna L Boudoures
- Division of Basic Science ResearchDepartment of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, 425 South Euclid Avenue, Campus Box 8064, St Louis, Missouri 63110, USA
| | - Maggie Chi
- Division of Basic Science ResearchDepartment of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, 425 South Euclid Avenue, Campus Box 8064, St Louis, Missouri 63110, USA
| | - Alysha Thompson
- Division of Basic Science ResearchDepartment of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, 425 South Euclid Avenue, Campus Box 8064, St Louis, Missouri 63110, USA
| | - Wendy Zhang
- Division of Basic Science ResearchDepartment of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, 425 South Euclid Avenue, Campus Box 8064, St Louis, Missouri 63110, USA
| | - Kelle H Moley
- Division of Basic Science ResearchDepartment of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, 425 South Euclid Avenue, Campus Box 8064, St Louis, Missouri 63110, USA
| |
Collapse
|
41
|
Bernardi P, Rasola A, Forte M, Lippe G. The Mitochondrial Permeability Transition Pore: Channel Formation by F-ATP Synthase, Integration in Signal Transduction, and Role in Pathophysiology. Physiol Rev 2015; 95:1111-55. [PMID: 26269524 DOI: 10.1152/physrev.00001.2015] [Citation(s) in RCA: 420] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The mitochondrial permeability transition (PT) is a permeability increase of the inner mitochondrial membrane mediated by a channel, the permeability transition pore (PTP). After a brief historical introduction, we cover the key regulatory features of the PTP and provide a critical assessment of putative protein components that have been tested by genetic analysis. The discovery that under conditions of oxidative stress the F-ATP synthases of mammals, yeast, and Drosophila can be turned into Ca(2+)-dependent channels, whose electrophysiological properties match those of the corresponding PTPs, opens new perspectives to the field. We discuss structural and functional features of F-ATP synthases that may provide clues to its transition from an energy-conserving into an energy-dissipating device as well as recent advances on signal transduction to the PTP and on its role in cellular pathophysiology.
Collapse
Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
| | - Andrea Rasola
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
| | - Michael Forte
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
| | - Giovanna Lippe
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
| |
Collapse
|
42
|
Abstract
Transmembrane (TM) helices of integral membrane proteins can facilitate strong and specific noncovalent protein-protein interactions. Mutagenesis and structural analyses have revealed numerous examples in which the interaction between TM helices of single-pass membrane proteins is dependent on a GxxxG or (small)xxx(small) motif. It is therefore tempting to use the presence of these simple motifs as an indicator of TM helix interactions. In this Current Topic review, we point out that these motifs are quite common, with more than 50% of single-pass TM domains containing a (small)xxx(small) motif. However, the actual interaction strength of motif-containing helices depends strongly on sequence context and membrane properties. In addition, recent studies have revealed several GxxxG-containing TM domains that interact via alternative interfaces involving hydrophobic, polar, aromatic, or even ionizable residues that do not form recognizable motifs. In multipass membrane proteins, GxxxG motifs can be important for protein folding, and not just oligomerization. Our current knowledge thus suggests that the presence of a GxxxG motif alone is a weak predictor of protein dimerization in the membrane.
Collapse
Affiliation(s)
- Mark G Teese
- Lehrstuhl für Chemie der Biopolymere, Technische Universität München , 85354 Freising, Germany.,Center for Integrated Protein Science Munich (CIPSM) , 81377 Munich, Germany
| | - Dieter Langosch
- Lehrstuhl für Chemie der Biopolymere, Technische Universität München , 85354 Freising, Germany.,Center for Integrated Protein Science Munich (CIPSM) , 81377 Munich, Germany
| |
Collapse
|
43
|
Structural determinants of human proton-coupled folate transporter oligomerization: role of GXXXG motifs and identification of oligomeric interfaces at transmembrane domains 3 and 6. Biochem J 2015; 469:33-44. [PMID: 25877470 DOI: 10.1042/bj20150169] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/16/2015] [Indexed: 11/17/2022]
Abstract
The human proton-coupled folate transporter (hPCFT) is expressed in solid tumours and is active at pHs characterizing the tumour microenvironment. Recent attention focused on exploiting hPCFT for targeting solid tumours with novel cytotoxic anti-folates. hPCFT has 12 transmembrane domains (TMDs) and forms homo-oligomers with functional significance. The hPCFT primary sequence includes GXXXG motifs in TMD2 (G(93)XXXG(97)) and TMD4 (G(155)XXXG(159)). To investigate roles of these motifs in hPCFT function, stability and surface expression, we mutated glycine to leucine to generate single or multiple substitution mutants. Only the G93L and G159L mutants preserved substantial [(3)H]methotrexate (Mtx) transport when expressed in hPCFT-null (R1-11) HeLa cells. Transport activity of the glycine-to-leucine mutants correlated with surface hPCFT by surface biotinylation and confocal microscopy with ECFP*-tagged hPCFTs, suggesting a role for GXXXG in hPCFT stability and intracellular trafficking. When co-expressed in R1-11 cells, haemagglutinin-tagged glycine-to-leucine mutants and His10-tagged wild-type (WT) hPCFT co-associated on nickel affinity columns, suggesting that the GXXXG motifs are not directly involved in hPCFT oligomerization. This was substantiated by in situ FRET experiments with co-expressed ECFP*- and YFP-tagged hPCFT. Molecular modelling of dimeric hPCFT structures showed juxtaposed TMDs 2, 3, 4 and 6 as potential structural interfaces between monomers. hPCFT cysteine insertion mutants in TMD3 (Q136C and L137C) and TMD6 (W213C, L214C, L224C, A227C, F228C, F230C and G231C) were expressed in R1-11 cells and cross-linked with 1,6-hexanediyl bismethanethiosulfonate, confirming TMD juxtapositions. Altogether, our results imply that TMDs 3 and 6 provide critical interfaces for formation of hPCFT oligomers, which might be facilitated by the GXXXG motifs in TMD2 and TMD4.
Collapse
|
44
|
Lee J, Ding S, Walpole TB, Holding AN, Montgomery MG, Fearnley IM, Walker JE. Organization of Subunits in the Membrane Domain of the Bovine F-ATPase Revealed by Covalent Cross-linking. J Biol Chem 2015; 290:13308-20. [PMID: 25851905 PMCID: PMC4505582 DOI: 10.1074/jbc.m115.645283] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Indexed: 12/21/2022] Open
Abstract
The F-ATPase in bovine mitochondria is a membrane-bound complex of about 30 subunits of 18 different kinds. Currently, ∼85% of its structure is known. The enzyme has a membrane extrinsic catalytic domain, and a membrane intrinsic domain where the turning of the enzyme's rotor is generated from the transmembrane proton-motive force. The domains are linked by central and peripheral stalks. The central stalk and a hydrophobic ring of c-subunits in the membrane domain constitute the enzyme's rotor. The external surface of the catalytic domain and membrane subunit a are linked by the peripheral stalk, holding them static relative to the rotor. The membrane domain contains six additional subunits named ATP8, e, f, g, DAPIT (diabetes-associated protein in insulin-sensitive tissues), and 6.8PL (6.8-kDa proteolipid), each with a single predicted transmembrane α-helix, but their orientation and topography are unknown. Mutations in ATP8 uncouple the enzyme and interfere with its assembly, but its roles and the roles of the other five subunits are largely unknown. We have reacted accessible amino groups in the enzyme with bifunctional cross-linking agents and identified the linked residues. Cross-links involving the supernumerary subunits, where the structures are not known, show that the C terminus of ATP8 extends ∼70 Å from the membrane into the peripheral stalk and that the N termini of the other supernumerary subunits are on the same side of the membrane, probably in the mitochondrial matrix. These experiments contribute significantly toward building up a complete structural picture of the F-ATPase.
Collapse
Affiliation(s)
- Jennifer Lee
- From the The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom and
| | - ShuJing Ding
- From the The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom and
| | - Thomas B Walpole
- From the The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom and
| | - Andrew N Holding
- The Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Martin G Montgomery
- From the The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom and
| | - Ian M Fearnley
- From the The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom and
| | - John E Walker
- From the The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom and
| |
Collapse
|
45
|
Bonora M, Wieckowski MR, Chinopoulos C, Kepp O, Kroemer G, Galluzzi L, Pinton P. Molecular mechanisms of cell death: central implication of ATP synthase in mitochondrial permeability transition. Oncogene 2015; 34:1475-86. [PMID: 24727893 DOI: 10.1038/onc.2014.96] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 02/20/2014] [Accepted: 02/27/2014] [Indexed: 12/14/2022]
Abstract
The term mitochondrial permeability transition (MPT) is commonly used to indicate an abrupt increase in the permeability of the inner mitochondrial membrane to low molecular weight solutes. Widespread MPT has catastrophic consequences for the cell, de facto marking the boundary between cellular life and death. MPT results indeed in the structural and functional collapse of mitochondria, an event that commits cells to suicide via regulated necrosis or apoptosis. MPT has a central role in the etiology of both acute and chronic diseases characterized by the loss of post-mitotic cells. Moreover, cancer cells are often relatively insensitive to the induction of MPT, underlying their increased resistance to potentially lethal cues. Thus, intense efforts have been dedicated not only at the understanding of MPT in mechanistic terms, but also at the development of pharmacological MPT modulators. In this setting, multiple mitochondrial and extramitochondrial proteins have been suspected to critically regulate the MPT. So far, however, only peptidylprolyl isomerase F (best known as cyclophilin D) appears to constitute a key component of the so-called permeability transition pore complex (PTPC), the supramolecular entity that is believed to mediate MPT. Here, after reviewing the structural and functional features of the PTPC, we summarize recent findings suggesting that another of its core components is represented by the c subunit of mitochondrial ATP synthase.
Collapse
Affiliation(s)
- M Bonora
- Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Interdisciplinary Centre for the Study of Inflammation (ICSI), University of Ferrara, Ferrara, Italy
| | - M R Wieckowski
- Department of Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - C Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - O Kepp
- 1] Equipe 11 labelisée par la Ligue Nationale contre le cancer, INSERM U1138, Centre de Recherche des Cordeliers, Paris, France [2] Université Paris Descartes/Paris 5, Sorbonne Paris Cité, Paris, France [3] Metabolomics and Cell Biology platforms, Gustave Roussy Comprehensive Cancer Center, Villejuif, France
| | - G Kroemer
- 1] Equipe 11 labelisée par la Ligue Nationale contre le cancer, INSERM U1138, Centre de Recherche des Cordeliers, Paris, France [2] Université Paris Descartes/Paris 5, Sorbonne Paris Cité, Paris, France [3] Metabolomics and Cell Biology platforms, Gustave Roussy Comprehensive Cancer Center, Villejuif, France [4] Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | - L Galluzzi
- 1] Equipe 11 labelisée par la Ligue Nationale contre le cancer, INSERM U1138, Centre de Recherche des Cordeliers, Paris, France [2] Université Paris Descartes/Paris 5, Sorbonne Paris Cité, Paris, France [3] Gustave Roussy Comprehensive Cancer Center, Villejuif, France
| | - P Pinton
- Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Interdisciplinary Centre for the Study of Inflammation (ICSI), University of Ferrara, Ferrara, Italy
| |
Collapse
|
46
|
Lytovchenko O, Naumenko N, Oeljeklaus S, Schmidt B, von der Malsburg K, Deckers M, Warscheid B, van der Laan M, Rehling P. The INA complex facilitates assembly of the peripheral stalk of the mitochondrial F1Fo-ATP synthase. EMBO J 2014; 33:1624-38. [PMID: 24942160 DOI: 10.15252/embj.201488076] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mitochondrial F1Fo-ATP synthase generates the bulk of cellular ATP. This molecular machine assembles from nuclear- and mitochondria-encoded subunits. Whereas chaperones for formation of the matrix-exposed hexameric F1-ATPase core domain have been identified, insight into how the nuclear-encoded F1-domain assembles with the membrane-embedded Fo-region is lacking. Here we identified the INA complex (INAC) in the inner membrane of mitochondria as an assembly factor involved in this process. Ina22 and Ina17 are INAC constituents that physically associate with the F1-module and peripheral stalk, but not with the assembled F1Fo-ATP synthase. Our analyses show that loss of Ina22 and Ina17 specifically impairs formation of the peripheral stalk that connects the catalytic F1-module to the membrane embedded Fo-domain. We conclude that INAC represents a matrix-exposed inner membrane protein complex that facilitates peripheral stalk assembly and thus promotes a key step in the biogenesis of mitochondrial F1Fo-ATP synthase.
Collapse
Affiliation(s)
- Oleksandr Lytovchenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Nataliia Naumenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Silke Oeljeklaus
- Department of Biochemistry and Functional Proteomics, Faculty for Biology, University of Freiburg, Freiburg, Germany BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Bernhard Schmidt
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Karina von der Malsburg
- Institute for Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, Freiburg, Germany
| | - Markus Deckers
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Bettina Warscheid
- Department of Biochemistry and Functional Proteomics, Faculty for Biology, University of Freiburg, Freiburg, Germany BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Martin van der Laan
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany Institute for Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, Freiburg, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| |
Collapse
|
47
|
Kabala AM, Lasserre JP, Ackerman SH, di Rago JP, Kucharczyk R. Defining the impact on yeast ATP synthase of two pathogenic human mitochondrial DNA mutations, T9185C and T9191C. Biochimie 2013; 100:200-6. [PMID: 24316278 DOI: 10.1016/j.biochi.2013.11.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 11/25/2013] [Indexed: 12/18/2022]
Abstract
Mutations in the human mitochondrial ATP6 gene encoding ATP synthase subunit a/6 (referred to as Atp6p in yeast) are at the base of neurodegenerative disorders like Neurogenic Ataxia and Retinitis Pigmentosa (NARP), Leigh syndrome (LS), Charcot-Marie-Tooth (CMT), and ataxia telangiectasia. In previous studies, using the yeast Saccharomyces cerevisiae as a model we were able to better define how several of these mutations impact the ATP synthase. Here we report the construction of yeast models of two other ATP6 pathogenic mutations, T9185C and T9191C. The first one was reported as conferring a mild, sometimes reversible, CMT clinical phenotype; the second one has been described in a patient presenting with severe LS. We found that an equivalent of the T9185C mutation partially impaired the functioning of yeast ATP synthase, with only a 30% deficit in mitochondrial ATP production. An equivalent of the mutation T9191C had much more severe effects, with a nearly complete block in yeast Atp6p assembly and an >95% drop in the rate of ATP synthesis. These findings provide a molecular basis for the relative severities of the diseases induced by T9185C and T9191C.
Collapse
Affiliation(s)
- Anna Magdalena Kabala
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland; Institut de Biochimie et Génétique Cellulaires, CNRS UMR5095, Université Bordeaux Segalen, 1 Rue Camille Saint-Saëns, Bordeaux 33077 cedex, France
| | - Jean-Paul Lasserre
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR5095, Université Bordeaux Segalen, 1 Rue Camille Saint-Saëns, Bordeaux 33077 cedex, France
| | - Sharon H Ackerman
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Jean-Paul di Rago
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR5095, Université Bordeaux Segalen, 1 Rue Camille Saint-Saëns, Bordeaux 33077 cedex, France
| | - Roza Kucharczyk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
| |
Collapse
|
48
|
Habersetzer J, Larrieu I, Priault M, Salin B, Rossignol R, Brèthes D, Paumard P. Human F1F0 ATP synthase, mitochondrial ultrastructure and OXPHOS impairment: a (super-)complex matter? PLoS One 2013; 8:e75429. [PMID: 24098383 PMCID: PMC3788808 DOI: 10.1371/journal.pone.0075429] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 08/14/2013] [Indexed: 01/18/2023] Open
Abstract
Mitochondrial morphogenesis is a key process of cell physiology. It is essential for the proper function of this double membrane-delimited organelle, as it ensures the packing of the inner membrane in a very ordered pattern called cristae. In yeast, the mitochondrial ATP synthase is able to form dimers that can assemble into oligomers. Two subunits (e and g) are involved in this supramolecular organization. Deletion of the genes encoding these subunits has no effect on the ATP synthase monomer assembly or activity and only affects its dimerization and oligomerization. Concomitantly, the absence of subunits e and g and thus, of ATP synthase supercomplexes, promotes the modification of mitochondrial ultrastructure suggesting that ATP synthase oligomerization is involved in cristae morphogenesis. We report here that in mammalian cells in culture, the shRNA-mediated down-regulation of subunits e and g affects the stability of ATP synthase and results in a 50% decrease of the available functional enzyme. Comparable to what was shown in yeast, when subunits e and g expression are repressed, ATP synthase dimers and oligomers are less abundant when assayed by native electrophoresis. Unexpectedly, mammalian ATP synthase dimerization/oligomerization impairment has functional consequences on the respiratory chain leading to a decrease in OXPHOS activity. Finally these structural and functional alterations of the ATP synthase have a strong impact on the organelle itself leading to the fission of the mitochondrial network and the disorganization of mitochondrial ultrastructure. Unlike what was shown in yeast, the impairment of the ATP synthase oligomerization process drastically affects mitochondrial ATP production. Thus we propose that mutations or deletions of genes encoding subunits e and g may have physiopathological implications.
Collapse
Affiliation(s)
- Johann Habersetzer
- Laboratoire des Systèmes Transducteurs d'Energie et Morphologie Mitochondriale, Université Bordeaux Segalen, IBGC, UMR 5095, Bordeaux, France ; CNRS, IBGC, UMR 5095, Bordeaux, France
| | | | | | | | | | | | | |
Collapse
|
49
|
Frey AJ, Ibrahim S, Gleim S, Hwa J, Smyth EM. Biased suppression of TP homodimerization and signaling through disruption of a TM GxxxGxxxL helical interaction motif. J Lipid Res 2013; 54:1678-1690. [PMID: 23493750 DOI: 10.1194/jlr.m036673] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thromboxane A2 (TXA2) contributes to cardiovascular disease (CVD) by activating platelets and vascular constriction and proliferation. Despite their preclinical efficacy, pharmacological antagonists of the TXA2 receptor (TP), a G protein-coupled receptor, have not been clinically successful, raising interest in novel approaches to modifying TP function. We determined that disruption of a GxxxGxxxL helical interaction motif in the human TP's (α isoform) fifth transmembrane (TM) domain suppressed TP agonist-induced Gq signaling and TPα homodimerization, but not its cell surface expression, ligand affinity, or Gq association. Heterodimerization of TPα with the functionally opposing prostacyclin receptor (IP) shifts TPα to signal via the IP-Gs cascade contributing to prostacyclin's restraint of TXA2 function. Interestingly, disruption of the TPα-TM5 GxxxGxxxL motif did not modify either IP-TPα heterodimerization or its Gs-cAMP signaling. Our study indicates that distinct regions of the TPα receptor direct its homo- and heterodimerization and that homodimerization is necessary for normal TPα-Gq activation. Targeting the TPα-TM5 GxxxGxxxL domain may allow development of biased TPα homodimer antagonists that avoid suppression of IP-TPα heterodimer function. Such novel therapeutics may prove superior in CVD compared with nonselective suppression of all TP functions with TXA2 biosynthesis inhibitors or TP antagonists.
Collapse
Affiliation(s)
- Alexander J Frey
- University of Pennsylvania Institute for Translational Medicine and Therapeutics, Smilow Center for Translational Research, Philadelphia, PA; and
| | - Salam Ibrahim
- University of Pennsylvania Institute for Translational Medicine and Therapeutics, Smilow Center for Translational Research, Philadelphia, PA; and
| | - Scott Gleim
- Yale University School of Medicine, Cardiovascular Research Center, Department of Internal Medicine, Section of Cardiovascular Medicine, New Haven, CT
| | - John Hwa
- Yale University School of Medicine, Cardiovascular Research Center, Department of Internal Medicine, Section of Cardiovascular Medicine, New Haven, CT
| | - Emer M Smyth
- University of Pennsylvania Institute for Translational Medicine and Therapeutics, Smilow Center for Translational Research, Philadelphia, PA; and.
| |
Collapse
|
50
|
ATP synthase oligomerization: From the enzyme models to the mitochondrial morphology. Int J Biochem Cell Biol 2013; 45:99-105. [DOI: 10.1016/j.biocel.2012.05.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 05/18/2012] [Accepted: 05/24/2012] [Indexed: 01/03/2023]
|