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Franco LVR, Su CH, Simas Teixeira L, Almeida Clarck Chagas J, Barros MH, Tzagoloff A. Allotopic expression of COX6 elucidates Atco-driven co-assembly of cytochrome oxidase and ATP synthase. Life Sci Alliance 2023; 6:e202301965. [PMID: 37604582 PMCID: PMC10442929 DOI: 10.26508/lsa.202301965] [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: 02/01/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/23/2023] Open
Abstract
The Cox6 subunit of Saccharomyces cerevisiae cytochrome oxidase (COX) and the Atp9 subunit of the ATP synthase are encoded in nuclear and mitochondrial DNA, respectively. The two proteins interact to form Atco complexes that serve as the source of Atp9 for ATP synthase assembly. To determine if Atco is also a precursor of COX, we pulse-labeled Cox6 in isolated mitochondria of a cox6 nuclear mutant with COX6 in mitochondrial DNA. Only a small fraction of the newly translated Cox6 was found to be present in Atco, which can explain the low concentration of COX and poor complementation of the cox6 mutation by the allotopic gene. This and other pieces of evidence presented in this study indicate that Atco is an obligatory source of Cox6 for COX biogenesis. Together with our finding that atp9 mutants fail to assemble COX, we propose a regulatory model in which Atco unidirectionally couples the biogenesis of COX to that of the ATP synthase to maintain a proper ratio of these two complexes of oxidative phosphorylation.
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Affiliation(s)
- Leticia Veloso R Franco
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
- https://ror.org/036rp1748 Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brasil
| | - Chen-Hsien Su
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Lorisa Simas Teixeira
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
| | | | - Mario Henrique Barros
- https://ror.org/036rp1748 Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brasil
| | - Alexander Tzagoloff
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
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Franco LVR, Su CH, Burnett J, Teixeira LS, Tzagoloff A. Atco, a yeast mitochondrial complex of Atp9 and Cox6, is an assembly intermediate of the ATP synthase. PLoS One 2020; 15:e0233177. [PMID: 32413073 PMCID: PMC7228087 DOI: 10.1371/journal.pone.0233177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/29/2020] [Indexed: 02/05/2023] Open
Abstract
Mitochondrial oxidative phosphorylation (oxphos) is the process by which the ATP synthase conserves the energy released during the oxidation of different nutrients as ATP. The yeast ATP synthase consists of three assembly modules, one of which is a ring consisting of 10 copies of the Atp9 subunit. We previously reported the existence in yeast mitochondria of high molecular weight complexes composed of mitochondrially encoded Atp9 and of Cox6, an imported structural subunit of cytochrome oxidase (COX). Pulse-chase experiments indicated a correlation between the loss of newly translated Atp9 complexed to Cox6 and an increase of newly formed Atp9 ring, but did not exclude the possibility of an alternate source of Atp9 for ring formation. Here we have extended studies on the functions and structure of this complex, referred to as Atco. We show that Atco is the exclusive source of Atp9 for the ATP synthase assembly. Pulse-chase experiments show that newly translated Atp9, present in Atco, is converted to a ring, which is incorporated into the ATP synthase with kinetics characteristic of a precursor-product relationship. Even though Atco does not contain the ring form of Atp9, cross-linking experiments indicate that it is oligomeric and that the inter-subunit interactions are similar to those of the bona fide ring. We propose that, by providing Atp9 for biogenesis of ATP synthase, Atco complexes free Cox6 for assembly of COX. This suggests that Atco complexes may play a role in coordinating assembly and maintaining proper stoichiometry of the two oxphos enzymes
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Affiliation(s)
- Leticia Veloso Ribeiro Franco
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
- Department of Microbiology, University of São Paulo, São Paulo, SP, Brazil
| | - Chen-Hsien Su
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
| | - Julia Burnett
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
| | - Lorisa Simas Teixeira
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
| | - Alexander Tzagoloff
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
- * E-mail:
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Chen XJ, Clark-Walker GD. The petite mutation in yeasts: 50 years on. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 194:197-238. [PMID: 10494627 DOI: 10.1016/s0074-7696(08)62397-9] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Fifty years ago it was reported that baker's yeast, Saccharomyces cerevisiae, can form "petite colonie" mutants when treated with the DNA-targeting drug acriflavin. To mark the jubilee of studies on cytoplasmic inheritance, a review of the early work will be presented together with some observations on current developments. The primary emphasis is to address the questions of how loss of mtDNA leads to lethality (rho 0-lethality) in petite-negative yeasts and how S. cerevisiae tolerates elimination of mtDNA. Recent investigation have revealed that rho 0-lethality can be suppressed by specific mutations in the alpha, beta, and gamma subunits of the mitochondrial F1-ATPase of the petite-negative yeast Kluyveromyces lactis and by the nuclear ptp alleles in Schizosaccharomyces pombe. In contrast, inactivation of genes coding for F1-ATPase alpha and beta subunits and disruption of AAC2, PGS1/PEL1, and YME1 genes in S. cerevisiae convert this petite-positive yeast into a petite-negative form. Studies on nuclear genes affecting dependence on mtDNA have provided important insight into the functions provided by the mitochondrial genome and the maintenance of structural and functional integrity of the mitochondrial inner membrane.
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Affiliation(s)
- X J Chen
- Molecular and Cellular Genetics Group, Research School of Biological Sciences, Australian National University, ACT, Australia
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4
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Herrmann JM, Stuart RA, Craig EA, Neupert W. Mitochondrial heat shock protein 70, a molecular chaperone for proteins encoded by mitochondrial DNA. J Biophys Biochem Cytol 1994; 127:893-902. [PMID: 7962074 PMCID: PMC2200046 DOI: 10.1083/jcb.127.4.893] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Mitochondrial heat shock protein 70 (mt-Hsp70) has been shown to play an important role in facilitating import into, as well as folding and assembly of nuclear-encoded proteins in the mitochondrial matrix. Here, we describe a role for mt-Hsp70 in chaperoning proteins encoded by mitochondrial DNA and synthesized within mitochondria. The availability of mt-Hsp70 function influences the pattern of proteins synthesized in mitochondria of yeast both in vivo and in vitro. In particular, we show that mt-Hsp70 acts in maintaining the var1 protein, the only mitochondrially encoded subunit of mitochondrial ribosomes, in an assembly competent state, especially under heat stress conditions. Furthermore, mt-Hsp70 helps to facilitate assembly of mitochondrially encoded subunits of the ATP synthase complex. By interacting with the ATP-ase 9 oligomer, mt-Hsp70 promotes assembly of ATP-ase 6, and thereby protects the latter protein from proteolytic degradation. Thus mt-Hsp70 by acting as a chaperone for proteins encoded by the mitochondrial DNA, has a critical role in the assembly of supra-molecular complexes.
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Affiliation(s)
- J M Herrmann
- Institut für Physiologische Chemie, Universität München, Germany
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5
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Hermolin J, Fillingame RH. H+-ATPase activity of Escherichia coli F1F0 is blocked after reaction of dicyclohexylcarbodiimide with a single proteolipid (subunit c) of the F0 complex. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)84937-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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6
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Schneider E, Altendorf K. Bacterial adenosine 5'-triphosphate synthase (F1F0): purification and reconstitution of F0 complexes and biochemical and functional characterization of their subunits. Microbiol Rev 1987; 51:477-97. [PMID: 2893973 PMCID: PMC373128 DOI: 10.1128/mr.51.4.477-497.1987] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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7
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Buss WC, Jaramillo E, Piatt MK. Coordinate increases and decreases in mitochondrial RNA and ATP syntheses produced by propranolol and rifampicin. Biochem Pharmacol 1987; 36:3293-7. [PMID: 2444231 DOI: 10.1016/0006-2952(87)90647-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A variety of compounds were examined for their capacity to alter RNA synthesis in isolated rat cardiac and hepatic mitochondria. The beta-adrenergic blocking agents propranolol and butoxamine, and the antiarrhythmic agent quinidine, produced a concentration-dependent stimulation of RNA synthesis in cardiac and hepatic mitochondria. In contrast, the antitubercular antibiotic rifampicin produced a concentration-dependent inhibition of RNA synthesis in cardiac and hepatic mitochondria. Propranolol, as a representative compound which stimulated RNA synthesis, was also found to stimulate ATP synthesis in isolated mitochondria, whereas rifampicin inhibited ATP synthesis. Coordinate increases and decreases in RNA and ATP syntheses suggest that agents which stimulate or inhibit RNA synthesis may rapidly alter ATP synthesis. This finding is consistent with the rapid turn-over of mitochondrial RNA with a messenger function (1.4 and 3.3 min in isolated rat cardiac and hepatic mitochondria), and it suggests that mitochondrial RNA must continue to be synthesized to maintain inner membrane systems required for ATP synthesis. Stimulation of RNA and ATP syntheses by propranolol through membrane stabilization or other actions represents a heretofore unrecognized action of propranolol which may contribute to its beneficial therapeutic effects.
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Affiliation(s)
- W C Buss
- Department of Pharmacology, University of New Mexico, School of Medicine, Albuquerque 87131
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8
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Ota A, Morishita H. Some properties of ATPase activity in the intact cells of yeast Saccharomycopsis fibuligera. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0020-711x(86)90238-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Abstract
Polyacrylamide gel electrophoresis (PAGE) of partially purified ATPase from vacuoles of Saccharomyces carlsbergensis under non-dissociating conditions revealed 3 bands with ATPase activity. Further PAGE in dissociating conditions showed the similarity in composition of these 3 ATPase preparations. They were assumed to contain the same vacuolar ATPase exhibiting, however, different electrophoretic mobility due to the formation of enzyme complexes with different proteins and phospholipids. The ATPase preparation with the highest electrophoretic mobility contained 6 subunits of 75, 62, 16, 14, 12 and 9 kDa. Inhibitors of vacuolar ATPase [14C]DCCD and [14C]NEM bound to a 9 kDa polypeptide, while [14C]DES associated with a polypeptide of 75 kDa. A partially purified preparation of the vacuolar ATPase was not phosphorylated by [gamma-32P]ATP under conditions when plasma membrane ATPase formed a phosphorylated intermediate. Our results show that vacuolar H+-ATPase consists of several polypeptides, does not form the phosphorylated intermediate, and evidently represents a new type of H+-ATPase of yeast.
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10
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Ota A. Properties of ATPase activity in intact vegetative cells and sporulating cells of yeast Saccharomyces cerevisiae. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1985; 17:775-80. [PMID: 2932354 DOI: 10.1016/0020-711x(85)90263-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The properties of ATPase activity were examined in the intact cells of yeast. The activity was stimulated by Mg2+, Mn2+ and Co2+. The activity was inhibited by NaN3 and by high concentrations of NaF, NaVO3 and PCMB. Optimal pH for the activity was approximately 8. The maximum value of the activity was obtained in the cells at the early stationary phase and it decreased in 3 hr after transfer to sporulation medium.
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Orian JM, Hadikusumo RG, Marzuki S, Linnane AW. Biogenesis of mitochondria: defective yeast H+-ATPase assembled in the absence of mitochondrial protein synthesis is membrane associated. J Bioenerg Biomembr 1984; 16:561-81. [PMID: 6242247 DOI: 10.1007/bf00743246] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We have investigated the extent to which the assembly of the cytoplasmically synthesized subunits of the H+-ATPase can proceed in a mtDNA-less (rho degree) strain of yeast, which is not capable of mitochondrial protein synthesis. Three of the membrane sector proteins of the yeast H+-ATPase are synthesized in the mitochondria, and it is important to determine whether the presence of these subunits is essential for the assembly of the imported subunits to the inner mitochondrial membrane. A monoclonal antibody against the cytoplasmically synthesized beta-subunit of the H+-ATPase was used to immunoprecipitate the assembled subunits of the enzyme complex. Our results indicate that the imported subunits of the H+-ATPase can be assembled in this mutant, into a defective complex which could be shown to be associated with the mitochondrial membrane by the analysis of the Arrhenius kinetics of the mutant mitochondrial ATPase activity.
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12
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Vassarotti A, Boutry M, Colson AM, Goffeau A. Independent loci for the structural genes of the yeast mitochondrial alpha and beta ATPase subunits. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)43224-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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13
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Boutry M, Vassarotti A, Ghislain M, Douglas M, Goffeau A. Isolation of the structural genes for the alpha and beta subunits of the mitochondrial ATPase from the fission yeast Schizosaccharomyces pombe. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)43223-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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14
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Amuro N, Okada S, Goto Y, Shukuya R. Synthesis of cytochrome c oxidase in the liver of Rana catesbeiana tadpole treated with griseofulvin. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 781:14-7. [PMID: 6320891 DOI: 10.1016/0167-4781(84)90118-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effect of griseofulvin treatment on the synthesis of cytochrome c oxidase was studied with the liver of the tadpole, Rana catesbeiana. (1) In the liver of tadpole treated with griseofulvin, a ferrochelatase inhibitor, the synthesis of heme a, but not cytochrome c oxidase protein, is inhibited. (2) The apocytochrome c oxidase which is formed in the liver of tadpole treated with griseofulvin is converted to the active holoenzyme by exogenously added heme a.
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15
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Finzi E, Beattie DS. The stimulation of yeast mitochondrial protein synthesis by low molecular weight cytoplasmic factors: requirement for intact mitochondria and lack of effect by folate derivatives. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1984; 16:177-82. [PMID: 6368283 DOI: 10.1016/0020-711x(84)90069-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Protein synthesis by GTP-supplemented yeast mitochondria is stimulated by a fraction of molecular weight less than 2,000 isolated from yeast high-speed supernatant (S-150). The low molecular weight fraction works independently of the respiratory chain as the stimulation effect is not cyanide-sensitive. Stimulation of mitochondrial protein synthesis by cytoplasmic factors is dependent upon the method of mitochondrial isolation. The low molecular weight stimulatory factor(s) are not reduced folate derivatives which supply formyl groups required for initiation of mitochondrial protein synthesis.
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16
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Lin CI, Ohnishi T, Clejan L, Beattie DS. The presence of the iron-sulfur protein (subunit V) of complex III in mitochondria of heme-deficient yeast cells lacking iron-sulfur clusters detectable by electron paramagnetic resonance. EUROPEAN JOURNAL OF BIOCHEMISTRY 1983; 137:179-83. [PMID: 6317381 DOI: 10.1111/j.1432-1033.1983.tb07812.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The presence of subunit V, the iron-sulfur protein, of complex III has been demonstrated in mitochondria from a mutant of Saccharomyces cerevisiae which lacks 5-aminolevulinic acid synthase and, hence, is devoid of heme. The mature form (24 K Da) of the iron-sulfur protein was observed in equal amounts in the heme-deficient and heme-sufficient cells with antiserum against subunit V and either the sensitive immuno-transfer technique or immunoprecipitation from dodecylsulfate-solubilized mitochondria. In addition, a slight shoulder with a molecular mass 1.5 kDa larger than the mature form was present in mitochondria from the heme-deficient cells. Electron paramagnetic resonance spectroscopy revealed the absence of iron-sulfur signals due to clusters S-1, S-2 and S-3 of succinate dehydrogenase or to Rieske's iron-sulfur cluster of complex III in mitochondria from the heme-deficient cells. The lack of iron-sulfur centers in these cells may be a consequence of the absence of sulfite reductase in the cells without heme.
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17
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Boutry M, Briquet M, Goffeau A. The alpha subunit of a plant mitochondrial F1-ATPase is translated in mitochondria. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32084-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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18
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19
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Marzuki S, Linnane AW. Synthesis and assembly of subunit 6 of the mitochondrial ATPase in yeast. Methods Enzymol 1983; 97:294-305. [PMID: 6228710 DOI: 10.1016/0076-6879(83)97141-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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20
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Lin CI, Gollub EG, Beattie DS. Synthesis of the proteins of complex III of the mitochondrial respiratory chain in heme-deficient cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 128:309-13. [PMID: 6295756 DOI: 10.1111/j.1432-1033.1982.tb06966.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The presence of several proteins of complex III of the respiratory chain has been demonstrated in mitochondria from a mutant of Saccharomyces cerevisiae lacking 5-aminolevulinic acid synthase and, hence, devoid of heme. The two 'core' proteins, apocytochrome b and the iron-sulfur protein, were observed in equal amounts in the heme-deficient and heme-sufficient cells with antiserum against complex III and the sensitive immuno-transfer technique. In addition, three other bands were detected with the complex III antiserum in the mitochondria from the cells lacking heme. One of these has a molecular weight similar to that reported for a precursor form of cytochrome c1. By contrast, when mitochondria from the heme-deficient cells were solubilized with mild detergents and treated with the complex III antiserum, almost no immunoprecipitation was obtained above that obtained with control serum. The presence of only one major labeled band with a molecular weight similar to subunit I was observed after gel electrophoresis. These results suggest that heme may be necessary for proper processing of the apoprotein of cytochrome c1 and for the assembly into the membrane of the subunits of complex III, rather than for the synthesis of the proteins.
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21
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Amuro N, Goto Y, Shukuya R. Biosynthesis of cytochrome c oxidase by isolated liver mitochondria of the tadpole, Rana catesbeiana. FEBS Lett 1982; 148:59-62. [PMID: 6293878 DOI: 10.1016/0014-5793(82)81242-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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22
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Goto Y, Amuro N, Shukuya R. Cytochrome c oxidase from the liver of bullfrog, Rana catesbeiana and change in its turnover rate during metamorphosis. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 719:102-9. [PMID: 6293583 DOI: 10.1016/0304-4165(82)90313-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
1. Cytochrome c oxidase was purified from the liver mitochondria of bullfrog (Rana catesbeiana). The heme a content of the purified enzyme was 13.5 nmol per mg protein. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate revealed that the enzyme protein was composed of nine polypeptide subunits having molecular weights of 42000, 27000, 25000, 20000, 15000, 13000, 8600, 5400 and 3600. The purified enzyme from the adult frog was immunological identified with that from the tadpole. 2. The ratio of synthesis and degradation of cytochrome c oxidase were 5.2- and 2.0-times higher at metamorphic climax than at premetamorphic stage, respectively. The amount of the enzyme in the liver was highest at metamorphic climax.
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Arselin de Châteaubodeau G, Guérin M. Cardiolipin-protein interactions in the phosphate binding activity of a proteolipid from yeast mitochondria. Action of phospholipases A2 and C and of cations. Biochimie 1982; 64:883-90. [PMID: 6817819 DOI: 10.1016/s0300-9084(82)80350-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A proteolipid able to bind phosphate has been isolated from yeast mitochondria. During the purification the active protein was always associated with cardiolipin. The cardiolipin requirement for the phosphate binding activity of this proteolipid has been studied using controlled lipid depletion with two phospholipases A2 and with phospholipase C. Only phospholipase A2 from pig pancreas, that deacylated cardiolipin, promoted inhibition of the proteolipid activity (but never more than 70 per cent). Phospholipase A2 from snake venom did not inhibit the binding activity of the proteolipid. Using thin layer chromatography with two sequential solvents it was possible to separate two cardiolipin subspecies; one of them was preferentially hydrolysed by phospholipase C of Bacillus cereus, leading to inhibition of the proteolipid activity. Ca2+ complexed to cardiolipin stoichiometrically (1-1) inhibited the proteolipid activity. This effect could be due to a conformational change in the cardiolipin-protein association.
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Keyhani E, Keyhani J. Biochemical characterization of the OXI mutants of the yeast Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 717:355-68. [PMID: 6288115 DOI: 10.1016/0304-4165(82)90190-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OXI mutants in Saccharomyces cerevisiae lack a functional cytochrome c oxidase. Wild type and OXI mutants were grown in the presence of radioactive delta-amino[14C]levulinic acid, a precursor of porphyrin and heme, and [3H]mevalonic acid, a precursor of the alkyl side-chain of heme a. SDS polyacrylamide gel electrophoresis of the delipidated mitochondria showed that delta-amino[14C]levulinic acid was distributed into three bands migrating in the regions of Mr 28 000, 13 500, and 10 000, while [3H]mevalonic acid was found in a single band with apparent Mr of 10 000. The immunoprecipitates obtained by incubating the solubilized mitochondria of any OXI mutant with antibodies against cytochrome c oxidase, showed, after delipidation, a high specific radioactivity due to delta-amino[14C]levulinic acid and [3H]mevalonic acid. This suggested that a prophyrin a was present in all these OXI mutants. HCl fractionation confirmed the presence of porphyrin a in the apooxidase of these mutants. Atomic absorption spectra of the immunoprecipitate of cytochrome c oxidase showed that copper was not detectable in the mutant OXI IIIa which lacked subunit 1, but was present in the mutant OXI IIIb, which exhibited a minor alteration in the electrophoretic mobility of subunit 1. In OXI I and II mutants there was a 50% reduction in the amount of copper in the immunoprecipitated cytochrome c oxidase. These observations may be interpretable as follows: (1) alterations in polypeptide biosynthesis due to the OXI mutations lead to an improper configuration of cytochrome c oxidase, so that ferrochelatase cannot transfer iron into porphyrin a; (2) subunit I is the binding site for copper, but the mutations in subunits II and III alter the binding site of one of the two copper atoms in subunit I.
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Boutry M, Goffeau A. Alterations of the alpha or beta subunits of the mitochondrial ATPase in yeast mutants. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 125:471-7. [PMID: 6214396 DOI: 10.1111/j.1432-1033.1982.tb06707.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Among 979 non-glycerol growers of the yeast Schizosaccharomyces pombe, 40 strains were found to be deficient in the mitochondrial ATPase activity. Three of them exhibited an alteration in either the alpha or beta subunits of the F1ATPase. The alpha subunit was not immunodetected in the A23/13 mutant. The beta subunit was not immuno-detected in the B59/1 mutant. The existence of these two mutants shows that the alpha and beta subunits can be present independently of each other in the inner mitochondrial membrane. The beta subunit of the mutant F25/28 had a slower electrophoretic mobility than that of the wild-type beta subunit. This phenotype indicates abnormal processing or specific modification of the beta subunit. All mutants showed reduced activities of the NADH-cytochrome c reductase and of the cytochrome oxidase and a decreased synthesis of cytochrome aa3 and cytochrome b. This pleiotropic phenotype appears to result from specific modifications in the mitochondrial protein synthesis. The mitochondrial synthesis of four polypeptides (three cytochrome oxidase and one cytochrome b subunits) was markedly decreased or absent while three new polypeptides (Mr = 54000, 20000 and 15000) were detected in all the mutants analysed. This observation suggests that a functional F1ATPase is necessary for the correct synthesis and/or assembly of the mitochondrially made components of the cytochrome oxidase and cytochrome b complexes.
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27
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Capeillere-Blandin C, Ohnishi T. Investigation of the iron-sulfur clusters in some mitochondrial mutants of Saccharomyces cerevisiae. A possible correlation between Rieske's iron-sulfur cluster and cytochrome b. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 122:403-13. [PMID: 6277636 DOI: 10.1111/j.1432-1033.1982.tb05895.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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28
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Lipsky N, Pedersen P. Perturbation by clofibrate of mitochondrial levels in animal cells. Implications for a model of mitochondrial genesis. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(19)68218-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Somlo M, Cosson J, Clavilier L, Krupa M, Laporte I. Identity problems concerning subunits of the membrane factor of the mitochondrial ATPase of Saccharomyces cerevisiae. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 122:369-74. [PMID: 6460623 DOI: 10.1111/j.1432-1033.1982.tb05890.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
As confirmed by fingerprint analysis, high-resolution acrylamide gel electrophoresis identifies subunits of the mitochondrial ATPase complex directly at the level of Coomassie-blue-stained yeast mitochondria. Using this technique, the following results were obtained. 1. Three classes of subunits have been found in the ATPase complex. (a) The classical F1 peptides of cytoribosomal origin (57, 53 and 30.5 kDa). (b) Two peptides of mitoribosomal origin with high cycloheximide-resistant label: one of 7.8 kDa (the OLII gene product), the second of 20 kDa (the OLI2 gene product). Neither of these peptides is readily stained by Coomassie blue in the purified ATPase complex, (c) Four Coomassie-blue-stained peptides (27.5, 25, 23.5 and 22.5 kDa), the last one being subunit 6, which (like class b) functionally qualify as subunits of the membrane factor of the ATPase complex. As shown by labeling with 35SO24- and 3H-labeled amino acids, their biosynthesis is only very slightly cycloheximide-resistant, although it is submitted to coordinate regulation distinct from that of the class F1 peptides. 2. Consequently it was shown that the OLI2 gene product, a 20-kDa peptide with high cycloheximide-resistant label, which was generally taken to be 'subunit 6' of the ATPase, is not in fact identical to this peptide.
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30
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Finzi E, Rinehart RW, Sperling M, Beattie DS. Control of yeast and mammalian mitochondrial protein synthesis by cytoplasmic factors. FEBS Lett 1982; 137:314-8. [PMID: 7037458 DOI: 10.1016/0014-5793(82)80374-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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31
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Edwards SW, Evans JB, Lloyd D. The mitochondrial adenosine triphosphatase of Acanthamoeba castellanii. Partial characterization and changes in activity during exponential growth. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1982; 71:495-500. [PMID: 6121661 DOI: 10.1016/0305-0491(82)90414-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
1. The mitochondrial adenosine triphosphatase (ATPase) of Acanthamoeba castellanii is Mg2+-requiring (optimum cation: ATP ratio of 1.5) and has two pH optima of activity (at pH 6.6 and 8.1). 2. ATPase activity of submitochondrial particles is effectively inhibited by twelve different inhibitors of energy conservation suggesting similarities in inhibitor-binding sites to other previously characterized complexes. 3. Gel filtration by passage through Sephadex G-50 increases ATPase activity of submitochondrial particles between 1.5 and 3.5 fold indicating the presence of a low molecular weight inhibitor protein. 4. After removal of the inhibitor protein, sensitivity to inhibitors of energy conservation decreases by between 1.5 and 14 fold. Crude F1-inhibitor preparations from A. castellanii, Schizosaccharomyces pombe, Tetrahymena pyriformis and bovine heart also inhibit ATPase activity. 5. Large variations in ATPase activity, F1-inhibitor protein activity, and amounts of immunologically-determined ATPase protein were observed during exponential growth, and the correlation between changes in these measurements is discussed. 6. The results are also discussed highlighting the similarities between the mitochondrial ATPase of A. castellanii and other mitochondrial ATPases.
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32
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Marcus DL, Ibrahim NG, Freedman ML. Age-related decline in the biosynthesis of mitochondrial inner membrane proteins. Exp Gerontol 1982; 17:333-41. [PMID: 7169093 DOI: 10.1016/0531-5565(82)90033-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Isolated mitochondria from rat livers of various ages show a gradual decline in the rate of inner membrane-matrix protein synthesis with advancing age of the animal. Rats at 112-120 weeks synthesize these proteins at only 40% of the rate of 2-8-week-old animals. The initial rates of incorporation of label were 145 cpm/mg/minute for the "old" animals, and 320 cpm/mg/minute for the "young" animal. No difference in either amino acid pool size or leakage of label through the mitochondrial membrane was detected in the two age groups. Treatment of the mitochondria with ferrous ammonium sulphate produced a 1.62 fold increase in mitochondrial protein synthesis in the young animal but not in the old. Hemin treatment produced a similar effect. These results suggest that the decrease in delta-aminolevulinic acid synthase activity seen with age (Paterniti et al., 1978) may be due to a decrease in the synthesis of mitochondrial inner membrane proteins.
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33
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Goffeau A, Slayman CW. The proton-translocating ATPase of the fungal plasma membrane. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 639:197-223. [PMID: 6461354 DOI: 10.1016/0304-4173(81)90010-0] [Citation(s) in RCA: 382] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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34
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Esparza M, Velours J, Guerin B. Existence of two different species of mitochondrially translated proteolipids in ATPase complex of yeast mitochondria. FEBS Lett 1981; 134:63-6. [PMID: 9222325 DOI: 10.1016/0014-5793(81)80551-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- M Esparza
- Institut de Biochimie Cellulaire et Neurochimie du CNRS, Bordeaux, France
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35
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Finzi E, Sperling M, Beattie D. Partial purification of cytosolic proteins which control yeast mitochondrial protein synthesis. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)68493-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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36
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Somasundaram T, Jayaraman J. Synthesis and assembly of cytochrome c oxidase in synchronous cultures of yeast. Biochemistry 1981; 20:5369-73. [PMID: 6271185 DOI: 10.1021/bi00522a003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Yeast cells growing synchronously in glucose medium accumulate in the cytosol, the cytosolically made subunits of cytochrome oxidase, during the G1 and early-S phases. The mitochondrially made subunits, on the other hand, are detected only after the mid-S phase. The cytosolically synthesized subunits are integrated into the membrane after the mid-S phase.
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37
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Mitochondrial ribosome assembly in Neurospora crassa. Purification of the mitochondrially synthesized ribosomal protein, S-5. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69100-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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38
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Kumar CC, Padmanaban G. Evidence for the involvement of a rapidly turning over protease in the degradation of cytochrome oxidase in Neurospora crassa. Biochem Biophys Res Commun 1981; 100:576-83. [PMID: 6268065 DOI: 10.1016/s0006-291x(81)80215-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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39
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Orian JM, Marzuki S. The largest mitochondrial translation product copurifying with the mitochondrial adenosine triphosphatase of Saccharomyces cerevisiae is not a subunit of the enzyme complex. J Bacteriol 1981; 146:813-5. [PMID: 6260757 PMCID: PMC217030 DOI: 10.1128/jb.146.2.813-815.1981] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Mitochondrial adenosine triphosphatase isolated from a double mutant of Saccharomyces cerevisiae lacking cytochrome b apoprotein and subunit II of cytochrome oxidase does not contain the mitochondrial translation product (approximate molecular weight, 32,000) previously suggested to be a subunit of the enzyme complex.
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40
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Keyhani E. The locked-cell hypothesis: on the origin of mitochondria and the transition from prokaryotic to eukaryotic cells. Ann N Y Acad Sci 1981; 361:376-96. [PMID: 6941731 DOI: 10.1111/j.1749-6632.1981.tb46533.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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41
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Keyhani E. THE LOCKED-CELL HYPOTHESIS. ON THE ORIGIN OF MITOCHONDRIA AND THE TRANSITION FROM PROKARYOTIC TO EUKARYOTIC CELLS. Ann N Y Acad Sci 1981. [DOI: 10.1111/j.1749-6632.1981.tb54379.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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42
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Orian JM, Murphy M, Marzuki S. Mitochondrially synthesized protein subunits of the yeast mitochondrial adenosine triphosphatase. A reassessment. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 652:234-9. [PMID: 6452168 DOI: 10.1016/0005-2787(81)90227-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Evidence is presented that a mitochondrial translation product (Mr, 32,000) previously thought to be a subunit of the membrane sector of the yeast mitochondrial ATPase is a contaminant, consisting of subunit II of the cytochrome oxidase complex and cytochrome b apoprotein. Our data suggest that only two subunits (Mr, 7600 and 20,000) of the mitochondrial ATPase are synthesized in the mitochondria.
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43
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Mahler HR, Jaynes PK, McDonough JP, Hanson DK. Catabolite repression in yeast: mediation by cAMP. CURRENT TOPICS IN CELLULAR REGULATION 1981; 18:455-74. [PMID: 6268368 DOI: 10.1016/b978-0-12-152818-8.50033-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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44
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Nussdorfer GG, Mazzocchi G, Rebuffat P, Zucchi SC, Robba C. Investigations on the turnover of adrenocortical mitochondria. XIV. A correlated biochemical and stereological study of the effects of chronic treatment with ethidium bromide on the growth maintenance of the rat zona fasciculata mitochondria. Anat Rec (Hoboken) 1980; 198:611-8. [PMID: 6163376 DOI: 10.1002/ar.1091980406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The effects of ethidium bromide (EB) on rat adrenocortical cells were investigated by biochemical and stereological methods. It was found that a treatment with ip. injections of 10 microgram/gm of EB every 12 hours induced a persistent inhibition of the incorporation of 3H-thymidine and 3H-uridine into the mitochondrial fraction, but not into the nuclear fraction. Chronic treatment with this dose of EB provoked in zona fasciculata cells of rats treated with maintenance doses of ACTH a noticeable decrease in the volume of the mitochondrial compartment (due to the decrease both in the number per cell and in the average volume of the organelles) and in the surface area of the mitochondrial cristae. These findings lend support to the hypothesis that the mechanism underlying the ACTH-induced maintenance of the growth of adrenocortical mitochondria involves mitochondrial DNA reduplication and transcription.
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45
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McDonough JP, Jaynes PK, Mahler HR. Partial characterization of the plasma membrane ATPase from a rho0 petite strain of Saccharomyces cerevisiae. J Bioenerg Biomembr 1980; 12:249-64. [PMID: 6452450 DOI: 10.1007/bf00744687] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Crude membrane preparations of a rho0 mutant of Saccharomyces cerevisiae exhibit Mg2+-dependent ATPase activity. Over the optimal pH range, 5.0-6.75, the apparent Vmax of the enzyme equals 590 nmoles of ATP hydrolyzed per minute per milligram protein, with an apparent Km for ATP of 1.3 mM. ATP hydrolysis is insensitive to ouabain, venturicidin, aurovertin, and the protein inhibitor described by Pullman and Monroy; inhibited by oligomycin (at high concentrations) and sodium orthovanadate, and it is sensitive to dicyclohexylcarbodiimide, p-hydroxymercuribenzoate, hydroxylamine, sodium fluoride, and sodium iodoacetate. The pH optimum and the inhibitor pattern distinguish the plasma membrane enzyme from the mitochondrial F1 ATPase still present in these cells (this activity is sensitive to efrapeptin, aurovertin, and the protein inhibitor, but resistant to DCCD). In addition, the activity of the plasma membrane enzyme and its affinity for ATP are responsive to changes in the composition of the growth medium, with the highest activity observed in cells grown on methyl-alpha-D-glucoside, a sugar which results not only in partial release from catabolite repression but also requires the induction of an active transport system for growth.
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46
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Ohashi A, Schatz G. Stimulation of in vitro mitochondrial protein synthesis by yeast cytoplasmic extracts is caused by guanyl nucleotides. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)43893-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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47
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Murphy M, Choo KB, Macreadie I, Marzuki S, Lukins HB, Nagley P, Linnane AW. Biogenesis of mitochondria: a temperature sensitivity mutation affecting the mitochondrially synthesized var1 protein of Saccharomyces cerevisiae. Arch Biochem Biophys 1980; 203:260-70. [PMID: 6250484 DOI: 10.1016/0003-9861(80)90176-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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48
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Kernich JJ, Liu DK. Effect of aldosterone on ribonucleic acid polymerase activity in rat kidney cortical and medullary mitochondria. Biochem Pharmacol 1980; 29:1575-81. [PMID: 7396988 DOI: 10.1016/0006-2952(80)90610-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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49
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Siemens TV, Nichols DL, Zitomer RS. Effect of mitochondrial functions on synthesis of yeast cytochrome c. J Bacteriol 1980; 142:499-507. [PMID: 6247323 PMCID: PMC294011 DOI: 10.1128/jb.142.2.499-507.1980] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The effects of the mitochondrial protein synthesis inhibitor chloramphenicol and the mitochondrial F0 adenosine triphosphatase inhibitor oligomycin on the synthesis of nucleus-encoded cytochrome c protein were studied. Both inhibitors stimulated cytochrome c protein synthesis in the derepressed state (growth in media containing 2% raffinose) but had no effect on the synthesis of the cytochrome c protein in the repressed state (growth in media containing 5% glucose). Oligomycin uncoupled the synthesis of the apoprotein from its processing into the hemoprotein. Neither antibiotic had a significant effect on the rate of glucose repression of cytochrome protein synthesis. The kinetics of cytochrome c derepression and the effects of these two antibiotics on these kinetics were also studied. Cells were derepressed by transfer from glucose- to faffinose-containing media, and the rate of cytochrome c synthesis increased from the repressed to the derepressed level during the second hour of derepression. Chloramphenicol delayed this derepression, but after 5 h the rate of cytochrome c protein synthesis increased to twice the rate of synthesis in uninhibited cells. On the other hand, oligomycin inhibited derepression of cytochrome c. These results are discussed with respect to the effects of mitochondrial function in the derepressed and repressed states and during the processes of repression and derepression of cytochrome c.
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50
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Beattie DS, Clejan L. Aggregates of yeast mitochondrial cytochrome b observed after electrophoresis. J Bioenerg Biomembr 1980; 12:35-45. [PMID: 7410343 DOI: 10.1007/bf00745011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mitochondrial translation produces obtained from yeast cells labeled in vivo in the presence of cycloheximide were separated by dodecylsulfate polyacrylamide gel electrophoresis. The labeled band, with a molecular weight of 30,000 corresponding to cytochrome b, was excised and subsequently transferred to a second gel. After electrophoretic separation, two labeled polypetides with apparent molecular weights of 67,000 and 27,000 became visible in addition to the cytochrome b band of 30,000 molecular weight. Heating of the cytochrome b band prior to transfer resulted in an increase in the amount of the labeled polypeptides migrating with a molecular weight of 67,000. Longer exposure during autoradiography of the gels of mitochondrial translation products resulted in the appearance of a double band with an apparent molecular weight of 67,000. Limited proteolysis of this 67,000 dalton protein with Staphylococcus aureus V8 protease revealed a peptide map similar to that obtained after proteolysis of cytochrome b. These results suggest that the polypeptide with an apparent molecular weight of 67,000 represents an aggregate of cytochrome b that is either present as such in the membrane or is formed in vitro during the experimental manipulation to prepare mitochondria for gel electrophoresis.
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