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Query: UNIPROT:P06889 (Mol)
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The atp operon from the extreme alkaliphile Bacillus firmus OF4 was cloned and sequenced, and shown to contain genes for the eight structural subunits of the ATP synthase, preceded by a ninth gene predicted to encode a 14 kDa hydrophobic protein. The arrangement of genes is identical to that of the atp operons from Escherichia coli, Bacillus megaterium, and thermophilic Bacillus PS3. The deduced amino acid sequences of the subunits of the enzyme are also similar to their homologs in other ATP synthases, except for several unusual substitutions, particularly in the a and c subunits. These substitutions are in domains that have been implicated in the mechanism of proton translocation through F0-ATPase, and therefore could contribute to the gating properties of the alkaliphile ATP synthase or its capacity for proton capture.
Mol Gen Genet 1991 Oct
PMID:Organization and nucleotide sequence of the atp genes encoding the ATP synthase from alkaliphilic Bacillus firmus OF4. 183 20

Phosphorylation of ribosomal protein S6 of mammals precedes activation of cell growth in numerous biological systems. We have cloned a cDNA for ribosomal protein S6 from T-47D human breast cancer cells by immunoscreening a lambda gt11 expression library with antibody raised against the mitochondrial Ca(2+)-binding ATPase inhibitor protein (CaBI) of bovine heart mitochondria (Yamada & Huzel: J Biol Chem 263: 11498-11503, 1988). Similar clones were obtained by the immunoscreening of a rat heart expression library. In agreement with others, the open reading frames of the cDNAs from the two species coded for the same amino acid sequence. No difference in S6 of the human neoplastic cells compared to that of non-neoplastic cells was found. However, common antigenic determinants in S6 and CaBI were indicated. Accordingly, S6 was purified from rat liver ribosomes and antiserum prepared. Immuno-dot blot and Western blot analyses showed high specific reactivity between S6, the cloned chimeric beta-galactosidase fusion protein from a cDNA clone, and CaBI with anti-S6 and anti-CaBI antibodies. The antibodies also showed a high degree of discrimination for S6 and CaBI. Neither interacted with the other ribosomal proteins nor with another ATPase inhibitor protein from bovine heart mitochondria. Neither interacted with the Ca(2+)-binding proteins, calmodulin, oncomodulin, Protein C, or Factor X. Prothrombin was weakly reactive with anti-CaBI but not with anti-S6. Thus, the results fulfill the specific criteria for the concept and operational definition of common protein epitopes in S6 and CaBI. However, neither prothrombin nor S6 fusion protein inhibited mitochondrial ATPase activity even at 20 times the concentrations at which CaBI gave 97% inhibition.
Mol Cell Biochem 1991 Nov 13
PMID:Antigenic reactivity of ribosomal protein S6 and the calcium-binding ATPase inhibitor protein of mammalian mitochondria. 183 89

We report the differential expression of the oligomycin-sensitive mitochondrial ATPase in pleomorphic bloodstream forms of Trypanosoma brucei brucei as observed with enzymatic assays and electron microscope histochemistry. As the cells differentiate from long slender to short stumpy forms, total specific activity of the mitochondrial ATPase in a crude mitochondrial fraction doubles and the oligomycin-sensitive specific activity increases 5-fold. Upon in vitro differentiation to procyclic forms, there is a further doubling of total specific activity and a further tripling of oligomycin-sensitive specific activity. The oligomycin-insensitive ATPase activity remained essentially constant throughout differentiation. We have attempted to characterize this oligomycin-insensitive activity utilizing inhibitors of several other ATPases.
Mol Biochem Parasitol 1991 Sep
PMID:Differential expression of the oligomycin-sensitive ATPase in bloodstream forms of Trypanosoma brucei brucei. 183 38

The effect of inhibition of the mitochondrial ATPase with oligomycin on the rate of ATP depletion and anaerobic glycolysis was studied in the totally ischemic dog heart. An oxygenated, buffered crystalloidal solution containing 10 microM oligomycin and 12 mM glucose was delivered at 100 mmHg pressure to the circumflex bed of the excised cooled heart. Buffered solution without oligomycin was delivered simultaneously to the anterior descending bed of the same heart. Little metabolic evidence of ischemia developed until the heart was made totally ischemic by incubating it in a sealed plastic bag at 37 degrees C. Successful inhibition of the mitochondrial ATPase was confirmed by the absence of both mitochondrial ATPase activity and the loss of respiratory control in mitochondria isolated from treated tissue. ATP, glycolytic intermediates and catabolites of the adenine nucleotide pool were measured in the control and treated beds at various intervals during 120 min of ischemia. Inhibition of the ATPase resulted in slowing of the rates of ATP depletion and anaerobic glycolysis (estimated by lactate accumulation). Also, degradation of the adenine nucleotide pool occurred more slowly in the inhibited group. These data establish that about 35% of the ATP utilization observed during the first 90 min of total ischemia in the canine heart is due to mitochondrial ATPase activity.
J Mol Cell Cardiol 1991 Dec
PMID:Effect of inhibition of the mitochondrial ATPase on net myocardial ATP in total ischemia. 183 1

Mitochondria contain a protein, hsp60, that is induced by heat shock and has been shown to function as a chaperonin in the assembly of mitochondrial enzyme complexes composed of proteins encoded by nuclear genes and imported from the cytosol. To determine whether products of mitochondrial genes are also assembled through an interaction with hsp60, we looked for association between hsp60 and proteins synthesized by isolated mitochondria. We have determined by electrophoretic, centrifugal, and immunological assays that at least two of those proteins become physically associated with hsp60. In mitochondrial matrix extracts, this association could be disrupted by the addition of Mg-ATP. One of the proteins that formed a stable association with hsp60 was the alpha subunit of the multicomponent complex F1-ATPase. We have not identified the other protein. These results indicate that hsp60 can function in the folding and assembly of mitochondrial proteins encoded by both mitochondrial and nuclear genes.
Mol Cell Biol 1990 Aug
PMID:Function of the maize mitochondrial chaperonin hsp60: specific association between hsp60 and newly synthesized F1-ATPase alpha subunits. 197 26

In this paper we have examined the effect of cold exposure on hepatic mitochondrial state 3 respiration and ATP synthesis, using succinate as the substrate, in euthyroid, hypothyroid and hyperthyroid rats. The results show that cold exposure does not elicit any variation in the above parameters in euthyroid and hyperthyroid rats, whereas when hypothyroid rats are exposed to cold, a significant increase (about +45%) occurs in state 3 respiration and ATP synthesis. We have also measured succinic dehydrogenase specific activity and uncoupled respiration during cold exposure in various thyroid states. The finding that cold exposure elicits no variation in the above parameters indicates that there is some control on ATP synthase and/or adenine nucleotide translocator. The above findings, as a whole, suggest that cold exposure acts on oxidative phosphorylation only if triiodothyronine is lacking, by controlling ATP synthase and/or adenine nucleotide translocator.
Mol Cell Endocrinol 1991 Jan
PMID:The effect of thyroid state and cold exposure on rat liver oxidative phosphorylation. 205 Feb 63

This report describes the first isolation and molecular characterization of the mitochondrial F1-ATPase from Trypanosoma brucei. The isolation procedure utilized is a modified chloroform extraction procedure. In contrast to earlier reports on the F1-ATPase from other trypanosomatids, the F1-ATPase we have isolated from the procyclic form of T. brucei a complex composed of five distinct subunits. Apparent molecular weights of these subunits are 55,000 [alpha], 42,000 [beta], 32,000 [gamma], 22,000 [delta], and 17,000 [epsilon]. The F1 moiety which possesses the active site of the H(+)-ATPase has an ATPase activity in the standard Tris-HCl coupled enzyme assay with a Vmax of 22.96 mumol min-1 (mg protein)-1 and a Km value of 0.60 mM. This ATPase activity is cold labile and is not susceptible to oligomycin inhibition as is the membrane bound enzyme. Upon reconstitution with F1-ATPase depleted membranes (urea particles) the ATPase regains oligomycin sensitivity to the same extent as that found in the intact inner membrane vesicles. ATP synthesis is also restored to these particles upon reconstitution with F1. These results indicate that this F1-ATPase as isolated is intact with respect to all the critical H(+)-ATPase functions.
Mol Biochem Parasitol 1990 Nov
PMID:The mitochondrial ATP synthase of Trypanosoma brucei: isolation and characterization of the intact F1 moiety. 214 43

The effect of the unc transcription terminator on expression of uncC, encoding the epsilon subunit of Escherichia coli F1-ATPase, from plasmids was studied. The cloned sequence in pTK1 included the uncC ribosome binding site, the uncC structural gene, and the unc transcription terminator. The cloned region in pSD37 was similar, but lacked the unc transcription terminator. Transformants carrying pTK1 produced the epsilon subunit of F1-ATPase, encoded by uncC, in 10-fold greater abundance than transformants carrying pSD37. Northern blots revealed similar differences in the steady-state uncC mRNA levels. The half-life of the message transcribed from pTK1 was 90-100 seconds, while that from pSD37 was 25-30 seconds. These studies indicate the importance of message stabilization through features at the 3' end of the transcript in ensuring adequate production of epsilon. We have exploited this stabilization to develop a simple, efficient, and gentle method of purifying the overproduced epsilon subunit.
Mol Microbiol 1990 Nov
PMID:The Escherichia coli unc transcription terminator enhances expression of uncC, encoding the epsilon subunit of F1-ATPase, from plasmids by stabilizing the transcript. 215 May 40

cDNA and genomic clones encoding the complete precursor polypeptide of the gamma-subunit of spinach chloroplast ATP synthase have been isolated and characterised. The longest cDNA (1320 bp), selected from a lambda gt11 spinach cDNA library, encoded a 364 amino acid residue protein (Mr 40,028) that included a putative 41 residue N-terminal transit peptide. All the gamma-subunit cDNAs analysed were derived from the same gene and Southern blot analysis of Bam HI restricted spinach DNA showed only one hybridising band (ca. 15 kb). Analysis of the cloned 15 kb genomic fragment, selected from a lambda EMBL4 spinach DNA library with a cDNA probe, confirmed there was a single gene for the gamma-subunit. Sequencing, primer extension and northern blot analysis showed the gene contains two introns, 1066 and 665 bp in length, a 173 bp 5' untranslated region and a 213 bp 3' untranslated region. A 1450 nucleotide gamma-subunit transcript was detected in RNA from light-grown and dark-grown spinach.
Plant Mol Biol 1990 Jun
PMID:The gamma-subunit of spinach chloroplast ATP synthase: isolation and characterisation of cDNA and genomic clones. 215 16

The precursors of the F1-ATPase beta-subunits from Nicotiana plumbaginifolia and Neurospora crassa were imported into isolated spinach (Spinacia oleracea L.) leaf mitochondria. Both F1 beta precursors were imported and processed to mature size products. No import of the mitochondrial precursor proteins into isolated intact spinach chloroplasts was seen. Moreover, the precursor of the 33 kDa protein of photosynthetic water-splitting enzyme was not imported into the leaf mitochondria. This study provides the first experimental report of in vitro import of precursor proteins into plant mitochondria isolated from photosynthetic tissue and enables studies of protein sorting between mitochondria and chloroplasts in a system which is homologous with respect to organelles. The results suggest a high organellar specificity in the plant cell for the cytoplasmically synthesized precursor proteins.
Plant Mol Biol 1990 Jun
PMID:Sorting of precursor proteins between isolated spinach leaf mitochondria and chloroplasts. 215 17


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