Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A selection procedure is described which permits a large number of Saccharomyces cerevisiae mutants to be screened for specific lesions in mitochondrial respiratory enzymes and the adenosine triphosphatase. The method has been used to isolate nuclear mutant strains with specific lesions in coenzyme QH2-cytochrome c reductase, cytochrome oxidase, and adenosine triphosphatase. In addition, two cytoplasmic mutants have been found whose primary defect is in cytochrome oxidase, and others have been found that show variable degrees of abnormalities in their mitochondrial translation products.
...
PMID:Assembly of the mitochondrial membrane system: isolation of nuclear and cytoplasmic mutants of Saccharomyces cerevisiae with specific defects in mitochondrial functions. 16 80

Mutants of Saccharomyces cereviaiae showing defects in cytochrome oxidase, coenzyme QH2-cytochrome c reductase, and rutamycin-sensitive ATPase are described. The mutations have been established to be nuclear, based on complementation with a cytoplasmic petite tester strain and 2:2 segregation of tetrads. Genetic analysis indicate the coenzyme QH2-cytochrome c reductase and cytochrome oxidase mutants fall into 9 and 10 different complementation groups, respectively. The mutants also form distinct classes based on absorption spectra of the mitochondrial cytochromes. Two of the ATPase mutants lack detectable F1 ATPase, while the third synthesizes F1 but does not integrate it into a membrane complex. The latter mutant is missing one of the mitochondrially synthesized subunits of the rutamycin-sensitive ATPase complex.
...
PMID:Assembly of the mitochondrial membrane system. Characterization of nuclear mutants of Saccharomyces cerevisiae with defects in mitochondrial ATPase and respiratory enzymes. 17 Feb 84

Mutants of Saccharomyces cervisiae with defects in enzymes of the electron transfer chain and in the rutamycin-sensitive ATPase have been isolated. Some of the mutants are specifically affected in either cytochrome oxidase, coenzyme QH2-cytochrome c reductase or ATPase. Other strains are deficient in both cytochrome oxidase and coenzyme QH2-cytochrome c reductase but still have rutamycin-sensitive ATPase. All the mutants reported in this study fail to be complemented by a rho0 tester derived from a respiratory competent strain. The meiotic spore progeny obtained by mating the mutants to a respiratory competent haploid yeast, when scored for growth on glycerol, show a non-Mendelian segregation of the phenotype. These two genetic tests indicate the mutations to be cytoplasmically inherited.
...
PMID:Assembly of the mitochondrial membrane system. Cytoplasmic mutants of Saccharomyces cerevisiae with lesions in enzymes of the respiratory chain and in the mitochondrial ATPase. 17 Dec 56

Cytochrome c oxidase has been purified from rat liver mitochondria using affinity chromatography. The preparation contains 10.5 to 13.4 nmol of heme a + a3 per mg of protein and migrates as a single band during polyacrylamide gel electrophoresis under nondissociating conditions. It has a heme a/a3 ratio of 1.12 and is free of cytochromes b, c, and c1 as well as the enzymes, NADH dehydrogenase, succinic dehydrogenase, coenzyme Q-cytochrome c reductase, and ATPase. The enzyme preparation consists of six polypeptides having apparent Mr of 66,000, 39,000, 23,000, 14,000, 12,500 and 10,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The peptide composition is similar to those found for cytochrome c oxidases from other systems. The enzymatic activity of the purified enzyme is completely inhibited by carbon monoxide or cyanide, partially inhibited by Triton X-100 and dramatically enhanced by Tween 80 or phospholipids.
...
PMID:Purification and characterization of cytochrome c oxidase from rat liver mitochondria. 21 98

Disruption of the gene for subunit 6 of the yeast cytochrome bc1 complex (QCR6) causes a temperature-sensitive petite phenotype in contrast to deletion of the coding region of QCR6, which shows no growth defect. Mitochondria from the petite strain carrying the disruption allele were devoid of ubiquinol-cytochrome c oxidoreductase activity but retained cytochrome c oxidase and oligomycin-sensitive ATPase activities. Optical spectra of cytochromes in mitochondrial membranes from the petite strain lacked a cytochrome b absorption band and had a reduced amount of cytochrome c1. Analysis of mitochondrial translation products showed normal synthesis of cytochrome b. Western analysis of mitochondrial membranes from this disruption strain indicates core protein 1 of the cytochrome bc1 complex is present in normal amounts, while cytochrome c1, the Rieske iron-sulfur protein, subunit 6, and subunit 7 were absent or present in very low amounts. Taken together, these findings indicate a loss of assembly of the cytochrome bc1 complex. High copy suppressors of the disruption strain were selected. Two separate families of suppressors were found. The first contained QCR6. The second family consisted of overlapping clones of a second gene distinct from QCR6. These plasmids contained QCR9, the gene which codes for subunit 9 of the yeast cytochrome bc1 complex. Suppression of the QCR6 disruption strain by overexpression of QCR9 indicates a critical interaction between these two proteins in the assembly of the cytochrome bc1 complex.
...
PMID:The petite phenotype resulting from a truncated copy of subunit 6 results from loss of assembly of the cytochrome bc1 complex and can be suppressed by overexpression of subunit 9. 165 16

The effects of arachidonic acid on the enzyme complexes in the electron transport system were investigated using submitochondrial particles from rat brain. Arachidonic acid irreversibly inhibited NADH-CoQ oxidoreductase (complex I) activity, but had no effect on the activities of succinate-CoQ oxidoreductase (complex II), CoQH2-cytochrome c oxidoreductase (complex III), cytochrome c oxidase (complex IV), ATPase (complex V), glutamate dehydrogenase, and malate dehydrogenase up to 50 microM. The inhibition was dose-dependent with an IC50 value of 110 nmol/mg protein. The Lineweaver-Burk plot revealed that the inhibition by arachidonic acid was noncompetitive against CoQ with a Ki value of 33 microM and uncompetitive against NADH with a Ki value of 22 microM.
...
PMID:Selective inhibition of NADH-CoQ oxidoreductase (complex I) of rat brain mitochondria by arachidonic acid. 190 30

We describe a collection of nuclear respiratory-defective mutants (pet mutants) of Saccharomyces cerevisiae consisting of 215 complementation groups. This set of mutants probably represents a substantial fraction of the total genetic information of the nucleus required for the maintenance of functional mitochondria in S. cerevisiae. The biochemical lesions of mutants in approximately 50 complementation groups have been related to single enzymes or biosynthetic pathways, and the corresponding wild-type genes have been cloned and their structures have been determined. The genes defined by an additional 20 complementation groups were identified by allelism tests with mutants characterized in other laboratories. Mutants representative of the remaining complementation groups have been assigned to one of the following five phenotypic classes: (i) deficiency in cytochrome oxidase, (ii) deficiency in coenzyme QH2-cytochrome c reductase, (iii) deficiency in mitochondrial ATPase, (iv) absence of mitochondrial protein synthesis, and (v) normal composition of respiratory-chain complexes and of oligomycin-sensitive ATPase. In addition to the genes identified through biochemical and genetic analyses of the pet mutants, we have cataloged PET genes not matched to complementation groups in the mutant collection and other genes whose products function in the mitochondria but are not necessary for respiration. Together, this information provides an up-to-date list of the known genes coding for mitochondrial constituents and for proteins whose expression is vital for the respiratory competence of S. cerevisiae.
...
PMID:PET genes of Saccharomyces cerevisiae. 221 20

The respiratory deficiency of two noncomplementing mutants of Saccharomyces cerevisiae (C41 and N28) has been shown to be due to mutations in HEM2, the structural gene for delta-aminolevulinate dehydratase. The mutants are unable to convert delta-aminolevulinic acid to porphobilinogen and are not complemented by the hem2 mutant GL4 (Gollub, E. G., Liu, K.-P., Dagan, J., Adlersberg, M., and Sprinson, D. B. (1977) J. Biol. Chem. 252, 2846-2854). A gene capable of complementing the respiratory deficiency of C41 and N28 has been cloned by transformation of a hem2 mutant with a recombinant plasmid library of wild type yeast nuclear DNA. The sequence of the protein encoded by the cloned gene exhibits extensive homology to the recently reported sequence of human delta-aminolevulinate dehydratase (Wetmur, J. G., Bishop, D. F., Cantelmo, C., and Desnick, R. J. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 7703-7707). Several approaches were taken to study the effect of heme on transcription of PET genes known to code for subunit components of respiratory enzymes and of mitochondrial ATPase. The first involved measurements of the steady state levels of mRNAs for subunit 5 of cytochrome oxidase and the beta subunit of F1 ATPase in wild type and in a hem2 mutant. Secondly, transcription of the genes coding for the cytochrome oxidase and ATPase subunits as well as of the COR1 gene coding for the 44-kDa core 1 subunit of coenzyme QH2-cytochrome c reductase was quantitated by fusing the 5'-flanking and part of the coding region of each gene to the lacZ gene of Escherichia coli in vectors capable of integrating into yeast chromosomal DNA. The different lacZ fusions were integrated into nuclear DNA of a wild type strain and of hem2 mutants allowing expression of beta-galactosidase to be studied as a function of intracellular heme. These experiments indicate that the promoters of the genes for subunits of the respiratory complexes are regulated by heme. In contrast, the expression of the ATPase subunit appears to be heme-independent. Because neither subunit 5 of cytochrome oxidase nor the core 1 subunit of coenzyme QH2-cytochrome c reductase are hemoproteins, transcriptional regulation by heme may be a general mechanism for controlling the synthesis of mitochondrial proteins involved in respiration.
...
PMID:Characterization of the yeast HEM2 gene and transcriptional regulation of COX5 and COR1 by heme. 244 51

In this paper selected data from 43 patients with histologically defined mitochondrial myopathies who have been investigated biochemically as previously described are presented. The defect was localized to NADH-ubiquinone oxidoreductase (complex I) in 22 cases and to ubiquinol-cytochrome c oxidoreductase (complex III) in a further 10. Two patients had defects of more than one respiratory enzyme complex and another had a deficiency of H+-ATPase. The lesion was not localized in two cases and in vitro mitochondrial studies were normal in five cases.
...
PMID:Human mitochondrial respiratory chain deficiencies. 284 94

Many of the polypeptides made on endogenous ribosomes inside of yeast mitochondria are hydrophobic "integral polypeptides" which are subunits of at least three oligomeric enzyme complexes (cytochrome c oxidase, rutamycin-sensitive ATPase, and coenzyme QH2-cytochrome c reductase) of the inner mitochondrial membrane. In order to elucidate the pathway(s) followed by these polypeptides into the inner membrane we have used an in vitro mitochondrial translation system from yeast. By inhibiting this system with aurintricarboxylic acid, we have been able to demonstrate and accumulate a transient precursor to subunit II of cytochrome c oxidase. This precursor, designated II', is approximately 1,500 daltons larger than mature subunit II and most likely is a form of subunit II with an NH2-terminal extension. Although this precursor appears to be processed cotranslationally under normal conditions, it does associate in unprocessed form with mitochondrial membranes when allowed to accumulate in the presence of aurintricarboxylic acid, and it can be processed postranslationally upon removal of the drug. None of the other mitochondrial translation products made in this system exhibits larger precursors. These results indicate that at least one mitochondrial translation product has a transient "leader sequence" a,d is inserted into the inner mitochondrial membrane and processed cotranslationally, but they suggest that other pathways may be followed by the other translation products.
...
PMID:Mitochondrial membrane biogenesis: identification of a precursor to yeast cytochrome c oxidase subunit II, an integral polypeptide. 624 38


1 2 Next >>

---