Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous studies have shown that most neuronal ATP is produced by oxidative metabolism, and consumed by Na+,K(+)-ATPase. We hypothesized that the distribution of Na+,K(+)-ATPase in brain would correlate with that of the energy-producing enzyme, cytochrome oxidase (CO). We localized these enzymes in monkey hippocampus and striate cortex by histochemistry and immunohistochemistry. Their distributions were generally similar, although some differences were observed. We also studied regulation of enzyme levels, using monocular impulse blockage with tetrodotoxin (TTX) to alter neuronal activity in the visual system. Parallel changes in CO and Na+,K(+)-ATPase activity were induced in striate cortex. These results provide further evidence that neuronal energy demands regulate CO levels and distribution.
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PMID:Coordination of ATP production and consumption in brain: parallel regulation of cytochrome oxidase and Na+, K(+)-ATPase. 132 57

Cytochrome-c-oxidase (complex IV) was histochemically studied in oncocytic adenoma (n = 10) and carcinoma of the thyroid gland (n = 3), cystadenolymphomas and oncocytic adenomas of the major salivary glands (n = 9), oncocytic neoplasia of the kidney (n = 1) and in 21 parathyroid glands with primary hyperparathyroidism and adenomatous proliferation (n = 17) and secondary hyperparathyroidism with hyperplasia (n = 4). Only in the parathyroids defects of cytochrome-c-oxidase were found being expressed in all 4 glands with hyperplasia (14 defects) and in 5 of the 17 adenomas (11 defects). All defects were confined to foci with oxyphil cell differentiation, the defect areas varying from 0.09 to 21.10 sq mm in hyperplastic glands and from 0.11 to 13.88 sq mm in adenomas, the size of the oxyphil foci varying from 0.12 sq mm-105.38 sq mm. However, not every oxyphil nodule of a gland was devoid of cytochrome-c-oxidase activity. Of 6 predominantly oxyphil adenomas, 4 showed no defects. No defects were observed either in 2 adenomas without oxyphil cells. Further enzymes of the respiratory chain, succinate dehydrogenase (complex II) and ATP synthetase, (complex V) were devoid of defects. In parathyroids with hyperplasia and oxyphil areas, defects of cytochrome-c-oxidase occurred significantly more often and tended to be larger than in adenomas, statistical analysis revealing a significant correlation between the occurrence of defects and the number of oxyphil foci but not with the total oxyphil area.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Random cytochrome-C-oxidase deficiency of oxyphil cell nodules in the parathyroid gland. A mitochondrial cytopathy related to cell ageing? 133 5

In vitro alterations induced by a 10 micrograms/ml and 50 micrograms/ml dose each of thiophenate and fenbendazole on the absorptive surfaces of Haemonchus contortus (Nematoda: Trichostrongylidae) were studied. The most significant changes were induced in the gut epithelium. Alkaline phosphatase and adenosine triphosphatase activities were decreased, succinic dehydrogenase activity was increased, while acid phosphatase and glucose-6-phosphatase were completely lost from the intestinal epithelium after treatment with either of the drugs. A stimulatory effect of these two anthelmintics was observe on lactic dehydrogenase and reduced nicotinamide adenine dinucleotide diaphorase distribution. Thiophenate caused an increase in the activities of glutamate dehydrogenase (GDH), glucose-6-phosphate dehydrogenase (G-6-PD) and nonspecific esterases and a decrease in reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-D) activity. Fenbendazole treatment led to the inhibition of GDH, while G-6-PD, NADPH-D, cytochrome oxidase, monoamine oxidase and nonspecific esterase activity remained unaltered in the epithelium.
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PMID:Histoenzymic effects of thiophenate and fenbendazole on the absorptive surfaces of Haemonchus contortus. 133 82

Electron microscopic enzyme cytochemical reactions of Entamoeba histolytica trophozoite showed that acid phosphatase (ACP) and cytidine monophosphatase (CMPase) were located in the lysosomes. The lysosome containing enzymes were distributed in the endoplasm and beneath the plasmalemma, and the releasing enzymes by lysosomes excreted outside of the plasmalemma and caused the injury to host cells. The cytochemical positive reactions of catalase and glucose-6-phosphatase (G-6-Pase) showed that E. histolytica contains microbodies and endoplasmic reticulum. The reactive products of peroxidase (POase) were seen in the lysosome-like structure. The reactions of cytochrome oxidase (COase) and succinate dehydrogenase (SDH) were both negative, indicating that E. histolytica lacked mitochondria. The reactions of thiamine pyrophosphatase (TPPase) and nicotinamide adenine dinucleotide phosphatase (NADPase) were both negative, indicating that E. histolytica lacked Golgi body. The reactions of Na(+)-K(+)-ATPase were located on plasmalemma.
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PMID:[Electron microscopic enzyme cytochemistry of Entamoeba histolytica trophozoite]. 133 24

Thymomodulin and Thymolymphotropin, biologically active thymus derivative peptides exert recovery effects on the functionality of some membrane bound, mitochondrial and lysosomal enzymes (monoamine oxidase, ATPase, phosphatases, cytochrome oxidase, succinate oxidase) affected by gamma-irradiation. These drugs exert antistress effect by re-establishing the function of hypothalamus-pituitary-adrenal axis and that of lymphoid organs.
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PMID:The effects of thymomodulin and thymolymphotropin on the stress response of neuroendocrine system by gamma-irradiated Wistar rat. 134 4

Transcription factor nuclear respiratory factor 1 (NRF-1) was originally identified as an activator of the cytochrome c gene and subsequently found to stimulate transcription through specific sites in other nuclear genes whose products function in the mitochondria. These include subunits of the cytochrome oxidase and reductase complexes and a component of the mitochondrial DNA replication machinery. Here we establish that a functional recognition site for NRF-1 is present in the ATP synthase gamma-subunit gene extending the proposed respiratory role of NRF-1 to complex V. In addition, biologically active NRF-1 sites are found in genes encoding the eukaryotic translation initiation factor 2 alpha-subunit and tyrosine aminotransferase, both of which participate in the rate-limiting step of their respective pathways of protein biosynthesis and tyrosine catabolism. The recognition sites from each of these genes form identical complexes with NRF-1 as established by competition binding assays, methylation interference footprinting, and UV-induced DNA cross-linking. Cloned oligomers of each NRF-1 binding site also stimulate the activity of a truncated cytochrome c promoter in transfected cells. The NRF-1 binding activities for the various target sites copurified approximately 33,000-fold and resided in a single protein of 68 kDa. These observations further support a role for NRF-1 in the expression of nuclear respiratory genes and suggest it may help coordinate respiratory metabolism with other biosynthetic and degradative pathways.
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PMID:Nuclear respiratory factor 1 activation sites in genes encoding the gamma-subunit of ATP synthase, eukaryotic initiation factor 2 alpha, and tyrosine aminotransferase. Specific interaction of purified NRF-1 with multiple target genes. 134 57

The mitochondrial import and assembly of the F1ATPase subunits requires, respectively, the participation of the molecular chaperones hsp70SSA1 and hsp70SSC1 and other components operating on opposite sides of the mitochondrial membrane. In previous studies, both the homology and the assembly properties of the F1ATPase alpha-subunit (ATP1p) compared to the groEL homologue, hsp60, have led to the proposal that this subunit could exhibit chaperone-like activity. In this report the extent to which this subunit participates in protein transport has been determined by comparing import into mitochondria that lack the F1ATPase alpha-subunit (delta ATP1) versus mitochondria that lack the other major catalytic subunit, the F1ATPase beta-subunit (delta ATP2). Yeast mutants lacking the alpha-subunit but not the beta-subunit grow much more slowly than expected on fermentable carbon sources and exhibit delayed kinetics of protein import for several mitochondrial precursors such as the F1 beta subunit, hsp60MIF4 and subunits 4 and 5 of the cytochrome oxidase. In vitro and in vivo the F1 beta-subunit precursor accumulates as a translocation intermediate in absence of the F1 alpha-subunit. In the absence of both the ATPase subunits yeast grows at the same rate as a strain lacking only the beta-subunit, and import of mitochondrial precursors is restored to that of wild type. These data indicate that the F1 alpha-subunit likely functions as an "assembly partner" to influence protein import rather than functioning directly as a chaperone. These data are discussed in light of the relationship between the import and assembly of proteins in mitochondria.
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PMID:The mitochondrial F1ATPase alpha-subunit is necessary for efficient import of mitochondrial precursors. 138 80

Previous work has shown that irrespective of the route of exposure methyl isocyanate (MIC) caused acute lactic acidosis in rats (Jeevaratnam et al., Arch. Environ. Contam. Toxicol. 19, 314-319, 1990) and the hypoxia was of stagnant type due to tissue hypoperfusion resulting from hypovolemic hypotension in rabbits administered MIC subcutaneously (Jeevarathinam et al., Toxicology 51, 223-240, 1988). The present study was designed to investigate whether MIC could induce histotoxic hyperoxia through its effects on mitochondrial respiration. Male Wistar rats were used for liver mitochondrial and submitochondrial particle (SMP) preparation. Addition of MIC to tightly coupled mitochondria in vitro resulted in stimulation of state 4 respiration, abolition of respiratory control, decrease in ADP/O ratio, and inhibition of state 3 oxidation. The oxidation of NAD(+)-linked substrates (glutamate + malate) was more sensitive (five- to sixfold) to the inhibitory action of MIC than succinate while cytochrome oxidase remained unaffected. MIC induced twofold delay in the onset of anerobiosis, and cytochrome b reduction in SMP with NADH in vitro confirms inhibition of electron transport at complex I region. MIC also stimulated the ATPase activity in tightly coupled mitochondria while lipid peroxidation remained unaffected. As its hydrolysis products, methylamine and N,N'-dimethylurea failed to elicit any change in vitro; these effects reveal that MIC per se acts as an inhibitor of electron transport and a weak uncoupler. Administration of MIC sc at lethal dose caused a similar change only with NAD(+)-linked substrates, reflecting impairment of mitochondrial respiration at complex I region and thereby induction of histotoxic hypoxia in vivo.
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PMID:In vitro and in vivo effect of methyl isocyanate on rat liver mitochondrial respiration. 147 Nov 48

Incubation of normal mitochondria at 45 degrees C results in increases of respiration and of total apparent proton conductance (TAPC, respiration/proton motive force) and in an upward shift of the flow-force relationships. Similar effects are observed during operation of the redox proton pumps at different sites of the respiratory chain. These effects are accompanied by an almost equivalent increase of the passive proton conductance (PPC, proton leakage/proton motive force). In mitochondria from 3,3,5-triiodo-L-thyronine (T3)-treated rats there are also increases of respiration and of TAPC and an upward shift of flow-force relationships, more pronounced at the level of the cytochrome oxidase proton pump. However, at variance from the incubation at 45 degrees C, in mitochondria from T3-treated rats there is only a slight increase of PPC. Addition of bovine serum albumin to normal mitochondria incubated at 45 degrees C results in a marked depression of TAPC in the nonlinear range of the flow-force relationships. An equivalent effect is not observed in mitochondria from T3-treated rats. The experimental results have been compared with computer simulations obtained on the basis of a chemiosmotic model of energy transduction. The increase of TAPC following incubation at high temperature is apparently due to changes of the proton conductance mainly at the level of PPC, while the increase of TAPC following T3 administration is rather due to changes presumably at the level of the redox or ATPase proton pumps.
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PMID:Mechanism of loss of thermodynamic control in mitochondria due to hyperthyroidism and temperature. 163 81

The mRNA levels of ATPase beta, ATPase 6, cytochrome oxidase (COX) VIb and COX I subunits were found to be 2.4-13.8-fold higher in brown adipose tissue (BAT) than in heart, skeletal muscle, brain and liver of mice. The comparison with tissue contents of ATPase and COX revealed that the selective, 5-11-fold reduction of ATPase in BAT is not caused by decreased transcription of ATPase genes. Likewise, the ATPase beta and COX VIb mRNA levels in cultured brown adipocytes were also not influenced by norepinephrine, which activated the expression of the UCP gene by two orders of magnitude. The results indicate that the biosynthesis of mitochondrial ATPase in BAT is post-transcriptionally regulated.
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PMID:Low content of mitochondrial ATPase in brown adipose tissue is the result of post-transcriptional regulation. 166 83


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