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)

We have identified a pineal night-specific ATPase (PINA), a novel splice variant of the ATP7B gene disrupted in Wilson disease (WD). PINA expression exhibits a dramatic diurnal rhythm in both pineal gland and retina with 100-fold greater expression at night than at day. PINA is expressed in pinealocytes and a subset of photoreceptors in adult rats and is transiently expressed in the retinal pigment epithelium and the ciliary body during retinal development. Nocturnal pineal expression of PINA is under the control of a suprachiasmatic nucleus clock mediated by superior cervical ganglion innervation of the pineal. In vitro, PINA expression in pineal cells can be stimulated by agents activating the cAMP signal transduction pathway. PINA is able to restore copper transport activity in Saccharomyces cerevisiae deficient in the homologous copper-transporting ATPase CCC2, suggesting that this protein may function as a copper transporter in rat pinealocytes. These studies suggest a potential role of rhythmic copper metabolism in pineal and/or retina circadian function.
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PMID:A novel pineal night-specific ATPase encoded by the Wilson disease gene. 992 Jun 65

Immunohistochemical localization of Copper-transporting P-type ATPase (ATP7B), a gene product responsible for Wilson disease, was visualized in the brain tissues of the Long-Evans agouti rat in detail using tissue-blotting technique and confocal laser microscopy. The ATP7B was intensely detected in neuronal cells of the hippocampal formation, olfactory bulbs, cerebellum, cerebral cortex and nuclei in the brainstem in which high amounts of copper and cuproenzymes, dopamine beta hydroxylase and Cu,Zn-superoxide dismutase (Cu,Zn-SOD) were detected. The present results suggest that ATP7B plays key roles in neurotransmissions of catecholamine pathway and preventing brain tissues from injury by superoxide radicals to regulate the cellular Cu concentration and/or activities of cuproenzymes related to neurotransmissions and a free radical metabolism. Furthermore, it is reasonable to assume that neurotoxicity due to abnormal copper accumulation or irregular regulation of cuproenzymes in the critical brain regions by mutation of the ATP7B gene leads to neurological failures of Wilson disease.
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PMID:Immunohistochemical determination of the Wilson Copper-transporting P-type ATPase in the brain tissues of the rat. 1033 72

Wilson's disease is a rare autosomal recessive inherited disorder of copper metabolism. Hepatic excretion of copper is impaired due to mutation of the gene for a copper-transporting adenosine triphosphatase, ATP7B. Copper accumulation in liver, brain, and other tissues may cause a wide spectrum of hepatic, neuropsychiatric, and other clinical manifestations. The diagnosis may be supported by measurement of serum ceruloplasmin, urinary copper excretion, and hepatic copper content as well as by detection of Kayser-Fleischer rings. Several treatments are available to increase urinary excretion and decrease intestinal absorption of copper.
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PMID:Wilson's disease: copper unfettered. 1040 26

The Atp7b protein is a copper-transporting ATPase expressed predominantly in the liver and to a lesser extent in most other tissues. Mutations in the ATP7B gene lead to Wilson disease, a copper toxicity disorder characterized by dramatic build-up of intracellular hepatic copper with subsequent hepatic and neuro-logical abnormalities. Using homologous recombination to disrupt the normal translation of ATP7B, we have generated a strain of mice that are homozygous mutants (null) for the Wilson disease gene. The ATP7B null mice display a gradual accumulation of hepatic copper that increases to a level 60-fold greater than normal by 5 months of age. An increase in copper concentration was also observed in the kidney, brain, placenta and lactating mammary glands of homo-zygous mutants, although milk from the mutant glands was copper deficient. Morphological abnormalities resembling cirrhosis developed in the majority of the livers from homozygous mutants older than 7 months of age. Progeny of the homozygous mutant females demonstrated neurological abnormalities and growth retardation characteristic of copper deficiency. Copper concentration in the livers of the newborn homozygous null mutants was decreased dramatically. In summary, inactivation of the murine ATP7B gene produces a form of cirrhotic liver disease that resembles Wilson disease in humans and the 'toxic milk' phenotype in the mouse.
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PMID:Null mutation of the murine ATP7B (Wilson disease) gene results in intracellular copper accumulation and late-onset hepatic nodular transformation. 1044 29

The accumulation of cisplatin is decreased in many cisplatin-resistant cell lines, and an active efflux pump for cisplatin exists in some of them, but it has not yet been identified. In this study, we transfected the copper-transporting P-type ATPase cDNA (ATP7B) into human epidermoid carcinoma KB-3-1 cells. The transfectant, KB/WD cell line, which overexpressed the P-type ATPase, ATP7B, was resistant to both cisplatin (8.9-fold) and copper (2.0-fold). The accumulation of cisplatin in KB/WD cells was lower than in mock-transfected KB/CV cells, and the efflux of cisplatin from KB/WD cells was enhanced compared with KB/CV cells. KB/WD cells were sensitive to other heavy metals, such as antimony, arsenate, arsenite, cadmium, and cobalt. ATP7B was overexpressed in cisplatin-resistant prostate carcinoma PC-5 cells but not in the parental PC-3 cells and the revertant PC-5R cells. ATP7B may be involved in cisplatin resistance in some tumors.
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PMID:Copper-transporting P-type adenosine triphosphatase (ATP7B) is associated with cisplatin resistance. 1072 92

The gene ATP7B responsible for Wilson's disease (WD) produces a protein which is predicted to be a copper-binding P-type ATPase, homologous to the Menkes disease gene (ATP7A). Various mutations of ATP7B have been identified. This study aimed to detect disease-causing mutations, to clarify their frequency and distribution, to determine whether genotype correlates with phenotype, and to determine the rate of abnormal findings in heterozygotes for the WD gene. We analyzed 41 unrelated Japanese WD families, including 47 patients. Twenty-one mutations, including nine novel ones, were identified. 2871delC (15.9%), 1708-5T-->G (11. 0%), and Arg778Leu (13.4%) were the most common mutations. 2871delC was detected mainly in eastern Japan and 1708-5T-->G in western Japan. The homozygotes for the 1708-5T-->G, 2871delC, or Arg778Leu mutations did not show a correlation with their phenotypes. Ceruloplasmin and copper levels were abnormally low in 28.6% and 35. 0% of heterozygotes, respectively. When patients and their families are screened for WD, a high rate of abnormal laboratory data in heterozygotes must be taken into account.
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PMID:Mutational analysis of ATP7B and genotype-phenotype correlation in Japanese with Wilson's disease. 1079 Feb 7

Copper is an essential trace element which forms an integral component of many enzymes. While trace amounts of copper are needed to sustain life, excess copper is extremely toxic. An attempt is made here to present the current understanding of the normal transport of copper in relation to the absorption, intracellular transport and toxicity. Wilson disease is a genetic disorder of copper transport resulting in the accumulation of copper in organs such as liver and brain which leads to progressive hepatic and neurological damage. The gene responsible for Wilson disease (ATP7B) is predicted to encode a putative copper-transporting P-type ATPase. An important feature of this ATPase is the presence of a large N-terminal domain that contains six repeats of a copper-binding motif which is thought to be responsible for binding this metal prior to its transport across the membrane. We have cloned, expressed and purified the N-terminal domain (approximately 70 kD) of Wilson disease ATPase. Metal-binding properties of the domain showed the protein to bind several metals besides copper; however, copper has a higher affinity for the domain. The copper is bound to the domain in Cu(I) form with a copper: protein ratio of 6.5:1. X-ray absorption studies strongly suggest Cu(I) atoms are ligated to cysteine residues. Circular dichroism spectral analyses suggest both secondary and tertiary structural changes upon copper binding to the domain. Copper-binding studies suggest some degree of cooperativity in binding of copper. These studies as well as detailed structural information of the copper-binding domain will be crucial in determining the specific role played by the copper-transporting ATPase in the homeostatic control of copper in the body and how the transport of copper is interrupted by mutations in the ATPase gene.
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PMID:Copper transport and its defect in Wilson disease: characterization of the copper-binding domain of Wilson disease ATPase. 1083 Aug 65

The transport and cellular metabolism of Cu depends on a series of membrane proteins and smaller soluble peptides that comprise a functionally integrated system for maintaining cellular Cu homeostasis. Inward transport across the plasma membrane appears to be a function of integral membrane proteins that form the channels that select Cu ions for passage. Two membrane-bound Cu-transporting ATPase enzymes, ATP7A and ATP7B, the products of the Menkes and Wilson disease genes, respectively, catalyze an ATP-dependent transfer of Cu to intracellular compartments or expel Cu from the cell. ATP7A and ATP7B work in concert with a series of smaller peptides, the copper chaperones, that exchange Cu at the ATPase sites or incorporate the Cu directly into the structure of Cu-dependent enzymes such as cytochrome c oxidase and Cu, Zn superoxide dismutase. These mechanisms come into play in response to a high influx of Cu or during the course of normal Cu metabolism.
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PMID:Cellular copper transport and metabolism. 1094 Mar 36

Wilson disease (WND) is caused by a deficiency of the copper-transporting enzyme, P-type ATPase (ATP7B). Twelve different mutations have previously been identified in Taiwan Chinese with Wilson disease. We, herein, report another 4 missense mutations, 1 of which is novel. We did haplotype analysis of Taiwanese WND chromosomes, using three well characterized short tandem repeat markers (haplotype was assigned in the order of D13S314-D13S301-D13S316). Association correlation was found between the mutations and their respective haplotypes. Haplotype-deduced pedigree analysis was shown to be helpful in the mutation analysis of WND chromosomes and in the molecular assessment of both pre-symptomatic WND patients and carriers. Given the complexity and heterogeneity of the mutation spectrum of ATP7B, we suggest that haplotype analysis should be performed before full-scale mutation analysis.
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PMID:Molecular analysis of Wilson disease in Taiwan: identification of one novel mutation and evidence of haplotype-mutation association. 1104 8

In patients with Wilson disease (WD), an autosomal recessive disorder, toxic accumulation of copper results in fatal liver disease and irreversible neuronal degeneration. ATP7B, the gene mutated in WD, contains 21 exons and encodes a copper-transporting ATPase. In this study, all exons of the ATP7B gene of nine WD patients were screened for alterations by conventional mutation detection enhancement (MDE) heteroduplex analysis, followed by direct sequencing of the regions that showed heteroduplex formation. For the first time, a novel deletion mutation (4193delC) in exon 21, causing a frameshift leading to premature truncation of the protein was detected in four of nine patients. The 4193delC removes several signals within the carboxyl terminal domain that may disrupt trafficking of ATP7B protein through trans-Golgi network at the cellular level.
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PMID:A novel deletion mutation within the carboxyl terminus of the copper-transporting ATPase gene causes Wilson disease. 1105 98


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