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

Human ATPase (hASNA-I) is a novel human gene recently cloned on the basis of homology to the arsA gene of bacteria. Its protein product is an ATPase that is free in the cytoplasm and bound in the perinuclear area and nucleolus in human cells. We prepared the hASNA-I-specific 5G8 monoclonal antibody and used it to investigate the expression of hASNA-I in normal human tissues and breast cancers. hASNA-I was detected immunohistochemically only in the epithelial cells of the liver, kidney, and stomach wall, in the adrenal medulla, in the islet cells of the pancreas, in the red pulp of the spleen, and in cardiac and skeletal muscle. No staining was observed in the uterus, testis, lung, thyroid, cerebellum, and large intestine. Although no staining was also observed in normal breast tissue, all four cases of breast fibroadenomas and all 15 cases of either primary or metastatic breast carcinoma demonstrated increased staining. No embryological or functional common denominator is readily apparent. However, the increased expression in malignant breast cells is of particular interest with respect to the use of this antibody for screening of cytological specimens.
 ...
PMID:Immunohistochemical analysis of the distribution of the human ATPase (hASNA-I) in normal tissues and its overexpression in breast adenomas and carcinomas. 977 23

1. The effects of prostaglandins E2 (PGE) and F2alpha (PGF) on membrane potential and isometric tension and cytoplasmic free calcium concentration ([Ca2+]i) and tension were studied in strips of uterine smooth muscle obtained from women undergoing Caesarean delivery at term and during established labour. 2. Prostaglandins (PGs) evoked a biphasic response. The excitatory component consisted of depolarization of the membrane, which initiated spike action potentials, an increase in [Ca2+]i and tension development. The membrane remained depolarized at -19 +/- 1 mV for about 2 min, then repolarized abruptly, [Ca2+]i promptly returned to basal levels, and tension development ceased. 3. This component of the response to PGE or PGF was followed by a slow hyperpolarization which reached -85 +/- 2 mV (n = 22) at term and -70 +/- 2 mV (n = 9) during labour, and during which spontaneous action potentials and tension development did not occur. 4. Nifedipine (10-6 M) abolished spontaneous activity, abolished PG-induced action potentials and reduced the increase in [Ca2+]i (9 +/- 3 %, n = 6), the depolarization (10 +/- 1 mV, n = 14), the tension (2 +/- 1 %, n = 14) and the hyperpolarization (9 +/- 1 mV, n = 14, at term). 5. A variety of K+ channel blockers were without effect on the peak amplitude of the PG-induced hyperpolarization but the latter did not occur in the presence of ouabain (10-6 M) or in K+-free or low-Na+ solutions, suggesting an involvement of the Na+-K+-ATPase pump. 6. In conclusion, a substantial dependence on Ca2+ influx through voltage-operated Ca2+ channels accounts for the importance of membrane potential in regulating contractions in human uterine smooth muscle. The classical excitatory effect of PGE and PGF is followed by hyperpolarization involving the Na+-K+-ATPase pump. The hyperpolarization restricts the response to a single contraction and decreases the frequency of subsequent contractions. The amplitude of the hyperpolarization decreases during labour, allowing contraction frequency to increase. Its persistence at this time ensures complete relaxation between each single robust contraction, preventing spasm of the uterus that would restrict blood flow to the fetus during delivery.
 ...
PMID:Hyperpolarization and slowing of the rate of contraction in human uterus in pregnancy by prostaglandins E2 and f2alpha: involvement of the Na+ pump. 983 29

The inhibiting effect of Pb2+, Zn2+ and Cd2+ on Mg(2+)-dependent superprecipitation and ATPase activity of myometrium actomyosin. The inhibiting effect of heavy metals cations on the both processes satisfies the succession: Pb2+ > Zn2+ > Cd2+. Cadmium and zinc ions in concentration of 1 mM stimulate the initial velocity (v0) of Mg(2+)-dependent superprecipitation by 25% and 80%, respectively, while the lead ions under the same concentration inhibit the initial velocity by 40%. It is possible that these results evidence for the direct effect of ions of heavy metals on active-myosin interaction (tested by v0). May be that the mechanisms of Cd2+ and Zn2+ action on the one hand and Pb2+, on the other hand, on the interaction of the contractile proteins of the uterus smooth muscle are different. Cations of Pb, Cd or Zn introduced to the incubation medium instead of Mg2+ (5 mM) also stimulate both superprecipitation and ATPase activity but the level of the both processes decreases by 65%, 20% and 5%, respectively, as compared to control (i.e. in presence of Mg2+). It is probable that the cadmium, zinc and lead cations can substitute magnesium ions in the active centre of myosine as well as in the sections of significance for the process of superprecipitation of actomyosine. At the same time the substitution is less efficient for realization of the superprecipitation reaction and ATP-hydrolase process than when magnesium ions are available in the incubation medium. EDTA and EGTA do not remove the inhibiting effect of Pb2+, Cd2+ and Zn2+ on the contractile activity and ATP-hydrolase reaction of actomyosine complex of the uterus smooth muscle. The results obtained prove that the ions of heavy metals can effect the uterus smooth muscles at the stage of actin-myosine interaction.
 ...
PMID:[Effect of heavy metal ions on superprecipitation and ATPase activity of uterine smooth muscle actomyosin activity]. 984 63

LEC rats are defective at the p-type copper transport ATPase gene (Atp7b) and exhibit excessive hepatic copper accumulation. However, copper concentration in fetal liver of LEC rats is lower than that of F344 normal rats. In this study, we made fetal backcrosses between LEC and F344 normal rats. At 19 days of gestation, hepatic copper concentrations of (LECXF344)F1XLEC and LECX(LECXF344)F1 fetuses were equivalent to those of F344 and LEC fetuses, respectively, irrespective of their Atp7b genotype. Furthermore, Atp7b expression was identified in the uterus and the maternal portion of placenta, but not in the fetal portion of placenta, in pregnant F344 rats. From these results, we speculate that the Atp7b product might contribute to a copper transport system from mother to fetus in the maternal portion, but not in the fetal portion of placenta.
 ...
PMID:Fetal copper uptake and a homolog (Atp7b) of the Wilson's disease gene in rats. 987 80

An expedient method for the purification of a calcium activated neutral protease (CANP) of the goat uterus has been designed. This enzyme, purified to homogeneity, has been used as a tool in the structural characterization of the estrogen receptor activation factor II (E-RAF II) that dimerizes with an alternative form of estrogen receptor (ER), the non-activated estrogen receptor (naER). The enzyme cleaves the E-RAF into two fragments, alpha and beta, of molecular mass 32 and 30 kDa, respectively. The beta retains the DNA binding activity, as well as the capacity to dimerize with the naER. On the other hand, the cholesterol binding activity and the ATPase function are shared by both alpha and beta fragments. The E-RAF domain that binds to the nuclear periphery appears to be localized on the beta fragment. The beta fragment, however, is incapable of entering the nucleus on its own.
 ...
PMID:Structural characterization of the goat uterine estrogen receptor activation factor using an endogenous calcium activated neutral protease. 1043 23

PDNP (phosphodiesterase I/nucleotide pyrophosphatase) is one of a series of ectoenzymes that are involved in hydrolysis of extracellular nucleotides. PDNP possesses ATPase (EC 3.6.1.3) and ATP pyrophosphatase (EC 3.6.1.8) activities. Mammalian PDNP consists of three closely related family proteins (PDNP1, -2, and -3), and they are expressed in different cell types and at different developmental stages. Rat PDNP3 is expressed in a subset of immature glial cells and in the alimentary tract. Human PDNP3 is expressed in glioma cells, prostate, and uterus, but not in the alimentary tract. We have cloned genomic DNA containing the whole coding region of the human PDNP3 gene and determined its exon-intron structure. The human PDNP3 gene spans over 60 kb and is organized into 25 exons and 24 introns. We determined the nucleotide sequence of the 5'-flanking region of human and rat PDNP3 genes. The upstream region of both species lacks a canonical TATA box and contains a putative binding site for CCAAT enhancer-binding proteins near the transcription start site. Promoter activity analysis of the 5'-flanking region revealed that the sequence around the CCAAT box is required for its transcriptional activity in 9L rat glioma cells. A gel shift assay demonstrated that 9L nuclear extract contains proteins that bind to this region.
 ...
PMID:Genomic structure and promoter analysis of the ecto-phosphodiesterase I gene (PDNP3) expressed in glial cells. 1052 96

At term of pregnancy, oxygen consumption by the human or ovine placenta accounts for 40 per cent of total oxygen uptake by the gravid uterus. In the sheep, most oxygen is used for oxidative phosphorylation of glucose; the remainder is probably utilized for non-mitochondrial processes. The ATP yield is expended mainly in protein synthesis and cation transport. The fractional protein synthesis rate of ovine placenta is 60 per cent per day. Applying these data to man, protein synthesis is estimated to account for about 30 per cent of placental oxygen uptake. Probably this reflects the high rates of synthesis of peptide and steroid hormones. The Na+ gradient is the basis for secondary active transport of amino acids and other substances, and the Na(+)-K(+)-pump probably accounts for 20-30 per cent of oxygen uptake, with a smaller contribution from Ca(2+)-ATPase. Placental oxygen uptake remains constant during acute reductions in uterine oxygen supply and is maintained at the expense of the fetus. In the longer term, in experimental models of fetal growth restriction, placental oxygen consumption is reduced to a greater extent than fetal oxygen consumption. Placental oxygen consumption is greatly reduced under in vitro experimental conditions, due largely to an inadequate oxygen supply. This results in reduced protein synthesis and possibly inhibition of Na(+)-K(+)-ATPase. However, if the placenta is subjected to hyperoxia, by raising the PO2 of the medium, there is an increase in anaerobic glycolysis and structural damage may ensue. Premature exposure of trophoblast to high oxygen tensions in vivo may result in reduced villous branching, but this is likely to be a cause, rather than a consequence, of reduced fetal growth and oxygen consumption.
 ...
PMID:Placental oxygen consumption. Part I: in vivo studies--a review. 1083 Nov 19

Estrogen and progesterone, while regulating uterine functions, also regulate the number of caveolae and the level of caveolin. Large numbers of caveolae, as well as elevated expression of caveolin-1 and caveolin-2 isoforms in the myometrium of ovariectomised (OVX) rats were detected. 17beta-estradiol (E2) has a downregulating effect: the treatment of OVX rats with E2 (5 microg/animal) reduced the formation of caveolae by approx. 90%. Western blots clearly demonstrated the reduction of membrane caveolin-1 and -2 content. Progesterone treatment (2.5 mg/animal) alone did not cause any substantial change, but prevented the effect of estrogen. Control experiments showed that the quantity of Na+/K+-ATPase, a plasma membrane protein excluded from caveolae, was not downregulated by E2. The administration of the pure estrogen receptor (ERalpha) antagonist ICI 182,780 (1 mg/animal) not only compensated for the inhibitory effect of E2, but further increased the level of caveolin-1 in the myometrium of OVX rats and facilitated the formation of caveolae by approximately 70%. In contrast, the partial antagonist tamoxifen (1 mg/animal) mimicked the effect of estrogen. The amount of caveolin also changed during pregnancy. During the first half of pregnancy the expression of caveolin was suppressed, but it gradually increased until delivery. Our results indicate that the formation and number of caveolae are influenced by the physiological state of the uterus in a hormone dependent manner.
 ...
PMID:Estrogen downregulates the number of caveolae and the level of caveolin in uterine smooth muscle. 1148 2

The general pharmacological properties of YJA20379-8 (3-butyryl-4-[(R)-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, CAS 187654-40-6), a new H+/K(+)-ATPase inhibitor with anti-ulcer activities, were investigated in mice, rats and guinea pigs. YJA20379-8 at oral doses of 25, 50 and 100 mg/kg did not affect the locomotor activity, hexobarbital hypnosis and motor coordination in mice. The drug did not have analgesic action and anticonvulsant action at the doses of 100 mg/kg p.o. The respiration and blood pressure were not affected at 10 mg/kg i.v. in rats. YJA20379-8 at 2 x 10(-4) g/ml did neither produce any contraction nor relaxation of isolated organs, such as guinea pig ileum, rat fundus, rat uterus and guinea pig vas deferens, and the drug antagonized the contractile responses to several spasmogens, such as acetylcholine, histamine, serotonin, L-phenylephrine, oxytocin and BaCl2. The drug up to 100 mg/kg p.o. did not affect pupil size and the intestinal propulsion of mice. And it did not show an anticarrageenan action at 100 mg/kg. In this general pharmacology study, hypothermic effect in mice, retardation in gastric emptying in rats, decreases in urine excretion in rats at oral doses of 50 and 100 mg/kg of YJA20379-8 and the spasmolytic activity could be found. However, no other effects were exhibited at a high oral dose of 100 mg/kg in animals in this study.
 ...
PMID:General pharmacological properties of YJA20379-8, a new H+/K(+)-ATPase inhibitor with anti-ulcer activities. 1155 27

The sarcoplasmic reticulum (SR) is present as an extensive network in uterine cells. In this chapter we examine its functional importance, relating in particular, to the control of contractility in pregnancy. The uterine SR has both ryanodine receptors (RyR) and inositol-1 ,4,5-trisphosphate InsP3 receptors (InsP3R). The RyR and subsequent Ca24-induced Ca2+ release play little role in either human or rat contractions or Ca2+ transients. There may be subtle, spatiotemporal effects at the single cell level. Caffeine, an agonist for RyR fails to release Ca2+ and indeed produces relaxation not contraction. InsP3 dearly causes release of Ca2+ from the uterine SR and an increase in force, although these changes are only small and transient compared to those occurring due to external Ca2+ entry. Inhibition of the SR Ca-ATPase by cyclopiazonic acid, empties Ca2+ from the SR. This is associated with an augmentation of force and Ca2+ transient. Thus the SR normally functions in the uterus to limit, not increase contractions. The mechanism may involve vectoral release of Ca2+ from the SR and activation of surface membrane K+ channels. This activation would tend to decrease L-type Ca2+ entry and hence reduce contraction. Thus the SR is playing a role in controlling membrane excitability and hence contractility. The SR also plays a role in the relaxation of force. This is not primarily due to a direct sequestering of large amounts of Ca2+, but rather that the SR directs Ca2+ to the surface membrane extrusion mechanisms, i.e. Ca-ATPase and Na+/Ca2+ exchanger. This enables them to act more efficiently, and therefore aids relaxation. Recent direct measurements of SR luminal content show decreases with agonist application but not during spontaneous activity; confirming the results described above. This technique will be used to better characterize the uterine SR, its control and relevance to normal and abnormal labours.
 ...
PMID:Role of the sarcoplasmic reticulum in uterine smooth muscle. 1216 16


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>