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)

The mouse BCM1 (OX45, Blast-1) antigen has been cDNA cloned and sequenced to provide data supporting the view that BCM1, LFA3, and CD2 constitute a subgroup within the Ig superfamily. Mouse BCM1 is widely expressed on leukocytes and is likely to be anchored to the cell surface by a glycosyl-phosphatidylinositol anchor, as is the case for rat and human BCM1 antigen. Genetic linkage studies by recombination and pulse field analysis showed the BCM1 locus (Bcm-1) to be on distal mouse chromosome 1 and to be linked within 1,600 kb to the locus for an ATPase alpha chain gene (Atpa-3). A similar relationship was established between the human BCM1 locus (BCM1) and ATP1A2, and other markers on chromosome 1q. Conservation of genomic organization within a segment of human chromosome 1q and mouse chromosome 1 was demonstrated. A similar situation is seen in the region of the CD2 and LFA3 genes between mouse chromosome 3 and human chromosome 1p. Furthermore, the CD2/LFA3 genes are linked within 580 kb to Atpa-1/ATP1A1 genes to provide a parallel situation to the linkage between Bcm-1/BCM1 and Atpa-3/ATP1A2 on chromosomes 1 (mouse) and 1q (human). Taken together, the data suggest duplication of a chromosome region including the precursors of the genes for BCM1, CD2, and LFA3, and the ATPase genes to give rise to the linkage groups now observed. The duplicated regions may have stayed together on chromosome 1 in the human (with the insertion of a centromere), while in the mouse, the genetic regions are proposed to have become dispersed in the formation of chromosomes 1 and 3. CD2 and LFA3 are more dissimilar in sequence than BCM1 and LFA3, and if the precursors of the CD2 and LFA3 loci formed before the proposed chromosome segment duplication, then a gene encoding a recognizer molecule for BCM1 may exist in linkage with Bcm-1/BCM1 on chromosome 1 (mouse) and 1q (human).
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PMID:Structure, expression, and genetic linkage of the mouse BCM1 (OX45 or Blast-1) antigen. Evidence for genetic duplication giving rise to the BCM1 region on mouse chromosome 1 and the CD2/LFA3 region on mouse chromosome 3. 169 56

A survey of 12 species has revealed that reversible ischemia-induced protonic inhibition of the cardiac muscle mitochondrial adenosine 5'-triphosphatase (ATPase) described by this author earlier (Rouslin, W. J. Biol. Chem. 258: 9657-9661, 1983) occurs only in animals with heart rates lower than approximately 200 beats/min. It was thus fully demonstrable in rabbit, dog, sheep, human, pig, and beef heart mitochondria. In contrast, the in situ ATPase inhibition was completely absent in six smaller species capable of heart rates of approximately 300 or more beats/min. These were chicken, pigeon, guinea pig, rat, hamster, and mouse. Analyses of the cardiac muscle mitochondria of 9 of the 12 species studied showed them to contain normal levels of mitochondrial ATPase inhibitor; the three smallest species, rat, hamster, and mouse contained only very low levels of inhibitor. Thus, although chicken, pigeon, and guinea pig heart mitochondria contained normal levels of ATPase inhibitor, they (like the rat, hamster, and mouse) showed no in situ ischemia-induced ATPase inhibition. This and other observations suggest that the lack of in situ ATPase inhibition in hearts capable of 300 or more beats/min may be due to the presence of either an in situ nonfunctional ATPase inhibitor protein or to an in situ uninhibitable form of the mitochondrial ATPase in the faster-paced hearts. Alternatively, the mitochondria of the fast-paced hearts may be insulated somehow against the cytosolic acidosis which develops during ischemia and which triggers the ATPase inhibition in the slow heart-rate hearts. In the faster paced hearts, ATP hydrolysis does not appear to be regulated by inhibitor binding to the ATPase under nonenergizing conditions.
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PMID:The mitochondrial adenosine 5'-triphosphatase in slow and fast heart rate hearts. 295 Jul 75

Selected biochemical characteristics of diaphragm muscle were compared among several orders of adult mammals (cattle, swine, rabbit, guinea pig, rat, and mouse) with known differences in resting breathing frequencies (f, range = 15-138). Diaphragms from smaller animals had significantly higher citrate synthase (CS) and phosphofructokinase (PFK) activities and substrate oxidation rates than larger animals. Ranges of activities for CS and PFK were 93-27 and 58-39 mumol.g-1.min-1, respectively; and 34-5 and 19-2 nmol.g-1.min-1 for [U-14C]glucose (GLU) and [1-14C]palmitate (PAL) oxidation, respectively. The percent of native fast myosin (FM) isoforms was significantly different among groups. Mouse diaphragm had the highest % FM (88.6%), whereas the lowest values (7.5%) were observed in cattle diaphragm. Myosin ATPase (M-ATPase, pH 9.8) activity was significantly lower in cattle (0.06 mumol.mg protein-1.min-1) and swine (0.38 mumol.mg protein-1.min-1) diaphragm than in other mammals (range of 1.14-0.67 mumol.mg protein-1.min-1). Correlation coefficients determined among means of measured biochemical parameters and established values of f indicated that CS activity and substrate oxidation rates were significantly correlated with f (r = 0.92, 0.92, 0.86 for CS, GLU, PAL, respectively) and the % FM increased with f. M-ATPase (pH 9.8) was significantly correlated with % FM (r = 0.85), whereas PFK and M-ATPase activities were not closely associated with f. It was concluded that f in mammals is significantly correlated with the biochemical parameters of aerobic capacity and is associated with the percent of FM isoforms in the diaphragm.
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PMID:Biochemical characteristics of mammalian diaphragms. 297 5

Effects of ouabain on a high K-induced contraction and intracellular Na and K contents of the ileal longitudinal muscle preparations isolated from various animal species was compared. In muscles of various animals (monkey, dog, cat, rabbit, guinea-pig, rat and mouse), the high K-induced contraction was inhibited by verapamil (5 X 10(-8) M) or ouabain (3 X 10(-6) M), and both the inhibitions were antagonized by an increase in external Ca in a competitive manner. Species differences were shown in the ouabain effect but not in the verapamil one. Regarding the sensitivity to ouabain, the muscles were divided into two groups, that is, the muscle from monkey, rabbit, guinea-pig or dog belongs to the high sensitivity group, and that from cat, rat or mouse belongs to the low one. The order of sensitivities of the muscles to ouabain in the relaxation was consistent with that in Na,K-ATPase inhibition, as reported by Repke et al. (1965). Intracellular Na contents of muscles were increased by an addition of ouabain to the high K solution, and the rate and amount of the accumulation of intracellular Na varied in these muscles. Except for the cat muscle, a high correlation was noted between the ouabain-induced relaxation and the amount of intracellular Na accumulation. However, the regression coefficients were variable: 4.1 in the monkey muscle, 2.2 in the rat one, and about 1.0 in the others. That is, the monkey muscle showing the high regression coefficient value probably has a high sensitivity to the inhibition of intracellular Na in the high K-induced contraction.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Species differences in the inhibitory effect of ouabain on high K-induced contraction in the ileal longitudinal muscle. 406 91

In the plasma membranes from several mammalian tissues (including normal and tumor tissues), a Mg2+ (or Ca2+)-dependent ATP phosphohydrolase activity is present in much greater amount than the (Na+ + K+)-ATPase. The ouabain-insensitive activity can be attributed to at least two enzymes, an ATPase (EC 3.6.1.3) and an ATP diphosphohydrolase (EC 3.6.1.5). The ATPase hydrolyzes ATP and other nucleoside triphosphates and is not inhibited by azide. The ATP diphosphohydrolase hydrolyzes both ATP and ADP (and other nucleoside tri- and diphosphates) and the hydrolysis of adenine nucleotides is strongly inhibited by 10 mM azide. The ratios of these two enzymes in the various membranes (as determined by the extent of azide inhibition) vary widely. The ATP diphosphohydrolase accounts for most of the Mg2+ (or Ca2+)-dependent ATP hydrolysis activity of the plasma membranes of liver (mouse), kidney (dog), two mouse sarcomas, and a human astrocytoma (xenograft in athymic mice). The ATPase is more dominant in the plasma membranes from mouse brain and human oat cell carcinoma. The widespread presence of the ATP diphosphohydrolase in plasma membrane from various types of tissues is demonstrated for the first time and is of particular interest in view of its relatively high activity in the plasma membranes of two sarcomas. The membrane-bound ATP diphosphohydrolase is characterized with respect to its metal ion activators, substrates, and inhibitors. These results should facilitate the distinction of this enzyme from other ATP hydrolyzing enzymes of plasma membranes in future investigations.
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PMID:The common occurrence of ATP diphosphohydrolase in mammalian plasma membranes. 630 14

The H+ and HCO3- transporters present in the medullary thick ascending limb (MTAL) of the kidney are involved in several functions, such as transepithelial transport, defense of cell pH and cell volume. Apical H+ secretion occurs via the NHE-3 and NHE-2 isoforms of the Na+/H+ exchanger, and H(+)-ATPase. The apical Na+/H+ exchanger is responsible for most of the apical step of transepithelial HCO3- absorption and is unresponsive to cell acidification under isosmotic conditions. Basolateral HCO3- efflux mechanisms may occur via the Cl-/HCO3- exchanger and via the cotransporters K+/HCO3- (in the rat) and Na-3HCO3- (in the mouse). However, the role of each transporter in transepithelial HCO3- absorption is currently unknown. Inhibition of the basolateral Na+/H+ exchanger (NHE-1) paradoxically inhibits the apical Na+/H+ exchanger. This cross talk is independent of cell pH and may involve variations in cell volume. Arginine vasopressin (AVP) and hyperosmolality induce a differential regulation of basolateral NHE-1 and the apical Na+/H+ exchanger. They stimulate the basolateral NHE-1, and the resulting cell alkalinization probably stimulates the pHi-sensitive AE2, which restores cell volume by cellular uptake of NaCl. They also inhibit the apical Na+/H+ exchanger, which reduces net HCO3- absorption and thus may prevent interstitial fluid alkalinization. Chronic metabolic acidosis markedly increases HCO3- absorptive capacity of MTAL, by stimulating at least the synthesis of apical NHE-3 protein, as in the proximal tubule. Conversely, chronic metabolic alkalosis reduces the apical NHE-3 transport activity by decreasing the synthesis of NHE-3 protein. The paradoxical increase in HCO3- absorptive capacity of MTAL observed in the model of chronic NaHCO3-load alkalosis should be due to other factors overcoming the inhibitory effect of alkalosis on NHE-3.
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PMID:H+ and HCO3- transporters in the medullary thick ascending limb of the kidney: molecular mechanisms, function and regulation. 955 30

Glucocorticoids (GC) and mineralocorticoids (MC) have profound regulatory effects upon the central nervous system (CNS). Hormonal regulation affects several molecules essential to CNS function. First, evidences are presented that mRNA expression of the alpha3 and beta1-subunits of the Na,K-ATPase are increased by GC and physiological doses of MC in a region-dependent manner. Instead, high MC doses reduce the beta1 isoform and enzyme activity in amygdaloid and hypothalamic nuclei, an effect which may be related to MC control of salt appetite. The alpha3-subunit mRNA of the Na,K-ATPase is also stimulated by GC in motoneurons of the injured spinal cord, suggesting a role for the enzyme in GC neuroprotection. Second, we provide evidences for hormonal effects on the expression of mRNA for the neuropeptide arginine vasopressin (AVP). Our data show that GC inhibition of AVP mRNA levels in the paraventricular nucleus is sex-hormone dependent. This sexual dimorphism may explain sex differences in the hypothalamic-pituitary-adrenal axis function between female and male rats. Third, steroid effects on the astrocyte marker glial fibrillary acidic protein (GFAP) points to a complex regulatory mechanism. In an animal model of neurodegeneration (the Wobbler mouse) showing pronounced astrogliosis of the spinal cord, in vivo GC treatment down-regulated GFAP immunoreactivity, whereas the membrane-active steroid antioxidant U-74389F up-regulated this protein. It is likely that variations in GFAP protein expression affect spinal cord neurodegeneration in Wobbler mice. Fourth, an interaction between neurotrophins and GC is shown in the injured rat spinal cord. In this model, intensive GC treatment increases immunoreactive low affinity nerve growth factor (NGF) receptor in motoneuron processes. Because GC also increases immunoreactive NGF, this mechanism would support trophism and regeneration in damaged tissues. In conclusion, evidences show that some molecules regulated by adrenal steroids in neurons and glial cells are not only involved in physiological control, but additionally, may play important roles in neuropathology.
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PMID:Regulation of gene expression by corticoid hormones in the brain and spinal cord. 969 80

This study was performed in order to test the hypothesis that the glucocorticoid hormone stimulates the formation of Na,K-ATPase in the inner ear of the mouse. An immunohistochemical study with respect to the presence and distribution of glucocorticoid receptors (GR) and Na,K-ATPase in the vestibular and cochlear regions of the inner ear was performed on a C57BL mouse with a null mutation of the glucocorticoid receptor (GR mutant mouse). The wild type C57BL mouse and the CBA mouse served as normal controls. As expected, the homozygous GR mutant mouse showed no specific staining for GR in the inner ear. The heterozygous GR mutant mouse showed faint staining of GR in the spiral limbus, the spiral ganglion, the organ of Corti and the utricle. This staining was markedly less than in the wild type C57BL mouse. Antibody labelling of Na,K-ATPase in the inner ear showed no significant difference between the homozygous and the heterozygous GR mutant mouse as compared to the control wild type C57BL mouse or the CBA mouse. Although earlier studies have shown a positive correlation between levels of glucocorticoid hormone in serum and the concentration of Na,K-ATPase in the inner ear, the hypothesis that glucocorticoid hormones alone stimulate the formation of Na,K-ATPase in the inner ear could not be confirmed by this study. Thus other regulating substances must be considered.
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PMID:Distribution of Na,K-ATPase is normal in the inner ear of a mouse with a null mutation of the glucocorticoid receptor. 982 12

Resolution of pulmonary oedema is mediated by active absorption of liquid across the alveolar epithelium. A key component of this process is the sodium-potassium ATPase (Na+K+-ATPase) enzyme located on the basolateral surface of epithelial cells and up-regulated during oedema resolution. We hypothesised that lung liquid clearance could be further up-regulated by lipid-mediated transfer and expression of exogenous Na+K+-ATPase cDNA. We demonstrate proof of this principle in a model of high permeability pulmonary oedema induced by intraperitoneal injection of thiourea (2.5 mg/kg) in C57/BL6 mice. Pretreatment of mice (24 h before thiourea) by nasal sniffing of cationic liposome (lipid #67)-DNA complexes encoding the alpha and beta subunits of Na+K+-ATPase (160 microg per mouse), significantly (P<0.01) decreased the wet:dry weight ratios measured 2 h after thiourea injection compared with control animals, pretreated with an equivalent dose of an irrelevant gene. Whole lung Na+K+-ATPase activity was significantly (P<0.05) increased in mice pretreated with Na+K+-ATPase cDNA compared both with untreated control animals as well as animals pretreated with the irrelevant gene. Nested RT-PCR on whole lung homogenates confirmed gene transfer by detection of vector-specific mRNA in three of four mice studied 24 h after gene transfer. This demonstration of a significant reduction in pulmonary oedema following in vivo gene transfer raises the possibility of gene therapy as a novel, localised approach for pulmonary oedema in clinical settings such as ARDS and lung transplantation.
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PMID:Pretreatment with cationic lipid-mediated transfer of the Na+K+-ATPase pump in a mouse model in vivo augments resolution of high permeability pulmonary oedema. 1084 56

Recent studies on myosin V report a number of kinetic differences that may be attributed to the different heavy chain (chicken vs mouse) and light chain (essential light chains vs calmodulin) isoforms used. Understanding the extent to which individual light chain isoforms contribute to the kinetic behavior of myosin V is of critical importance, since it is unclear which light chains are bound to myosin V in cells. In addition, all studies to date have used alpha-skeletal muscle actin, whereas myosin V is in nonmuscle cells expressing beta- and gamma-actin. Therefore, we characterized the actin and light chain dependence of single-headed myosin V kinetics. The maximum actin-activated steady-state ATPase rate (V(max)) of a myosin V construct consisting of the motor domain and first light chain binding domain is the same when either of two essential light chain isoforms or calmodulin is bound. However, with bound calmodulin, the K(ATPase) is significantly higher and there is a reduction in the rate and equilibrium constants for ATP hydrolysis, indicating that the essential light chain favors formation of the M. ADP.P(i) state. No kinetic parameters of myosin V are strongly influenced by the actin isoform. ADP release from the actin-myosin complex is the rate-limiting step in the ATPase cycle with all actin and light chain isoforms. We postulate that although there are significant light-chain-dependent alterations in the kinetics that could affect myosin V processivity in in vitro assays, these differences likely are minimized under physiological conditions.
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PMID:Actin and light chain isoform dependence of myosin V kinetics. 1108 68


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