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)

In this report we describe a rapid, high-yield protocol for the isolation of apical (AP) and basolateral (BL) plasma membrane domains from monolayers of bovine aortic endothelial cells (BAECs) grown on tissue culture dishes as well as microcarrier beads. Using a modified cationic colloidal silica microbead membrane-isolation procedure, which deposits a uniform silica-polyacrylate pellicle over the entire AP membrane surface, a 4- to 9.6-fold relative enrichment of AP membrane and a 3.55- to 3.67-fold relative enrichment of BL membrane was obtained when the isolated domains were examined for silica and Na+/K(+)-ATPase, respectively. Immunoblotting of the isolated membrane domains displayed the presence of angiotensin-converting enzyme (ACE) exclusively in the AP domain and collagen receptors (CRs) highly enriched in the BL membrane domain when monolayers were grown on a gelatin substratum.
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PMID:Examination of transcellular membrane protein polarity of bovine aortic endothelial cells in vitro using the cationic colloidal silica microbead membrane-isolation procedure. 133 Nov 35

We have fused full length and the carboxyl-half of human MDR1 cDNA with the E. coli lacZ gene via a collagen linker and allowed their expression in yeast Saccharomyces cerevisiae. Using antibodies against beta-galactosidase we partially purified the fusion proteins by immunoprecipitation and show here that the full length fusion protein has ATPase activity. By contrast, the fusion protein containing the carboxyl-half of P-glycoprotein did not show ATPase activity, indicating that both domains of P-glycoprotein are necessary. By treatment of the immunoprecipitated fusion protein with collagenase, P-glycoprotein was released from the beta-galactosidase moiety. The results shown here open the possibility for a large scale purification of P-glycoprotein using this site specifically cleavable fusion protein.
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PMID:Production of a site specifically cleavable P-glycoprotein-beta-galactosidase fusion protein. 136 54

The clinical syndrome of heart failure occurs as a consequence of the limitation of compensatory mechanisms, such as cardiac hypertrophy. To clarify transcriptional changes in specific genes in failing hearts, we examined the expression of cardiac Ca(2+)+Mg(2+)-dependent ATPase in the sarcoplasmic reticulum and transforming growth factor beta genes in the ventricles of rat hypertrophied heart, and the expression of guanine nucleotide-binding protein and "fetal" contractile protein genes in the ventricles of cardiomyopathic Syrian hamsters of Bio14.6. Northern blot analysis of total cellular RNA revealed that the mRNA levels of Ca(2+)+Mg(2+)-dependent ATPase were decreased by pressure overload and became 32% of sham in 1 month, and were correlated with corresponding protein levels. Transforming growth factor beta mRNA, a potent activator of collagen synthesis, was increased by pressure overload. The expression levels of the Gs alpha mRNA, which stimulated the adenylate cyclase, in Bio14.6 ventricles were lower than the levels in ventricles of the F1B hamster strain, and decreased as the stage of cardiomyopathy progressed. Moreover, re-expression of fetal mRNA was observed in the ventricle of cardiomyopathic Syrian hamsters of the Bio14.6 strain. These results indicate that reprogramming of cardiac gene expression both of myofibrillar and nonmyofibrillar components might occur in the failing heart.
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PMID:Molecular mechanism of hypertrophied failing heart--abnormalities of the diastolic properties and contractility. 138 37

To study the diastolic properties of the heart includes examining active relaxation, passive ventricular stiffness and atrial contraction. (i) The main determinant of active relaxation is the adenosine triphosphate (ATP) concentration. Relaxation needs to occur so that the ATP content of the cell can be decreased by activation of the myosin ATPase, which in turn depends upon an intracellular messenger, elevation of the calcium transient. In a model of cardiac hypertrophy active relaxation is always slower. This slowing accompanies a slowing of the calcium transient, a diminution in the activity of the Na+/Ca2+ exchanger, a change in the properties of Na+, K+ ATPase and a decreased concentration of Ca2+ ATPase in the sarcoplasmic reticulum. (ii) Chamber stiffness is likely to be increased only in relation to the degree of ventricular hypertrophy. The main, if not unique, determinant of ventricular diastolic tissue stiffness is the structure and concentration of the collagen. Consequently tissue stiffness is augmented in cardiac hypertrophy in which the ventricular collagen concentration is elevated. It is important that both clinically and experimentally cases of cardiac hypertrophy, even those resulting from pressure overload in which myocardial stiffness and cardiac collagen concentration remain unchanged, have been documented. A good example of this is the DOCA-salt model of arterial hypertension. (iii) Atrial contraction is normally more rapid than ventricular contraction, the biological basis for which is the difference in isomyosin content.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Biological basis of diastolic dysfunction of the hypertensive heart. 139 55

The mechanism of NaCl transport across the epithelium of intact MDCK cysts grown in a collagen gel matrix was investigated. Double-barreled microelectrodes were used to measure basolateral membrane PD (Vbl), transepithelial PD (Vt), and intracellular (Cli) and intralumenal (Clcy) Cl- activities in cysts under different conditions. In a control Ringer's solution (RS), Cli (60 +/- 1 mM) and Clcy (107 +/- 2 mM) exceeded the values corresponding to electrochemical equilibrium across the basolateral membrane and epithelium, respectively. Cli was reduced by superfusing the cysts with a low Cl- RS (Cli, 20 +/- 3 mM), a low Na+ RS (Cli, 40 +/- 4 mM), or by adding amiloride to the control RS (Cli, 46 +/- 1 mM). Cli was unaffected by removal of either K+ or HCO3- from the RS or by adding furosemide or SITS to the control RS. Vbl in the control RS was -50 +/- 2 mV and was affected only by removal from the RS of K+ (Vbl, -31 +/- 3 mV) or HCO3- (Vbl, -29 +/- 4 mV) or by the addition of SITS to the control RS (Vbl, -59 +/- 5 mV). Vt in control RS was -2 +/- 0.2 mV (lumen negative), and was increased by reducing bath Na+ (Vt, -37 +/- 2 mV) but not by reducing bath Cl-. These data indicate that Cl- is secreted in a basolateral to apical direction by the cyst epithelium. Basolateral Cl- transport probably occurs mainly by an electroneutral Cl-/HCO3- exchanger. Transepithelial Na+ transport seems to occur via a paracellular route which appears to be cation selective. These experiments also support the existence, in the basolateral membrane, of a Na+/K+ ATPase, a Na+/H+ exchanger, and possibly a Na+/HCO3-/CO3(2-) transporter.
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PMID:NaCl transport by Madin Darby canine kidney cyst epithelial cells. 140 15

The basement membrane stimulates the differentiation and polarity of simple transporting epithelia. We demonstrated for the retinal pigment epithelium (RPE) of chicken embryos that polarity develops gradually. Although the RPE and an immature basement membrane are established on embryonic day 4 (E4), the distribution of the Na,K-ATPase and a family of basement membrane receptors containing the beta 1 subunit of integrin is nonpolarized. The percentage of polarized cells increases gradually until cells in all regions of the epithelium are polarized on E11. During this time, the basement membrane increases in size and complexity to form Bruch's membrane. To study the ability of the basement membrane to stimulate the polarized distribution of the beta 1 integrins or the Na,K-ATPase, RPE was harvested from E7, E9, or E14 embryos and cultured on Bruch's membrane isolated (in association with the choroid) from E14 embryos. As a control, the RPE was plated on the side of the choroid lacking a Bruch's membrane. The distribution of the beta 1 integrins and the Na,K-ATPase was determined by indirect immunofluorescence. Bruch's membrane stimulated the polarized distribution of the beta 1 integrins regardless of the developmental age of the RPE even though E7 RPE is nonpolarized in vivo. To examine the role of individual matrix components, RPE was plated on matrix-coated filters. The polarized distribution of the beta 1 integrins was stimulated by laminin, collagen IV, and Matrigel but not by fibronectin. Interestingly, laminin and collagen IV are present in the basement membrane on E4 when RPE is not polarized in vivo. Under no circumstances was the distribution of the Na,K-ATPase polarized. These data indicate that the basement membrane influences the distribution of a subset of plasma membrane proteins but that other factors are required for full polarity.
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PMID:Basement membrane stimulates the polarized distribution of integrins but not the Na,K-ATPase in the retinal pigment epithelium. 166 92

Cardiac hypertrophy which occurs during chronic arterial hypertension is one of the numerous examples of biological adaptation to environmental requirements. As such, it is obtained at random by trial and error, and adaptation represents the sum of various modifications in gene expression, including the shift in isomyosin or in iso-Na+,K(+)-ATPase, the decrease in beta 1-adrenergic or muscarinic receptors or in sarcoplasmic reticulum Ca(2+)-ATPase densities, and the unchanged density in calcium channels and current. Some of these changes are beneficial at the cellular level but are finally detrimental for the organism as a whole, such as slowing of maximum shortening velocity (Vmax). The prolonged calcium transient is likely to be a consequence of the various modifications of the membranes phenotype and provides a rational basis for arrhythmogenicity of the hypertrophied heart. There are also detrimental modifications, such as the increased collagen concentration and vascular hypertrophy, which may result from the accompanying changes in plasma content in several hormones or peptides.
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PMID:Biological adaptation and dysadaptation of the heart to chronic arterial hypertension: a review. 168 53

Skeletal muscle grafts performed with neurovascular repair are used extensively in clinical situations. However, most controlled experimental studies on the efficacy of such grafts have been conducted on muscles with a relatively small mass and over a limited recovery period. Therefore, selected cellular and matrix component properties of the comparatively large dog gracilis muscle (75 g) were studied 9-12 mo after orthotopic neurovascular grafting. The grafted muscle wet weights were 71% of the contralateral control (sham-operated) muscles. In addition, the concentrations of noncollagenous protein (13%), DNA (28%), and RNA (34%) were significantly reduced in the grafts. However, the concentration of collagen was significantly higher (41%) in the grafts. In this regard, the type III collagen phenotype showed the greatest relative increase. There was no difference between the grafted and control proteoglycan concentration. The metabolic profiles of the grafted muscles were significantly different from control. The activities of myofibrillar adenosinetriphosphatase (34%) and alpha-glycerophosphate dehydrogenase (25%) were reduced, whereas citrate synthase remained unchanged. These data suggest that recovery of up to 1 yr was insufficient for the normalization of several connective tissue matrix components and biochemical properties of the grafts.
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PMID:Incomplete normalization of dog gracilis muscle grafts with neurovascular repair despite long-term recovery. 169 Jun 97

In order to clarify the neoplastic-mesenchymal cell interaction, tumor structures were histologically classified into duct, solid and scattered types, and stromal changes were observed in each type with histochemical techniques. The quantitative and qualitative differences of the stromal components as proteoglycan and collagen were histochemically differed in these morphological features. Ca++ ATPase was ultrastructurally localized on the plasma membrane of myoepithelial cell in salivary glands. The activity of Ca++ ATPase changes in tumor cell differentiation of pleomorphic adenoma and adenoid cystic carcinoma. These results suggest that the stromal components and Ca++ ATPase play an important role on the tumor cell proliferation and differentiation in these tumors.
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PMID:[The role of stromal components and Ca++ ATPase in pleomorphic adenoma and adenoid cystic carcinoma]. 171 15

A study is performed on the long-term effect of the chloracetanilide herbicide "Acetochlor" in doses 21.0; 10.6: 5.5 and 2.6 mg/kg-1 in conditions of 6-month oral application and 2-month rehabilitation period on the metabolite processes and the balance of the connective-tissue components in the myocardium and aorta of male white rats. A complex of biochemical and histological methods are performed (activity of succinate dehidrogenase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, adenosin triphosphatase, cytochrome oxidase, fructoso-1,6-diphosphatase, level of the thiol groups, soluble globular, elastine, collagen fractions, insoluble collagen and elastine, general and sulphated glucosamino glycanes). The dose 21.0 mg/kg-1 leads to blocking of the thyol groups, inactivation of succinate dehydrogenase, cytochrome oxidase, adenosin triphosphatase, fructose-1,6-diphosphatase, glucose-6-phosphate dehydrogenase, activation of lactate dehydrogenase, decrease of the soluble globular, elastine, and collagen fractions and increase of the glucoseaminoglycanes in the heart muscle and aorta. The changes established in the heart muscle at 10,6 mg/kg-1 certify for stronger sensitivity of the organ of the aorta wall. The presence of single changes in the examined indices, their complete dying out after the rehabilitation period and absence of structural changes in the myocardium and aorta permit the dose of 5.5 mg/kg-1 to be accepted as not effective in the conditions of chronic experiment concerning the cardiovascular system.
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PMID:[The effect of the acetanilide herbicide Acetochlor on the cardiovascular system of white rats]. 179 94


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