Distribution, cloning, and characterization of porcine nucleoside triphosphate diphosphohydrolase‐1

Lemmens, Raf; Vanduffel, Luc; Kittel, Ágnes; Beaudoin, Adrien R.; Benrezzak, Ouhida; Sévigny, Jean

doi:10.1046/j.1432-1327.2000.01462.x

Cited by 33 publications

(22 citation statements)

References 42 publications

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“…Furthermore, nothing is known about the functional integration of either NTPDase1 or NTPDase2 with each other or other ectonucleotidases/NTPDases. Biochemical analyses of murine and porcine cardiac tissues have demonstrated ATPase/ ADPase ratios of 10, suggesting expression of enzymes with preferential ATPase activity (this paper and Lemmens et al 29 ). Given the levels of NTPDase2 messenger RNA (mRNA) expression in murine and human hearts, this enzyme would be a likely candidate responsible for such an activity.…”

Section: Introductionmentioning

confidence: 68%

“…These data are comparable to prior observations in pig tissues. 29 To identify the relative contribution of NTPDase1 to the total NTPDase activities in heart tissues, we then contrasted the activity of homogenates derived from cd39 ϩ/ϩ and cd39 Ϫ/Ϫ tissues. Both ATPase and ADPase activities in cardiac tissue preparations from NTPDase1-null mice were not significantly different in wild-type tissues.…”

Section: Ntpdase Activity In Mouse Hearts and Transfected Cellsmentioning

confidence: 99%

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Differential catalytic properties and vascular topography of murine nucleoside triphosphate diphosphohydrolase 1 (NTPDase1) and NTPDase2 have implications for thromboregulation

Sévigny

Sundberg

Braun

et al. 2002

Blood

206

175

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Nucleoside triphosphate diphosphohydrolases (NTPDases) are a recently described family of ectonucleotidases that differentially hydrolyze the ␥ and ␤ phosphate residues of extracellular nucleotides. Expression of this enzymatic activity has the potential to influence nucleotide P2 receptor signaling within the vasculature. We and others have documented that NTPDase1 (CD39, 78 kd) hydrolyzes both triphosphonucleosides and diphosphonucleosides and thereby terminates platelet aggregation responses to adenosine diphosphate (ADP). In contrast, we now show that NTPDase2 (CD39L1, 75 kd), a preferential nucleoside triphosphatase, activates platelet aggregation by converting adenosine triphosphate (ATP) to ADP, the specific agonist of P2Y 1 and P2Y 12 receptors. We developed specific antibodies to murine NTPDase1 and NTPDase2 and observed that both enzymes are present in the cardiac vasculature; NTPDase1 is expressed by endothelium, endocardium, and to a lesser extent by vascular smooth muscle, while NTPDase2 is associated with the adventitia of muscularized vessels, microvascular pericytes, and other cell populations in the subendocardial space. Moreover, NTPDase2 represents a novel marker for microvascular pericytes. IntroductionNucleoside triphosphate diphosphohydrolases (NTPDases) are a family of ectonucleotidases, previously classified as E-type ATPases, ATPDases, ecto-ATPases, or ecto-apyrases. 1-3 These enzymes differentially hydrolyze the terminal ␥ and ␤ phosphate residues of nucleotides, resulting in the rapid formation of the respective diphosphonucleosides and/or monophosphonucleosides. To date, 6 members of this NTPDase family have been identified. 3-13 NTPDase1, NTPDase2, and NTPDase3 are transmembrane proteins associated with the plasma membrane with an active site facing the extracellular space. 4,5,7,9,14 These NTPDase members have been demonstrated to differ in their substrate specificity. For example, NTPDase1 (CD39 [human] or cd39 [murine]) hydrolyzes both nucleoside triphosphates and diphosphates-eg, adenosine triphosphate (ATP) and adenosine diphosphate (ADP), 4,5 -whereas NTPDase2 (CD39L1) is a preferential nucleoside triphosphatase or ATPase. 7,[14][15][16] Extracellular nucleotides in various forms, and at different concentrations, activate multiple P2 receptors: ionotropic P2X and metabotropic P2Y receptors. [17][18][19][20] While NTPDases would be anticipated to generally terminate P2 receptor agonist signaling, we have also observed that NTPDase1 may prevent receptor desensitization by the catalysis of extracellular nucleotides. 21 NTPDase1 may then also facilitate subsequent responses to "pulses" of nucleotides. In addition, NTPDases in tandem with ecto-5Ј-nucleotidase may facilitate the salvage of nucleotides by the ultimate generation of dephosphorylated forms that are taken up by cells via specific transporters. 1,22 NTPDase1 is the major ectonucleotidase at the luminal surface of blood vessels. 5,21,23,24 By converting the ADP released from activated platelets, NTPDase1 modulates platel...

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Section: Introductionmentioning

confidence: 68%

Section: Ntpdase Activity In Mouse Hearts and Transfected Cellsmentioning

confidence: 99%

Differential catalytic properties and vascular topography of murine nucleoside triphosphate diphosphohydrolase 1 (NTPDase1) and NTPDase2 have implications for thromboregulation

Sévigny

Sundberg

Braun

et al. 2002

Blood

206

175

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“…No staining was seen in the hepatic parenchyma. Thus, similar to its vascular distribution in other systems, 8,9 NTPDase1 is restricted to vascular endothelia within the liver. Fig.…”

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confidence: 69%

“…[5][6][7] Several of these enzymes have been cloned and characterized at the molecular level. NTPDase1 has been identified as a vascular NTPDase expressed at endothelial and leiomyocyte plasma membranes 8,9 and is a critical regulator of platelet aggregation. 10 NTPDase2 is an NTPDase that is expressed by epithelial organs and cell lines, 11,12 but its specific physiologic function is unknown.…”

mentioning

confidence: 99%

The ecto-nucleoside triphosphate diphosphohydrolase NTPDase2/CD39L1 is expressed in a novel functional compartment within the liver

et al. 2002

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Extracellular nucleotides regulate diverse biological functions and are important in the regulation of liver metabolism, hepatic blood flow, and bile secretion. Ecto-nucleoside triphosphate diphosphohydrolases (NTPDases) hydrolyze extracellular nucleotides and are therefore potential regulators of nucleotide-mediated signaling. To examine this, we have contrasted the structural and functional distributions of the 2 characterized membranebound NTPDases NTPDase1 and NTPDase2 within the rat liver. Hepatic expression of NTPDase2 was determined and contrasted to NTPDase1 using confocal immunofluorescence, immunoelectron microscopy, reverse-transcription polymerase chain reaction, Northern blot analysis, Western blot analysis, and functional assays. NTPDase2 was expressed in the periportal region surrounding intrahepatic bile ducts, whereas NTPDase1 was found in hepatic arteries, portal veins, and hepatic central veins, consistent with its known vascular distribution. Functional and molecular expression of NTPDase2 was shown in portal fibroblasts near basolateral membranes of bile duct epithelia. In conclusion, NTPDase2 is expressed in a novel cellular compartment surrounding intrahepatic bile ducts, namely portal fibroblasts. This distribution may represent a previously unrecognized mechanism for regulation of nucleotide signaling in bile ducts and other epithelia. (HEPATOLOGY 2002;36:1135-1144 B ile duct epithelia, or cholangiocytes, secrete fluid and electrolytes in response to extracellular nucleotides through activation of specific P2Y nucleotide receptors. [1][2][3][4] Cholangiocytes express both apical and basolateral P2Y receptors but basolateral cholangiocyte P2Y receptors are activated only by nonhydrolyzable nucleotide analogues, 4 and there is functional evidence for a distinct pathway for degradation of nucleotides at the basolateral membrane. 3 These observations suggest that nucleotide hydrolysis is a primary means to regulate cholangiocyte P2Y receptor activation at the basolateral membrane.Hydrolysis of extracellular nucleotides may largely occur through proteins belonging to a family of recently identified ecto-nucleoside triphosphate diphosphohydrolases (NTPDases). 5-7 Several of these enzymes have been cloned and characterized at the molecular level. NTPDase1 has been identified as a vascular NTPDase expressed at endothelial and leiomyocyte plasma membranes 8,9 and is a critical regulator of platelet aggregation. 10 NTPDase2 is an NTPDase that is expressed by epithelial organs and cell lines, 11,12 but its specific physiologic function is unknown.Here we show that NTPDase2 is expressed in a newly described cellular population of liver cells, that of portal fibroblasts. By interacting with cholangiocyte nucleotide signaling processes, portal fibroblasts may represent a novel functional compartment of liver cells, thus showing a distinct functional interaction between liver epithelia and stromal cells. Materials and MethodsAnimals and Materials. Male Sprague-Dawley rats (180-250 g) were used for al...

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“…The majority of the ecto-ATPDases that have been cloned are closely related to CD39, a cell surface antigen that is expressed on activated lymphocytes [11,12]. CD39s from several species have 60-90% identity in their primary sequences [12][13][14][15]. Biochemical and immunolocalization studies indicated that CD39s are vascular ecto-ATPDases [16][17][18][19][20].…”

mentioning

confidence: 99%

Purification, characterization, cloning, and expression of the chicken liver ecto‐ATP‐diphosphohydrolase

Knowles

Nagy

Strobel

et al. 2002

European Journal of Biochemistry

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We previously demonstrated that the major ecto‐nucleoside triphosphate phosphohydrolase in the chicken liver membranes is an ecto‐ATP‐diphosphohydrolase (ecto‐ ATPDase) [Caldwell, C., Davis, M.D. & Knowles, A.F. (1999) Arch. Biochem. Biophys. 362, 46–58]. Enzymatic properties of the liver membrane ecto‐ATPDase are similar to those of the chicken oviduct ecto‐ATPDase that we have previously purified and cloned. Using antibody developed against the latter, we have purified the chicken liver ecto‐ATPDase to homogeneity. The purified enzyme is a glycoprotein with a molecular mass of 85 kDa and a specific activity of ≈ 1000 U·mg protein−1. Although slightly larger than the 80‐kDa oviduct enzyme, the two ecto‐ATPDases are nearly identical with respect to their enzymatic properties and mass of the deglycosylated proteins. The primary sequence of the liver ecto‐ATPDase deduced from its cDNA obtained by RT‐PCR cloning also shows only minor differences from that of the oviduct ecto‐ATPDase. Immunochemical staining demonstrates the distribution of the ecto‐ATPDase in the bile canaliculi of the chicken liver. HeLa cells transfected with the chicken liver ecto‐ATPDase cDNA express an ecto‐nucleotidase activity with characteristics similar to the enzyme in its native membranes, most significant of these is stimulation of the ATPDase activity by detergents, which inhibits other members of the ecto‐ nucleoside triphosphate diphosphohydrolase (E‐NTPDase) family. The stimulation of the expressed liver ecto‐ATPDase by detergents indicates that this property is intrinsic to the enzyme protein, and cannot be attributed to the lipid environment of the native membranes. The molecular identification and expression of a liver ecto‐ATPDase, reported here for the first time, will facilitate future investigations into the differences between structure and function of the different E‐NTPDases, existence of liver ecto‐ATPDase isoforms in different species, its alteration in pathogenic conditions, and its physiological function.

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Distribution, cloning, and characterization of porcine nucleoside triphosphate diphosphohydrolase‐1

Cited by 33 publications

References 42 publications

Differential catalytic properties and vascular topography of murine nucleoside triphosphate diphosphohydrolase 1 (NTPDase1) and NTPDase2 have implications for thromboregulation

Differential catalytic properties and vascular topography of murine nucleoside triphosphate diphosphohydrolase 1 (NTPDase1) and NTPDase2 have implications for thromboregulation

The ecto-nucleoside triphosphate diphosphohydrolase NTPDase2/CD39L1 is expressed in a novel functional compartment within the liver

Purification, characterization, cloning, and expression of the chicken liver ecto‐ATP‐diphosphohydrolase

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