Sequential hydrolysis of the γ- and β-phosphate groups of ATP by the ATP diphosphohydrolase from pig pancreas

Laliberte, Jean Francois; Beaudoin, Adrien R.

doi:10.1016/0167-4838(83)90352-7

Cited by 41 publications

(19 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, a modest and transient accumulation of ADP could be detected for human and mouse NTPDase1 that was not observed during ATP hydrolysis by rat NTPDase1. These results are consistent with the observation that pig pancreas ATPDase (truncated form of NTPDase1) hydrolyzed ATP in a step favored manner; ATP to AMP via ADP [31]. Another minor variance observed between human NTPDases 2 and 3, and their murine orthologues was their preference for adenine to uracil nucleotides as substrates.…”

Section: Discussionsupporting

confidence: 89%

Comparative hydrolysis of P2 receptor agonists by NTPDases 1, 2, 3 and 8

Kukulski

Lévesque

Lavoie

et al. 2005

Purinergic Signalling

273

328

View full text Add to dashboard Cite

Nucleoside triphosphate diphosphohydrolases 1, 2, 3 and 8 (NTPDases 1, 2, 3 and 8) are the dominant ectonucleotidases and thereby expected to play important roles in nucleotide signaling. Distinct biochemical characteristics of individual NTPDases should allow them to regulate P2 receptor activation differentially. Therefore, the biochemical and kinetic properties of these enzymes were compared. NTPDases 1, 2, 3 and 8 efficiently hydrolyzed ATP and UTP with Km values in the micromolar range, indicating that they should terminate the effects exerted by these nucleotide agonists at P2X1- and P2Y2,4,11 receptors. Since NTPDase1 does not allow accumulation of ADP, it should terminate the activation of P2Y1,12,13 receptors far more efficiently than the other NTPDases. In contrast, NTPDases 2, 3 and 8 are expected to promote the activation of ADP specific receptors, because in the presence of ATP they produce a sustained (NTPDase2) or transient (NTPDases 3 and 8) accumulation of ADP. Interestingly, all plasma membrane NTPDases dephosphorylate UTP with a significant accumulation of UDP, favoring P2Y6 receptor activation. NTPDases differ in divalent cation and pH dependence, although all are active in the pH range of 7.0-.5. Various NTPDases may also distinctly affect formation of extracellular adenosine and therefore adenosine receptor-mediated responses, since they generate different amounts of the substrate (AMP) and inhibitor (ADP) of ecto-5-nucleotidase, the rate limiting enzyme in the production of adenosine. Taken together, these data indicate that plasma membrane NTPDases hydrolyze nucleotides in a distinctive manner and may therefore differentially regulate P2 and adenosine receptor signaling.

show abstract

Section: Discussionsupporting

confidence: 89%

Comparative hydrolysis of P2 receptor agonists by NTPDases 1, 2, 3 and 8

Kukulski

Lévesque

Lavoie

et al. 2005

Purinergic Signalling

273

328

View full text Add to dashboard Cite

show abstract

“…Our results suggest that the hydrolysis of ATP by ecto‐apyrase proceeds directly to AMP without the liberation of free ADP as an intermediate product. These results are very similar to those obtained with an apyrase preparation purified to near homogeneity from porcine zymogen granule membranes [28]. In contrast, ADP is released from ecto‐ATPase and accumulates in the medium.…”

Section: Discussionsupporting

confidence: 87%

Functional characterization of rat ecto‐ATPase and ecto‐ATP diphosphohydrolase after heterologous expression in CHO cells

Heine

Braun

Heilbronn

et al. 1999

European Journal of Biochemistry

143

150

View full text Add to dashboard Cite

The recently cloned ecto-ATPase and ecto-apyrase (ecto-ATP diphosphohydrolase) are plasma-membranebound enzymes responsible for the extracellular degradation of nucleoside 5 H -triphosphates and nucleoside 5 H -diphosphates. We expressed the rat-derived enzymes in CHO cells to compare their molecular and functional properties. Sequence-specific polyclonal antibodies differentiate between the two proteins and reveal identical molecular masses of 70±80 kDa. Both enzymes are stimulated by either Ca 2+ or Mg 2+ and reveal a broad substrate specificity towards purine and pyrimidine nucleotides. Whereas ecto-apyrase hydrolyzes nucleoside 5 H -diphosphates at a rate <20±30% lower than nucleoside-5 H -triphosphates, ecto-ATPase hydrolyzes nucleoside-5 H -diphosphates only to a marginal extent. The sensitivity of the two enzymes to the inhibitors of P2 receptors suramin, PPADS and reactive blue differs. Hydrolysis of ATP by ecto-ATPase leads to the accumulation in the medium of extracellular ADP as an intermediate product, whereas ecto-apyrase dephosphorylates ATP directly to AMP. Our results suggest that previous data describing extracellular hydrolysis of ATP by a variety of intact cellular systems with unidentified ecto-nucleotidases may be explained by the coexpression of ecto-ATPase and ecto-apyrase.Keywords: ADP; ATP; ecto-apyrase; ecto-ATPase; ecto-ATP diphosphohydrolase.A surface-located enzyme cascade catalyzes the sequential degradation of extracellular ATP to ADP, AMP and adenosine in a large variety of tissues and cell types. Until recently ecto-5 Hnucleotidase, which catalyzes the final hydrolysis step from AMP to adenosine was the only enzyme defined in molecular terms [1]. The ATP and ADP hydrolyzing ecto-nucleotidases are not inhibited by known inhibitors of intracellular ATPases such as P-type, F-type and V-type ATPases or alkaline phosphatase, suggesting that they represent a novel class of nucleotidehydrolyzing enzymes [2,3]. A major function of the extracellular enzyme chain appears to be termination of the physiological action of nucleotides released from cells. Nucleotides represent a ubiquitous class of cell-to-cell signaling substances eliciting physiological responses in every tissue. ATP, ADP, UTP and UDP exert their function via surface-located receptors, which have a tissue distribution as broad as that of the ecto-nucleotidases. Their receptor-mediated actions are involved in a large variety of physiological and pathophysiological functions [4].Considerable progress has now been made in unraveling the molecular structures of ATP and ADP hydrolyzing ecto-nucleotidases. The first enzyme identified was an ATP diphosphohydrolase (ecto-apyrase) that can hydrolyze either ATP or ADP. Human placental ATP diphosphohydrolase [5] is identical to the lymphoid cell activation antigen CD39 [6]. Expression of human CD39 in COS-7 cells leads to an increase in surface-located ATPase and ADPase activity [7,8]. Moreover, recombinant human and mouse CD39 inhibits ADP-induced platelet aggregation [8,9]. The prima...

show abstract

“…The status of cytochrome c, Bad, Bak, Bax, and Bcl-2 were determined by Western blot analyses cytosolic extract (Figure 3) suggested either that HL-60 cells already contained a sufficient amount of dATP in the cytosol to meet the requirement for caspase-3 activation or that the reaction was dATP independent. To test these hypotheses, the effect of apyrase, which metabolizes deoxynucleoside or nucleoside di-and triphosphates into deoxynucleoside or nucleoside monophosphates (Lebel et al, 1980;Laliberte et al, 1983) on the process of cytochrome c-dependent activation of the endogenous caspase-3 in the HL-60 S-100 cytosolic extract was investigated. As a control, the effect of 5'-nucleotidase, which converts deoxnucleoside or nucleoside monophosphates into deoxynucleosides or nucleosides, was also investigated.…”

Section: Hcw-2 Cells Lack Cif Activitymentioning

confidence: 99%