Cloning and functional characterisation of the mouse P2X<sub>7</sub> receptor

Chessell, Iain P.; Simon, József; Hibell, A. D.; Michel, Anton D.; Barnard, E.A.; Humphrey, P. P. A.

doi:10.1016/s0014-5793(98)01332-5

Cited by 139 publications

(165 citation statements)

References 12 publications

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“…This phenomenon however is not common to all mammalian species. Both BzATP-and ATPinduced responses for murine P2X 7 are similar in magnitude [31], while BzATP is a partial agonist of guinea pig P2X 7 compared to ATP [32]. The Hill coefficients, on average, were higher for canine erythrocytes compared to human erythrocytes indicating a greater degree of cooperativity for multiple agonist-binding sites for canine P2X 7 compared to human P2X 7 .…”

Section: Discussionmentioning

confidence: 92%

The P2X7 receptor mediates the uptake of organic cations in canine erythrocytes and mononuclear leukocytes: comparison to equivalent human cell types

Stevenson

Taylor

Wiley

et al. 2009

Purinergic Signalling

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We previously demonstrated that canine erythrocytes express the P2X 7 receptor, and that the function and expression of this receptor is greatly increased compared with human erythrocytes. Using 86 Rb + (K + ) and organic cation flux measurements, we further compared P2X 7 in erythrocytes and mononuclear leukocytes from these species. Concentration response curves of BzATP-and ATP-induced 86 Rb + efflux demonstrated that canine P2X 7 was less sensitive to inhibition by extracellular Na + ions compared to human P2X 7 . In contrast, canine and human P2X 7 showed a similar sensitivity to the P2X 7 antagonists KN-62 and Mg 2+ . KN-62 and Mg 2+ also inhibited ATPinduced choline + uptake into canine and human erythrocytes. BzATP and ATP but not ADP or NAD induced ethidium + uptake into canine monocytes, T-and B-cells. ATP-induced ethidium + uptake was twofold greater in canine T-cells compared to canine B-cells and monocytes. KN-62 inhibited the ATP-induced ethidium + uptake in each cell type. P2X 7 -mediated uptake of organic cations was 40-and fivefold greater in canine erythrocytes and lymphocytes (T-and B-cells), respectively, compared to equivalent human cell types. In contrast, P2X 7 function was threefold lower in canine monocytes compared to human monocytes.Thus, P2X 7 activation can induce the uptake of organic cations into canine erythrocytes and mononuclear leukocytes, but the relative levels of P2X 7 function differ to that of equivalent human cell types.

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Section: Discussionmentioning

confidence: 92%

The P2X7 receptor mediates the uptake of organic cations in canine erythrocytes and mononuclear leukocytes: comparison to equivalent human cell types

Stevenson

Taylor

Wiley

et al. 2009

Purinergic Signalling

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“…T he P2X 7 receptor, P2X 7 R, is a member of the ionotropic family of purinergic receptors that respond to extracellular nucleotides and nucleosides (1)(2)(3). It differs from other members of this family, however, in its relatively low affinity for ATP, the presence of a long C-terminal region that contains several protein-protein interaction domains, and the activation of two membrane conductance states upon receptor ligation.…”

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confidence: 99%

“…It differs from other members of this family, however, in its relatively low affinity for ATP, the presence of a long C-terminal region that contains several protein-protein interaction domains, and the activation of two membrane conductance states upon receptor ligation. Following brief exposure to ATP a nonselective cation channel is activated, whereas following prolonged or repeated applications of high dose ATP multimeric channels or pores may form that allow passage of solutes as large as 900 kDa (1)(2)(3)(4)(5).…”

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confidence: 99%

“…In B cells, permeability assays indicate the formation of a much smaller pore following activation with ATP than that found in macrophages, and B cells show only a low level of susceptibility to ATP-mediated cytotoxicity (26,27). In T cells, it has been proposed that cell lysis occurs through a mechanism involving NADdependent ribosylation by ADP-ribosyltransferase (ART) 3 2.…”

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confidence: 99%

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Exacerbation of Experimental Autoimmune Encephalomyelitis in P2X7R−/− Mice: Evidence for Loss of Apoptotic Activity in Lymphocytes

Chen

Brosnan

2006

The Journal of Immunology

119

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The purinergic receptor P2X7R is a nucleotide-gated ion channel that has been proposed to function as a major regulator of inflammation. In this study we examined the role of this receptor in regulating inflammation in the CNS by determining the effects of the loss of this receptor (P2X7R−/−) on experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. We show here that P2X7R−/− mice developed more severe clinical and pathological expression of EAE than wild type (WT) controls and that spleen and lymph node cells from P2X7R−/− mice proliferated more vigorously to Ag in vitro. Bone marrow (BM) radiation chimeras revealed that enhanced susceptibility to EAE was detected in chimeric mice of WT host engrafted with P2X7R−/− BM cells, indicating that the genotype of the BM cells regulated disease susceptibility. Coculture of P2X7R−/− macrophages with WT lymphocytes and vice versa showed that enhanced proliferative activity resided within the P2X7R−/− lymphocyte population and correlated with reduced levels of IFN-γ and NO and apoptosis of lymphocytes. mRNA and protein for IFN-γ were also significantly reduced in the CNS of P2X7R−/− mice with EAE. FACS analysis of cells isolated from the CNS showed significantly fewer annexin V/propidium iodide-positive lymphocytes in the CNS of P2X7R−/− mice early in the disease, and TUNEL staining of inflamed CNS tissues supported this result. From these data we conclude that enhanced susceptibility of P2X7R−/− mice to EAE reflects a loss of apoptotic activity in lymphocytes, supporting an important role for this receptor in lymphocyte homeostasis.

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“…The binding site for KN-62, 1, resides within the first 335 residues of the human P2X 7 receptor, likely within the large extracellular loop (13,21). While it is not feasible to model this binding interaction, due to lack of a high-resolution template for this ion channel and uncertainty about the oligomeric nature of the channel (27), chemical probes of the receptor may be very useful in studying the structure.…”

Section: Discussionmentioning

confidence: 99%

Functionalized Congeners of Tyrosine-Based P2X₇ Receptor Antagonists: Probing Multiple Sites for Linking and Dimerization

et al. 2002

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Chemically funtionalized analogues of antagonists of the P2X 7 receptor, an ATP-gated cation channel, were synthesized as tools for biophysical studies of the receptor. These functionalized congeners were intended for use in chemical conjugation with retention of biological potency. The antagonists were L-tyrosine derivatives, related to [N-benzyloxycarbonyl-O-(4-arylsulfonyl)-Ltyrosyl]benzoylpiperazine (such as MRS2409, 2). The analogues were demonstrated to be antagonists in an assay of human P2X 7 receptor function, consisting of inhibition of ATP-induced K + efflux in HEK293 cells expressing the recombinant receptor. The analogues were of the general structure R 1 -Tyr(OR 2 )-piperazinyl-R 3 , in which three positions (R 1 -R 3 ) were systematically varied in structure through introduction of chemically reactive groups. Each of the three positions was designed to incorporate a 3-or 4-nitrophenyl group. The nitro groups were reduced using NaBH 4 -copper(II) acetylacetonate to amines, which were either converted to the isothiocyanate groups, as potential affinity labels for the receptor, or acylated, as models for conjugation. An alternate route to N α -3-aminobenzyloxycarbonyl functionalization was devised.The various positions of functionalization were compared for effects on biological potency, and the R 2 and R 3 positions were found to be most amenable to derivatization with retention of high potency. Four dimeric permutations of the antagonists were synthesized by coupling each of the isothiocyanate derivatives to either the precursor amine or to other amine congeners. Only dimers linked at the R 2 -position were potent antagonists. In concentration-response studies, two derivatives, a 3-nitrobenzyloxycarbonyl derivative 18 and a 4-nitrotoluenesulfonate 26b, displayed IC 50 values of roughly 100 nM as antagonists of P2X 7 receptor-mediated K + flux.

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Cloning and functional characterisation of the mouse P2X₇ receptor

Cited by 139 publications

References 12 publications

The P2X7 receptor mediates the uptake of organic cations in canine erythrocytes and mononuclear leukocytes: comparison to equivalent human cell types

The P2X7 receptor mediates the uptake of organic cations in canine erythrocytes and mononuclear leukocytes: comparison to equivalent human cell types

Exacerbation of Experimental Autoimmune Encephalomyelitis in P2X7R−/− Mice: Evidence for Loss of Apoptotic Activity in Lymphocytes

Functionalized Congeners of Tyrosine-Based P2X₇ Receptor Antagonists: Probing Multiple Sites for Linking and Dimerization

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Cloning and functional characterisation of the mouse P2X7 receptor

Cited by 139 publications

References 12 publications

The P2X7 receptor mediates the uptake of organic cations in canine erythrocytes and mononuclear leukocytes: comparison to equivalent human cell types

The P2X7 receptor mediates the uptake of organic cations in canine erythrocytes and mononuclear leukocytes: comparison to equivalent human cell types

Exacerbation of Experimental Autoimmune Encephalomyelitis in P2X7R−/− Mice: Evidence for Loss of Apoptotic Activity in Lymphocytes

Functionalized Congeners of Tyrosine-Based P2X7 Receptor Antagonists: Probing Multiple Sites for Linking and Dimerization

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Product

Resources

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Cloning and functional characterisation of the mouse P2X₇ receptor

Functionalized Congeners of Tyrosine-Based P2X₇ Receptor Antagonists: Probing Multiple Sites for Linking and Dimerization