Regulation of p42/p44 mitogen-activated protein kinase by the human adenosine A3 receptor in transfected CHO cells.
In this study we have investigated whether the human adenosine A3 receptor activates p42/p44 mitogen-activated protein kinase (MAPK) in transfected Chinese hamster ovary (CHO) cells (designated CHO-A3). The high affinity adenosine A3 receptor agonist IB-MECA (1-deoxy-1-[6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-N-methyl-beta-D-ribofuranuronamide) stimulated time (peak activation occurring after 5 min) and concentration-dependent (pEC50=9.0+/-0.2) increases in p42/p44 MAPK in CHO-A3 cells. Adenosine A3 receptor-mediated increases in p42/p44 MAPK were sensitive to pertussis toxin and the MAPK kinase 1 inhibitor PD 98059 (2'-amino-3'-methoxyflavone). The broad range protein tyrosine kinase inhibitor genistein and the phosphatidylinositol 3-kinase inhibitors wortmannin and LY 294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one) also blocked adenosine A3 receptor stimulation of p42/p44 MAPK. In contrast, inhibition of protein kinase C had no significant effect on adenosine A3 receptor-induced p42/p44 MAPK activation. IB-MECA (pEC50=10.1+/-0.2) also increased the expression of luciferase in CHO-A3 cells transiently transfected with a luciferase reporter gene containing the c-fos promoter. Furthermore, IB-MECA-induced increases in luciferase gene expression were sensitive to pertussis toxin, PD 98059, genistein, wortmannin and LY 294002. In conclusion, we have shown that the human adenosine A3 receptor stimulates p42/p44 MAPK and c-fos-mediated luciferase gene expression in transfected CHO cells.
Graham
S
S
Department of Life Sciences, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK.
Combes
P
P
Crumiere
M
M
Klotz
K N
KN
Dickenson
J M
JM
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D016466:CHO Cells; D002867:Chromones / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D008156:Luciferases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D043684:Receptor, Adenosine A3; D018047:Receptors, Purinergic P1 / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000077191:Wortmannin
D000241:Adenosine; D000730:Androstadienes; D002867:Chromones; D005576:Colforsin; D000242:Cyclic AMP; D004791:Enzyme Inhibitors; D005419:Flavonoids; D008156:Luciferases; D019950:Mitogen-Activated Protein Kinase 1; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D043684:Receptor, Adenosine A3; D018047:Receptors, Purinergic P1; D011993:Recombinant Fusion Proteins; D000077191:Wortmannin; C084956:N(6)-(3-iodobenzyl)-5'-N-methylcarboxamidoadenosine; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one