HEK293 human embryonic kidney cells endogenously express the P2Y1 and P2Y2 receptors.
Adenine and uridine nucleotide-promoted inositol phosphate accumulation was studied in HEK293 cells. Concentration effect curves for ADP, ATP, and 2ClATP were complex and could be resolved by a two-site model into low and high potency components, suggesting the involvement of two receptors. The maximal effect observed for the P2Y1 receptor-selective agonists 2MeSATP and 2MeSADP was 65-70% of that observed with ATP, ADP, or 2ClATP, and the concentration effect curves for these two analogs were consistent with their interaction at a single site. The P2Y1 receptor-selective antagonist PPADS completely blocked 2MeSATP-stimulated inositol phosphate accumulation, but only partially antagonized the response to ATP. UTP also was an agonist, but the maximal effect observed was approximately 25% of that observed with ATP or ADP. In the presence of maximally effective concentrations of UTP, the concentration effect curves to 2C1ATP and ADP followed law of mass action interaction at a single site, and their maximal elevation of inositol phosphate accumulation was equivalent to that observed with 2MeSATP and 2MeSADP. The order of potency of adenine nucleotide agonists in the presence of a maximally effective concentration of UTP was consistent with that for interaction with a P2Y1 receptor. Thus, HEK293 cells apparently express two subtypes of P2Y receptors that respond to ADP or ATP in an additive manner: a P2Y1 receptor, which is selectively activated by 2MeSADP, and a P2Y2 receptor, which is selectively activated by UTP.
Schachter
J B
JB
Department of Pharmacology, University of North Carolina, School of Medicine, Chapel Hill 27599-7365, USA.
Sromek
S M
SM
Nicholas
R A
RA
Harden
T K
TK
D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D006801:Humans; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000096:biosynthesis*; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; D013268:Stimulation, Chemical; D013873:Thionucleotides / Q000494:pharmacology
D007295:Inositol Phosphates; C546382:P2RY1 protein, human; C546385:P2RY2 protein, human; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; D013873:Thionucleotides; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; C002480:methylthio-ADP; C006979:2-chloro-ATP; D011732:Pyridoxal Phosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; C008501:2-methylthio-ATP