The cellular responses to ATP are mediated by specific high-affinity r
eceptors designated as Pt purinoceptors, five subclasses of which have
been defined pharmacologically - P-2X, P-2Y, P-2U, P-2T, and P-2Z. A
cDNA clone encoding a rat P-2Y purinoceptor was isolated from an insul
inoma cDNA library. The 373-amino acid rat P-2Y purinoceptor sequence
has 85.7% and 37.8% identity with chicken P-2Y and rat P-2U purinocept
ors, respectively. The sequence of the mouse P-2Y purinoceptor was als
o determined and there was 97.1% amino acid identity with the correspo
nding rat sequence. RNA blotting studies showed that rat P-2Y purinoce
ptor mRNA was expressed at variable levels in many tissues including h
eart, brain, spleen, lung, liver, skeletal muscle and kidney, although
it was not detected in testis. The cloned rat P-2Y purinoceptor was e
xpressed in Xenopus laevis oocytes and possessed the properties expect
ed for this receptor subtype. (C) 1995 Academic Press, Inc.