Molecular cloning and expression of a prostaglandin E2 receptor of the EP3 beta subtype from rat hepatocytes.
Rat hepatocytes have previously been reported to possess prostaglandin E2 receptors of the EP3-type (EP3-receptors) that inhibit glucagon-stimulated glycogenolysis by decreasing cAMP. Here, the isolation of a functional EP3 beta receptor cDNA clone from a rat hepatocyte cDNA library is reported. This clone can be translated into a 362-amino-acid protein, that displays over 95% homology to the EP3 beta receptor from mouse mastocytoma. The amino- and carboxy-terminal region of the protein are least conserved. Transiently transfected HEK 293 cells expressed a single binding site for PGE2 with an apparent Kd of 15 nM. PGE2 > PGF2 alpha > PGD2 competed for [3H]PGE2 binding sites as did the EP3 receptor agonists M&B 28767 = sulprostone > misoprostol but not the EP1 receptor antagonist SC 19220. In stably transfected CHO cells M&B 28767 > sulprostone = PGE2 > misoprostol > PGF2 alpha inhibited the forskolin-elicited cAMP formation. Thus, the characteristics of the EP3 beta receptor of rat hepatocytes closely resemble those of the EP3 beta receptor of mouse mastocytoma.
Neuschäfer-Rube
F
F
Institut für Biochemie und Molekular Zellbiologie, Georg-August-Universität, Göttingen, Germany.
DeVries
C
C
Hänecke
K
K
Jungermann
K
K
Püschel
G P
GP
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002478:Cells, Cultured; D003001:Cloning, Molecular; D006224:Cricetinae; D018076:DNA, Complementary; D008024:Ligands; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D017208:Rats, Wistar; D018078:Receptors, Prostaglandin E / Q000187:drug effects / Q000235:genetics*
D018076:DNA, Complementary; D008024:Ligands; D018078:Receptors, Prostaglandin E