TY - JOUR
T1 - Three distinct types of GnRH receptor characterized in the bullfrog
AU - Wang, Li
AU - Bogerd, Jan
AU - Choi, Hueng S.
AU - Seong, Jae Y.
AU - Soh, Jae M.
AU - Chun, Sang Y.
AU - Blomenröhr, Marion
AU - Troskie, Brigitte E.
AU - Millar, Robert P.
AU - Yu, Wen H.
AU - McCann, Samuel M.
AU - Kwon, Hyuk B.
PY - 2001/1/2
Y1 - 2001/1/2
N2 - It has been proposed recently that two types of GnRH receptors (GnRHR) exist in a particular species. Here we present data demonstrating that at least three types of GnRHR are expressed in a single diploid species, the bullfrog. Three different cDNAs, encoding distinct types of bullfrog GnRHR (bfGnRHR-1, bfGnRHR-2, and bfGnRHR-3), were isolated from pituitary and hindbrain of the bullfrog. BfGnRHR-1 mRNA was expressed predominantly in pituitary, whereas bfGnRHR-2 and -3 mRNAs were expressed in brain. The bfGnRHR-1, bfGnRHR-2, and bfGnRHR-3 proteins have an amino acid identity of ≈30% to ≈35% with mammalian GnRHRs and ≈40% to ≈50% with nonmammalian GnRHRs. Interestingly, bfGnRHR-2 has an 85% amino acid homology with Xenopus GnRHR. Less than 53% amino acid identity was observed among the three bfGnRHRs. All isolated cDNAs encode functional receptors because their transient expression in COS-7 cells resulted in a ligand-dependent increase in inositol phosphate production. Notably, all three receptors exhibited a differential ligand selectivity. For all receptors, cGnRH-II has a higher potency than mGnRH. In addition, salmon GnRH also has a strikingly high potency to stimulate all three receptors. In conclusion, we demonstrated the presence of three GnRHRs in the bullfrog. Their expression in pituitary and brain suggests that bfGnRHRs play an important role in the regulation of reproductive functions in the bullfrog.
AB - It has been proposed recently that two types of GnRH receptors (GnRHR) exist in a particular species. Here we present data demonstrating that at least three types of GnRHR are expressed in a single diploid species, the bullfrog. Three different cDNAs, encoding distinct types of bullfrog GnRHR (bfGnRHR-1, bfGnRHR-2, and bfGnRHR-3), were isolated from pituitary and hindbrain of the bullfrog. BfGnRHR-1 mRNA was expressed predominantly in pituitary, whereas bfGnRHR-2 and -3 mRNAs were expressed in brain. The bfGnRHR-1, bfGnRHR-2, and bfGnRHR-3 proteins have an amino acid identity of ≈30% to ≈35% with mammalian GnRHRs and ≈40% to ≈50% with nonmammalian GnRHRs. Interestingly, bfGnRHR-2 has an 85% amino acid homology with Xenopus GnRHR. Less than 53% amino acid identity was observed among the three bfGnRHRs. All isolated cDNAs encode functional receptors because their transient expression in COS-7 cells resulted in a ligand-dependent increase in inositol phosphate production. Notably, all three receptors exhibited a differential ligand selectivity. For all receptors, cGnRH-II has a higher potency than mGnRH. In addition, salmon GnRH also has a strikingly high potency to stimulate all three receptors. In conclusion, we demonstrated the presence of three GnRHRs in the bullfrog. Their expression in pituitary and brain suggests that bfGnRHRs play an important role in the regulation of reproductive functions in the bullfrog.
UR - http://www.scopus.com/inward/record.url?scp=0035793085&partnerID=8YFLogxK
U2 - 10.1073/pnas.98.1.361
DO - 10.1073/pnas.98.1.361
M3 - Article
C2 - 11120886
AN - SCOPUS:0035793085
SN - 0027-8424
VL - 98
SP - 361
EP - 366
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 1
ER -