Molecular cloning of the bullfrog kisspeptin receptor GPR54 with high sensitivity to Xenopus kisspeptin.
Kisspeptin and its receptor, GPR54, play important roles in mammalian reproduction and cancer development. However, little is known about their function in nonmammalian species. In the present study, we have isolated the cDNA encoding the kisspeptin receptor, GPR54, from the bullfrog, Rana catesbeiana. The bullfrog GPR54 (bfGPR54) cDNA encodes a 379-amino acid heptahelical G protein-coupled receptor. bfGPR54 exhibits 45-46% amino acid identity with mammalian GPR54s and 70-74% identity with fish GPR54s. RT-PCR analysis showed that bfGPR54 mRNA is highly expressed in the forebrain, hypothalamus and pituitary. Upon stimulation by synthetic human kisspeptin-10 with Phe-amide residue at the C-terminus (h-Kiss-10F), bfGPR54 induces SRE-luc activity, a PKC-specific reporter, evidencing the PKC-linked signaling pathway of bfGPR54. Using a blast search, we found a gene encoding a kisspeptin-like peptide in Xenopus. The C-terminal decapeptide of Xenopus kisspeptin shows higher amino acid sequence identity to fish Kiss-10s than mammalian Kiss-10s. A synthetic Xenopus kisspeptin peptide (x-Kiss-12Y) showed a higher potency than mammalian Kiss-10s in the activation of bfGPR54. This study expands our understanding of the physiological roles and molecular evolution of kisspeptins and their receptors.
Laboratory of G Protein-Coupled Receptors, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul 136-705, Republic of Korea.
Jung Sun
JS
Moon
Yeo Reum
YR
Lee
Da Young
DY
Oh
Jong Ik
JI
Hwang
Ju Yeon
JY
Lee
Jae Il
JI
Kim
Hubert
H
Vaudry
Hyuk Bang
HB
Kwon
Jae Young
JY
Seong
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D005260:Female; D006801:Humans; D008024:Ligands; D008297:Male; D008969:Molecular Sequence Data; D011892:Rana catesbeiana; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology; D014018:Tissue Distribution; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D014981:Xenopus; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*
D008024:Ligands; D043562:Receptors, G-Protein-Coupled; D025521:Tumor Suppressor Proteins; D029867:Xenopus Proteins