title: Molecular characterization of the GHRH/GHRH-R and its effect on GH synthesis and release in orange-spotted grouper (Epinephelus coioides).
abstract: Growth hormone-releasing hormone (GHRH) is a hypothalamic neuropeptide that stimulates growth hormone (GH) synthesis and secretion in the pituitary gland. In this paper, the full-length cDNAs of orange-spotted grouper GHRH and its receptor (GHRH-R) were cloned. The grouper GHRH cDNA is 713 bp in length and encodes a 141-aa precursor that includes an 18-aa signal peptide, a 27-aa mature GHRH mature peptide and a 47-aa carboxyl terminus. The grouper GHRH-R cDNA sequence is 1495 bp in length, encoding a 422-aa receptor with seven transmembrane domains. Tissue distribution analyses showed that both GHRH and GHRH-R mRNAs were predominantly expressed in the brain, while the GHRH-R mRNA was also abundantly detected in the pituitary gland. Both GHRH and GHRH-R mRNAs were expressed throughout embryonic development from the multi-cell stage to the newly hatched larvae stage, and the highest GHRH and GHRH-R expressions appeared at the brain vesicle stage and the heart stage, respectively. In vitro studies performed on the grouper pituitary primary cells showed that a synthetic grouper GHRH-NH(2) increased both GH mRNA expression and GH protein release in a dose-dependent manner. Together, these results suggest that the newly obtained grouper GHRH was able to stimulate GH synthesis and release, similar to its mammalian counterparts.
authors: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, PR China.
authors: Yuehua
authors: Y
authors: Qian
authors: Aifen
authors: A
authors: Yan
authors: Haoran
authors: H
authors: Lin
authors: Wensheng
authors: W
authors: Li
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005260:Female; D013006:Growth Hormone / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D010473:Perciformes / Q000378:metabolism*; D018013:Receptors, Neuropeptide / Q000378:metabolism*; D018017:Receptors, Pituitary Hormone-Regulating Hormone / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D018013:Receptors, Neuropeptide; D018017:Receptors, Pituitary Hormone-Regulating Hormone; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; C048250:somatotropin releasing hormone receptor