Very Nicole M, Kittilson Jeffrey D, Norbeck Lindsey A, Sheridan Mark A
Department of Biological Sciences and Regulatory Biosciences Center, North Dakota State University, Fargo, ND 58105, USA.
Comp Biochem Physiol B Biochem Mol Biol. 2005 Apr;140(4):615-28. doi: 10.1016/j.cbpc.2004.12.008. Epub 2005 Jan 22.
Growth hormone (GH) plays important roles in a vast array of physiological processes, including growth, metabolism, and reproduction. In this study, cDNAs for two unique growth hormone receptor variants were cloned and sequenced from rainbow trout. The two cDNAs, one consisting of 2920 bp and the other of 2820 bp, share 87.2% identity in nucleotide sequence and 85.5% identity in deduced amino acid sequence and presumably arose through gene duplication. The cDNAs encode for putative 593- and 594-amino acid growth hormone receptors (designated GHR1 and GHR2, respectively), each containing a single transmembrane domain and other motifs characteristic of the receptor family. Both GHR1 and GHR2 mRNAs were present in all tissues examined. Trout GHR mRNAs are differentially expressed, both in terms of abundance among tissues and in terms of abundance within selected tissues. GHR1 was more abundant than GHR2 in the brain, whereas GHR2 was more abundant than GHR1 in pancreas and spleen. These findings expand our understanding of the evolution of the GH receptor family and suggest that independent mechanisms serve to regulate the tissue-specific expression of GHR mRNAs.
生长激素（GH）在包括生长、代谢和繁殖在内的一系列生理过程中发挥着重要作用。在本研究中，从虹鳟鱼中克隆并测序了两种独特的生长激素受体变体的cDNA。这两个cDNA，一个由2920 bp组成，另一个由2820 bp组成，核苷酸序列的同一性为87.2%，推导的氨基酸序列的同一性为85.5%，推测是通过基因复制产生的。这些cDNA编码推定的593和594个氨基酸的生长激素受体（分别命名为GHR1和GHR2），每个受体都含有一个单一的跨膜结构域和受体家族的其他基序。GHR1和GHR2的mRNA在所有检测的组织中均存在。虹鳟鱼GHR的mRNA在组织间丰度以及在选定组织内的丰度方面均存在差异表达。在脑中GHR1比GHR2更丰富，而在胰腺和脾脏中GHR2比GHR1更丰富。这些发现扩展了我们对GH受体家族进化的理解，并表明独立的机制用于调节GHR mRNA的组织特异性表达。
