黄鳍鲷（Sparus latus）两种生长激素受体的cDNA克隆及组织表达分析

采用RT-PCR方法克隆了黄鳍鲷两种生长激素受体（Growth hormone receptor,GHR）的cDNA序列,序列分析表明：GHR1开放阅读框为1935bp,共编码645个氨基酸,GHR2开放阅读框为1749bp,共编码583个氨基酸,GHR1与GHR2的氨基酸同源性为36.7%。GHR1和GHR2在分子结...

cDNAs CLONING AND TISSUES EXPRESSION OF TWO GROWTH HORMONE RECEPTORS IN YELLOW-FIN BREAM SPARUS LATUS

Growth hormone (GH) has many important physiological roles in the control of growth, metabolism and reproduction, which is mediated by growth hormone receptor (GHR). In this study, two cDNAs encoding GHR were isolated from the liver of yellow-fin bream Sparus latus. The two cDNAs, one consisting of 1935bp and the other of 1749bp, encoding for putative 645- and 583-amino acid GHR (designated GHR1 and GHR2, respectively), shared 36.7% identity in deduced amino acid sequence. GHR1 and GHR2 showed the conserved structural characteristics of GHR family, including the FGEFS motif, the box1 and box2 regions, extracellular cysteine residues and intracellular tyrosine residues. However, there were differences of structural features between the two receptors as well. GHR2 lacked one pair of extracellular cysteines and 4 intracellular tyrosine residues which were conservative in GHR1. The structural discrepancies thus undoubtedly indicated the distinct biological functions of GHR1 and GHR2. Real-time RT-PCR analysis showed that both GHR1 and GHR2 mRNAs were presented in all tissues tested and expressed extremely highly in the liver. In most tissues, GHR2 expressed significantly higher than GHR1. The expression distinction of GHR1 and GHR2 in pituitary and peripheral tissues like liver, muscle, spleen, kidney and gonad indicated that the two receptors may have different biological functions.