Maugars Gersende, Schmitz Monika
Department of Aquaculture, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden.
Gen Comp Endocrinol. 2006 Oct;149(1):108-17. doi: 10.1016/j.ygcen.2006.04.011. Epub 2006 Jun 9.
Two cDNAs encoding the FSH receptor (FSHR) and the LH receptor (LHR) from Atlantic salmon (Salmo salar) were cloned and characterized. The predicted protein sequence for FSHR comprises a mature protein of 635 amino acids (aa) and a signal peptide of 23aa, and for LHR a mature protein of 701aa and a signal peptide of 27aa. Multiple sequence alignment of Atlantic salmon FSHR and LHR with gonadotropin receptor sequences of available teleosts and representative vertebrates revealed high sequence homology with other salmonids (97-98% for both receptors); amino acid identities ranged from 59 to 67% for FSHR and 47-79% for LHR compared with other teleosts, and between 50 and 52% compared with other vertebrates. The salmon FSHR and LHR showed the typical characteristics of glycoprotein receptors, including a long N-terminal extracellular domain (ECD), seven transmembrane domains and a short C-terminal intracellular domain. The ECD of the Atlantic salmon FSHR and LHR were composed of nine imperfect leucine-rich repeats forming the potential recognition sites for the corresponding hormone. The comparative analysis of the recognition sites in the Atlantic salmon gonadotropin receptors with the corresponding sites in the human receptors showed that the nature of the residues involved in the key contacts with the glycoprotein alpha-subunit were highly conserved. In contrast the recognition sites for the specific beta-subunits showed clear differences between the two salmon gonadotropin receptors and the human receptors. In the salmon LHR the recognition sites for the LH beta-subunit were relatively conserved, while the recognition sites for the FSH beta-subunit in the salmon FSHR showed a higher divergence, suggesting different evolution rates for the two teleost gonadotropin receptors. Both FSHR and LHR were mainly expressed in the ovary and testis, but were also detected at low abundance in extra-gonadal tissues such as gills, brain, liver and heart.
克隆并鉴定了来自大西洋鲑（Salmo salar）的两个编码促卵泡激素受体（FSHR）和促黄体生成素受体（LHR）的cDNA。预测的FSHR蛋白序列包含一个由635个氨基酸（aa）组成的成熟蛋白和一个23aa的信号肽，而LHR的成熟蛋白由701aa组成，信号肽为27aa。大西洋鲑FSHR和LHR与现有硬骨鱼和代表性脊椎动物的促性腺激素受体序列的多序列比对显示，它们与其他鲑科鱼类具有高度的序列同源性（两种受体均为97 - 98%）；与其他硬骨鱼相比，FSHR的氨基酸同一性在59%至67%之间，LHR为47%至79%，与其他脊椎动物相比在50%至52%之间。鲑鱼FSHR和LHR表现出糖蛋白受体的典型特征，包括一个长的N端细胞外结构域（ECD）、七个跨膜结构域和一个短的C端细胞内结构域。大西洋鲑FSHR和LHR的ECD由九个不完美的富含亮氨酸重复序列组成，形成了相应激素的潜在识别位点。对大西洋鲑促性腺激素受体中的识别位点与人类受体中的相应位点进行比较分析表明，与糖蛋白α亚基关键接触的残基性质高度保守。相比之下，两种鲑鱼促性腺激素受体与人类受体中特定β亚基的识别位点存在明显差异。在鲑鱼LHR中，促黄体生成素β亚基的识别位点相对保守，而鲑鱼FSHR中促卵泡激素β亚基的识别位点差异较大，这表明两种硬骨鱼促性腺激素受体的进化速率不同。FSHR和LHR都主要在卵巢和睾丸中表达，但在鳃、脑、肝和心脏等性腺外组织中也能检测到低丰度表达。
