大菱鲆促黄体激素受体基因的克隆及其生物信息学分析

Cloning and bioinformatics analysis of LHR gene in Scophthalmus maximus

通过兼并引物扩增及RACE技术,克隆大菱鲆促黄体激素受体(luteinizing hormone receptor,LHR)基因,分析其相应生物信息学特征和组织表达。结果显示:LHR基因序列全长3 184 bp,编码685个氨基酸,同大西洋庸鲽同源性最高。氨基酸序列分析发现,该基因编码蛋白为疏水性蛋白,相对分子量76.54 ku,理论等电点7.22,存在信号肽序列和跨膜区;亚细胞定位主要在内质网和细胞膜;预测该蛋白含有33个磷酸化位点、5个糖基化位点、6个富含亮氨酸重复序列、7个跨膜保守结构域,二级结构以无规则卷曲为主,三级结构其结构域呈α螺旋状构象;蛋白功能预测表明,LHR主要在辅助、运载、翻译和代谢调节过程中发挥关键作用。组织表达分析表明,LHR基因除在卵巢大量表达外,在其他非性腺组织也有表达,尤其是在肝脏表达较高。上述结果为深入探讨LHR基因在大菱鲆性腺发育过程中的生物学功能奠定了遗传信息基础,也为研究其他海水养殖鱼类生殖调控提供重要参考。

The complete cDNA sequence of luteinizing hormone receptor （LHR）gene in turbot （Scophthalmus maximus L）was cloned by degenerate primer PCR amplification and RACE technology, and provided a bioinformatics foundation and tissue expression for the study of LHR genetic characters. The full length of LHR gene is 3 814 bp,encodes 685 amino acids and shares a higher degree of homology with the Hippoglossus hippoglossus. The amino acid sequence analysis revealed that the LHR gene encoded hydrophobic protein and its relative molecular weight was 76. 54 ku, isoelectric point was 7. 22, and contained signal peptides and transmembrane domains. Subcellular localization of LHR was in endoplasmic reticulum and cell membrane. Meanwhile, the amino acids sequence contains thirty-three phosphorylation sites,five glycosylation sites,6 leucine-rich repeats, SCOP, PDB and seven conserved transmembrane helix domains. Furthermore,the secondary structure of LHR was mainly composed of random coil. The tertiary structure of domain area of LHR protein showed eL-helix structure. In addition, we found LHR protein probably plays a key role in transport, translation and metabolism process. Tissue expression analysis showed LHR mRNA was preferentially expressed in ovary, whereas strong amplification signal was also detected in liver. Therefore,the above results laid a genetic information foundation for further study of the LHR gene function in the turbot gonads development, providing the theoretical basis for fish breeding in marine aquaculture.