黑线仓鼠Htr1a克隆及生物信息学分析

Clone and Bioinformatic Analysis of Htr1a in Cricetulus Barabensis

Htr1a是介导5-HT系统功能的关键,主要分布于额叶皮层、海马、外侧隔、中缝背核、脊髓前角等.该研究以黑线仓鼠(Cricetulus barabensis)为实验材料,用RT-PCR技术克隆黑线仓鼠Htr1a的部分cDNA序列1486bp(GeneBank登录号:MH169583),运用生物信息学对Htr1a核酸序列以及蛋白质序列进行分析,构建系统进化树.研究结果表明:克隆的Htr1a部分cDNA序列包含一个完整的开放阅读框1269bp,部分5′,非翻译区和部分3′,非翻译区,共编码422个氨基酸.Htr1a蛋白质分子量为46332.47Da,等电点为9.18,该蛋白质有7个跨膜螺旋,一个G蛋白偶联受体家族标签,不含有信号肽,不属于分泌蛋白,疏水性分析也表明其符合膜蛋白的特征;同源性比对和系统进化树分析显示,黑线仓鼠与中国仓鼠(Cricetulus griseus)亲缘关系相近,与啮齿类较近,而与其他哺乳类和鸟类物种的亲缘关系均较远,这与传统的物种分类相一致.以上结果证实本实验成功克隆到黑线仓鼠Htr1a的部分cDNA序列,为进一步探究黑线仓鼠5-HT系统功能奠定了分子生物学基础.

Serotonin IA （5 hydroxytryptamine receptor IA, Htrla） is the key to mediate the 5 HT system function, which distributed mainly in the frontal cortex, hippocampus, lateral septum, dorsal ra phe nucleus, spinal anterior horn. Based on the striped hamsters （Cricetulus barabensis）for materials, the cDNA sequence of Htrlawas cloned by RT PCR. The nucleic acid sequences and protein sequences of Htrlawere analyzed by bioinformatics. The results show that the sequence is 1486 bp in length, containing part of the 5＇ noncoding region, part of the 3＇ noncoding region and a complete open reading frame of 1269bp which encodes a polypeptide of 422 amino acids residues （GeneBank ID.. MH169583）. The Htrla protein has a molecular weight of 46332.47 Da and an isoelectric point of 9.18. The protein has 7 trans membrane helices, a G protein coupled receptor family tag, no signal peptide, doees not belong to a secre ted protein, and hydrophobicity analysis also shows that it conforms to the membrane protein characteris tics. Homology comparison and phylogenetic tree analysis show that the striped hamster （Cricetulus barabensis）is closest to the Chinese hamster （Cricetulus griseus）and related to rodents more closely, but has a distant relationship with other mammals and bird species, which is consistent with traditional species taxonomy. The above results confirm that this experiment cloned part of the cDNA sequence of the striped hamster Htrlasuccessfully, which lay a foundation for further exploration of the function of 5 HT system in the striped hamster.