毛尖紫萼藓GpUCH基因克隆及表达分析

从毛尖紫萼藓干旱cDNA文库中筛选了一条与抗旱相关的泛素羧基末端水解酶基因的EST序列，采用RACE技术从毛尖紫萼藓中克隆出了该基因的cDNA全长序列，命名为白UCH。对该基因的序列特征、进化关系和表达谱进行了分析，为全面研究其功能奠定了基础。该基因cDNA全长951bp，开放阅读框711bp，共编码236个氨基酸。生物信息学分析显示，印UCH基因相对分子质量为25．7kD，等电点为4．67，为不稳定蛋白，属于跨膜蛋白但不存在信号肽。系统进化树分析表明，GpUCH与小立碗藓UCH蛋白一致性较高。实时荧光定量PCR结果显示，GpUCH基因在复水和干旱的条件下均能表达，但是在不同的条件下表达情况差异显著。表明该基因可能在毛尖紫萼藓干旱过程中发挥一定的作用。

Cloning and Expression Analysis of GpUCH Gene in Grimmia pilifera

A drought-resistance gene was cloned from drought cDNA library of Grimmia pilifera, the gene relatived to ubiquitin carboxy terminal hydrolytic enzymes （ UCH）, named GpUCH. The cDNA fragment of GpUCH was cloned from Grimmia pilifera through rapid amplification of eDNA ends （RACE）. To further study the function of GpUCH gene, it was necessary to describe the sequence characteristics, evolutionary relationship and gene expression. The full length eDNA was 951 bp with an pen reading frame of 711 bp which encoded 237 amino acid with a molecular weight of 25.7 kD, and the isoelectric point is 4. 67. The result of bioinformatics showed that this protein was unstable transmembrane protein and had no signal peptide. The phylogenetic tree showed that GpUCH and Physcomitrella patens UCH protein had a close relationship. QRT-PCR analysis showed that the expression of GpUCH gene was induced in both rehydration and dehydration. Under different conditions the expression of GpUCH were obviously varius. The results suggested that GpUCH gene might play an important role in drought stress.