巴西橡胶树磷脂酰肌醇转移蛋白cDNA的克隆及其序列分析

本文从巴西橡胶树(Hevea brasiliensis)差减cDNA文库中筛选到一个与磷脂酰肌醇转移蛋白(phos-phatidylinositol transfer protein)同源性较高的基因片段,并根据该基因片段序列信息,设计特异性引物,采用cDNA末端快速扩增技术RACE(rapid amplification of cDNA ends)进行差异片段的5'和3'端的扩增,并获得长度为1081bp的全长cDNA克隆R291(GenBank登陆号:AY589690)。序列分析表明,该基因包含702bp的开放阅读框,编码234个氨基酸,推测其蛋白质的分子量为26.8kD,等电点为6.51,有一个的跨膜螺旋区(氨基酸位点为83～103)。R291基因含有一个脂质结合保守区(Sec14p-like lipid-binding domain),具有CRAL-TRIO脂质结合结构域,推测该基因是一个磷脂酰肌醇转移蛋白基因。该基因的克隆将为橡胶树磷脂酰肌醇代谢的研究奠定了基础,将有助于进一步了解磷脂酰肌醇代谢与胶乳再生之间的关系。

Cloning and Sequence Analysis of Phosphatidylinositol Transfer Protein cDNA from Hevea brasilensis

In this paper, a cDNA clone was isolated related to lipid transportation and metabolism by screening of a subtracted latex cDNA library of Hevea brasiliensis. According to its sequences information, a novel full-length cDNA termed R291 (GenBank number: AY589690) was obtained by using rapid amplification of cDNA ends (RACE). R291 was 1 081 bp long containing a 702 bp ORF, encoding 234 amino acids with a theoretical molecu lar weight of 26.8 kD and an isoeleetric point of 6.51. In addition, hydropathy and transmembrane motif analysis of de-duced amino acid sequences indicated that R29I possessed a transmembrane spanning domain (from the amino acid site from 83 to 103). The result of the conserved domains analysis demonstrated that R291 had a Sec14p-like lipid-binding domain and a CRAL/TRIO region. Multialignment presumed that R291 might be a phosphatidylinos-itol transfer protein gene. The cloning of this gene would establish the basic for metabolisim ofHevea brasiliensis phosphatidylinositol, and would help to further understand relation between metabolisim of phosphatidylinositol and latex regeneration.