绿竹BoCOBL基因的分子特征及其表达分析

Molecular Characteristics and Expression Analysis of BoCOBL Gene from Green Bamboo(Bambusa oldhamii)

为探讨COBRA相像蛋白(COBL)在竹子细胞发育过程中的作用,采用RT-PCR和RACE技术,从绿竹(Bambusa oldhamii)叶片中克隆到1个COBL同源基因BoCOBL(GenBank登录号:EU247930),cDNA全长为1743 bp。序列分析表明,BoCOBL编码含451个氨基酸的COBL蛋白,其N端具有1个明显的跨膜螺旋结构,C端具有1个糖基磷脂酰肌醇锚定蛋白信号序列,属于糖基磷脂酰肌醇锚定蛋白家族,为典型的膜蛋白。通过构建BoCOBL::GFP融合表达载体,并转化到烟草(Nicotiana tabacum)悬浮细胞中,表达分析表明BoCOBL::GFP融合蛋白定位于细胞膜上,而对照GFP的分布无特异性,证明BoCOBL基因编码的蛋白为膜蛋白。组织特异性表达分析表明,BoCOBL基因的表达模式为组成型,在根、茎、叶片和叶鞘中均有表达,但在茎中的表达丰度略低。这为深入研究BoCOBL基因在竹子中的功能奠定了基础。

In order to understand the function of COBL similar protein in bamboo, BoCOBL, a COBL homologous gene, was donned from Bambusa oldhamii by RT-PCR and RACE methods. The full-length cDNA of BoCOBL was 1743 bp （GenBank accession No.： EU247930）. Sequence analysis showed that BoCOBL encoded 451 amino acids with a transmembrane helical structure at the N-terminal and a glycosylphosphatidylinositol- anchored protein signal sequence at the C-terminal, which indicated that it was a membrane protein, belonging to glycosylphosphatidyl inositol-anchored protein family. The expression vector of BoCOBL：：GFP was constructed and transformed into suspension cells of tobacco. The BoCOBL：：GFP proteins were mainly located on the cytoplasmic membrane, while the control of GFP proteins was non-specific in the transformed cells. So, it was confirmed that the protein encoded by BoCOBL was a membrane protein. The analysis of tissue specific expression indicated that the expression of BoCOBL was constitutive, with similar level in root, leaf and sheath, while slightly low in stem. These results would be helpful for further study on the function of BoCOBL in bamboo.