额种子蛋白体靶向表达口服重组胰岛素原载体构建及转化水稻

应用水稻种子生物反应器开发口服重组胰岛素原具有重要应用前景。通过分子设计保证重组胰岛素原在人体肠道内的自主加工成熟,根据水稻密码子偏爱性人工合成了霍乱毒素β亚基和人胰岛素原的融合基因(cholera toxin B subunit fused with human proinsulin,CTBIN),并在C末端添加内质网滞留信号KDEL。通过PCR技术从粳稻品种日本晴全基因组中克隆谷蛋白启动子及其信号肽序列pGluB1sig(GluB1 promoter and its signal peptide)用于驱动融合基因CTBIN的表达,插入载体pCAMBIA1302,构建了水稻种子蛋白体靶向表达口服重组胰岛素原的载体pCAMBIA1302-pGluB1sig-CTBIN-Nos。采用农杆菌介导法转化日本晴,获得了46株转基因水稻植株,Western杂交检测到CTB-人胰岛素原融合蛋白在水稻种子中表达。

Construction of Seed Protein Body Targeted Expression Vector and Transformation Rice for Oral Recombinant Proinsulin

Developent of oral recombinant proinsulin using rice seeds as bioreactor shows good application future. A fusion gene of the cholera toxin B subunit and human proinsulin (CTBIN) with an endoplasmic reticulum retention signal (KDEL) at C-terminus was designed for its self-maturation process in human gut and synthesized according to the optimized code usage bias of rice. The synthetic CTBIN was introduced to the vector pCAMBIA1302 and expressed under the 2.4 kb promoter sequence of rice glutelin GluB1 with its signal peptide (pGluB1sig), which was cloned by PCR from the japonica rice Nipponbare genome. Thus the rice seed protein body targeted expression vector pCAMBIA1302-pGluB1sig-CTBIN-Nos for oral delivery of recombinant proinsulin was constructed and then transformed into Nipponbare via Agrobacterium-mediated method. Totally 46 transgenic rice plants were obtained and the expression of the fusion protein CTB::Human proinsulin in rice seeds was detected by Western-blot.