Sasada R, Marumoto R, Igarashi K
Central Research Division, Takeda Chemical Industries, Ltd., Osaka, Japan.
Cell Struct Funct. 1988 Apr;13(2):129-41. doi: 10.1247/csf.13.129.
Expression plasmids were constructed containing chemically synthesized human epidermal growth factor (EGF) gene fused in a frame to a leader sequence of human interleukin-2 (IL-2) gene under the control of a viral promoter. COS7 cells transfected with the plasmids synthesized and secreted EGF. Transfection of mouse A9 cells or BALB/3T3 clone A31 cells with the plasmids permitted the isolation of cell lines secreting the product which showed EGF activity. In particular, A31 transformed cells secreting human EGF grew well even in a medium containing a minimal level of serum. Using similar vectors having IgE cDNA (C2-C4) in place of EGF gene, a human IgE Fc fragment was also produced and secreted in mouse cells. These results show that heterologous leader sequences are useful for the expression and secretion of proteins whose genes lack leader sequences.
构建了表达质粒，其包含化学合成的人表皮生长因子（EGF）基因，该基因在病毒启动子的控制下与人类白细胞介素-2（IL-2）基因的前导序列框内融合。用这些质粒转染的COS7细胞合成并分泌EGF。用这些质粒转染小鼠A9细胞或BALB/3T3克隆A31细胞，可分离出分泌具有EGF活性产物的细胞系。特别地，分泌人EGF的A31转化细胞即使在含有最低水平血清的培养基中也生长良好。使用具有IgE cDNA（C2-C4）代替EGF基因的类似载体，人IgE Fc片段也在小鼠细胞中产生并分泌。这些结果表明，异源前导序列对于缺乏前导序列的基因的蛋白质的表达和分泌是有用的。
