Kawai-Yamada M, Jin L, Yoshinaga K, Hirata A, Uchimiya H
Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Proc Natl Acad Sci U S A. 2001 Oct 9;98(21):12295-300. doi: 10.1073/pnas.211423998. Epub 2001 Oct 2.
We recently isolated the AtBI-1 (Arabidopsis Bax Inhibitor-1) gene, the expression of which suppressed Bax-induced cell death in yeast. To determine whether the same is true in the plant system, transgenic Arabidopsis plants overexpressing Bax protein under a dexamethasone (DEX)-inducible promoter were generated. On DEX treatment, such transgenic plants exhibited marked cell death at the whole-plant level, cell shrinkage, membranous destruction, and other apoptotic phenotypes. Transgenic Bax plants were retransformed with a vector containing the AtBI-1 gene (tagged with green fluorescent protein) under the control of the cauliflower mosaic virus 35S promoter. Plants expressing both Bax and AtBI-1 were able to maintain growth on DEX-treatment by sustaining intracellular integrity. Thus, we present here direct genetic evidence that the plant antiapoptotic protein AtBI-1 is biologically active in suppressing the mammalian Bax action in planta.
我们最近分离出了AtBI-1(拟南芥Bax抑制剂-1)基因,其表达可抑制酵母中Bax诱导的细胞死亡。为了确定在植物系统中是否也是如此,我们构建了在糖皮质激素(DEX)诱导型启动子控制下过表达Bax蛋白的转基因拟南芥植株。经DEX处理后,此类转基因植株在全株水平上表现出明显的细胞死亡、细胞萎缩、膜结构破坏及其他凋亡表型。用一个含有在花椰菜花叶病毒35S启动子控制下的AtBI-1基因(标记有绿色荧光蛋白)的载体对转基因Bax植株进行再次转化。同时表达Bax和AtBI-1的植株在DEX处理下能够通过维持细胞内完整性来保持生长。因此,我们在此提供直接的遗传学证据,证明植物抗凋亡蛋白AtBI-1在抑制植物中哺乳动物Bax的作用方面具有生物学活性。