Oshima Reiko, Yoshinaga Keiko, Ihara-Ohori Yuri, Fukuda Ryouichi, Ohta Akinori, Uchimiya Hirofumi, Kawai-Yamada Maki
Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
FEBS Lett. 2007 Oct 2;581(24):4627-32. doi: 10.1016/j.febslet.2007.08.054. Epub 2007 Sep 7.
Bax inhibitor-1 (BI-1) is an evolutionarily conserved cell death suppresser in animals, yeast, and plants. In this study, yeast strains carrying single-gene deletions were screened for factors related to cell death suppression by Arabidopsis BI-1 (AtBI-1). Our screen identified mutants that failed to survive Bax-induced lethality even with AtBI-1 coexpression (Bax suppressor). The Deltacox16 strain was isolated as a BI-1-inactive mutant; it was disrupted in a component of the mitochondrial cytochrome c oxidase. Other mutants defective in mitochondrial electron transport showed a similar phenotype. ATP levels were markedly decreased in all these mutants, suggesting that BI-1 requires normal electron transport activity to suppress cell death in yeast.
Bax抑制因子-1（BI-1）是动物、酵母和植物中一种进化上保守的细胞死亡抑制因子。在本研究中，对携带单基因缺失的酵母菌株进行筛选，以寻找与拟南芥BI-1（AtBI-1）抑制细胞死亡相关的因子。我们的筛选鉴定出即使与AtBI-1共表达也无法在Bax诱导的致死性中存活的突变体（Bax抑制因子）。Δcox16菌株被分离为BI-1失活突变体；它在线粒体细胞色素c氧化酶的一个组分中发生了破坏。线粒体电子传递有缺陷的其他突变体表现出类似的表型。所有这些突变体中的ATP水平均显著降低，这表明BI-1需要正常的电子传递活性来抑制酵母中的细胞死亡。
