Akiyama Y, Ito K
Department of Cell Biology, Kyoto University, Japan.
Mol Gen Genet. 1995 Nov 15;249(2):202-8. doi: 10.1007/BF00290367.
An Escherichia coli membrane protein, FtsH, has been implicated in several cellular processes, including integration of membrane proteins, translocation of secreted proteins, and degradation of some unstable proteins. However, how it takes part in such diverse cellular events is largely unknown. We previously isolated dominant negative ftsH mutations and proposed that FtsH functions in association with some other cellular factor(s). To test this proposal we isolated multicopy suppressors of dominant negative ftsH mutations. One of the multicopy suppressor clones contained an N-terminally truncated version of a new gene that was designated fdrA. The FdrA fragment suppressed both of the phenotypes--increased abnormal translocation of a normally cytoplasmic domain of a model membrane protein and retardation of protein export--caused by dominant negative FtsH proteins. The intact fdrA gene (11.9 min on the chromosome) directed the synthesis of a 60 kDa protein in vitro.
一种大肠杆菌膜蛋白FtsH参与了多种细胞过程，包括膜蛋白整合、分泌蛋白转运以及一些不稳定蛋白的降解。然而，它如何参与这些多样的细胞事件在很大程度上尚不清楚。我们之前分离出了显性负性ftsH突变，并提出FtsH与其他一些细胞因子协同发挥作用。为了验证这一推测，我们分离出了显性负性ftsH突变的多拷贝抑制子。其中一个多拷贝抑制子克隆包含一个新基因的N端截短版本，该基因被命名为fdrA。FdrA片段抑制了由显性负性FtsH蛋白引起的两种表型——模型膜蛋白正常胞质结构域异常转运增加以及蛋白质输出延迟。完整的fdrA基因（位于染色体上11.9分钟处）在体外指导合成一种60 kDa的蛋白质。
