期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 100, 期 23, 页码 13603-13608出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.2235180100
关键词
transcription activation; ClpXP; disulfide stress
资金
- NIGMS NIH HHS [R01 GM045898, R01 GM050895, GM50895, GM45898] Funding Source: Medline
The Spx protein of Bacillus subtilis represses activator-stimulated transcription by interacting with the C-terminal domain of RNA polymerase (RNAP) a subunit. Its concentration increases in cells lacking the ATP-dependent protease, ClpXP, resulting in severe effects on growth and developmental processes. Microarray analysis was undertaken to identify genes that are induced or repressed when Spx interacts with RNAP. The induced genes included those encoding products known to function in maintaining thiol homeostasis. Two genes, thioredoxin (trxA) and thioredoxin reductase (trxB), are transcriptionally induced under conditions of thiol-specific oxidative (disulfide) stress by a mechanism involving Spx-RNAP interaction. Disulfide stress also results in an increase in Spx-dependent transcriptional repression. The increase in Spx activity in cells encountering disulfide stress is due in part to a posttranscriptional mechanism of spx control resulting in an increase in Spx concentration. An spx null mutant and a strain bearing an allele of rpoA that prevents Spx-RNAP interaction show hypersensitivity to disulfide stress. From these results, it is proposed that Spx is an activator that mobilizes the operations necessary to reverse the effects of oxidative damage, but it also serves as a negative regulator that causes the postponement of developmental programs and energy-consuming growth-related functions while the cell copes with the period of stress.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据