化应激:转录因子OxyRR的激活
A Hausladen1, C T Privalle, T Keng
1Department of Medicine, Duke University Medical Center Durham, North Carolina 27710, USA.
Cell
|September 6, 1996
概括
一些S-尼特罗斯醇 (RSNO) 诱导大肠杆菌的尼特罗斯压力,通过S-尼特罗斯化激活OxyR转录因子. 这种反应有助于细菌适应压力并生存.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 过氧化 (H2O2) 在大肠杆菌中引起氧化应激,影响像谷氨这样的细胞标.
- 转录激活剂OxyR调节了对H2O2排毒的基因,以应对氧化应激.
研究的目的:
- 调查S-尼托醇 (RSNO) 对大肠杆菌的影响.
- 了解细胞和基因对RSNO诱导的压力的反应,称为"化压力".
主要方法:
- 监测暴露于RSNO的大肠杆菌中的细胞内硫醇水平.
- 通过S-化对OxyR的转录激活的评估.
- 分析与排毒途径相关的基因表达.
主要成果:
- 发现RSNO降低了大肠杆菌中的细胞内硫醇水平.
- 对OxyR的S-化导致其转录激活.
- 这种反应与RSNO的代谢命运和细菌生存有关.
结论:
- S-化作为一个信号机制,扩展到细菌的转录调节.
- 大肠杆菌具有适应化应激的代谢途径.
- 这种适应机制有助于细菌的弹性和从静止中获救.
相关概念视频
Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
Eukaryotic Transcription Activators
Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
Transcriptional Regulation: Riboswitches
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...


