相关实验视频
Updated: Jan 7, 2026

08:26
Monitoring Stub1-Mediated Pexophagy
Published on: May 12, 2023
2.0K
PexR 是细菌中过氧化物应激反应的非正规调节剂
Eva Bastida-Martínez1,2, Irene Del Rey-Navalón1, Naike Ye3
1Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQF-CSIC), Universidad de Murcia, Murcia 30100, Spain.
Nucleic acids research
|December 31, 2025
概括
研究人员在Myxococcus xanthus中发现了PexR,这是一种控制过氧化应激反应基因 (ahpC和katB) 的新型调节剂. 这种双重功能蛋白质既起抑制作用又起激活作用,对于氧化应激下细胞生存至关重要.
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:
- 细胞利用过氧化和催化酶来管理过氧化应激.
- OxyR和PerR是典型的细菌转录调节器,可感知过氧化 (H2O2).
- 研究了一种新的H2O2诱导基因表达的调节机制.
研究的目的:
- 在Myxococcus xanthus.中识别和描述一种非正规的H2O2感应调节器.
- 阐明PexR在控制过氧素 (ahpC) 和催化酶 (katB) 基因表达中的机制.
- 评估PexR介导的共同调节对细胞生长和存活的重要性.
主要方法:
- 对ahpC,katB和pexR基因的遗传删除.
- 在不同的过氧化物条件下对基因表达的分析.
- 生物化学表征PexR蛋白的功能,包括其GAF域.
- 基因组分析以确定保存的PexR同类物和调控元素.
主要成果:
- PexR是一种ATP结合蛋白,作为ahpC和katB的双抑制剂激活剂.
- 佩克斯R激活了H2O2诱导的s54-依赖的ahpC和katB的表达.
- 在非压力条件下,PexR抑制了家庭 σA-依赖的ahpC表达.
- 删除ahpC会导致型,并与katB或pexR结合删除会导致合成致死性.
- PexR的N端GAF域感知H2O2,导致自抑制释放和激活s54依赖转录.
结论:
- 通过PexR介导的AhpC和KatB的共同调节对于Myxococcus xanthus的生长至关重要.
- PexR代表了一类新的H2O2传感器和调节器,与OxyR和PerR不同.
- 发现PexR扩大了细菌中已知的过氧化物应激反应机制的范围.
- 保存的PexR同类体表明,在细菌族群中存在广泛的调控策略.
相关概念视频
Other Stress Responses in Bacteria
310
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
310
Stringent Response in E. coli
257
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
257
Regulation of the Unfolded Protein Response
2.9K
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
2.9K
Protein Import into the Peroxisomes
5.2K
Cells contain membrane-bound organelles called peroxisomes that oxidize organic molecules by transferring hydrogen atoms to oxygen, producing hydrogen peroxide. Peroxisomes enzymatically convert the released hydrogen peroxide into water and oxygen.
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
5.2K
Global Regulatory Systems
545
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
545
Peroxisomes
19.9K
Peroxisomes are specialized organelles present in fungi, plant, and animal cells. It can vary in number, size, morphology, and activity depending on the type of tissue and the nutritional state of the cell. For example, cells with active lipid metabolism, such as adipocytes, neurons, and hepatocytes, have more peroxisomes than other cells in the body. Besides their primary role in breaking down complex organic molecules, peroxisomes can also synthesize specific macromolecules and participate in...
19.9K

