Scholarlink

<p>High cytoplasmic cysteine levels are potentially dangerous because they can promote ROS formation. Here, we show that NH<sub>4</sub>Cl depletion increases free cysteine concentrations in <i>E. coli</i> and <i>B. subtilis</i> and triggers mechanisms of its homeostasis. In <i>E. coli</i>, excess cysteine was reduced by a twofold increase in the rate of its incorporation into glutathione, export into the medium, and degradation to form H<sub>2</sub>S. H<sub>2</sub>S production was reduced fourfold in the starved <i>E. coli mstA</i> mutant, indicating an important role of 3-mercaptopyruvate sulfotransferase in cysteine degradation. In <i>B. subtilis</i>, intra- and extracellular cysteine concentrations were 2.2- and 4.8-fold higher than in <i>E. coli</i>. Ammonium depletion caused accelerated cysteine export and intense H<sub>2</sub>S release; bacillithiol levels were unchanged. Overall, changes in low molecular weight thiols during nitrogen starvation were similar to their changes during other stresses we have studied previously, indicating that they may be part of a universal stress response.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Ammonium depletion induces changes in low molecular weight thiol levels in Escherichia coli and Bacillus subtilis

  • 期刊论文

  • 发表日期：

    2025年8月28日

查看全文
  • Galina Smirnova,
  • Aleksey Tyulenev,
  • Lyubov Sutormina,
  • Tatyana Kalashnikova,
  • Natalia Zhulanova,
  • Nadezda Muzyka,
  • Vadim Ushakov,
  • Oleg Oktyabrsky

摘要

High cytoplasmic cysteine levels are potentially dangerous because they can promote ROS formation. Here, we show that NH4Cl depletion increases free cysteine concentrations in E. coli and B. subtilis and triggers mechanisms of its homeostasis. In E. coli, excess cysteine was reduced by a twofold increase in the rate of its incorporation into glutathione, export into the medium, and degradation to form H2S. H2S production was reduced fourfold in the starved E. coli mstA mutant, indicating an important role of 3-mercaptopyruvate sulfotransferase in cysteine degradation. In B. subtilis, intra- and extracellular cysteine concentrations were 2.2- and 4.8-fold higher than in E. coli. Ammonium depletion caused accelerated cysteine export and intense H2S release; bacillithiol levels were unchanged. Overall, changes in low molecular weight thiols during nitrogen starvation were similar to their changes during other stresses we have studied previously, indicating that they may be part of a universal stress response.