Selenium-dependent gene regulation in Archaea

古细菌中硒依赖性基因调控

• 批准号: 422447039
• 负责人: Professor Dr. Michael Rother
• 金额: --
• 依托单位: Professur für Mikrobielle Diversität
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/422447039?language=en
• 关键词: Selenium; dependent; gene; regulation; Archaea

Selenium is an essential trace element for many members of all three domains of life, but how selenium is transported into cells is unknown. Selenium exerts its biological function through the co-translationally inserted amino acid selenocysteine (Sec) and the tRNA modification 2-selenouridine (SeU). The methanogenic archaeon Methanococcus maripaludis employs Sec-containing proteins in its central energy metabolism, hydrogenotrophic methanogenesis. However, when selenium is scarce, a set of selenium-independent isoenzymes is induced, rendering growth independent of this trace element. However, how the cellular selenium status is sensed, and how this information is transduced to alter gene expression is unknown. Selenophosphate, which is the biosynthetic precursor of both Sec and SeU, is an attractive candidate for representing the cellular selenium status. Furthermore, phenotypic analyses of M. maripaludis mutants suggest involvement of the LysR-type transcription regulator HrsM in selenium-dependent activation of the selenoprotein genes and repression of the isogenes, but the mechanism of HrsM-dependent gene regulation is unknown. To elucidate how (and in what form) M. maripaludis transports selenium into the cell, to define the metabolic cue representing the cellular selenium status, and to unravel the mechanism HrsM either activates or represses gene expression in a selenium-dependent manner, is the aim of the proposed project.

硒是生命所有三个领域的许多成员的必需微量元素，但硒如何被运输到细胞中尚不清楚。硒通过协同插入的氨基酸硒代半胱氨酸（Sec）和tRNA修饰的2-硒尿苷（SeU）发挥其生物学功能。产甲烷古菌Methanococcus maripaludis在其中心能量代谢--氢营养型甲烷生成中使用含Sec的蛋白质。然而，当硒缺乏时，诱导一组硒非依赖性同工酶，使生长独立于这种微量元素。然而，细胞硒状态是如何被感知的，以及这种信息如何被转导以改变基因表达尚不清楚。硒磷酸盐是Sec和SeU的生物合成前体，是代表细胞硒状态的有吸引力的候选者。此外，对M. maripaludis突变体表明参与的LysR型转录调节HrsM的硒依赖性激活的硒蛋白基因和抑制的isogenes，但HrsM依赖的基因调控的机制是未知的。为了阐明如何（以及以何种形式）M。maripaludis将硒转运到细胞中，以确定代表细胞硒状态的代谢线索，并解开HrsM以硒依赖性方式激活或抑制基因表达的机制，是拟议项目的目的。