Bacillithiol is a major buffer of the labile zinc pool in Bacillus subtilis.
Bacillithiol is a major buffer of the labile zinc pool in Bacillus subtilis.
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DOI：
10.1111/mmi.12794
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发表时间：
2014-11
影响因子：
3.6
通讯作者：
Helmann JD
中科院分区：
文献类型：
--
作者：
Ma Z;Chandrangsu P;Helmann TC;Romsang A;Gaballa A;Helmann JD
细胞内锌水平受到严格调控，因为锌是许多酶的重要辅因子，但过量存在时可能有毒。大多数细胞内锌与蛋白质紧密结合，并在合成过程中从一个不明确的动力学不稳定的锌池。在枯草芽孢杆菌中，通过与金属调节剂Zur平衡来感测该不稳定库，作为锌充足的指示，并且通过CzrA来感测该不稳定库，作为锌过量的指示。在这里，我们证明，低分子量的硫醇bacillithiol（BSH）作为一个主要的缓冲液的不稳定的锌池。在转换到锌过量的条件下，细胞在低分子量池中瞬时积累锌，并且这种积累在很大程度上依赖于BSH。缺乏BSH的细胞对锌胁迫更敏感，并且它们在较低的外部锌浓度下诱导锌流出。巯基反应剂，如二酰胺和镉诱导锌流出干扰锌缓冲功能的BSH。我们的数据提供了新的见解，细胞内锌缓冲，并可能有广泛的相关性，因为存在BSH的病原体和锌螯合在先天免疫中的作用。
Intracellular zinc levels are tightly regulated since zinc is an essential cofactor for numerous enzymes, yet can be toxic when present in excess. The majority of intracellular zinc is tightly associated with proteins and is incorporated during synthesis from a poorly defined pool of kinetically labile zinc. In Bacillus subtilis, this labile pool is sensed by equilibration with the metalloregulator Zur, as an indication of zinc sufficiency, and by CzrA, as an indication of zinc excess. Here, we demonstrate that the low molecular weight thiol bacillithiol (BSH) serves as a major buffer of the labile zinc pool. Upon shift to conditions of zinc excess, cells transiently accumulate zinc in a low molecular weight pool, and this accumulation is largely dependent on BSH. Cells lacking BSH are more sensitive to zinc stress, and they induce zinc efflux at lower external zinc concentrations. Thiol reactive agents such as diamide and cadmium induce zinc efflux by interfering with the Zn-buffering function of BSH. Our data provide new insights into intracellular zinc buffering and may have broad relevance given the presence of BSH in pathogens and the proposed role of zinc sequestration in innate immunity.
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影响因子：
3.6
作者：
Chandrangsu P;Dusi R;Hamilton CJ;Helmann JD
通讯作者：
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影响因子：
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