Low membrane fluidity triggers lipid phase separation and protein segregation in living bacteria.
Low membrane fluidity triggers lipid phase separation and protein segregation in living bacteria.
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DOI：
10.15252/embj.2021109800
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发表时间：
2022-03-01
期刊：
影响因子：
--
通讯作者：
Strahl H
中科院分区：
文献类型：
--
作者：
Gohrbandt M;Lipski A;Grimshaw JW;Buttress JA;Baig Z;Herkenhoff B;Walter S;Kurre R;Deckers-Hebestreit G;Strahl H
所有活着的生物体都会根据环境或饮食的变化来调整其膜脂成分。这些保守的膜适应过程已被广泛研究。然而，与调节脂质成分有关的膜生物学的关键概念，包括维持稳定的膜流动性水平的同质粘性适应，以及导致结构域形成的凝胶-液体相分离，在很大程度上依赖于模型膜或脂质提取物的体外研究。利用细菌模式生物大肠杆菌和枯草芽孢杆菌，我们现在发现，体内膜流动性不足会干扰必要的复杂细胞过程，包括胞质分裂、包膜扩张、染色体复制/分离和膜电位的维持。此外，我们证明，极低的膜流动性确实能够在完整的、蛋白质密集的活细胞膜中引发大规模的脂相分离和蛋白质分离；这一过程与能够支持生长的最低流动性水平相吻合。重要的是，体内脂质相分离与膜扩散屏障功能的崩溃无关，从而解释了为什么低流动性诱导的相分离过程在生物上是可逆的。细菌的基本细胞过程，包括胞质分裂、包膜扩张、染色体复制/分离和膜电位的维持，都受到膜流动性的影响。
All living organisms adapt their membrane lipid composition in response to changes in their environment or diet. These conserved membrane‐adaptive processes have been studied extensively. However, key concepts of membrane biology linked to regulation of lipid composition including homeoviscous adaptation maintaining stable levels of membrane fluidity, and gel‐fluid phase separation resulting in domain formation, heavily rely upon in vitro studies with model membranes or lipid extracts. Using the bacterial model organisms Escherichia coli and Bacillus subtilis, we now show that inadequate in vivo membrane fluidity interferes with essential complex cellular processes including cytokinesis, envelope expansion, chromosome replication/segregation and maintenance of membrane potential. Furthermore, we demonstrate that very low membrane fluidity is indeed capable of triggering large‐scale lipid phase separation and protein segregation in intact, protein‐crowded membranes of living cells; a process that coincides with the minimal level of fluidity capable of supporting growth. Importantly, the in vivo lipid phase separation is not associated with a breakdown of the membrane diffusion barrier function, thus explaining why the phase separation process induced by low fluidity is biologically reversible. Essential cellular processes in bacteria, including cytokinesis, envelope expansion, chromosome replication/segregation and maintenance of membrane potential, are impaired by low membrane fluidity.
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影响因子：
64.8
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通讯作者：
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影响因子：
4.8
作者：
Brandt, Karsten;Maiwald, Sarah;Deckers-Hebestreit, Gabriele
通讯作者：
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影响因子：
3.2
作者：
BROEKMAN, JH;STEENBAKKERS, JF
通讯作者：
STEENBAKKERS, JF
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1.2
作者：
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通讯作者：
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