Biogenesis, transport and remodeling of lysophospholipids in Gram-negative bacteria.
Biogenesis, transport and remodeling of lysophospholipids in Gram-negative bacteria.
复制标题
革兰氏阴性菌中溶血磷脂的生物发生、运输和重塑。
DOI：
10.1016/j.bbalip.2016.11.015
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Bogdanov,Mikhail
中科院分区：
文献类型：
--
作者：
Zheng,Lei;Lin,Yibin;Lu,Shuo;Zhang,Jiazhe;Bogdanov,Mikhail
溶血磷脂（LPL）是细菌磷脂代谢的中间产物。与它们的二酰基对应物不同，这些倒锥形分子具有洗涤剂的物理特性，能够改变局部膜特性，如曲率。LPL作为细胞生长因子或有效的脂质介质的功能已在真核细胞中得到广泛证实，但在细菌中仍不明确。在革兰氏阴性菌的包膜中，LPL来源于多种内源性和外源性来源。虽然几个翻转酶，移动非甘油磷脂跨越细菌内膜的特点，溶血磷脂转运蛋白LplT似乎是第一个例子的细菌蛋白能够促进快速逆行易位溶血形式的甘油磷脂跨越细胞质膜革兰氏阴性菌。LplT以相当的效率运输三种细菌膜磷脂的溶血形式，但不包括其他溶血脂质种类。一旦LPL被LplT翻转到内膜的细胞质侧，其二酰基形式通过外周酶酰基-ACP合成酶/LPL酰基转移酶（Aas）的作用有效地再生。LplT-Aas还通过将其两种溶血衍生物二酰基或脱酰基心磷脂转化为三酰基形式来介导新的心磷脂重塑。这种偶联的重塑系统提供了独特的细菌膜磷脂修复机制。LplT对溶血脂质的严格选择性允许该系统在主要含有二酰基磷脂的环境中实现有效的脂质修复。由一对对称离子锁接合的摇杆开关模型可以促进交替的底物进入以驱动LPL翻转到细菌细胞中。这篇文章是一个特殊问题的一部分，题为：细菌脂质编辑罗素E。主教
Lysophospholipids (LPLs) are metabolic intermediates in bacterial phospholipid turnover. Distinct from their diacyl counterparts, these inverted cone-shaped molecules share physical characteristics of detergents, enabling modification of local membrane properties such as curvature. The functions of LPLs as cellular growth factors or potent lipid mediators have been extensively demonstrated in eukaryotic cells but are still undefined in bacteria. In the envelope of Gram-negative bacteria, LPLs are derived from multiple endogenous and exogenous sources. Although several flippases that move non-glycerophospholipids across the bacterial inner membrane were characterized, lysophospholipid transporter LplT appears to be the first example of a bacterial protein capable of facilitating rapid retrograde translocation of lyso forms of glycerophospholipids across the cytoplasmic membrane in Gram-negative bacteria. LplT transports lyso forms of the three bacterial membrane phospholipids with comparable efficiency, but excludes other lysolipid species. Once a LPL is flipped by LplT to the cytoplasmic side of the inner membrane, its diacyl form is effectively regenerated by the action of a peripheral enzyme, acyl-ACP synthetase/LPL acyltransferase (Aas). LplT-Aas also mediates a novel cardiolipin remodeling by converting its two lyso derivatives, diacyl or deacylated cardiolipin, to a triacyl form. This coupled remodeling system provides a unique bacterial membrane phospholipid repair mechanism. Strict selectivity of LplT for lyso lipids allows this system to fulfill efficient lipid repair in an environment containing mostly diacyl phospholipids. A rocker-switch model engaged by a pair of symmetric ion-locks may facilitate alternating substrate access to drive LPL flipping into bacterial cells. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.