Varying the position of phospholipid acyl chain unsaturation modulates hopanoid and sterol ordering.
Varying the position of phospholipid acyl chain unsaturation modulates hopanoid and sterol ordering.
复制标题
改变磷脂酰基链不饱和度的位置可调节霍帕尼和甾醇的排序。
DOI：
10.1101/2023.09.06.556521
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Saenz,JamesP
中科院分区：
文献类型：
--
作者：
Nguyen,Ha-Ngoc-Anh;Sharp,Liam;Lyman,Edward;Saenz,JamesP
细胞膜必须平衡机械稳定性和流动性，以作为屏障和组织平台。这种平衡的关键是烃链的有序化和脂质的堆积。许多真核生物合成固醇，其独特地能够调节脂质顺序以使膜稳定性与流动性分离。古老的甾醇类似物被称为hopanoids在许多细菌中发现，并提出作为祖先排序脂质。在现存的生物体中，甾醇和类胡帕酸的并列促使我们问为什么这两种途径都存在，特别是考虑到它们对脂质的趋同能力。在这项工作中，模拟，单层实验和细胞分析表明，hopanoids和甾醇顺序不饱和磷脂不同的基础上的位置的双键在磷脂酰基链。我们发现，胆固醇和diplopterol的甲基基团分布导致不饱和脂质的不同效果。与胆固醇不同，在花中浆菌中，diplopterol的有序化能力降低了膜对渗透压的抵抗力。这些发现表明，胆固醇更广泛的脂质排序能力可能促进了对真核细胞膜中更多样化的脂质组学景观的探索。
The cell membrane must balance mechanical stability with fluidity to function as both a barrier and an organizational platform. Key to this balance is the ordering of hydrocarbon chains and the packing of lipids. Many eukaryotes synthesize sterols, which are uniquely capable of modulating the lipid order to decouple membrane stability from fluidity. Ancient sterol analogs known as hopanoids are found in many bacteria and proposed as ancestral ordering lipids. The juxtaposition of sterols and hopanoids in extant organisms prompts us to ask why both pathways persist, especially in light of their convergent ability to order lipids. In this work, simulations, monolayer experiments, and cellular assays show that hopanoids and sterols order unsaturated phospholipids differently based on the position of double bonds in the phospholipid acyl chain. We find that cholesterol and diplopterol's methyl group distributions lead to distinct effects on unsaturated lipids. InMesoplasma florum, diplopterol's constrained ordering capacity reduces membrane resistance to osmotic stress, unlike cholesterol. These findings suggest that cholesterol's broader lipid-ordering ability may have facilitated the exploration of a more diverse lipidomic landscape in eukaryotic membranes.