Osmotic gradients induce bio-reminiscent morphological transformations in giant unilamellar vesicles.
Osmotic gradients induce bio-reminiscent morphological transformations in giant unilamellar vesicles.
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DOI：
10.3389/fphys.2012.00120
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发表时间：
2012
影响因子：
4
通讯作者：
Kraut RS
中科院分区：
文献类型：
--
作者：
Oglęcka K;Sanborn J;Parikh AN;Kraut RS
我们报道了在存在跨囊泡渗透梯度的情况下，观察到由二元和三元脂质混合物组成的巨大的单层和多层囊泡中的大规模、平面内和平面外的膜变形。我们研究的脂类混合物由DOPC和DPPC脂类的二元混合物以及由POPC、鞘磷脂和胆固醇组成的三元混合物组成，它们都在热力学平衡下在室温下为选定的组成范围产生共存相。在净渗透梯度的存在下，我们发现这些混合物的面内相分离势发生了很大的变化，并发生了各种面外形态重塑事件。我们观察到的膜变形序列与活细胞中的生物对应物显示出惊人的相似之处，包括囊泡形成、膜分裂和融合、管状和珍珠化，以及被困住的囊泡通过大的、自我修复的瞬时毛孔从多个间隔的巨大单板层囊泡中排出。这些观察结果表明，通过膜边界的简单渗透梯度引入的力可以触发依赖形状的膜和囊泡运输活动。我们推测，渗透压梯度与膜特性的这种耦合可能提供了脂质介导的机制，在膜分区的早期进化过程中，在没有渗透调节蛋白机制的情况下，对渗透胁迫进行补偿。
We report observations of large-scale, in-plane and out-of-plane membrane deformations in giant uni- and multilamellar vesicles composed of binary and ternary lipid mixtures in the presence of net transvesicular osmotic gradients. The lipid mixtures we examined consisted of binary mixtures of DOPC and DPPC lipids and ternary mixtures comprising POPC, sphingomyelin and cholesterol over a range of compositions – both of which produce co-existing phases for selected ranges of compositions at room temperature under thermodynamic equilibrium. In the presence of net osmotic gradients, we find that the in-plane phase separation potential of these mixtures is non-trivially altered and a variety of out-of-plane morphological remodeling events occur. The repertoire of membrane deformations we observe display striking resemblance to their biological counterparts in live cells encompassing vesiculation, membrane fission and fusion, tubulation and pearling, as well as expulsion of entrapped vesicles from multicompartmental giant unilamellar vesicles through large, self-healing transient pores. These observations suggest that the forces introduced by simple osmotic gradients across membrane boundaries could act as a trigger for shape-dependent membrane and vesicle trafficking activities. We speculate that such coupling of osmotic gradients with membrane properties might have provided lipid-mediated mechanisms to compensate for osmotic stress during the early evolution of membrane compartmentalization in the absence of osmoregulatory protein machinery.
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影响因子：
2
作者：
KOSLOV, MM;MARKIN, VS
通讯作者：
MARKIN, VS
影响因子：
3.4
作者：
KAS, J;SACKMANN, E
通讯作者：
SACKMANN, E
影响因子：
64.5
作者：
Chipuk JE;McStay GP;Bharti A;Kuwana T;Clarke CJ;Siskind LJ;Obeid LM;Green DR
通讯作者：
Green DR
影响因子：
3.4
作者：
Khalifat, Nada;Puff, Nicolas;Angelova, Miglena I.
通讯作者：
Angelova, Miglena I.
影响因子：
8.6
作者：
BARZIV, R;MOSES, E
通讯作者：
MOSES, E