Structural determinants for partitioning of lipids and proteins between coexisting fluid phases in giant plasma membrane vesicles
Structural determinants for partitioning of lipids and proteins between coexisting fluid phases in giant plasma membrane vesicles
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DOI：
10.1016/j.bbamem.2007.08.028
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发表时间：
2008-01-01
影响因子：
3.4
通讯作者：
Baird, Barbara
中科院分区：
文献类型：
--
作者：
Sengupta, Prabuddha;Hammond, Adam;Baird, Barbara
脂质和蛋白质组织异质性的结构基础是真核细胞质膜的基本问题。目前的假设是参与液体有序（Lo）膜结构域（脂筏）的膜功能的动态区室化，但它一直很难证明这些域在活细胞中的存在。最近，巨大的质膜囊泡（GPMV）获得的化学诱导起泡的培养细胞被发现相分离成光学可分辨的，共存的流体域包含LO样和液体无序（Ld）样相的荧光探针鉴定。在本研究中，我们使用这些GPMV调查的结构基础分配选定的脂质和蛋白质之间共存的LO样/LD样的流体相组成复杂的膜。我们的研究结果与脂质探针表明，极性头基的结构，除了酰基链饱和度，可以显着影响分区。我们发现，蛋白质的膜锚和蛋白质的聚集状态都显着影响其分布在共存的流体相在这些生物膜。我们的研究结果表明，GPMV的值为表征相偏好的蛋白质和脂质探针在没有洗涤剂和其他扰动的膜结构。(c)2007 Elsevier B. V.保留所有权利。
The structural basis for organizational heterogeneity of lipids and proteins underlies fundamental questions about the plasma membrane of eukaryotic cells. A current hypothesis is the participation of liquid ordered (Lo) membrane domains (lipid rafts) in dynamic compartmentalization of membrane function, but it has been difficult to demonstrate the existence of these domains in live cells. Recently, giant plasma membrane vesicles (GPMVs) obtained by chemically induced blebbing of cultured cells were found to phase separate into optically resolvable, coexisting fluid domains containing Lo-like and liquid disordered (Ld)-like phases as identified by fluorescent probes. In the present study, we used these GPMVs to investigate the structural bases for partitioning of selected lipids and proteins between coexisting Lo-like/Ld-like fluid phases in compositionally complex membranes. Our results with lipid probes show that the structure of the polar headgroups, in addition to acyl chain saturation, can significantly affect partitioning. We find that the membrane anchor of proteins and the aggregation state of proteins both significantly influence their distributions between coexisting fluid phases in these biological membranes. Our results demonstrate the value of GPMVs for characterizing the phase preference of proteins and lipid probes in the absence of detergents and other perturbations of membrane structure. (c) 2007 Elsevier B.V. All rights reserved.