Ganglioside GM1 increases line tension at raft boundary in model membranes

被引：10

作者：

Akimov S.A. ^{[1
]}

Hlaponin E.A. ^{[1
]}

Bashkirov P.V. ^{[1
]}

Boldyrev I.A. ^{[2
]}

Mikhalyov I.I. ^{[2
]}

Telford W.G. ^{[3
]}

Molotkovskaya I.M. ^{[2
]}

机构：

[1] Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow 119991

[2] Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997

[3] Experimental Transplantation and Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892

来源：

Biochemistry (Moscow) Supplement Series A: Membrane and Cell Biology | 2009年 / 3卷 / 2期

基金：

美国国家卫生研究院; 俄罗斯基础研究基金会;

关键词：

Apoptosis; Ganglioside; Line tension; Raft;

D O I：

10.1134/S1990747809020159

中图分类号：

学科分类号：

摘要：

Gangliosides are significant participants in suppression of immune system during tumor processes. It was shown that they can induce apoptosis of T-lymphocytes in a raft-dependent manner. Fluorescence confocal microscopy was used to study distribution and influence of ganglioside GM1 on raft properties in giant unilamellar vesicles. Both raft and non-raft phase markers were utilized. No visible phase separation was observed without GM1 unless lateral tension was applied to the membrane. At 2 mol % of GM1 large domains appeared indicating macroscopic phase separation. Increase of GM1 content to 5 mol % resulted in shape transformation of the domains consistent with growth of line tension at the domain boundary. At 10 mol % of GM1 almost all domains were pinched out from vesicles, forming their own homogeneous liposomes. Estimations showed that the change of the GM1 content from 2 to 5-10 mol % resulted in a several-fold increase of line tension. This finding provides a possible mechanism of apoptosis induction by GM1. Incorporation of GM1 into a membrane leads to an increase of the line tension. This results in a growth of the average size of rafts due to coalescence or merger of small domains. Thus, necessary proteins can find themselves in one common raft and start the corresponding cascade of reactions. © Pleiades Publishing, Ltd. 2009.

引用

页码：216 / 222

页数：6

共 31 条

[31] Yuan C., Furlong J., Burgos P., Johnston L.J., The Size of Lipid Rafts: An Atomic Force Microscopy Study of Ganglioside GM1 Domains in Sphingomyelin/DOPC/Cholesterol Membranes, Biophys. J., 82, pp. 2526-2535, (2002)

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