Distinct localization of lipid rafts and externalized phosphatidylserine at the surface of apoptotic cells
Distinct localization of lipid rafts and externalized phosphatidylserine at the surface of apoptotic cells
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DOI：
10.1016/j.bbrc.2004.11.135
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发表时间：
2005-02-04
影响因子：
3.1
通讯作者：
Nakanishi, Y
中科院分区：
文献类型：
--
作者：
Ishii, H;Mori, T;Nakanishi, Y
在某些情况下，磷脂酰丝氨酸(PS)的外化不仅发生在活细胞中，也发生在凋亡细胞中。最近的研究表明，外化PS定位于活的活化免疫细胞的脂筏中。我们发现脂筏和PS以相互排斥的方式存在于凋亡细胞中。当脂筏被破坏时，暴露于PS的凋亡细胞的数量减少。BCtheta选择性地与胆固醇富集区的胆固醇结合，不能有效地识别凋亡细胞的脂筏。从凋亡细胞中成功制备出富含GM1的脂筏，但脂筏蛋白LAT在制备过程中并未得到丰富。此外，诱导细胞凋亡后，脂筏中PS和磷脂酰乙醇胺的含量似乎发生了变化，而胆固醇的含量却没有变化。这些结果表明，在细胞凋亡过程中，脂筏的结构发生了改变，尽管其定位与PS不同，但参与了PS的外化。(C)2004 Elsevier Inc.保留所有权利。
Externalization of phosphatidylserine (PS) takes place in apoptotic cells as well as in viable cells under certain circumstances. Recent studies showed that externalized PS is localized at the lipid raft in viable activated immune cells. We found that lipid rafts and PS existed in a mutually exclusive manner in apoptotic cells. The number of PS-exposing apoptotic cells decreased when lipid rafts were disrupted. BCtheta, which binds selectively to cholesterol in a cholesterol-rich region, did not effectively recognize lipid rafts of apoptotic cells. Lipid rafts rich in GM1 were successfully prepared from apoptotic cells, but the lipid raft protein LAT was not enriched in the preparation. Furthermore, the amount of PS and phosphatidylethanolamine but not of cholesterol in lipid rafts appeared to change after induction of apoptosis. These results suggest that lipid rafts are structurally modified during apoptosis and, despite being localized differently from PS, are involved in the externalization of PS. (C) 2004 Elsevier Inc. All rights reserved.