Regulated Externalization of Phosphatidylserine at the Cell Surface

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作者：

K Balasubramanian，B Mirnikjoo，AJ Schroit

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摘要：

The regulated loss of plasma membrane phosphatidylserine (PS) asymmetry is critical to many biological processes. In particular, the appearance of PS at the cell surface, a hallmark of apoptosis, prepares the dying cell for engulfment and elimination by phagocytes. While it is well established that PS externalization is regulated by activation of a calcium-dependent phospholipid scramblase activity in concert with inactivation of the aminophospholipid translocase, there is no evidence indicating that these processes are triggered and regulated by apoptotic regulatory mechanisms. Using a novel model system, we show that PS externalization is inducible, reversible, and independent of cytochrome c release, caspase activation, and DNA fragmentation. Additional evidence is presented indicating that the outward movement of plasma membrane PS requires sustained elevation in cytosolic Ca2+ in concert with inactivation of the aminophospholipid translocase and is inhibited by calcium channel blockers.

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关键词：

Regulated Externalization Phosphatidylserine

DOI：

10.1074/jbc.M700202200

被引量：

241

年份：

2007