Localization and turnover of phosphatidylinositol 4,5-bisphosphate in caveolin-enriched membrane domains
Localization and turnover of phosphatidylinositol 4,5-bisphosphate in caveolin-enriched membrane domains
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DOI：
10.1074/jbc.271.43.26453
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发表时间：
1996-10-25
影响因子：
4.8
通讯作者：
Casey, L
中科院分区：
文献类型：
--
作者：
Pike, LJ;Casey, L
小窝是小的质膜内陷，与细胞信号传导有关。在A431细胞中，发现约一半的总细胞磷脂酰肌醇4，5-二磷酸（PtdIns 4，5-P-2）定位于低密度，富含小窝蛋白的Triton不溶性膜结构域。在37 ℃下用表皮生长因子或缓激肽处理细胞5分钟导致该小窝PtdIns 4，5-P-2减少约50%，而质膜PtdIns 4，5-P-2的水平没有变化。这些数据表明，存在于细胞中的PtdIns 4，5-P-2在很大程度上是区室化的，并且小窝PtdIns 4，5-P-2受到酶刺激的磷脂酶C的水解。由于生长因子受体、7个跨膜结构域受体、异源三聚体G蛋白和三磷酸肌醇受体都已被证明富集在细胞膜小窝中，这些发现表明，细胞内对三磷酸肌醇的产生和反应都是高度区室化的。
Caveolae are small, plasma membrane invaginations that have been implicated in cell signaling. In A431 cells, approximately half of the total cellular phosphatidylinositol 4,5-bisphosphate (PtdIns 4,5-P-2) was found to be localized in low density, Triton-insoluble membrane domains enriched in caveolin. Treatment of cells with either epidermal growth factor or bradykinin for 5 min at 37 degrees C resulted in approximately a 50% decrease in this caveolar PtdIns 4,5-P-2 with no change in the levels of plasma membrane PtdIns 4,5-P-2. These data suggest that the PtdIns 4,5-P-2 present in cells is largely compartmentalized and that the caveolar PtdIns 4,5-P-2 is subject to hydrolysis by hormone-stimulated phospholipase C. As growth factor receptors, seven transmembrane domain receptors, heterotrimeric G proteins, and the inositol trisphosphate receptor have all been shown to be enriched in caveolae, these findings suggest that both the generation and response to inositol trisphosphate is highly compartmentalized within the cell.