Rapid Turnover Rate of Phosphoinositides at the Front of Migrating MDCK Cells
Rapid Turnover Rate of Phosphoinositides at the Front of Migrating MDCK Cells
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DOI：
10.1091/mbc.e08-03-0315
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发表时间：
2008-10-01
影响因子：
3.3
通讯作者：
Matsuda, Michiyuki
中科院分区：
文献类型：
--
作者：
Nishioka, Teruko;Aoki, Kazuhiro;Matsuda, Michiyuki
磷酸肌苷（PtdInss）在细胞极化和运动中起关键作用。利用基于Forster共振能量传递的一系列生物传感器，我们检测了PtdInss和二酰基甘油（DAG）在随机迁移的Madin-Darby犬肾（MDCK）细胞中的分布和代谢。磷脂酰肌醇（4,5）二磷酸、磷脂酰肌醇(3,4,5)-三磷酸（PIP3）、磷脂酰肌醇(3,4)-二磷酸和DAG的浓度在细胞前部质膜处高于细胞后部质膜处。估计PtdInss浓度在迁移MDCK细胞前后之间的差异小于两倍。为了从获得的PtdIns浓度图中解码PtdIns代谢酶的空间活性，我们建立了PtdIns代谢的一维反应扩散模型。在该模型中，磷脂酰肌醇单磷酸5-激酶、磷脂酰肌醇3-激酶、磷脂酶C和PIP3 5-磷酸酶的活性在细胞前部质膜处高于后部质膜处。这一结果表明，虽然PtdInss在稳态水平上的差异小于两倍，但PtdInss在迁移MDCK细胞的前部比后部翻转得更快。
Phosphoinositides (PtdInss) play key roles in cell polarization and motility. With a series of biosensors based on Forster resonance energy transfer, we examined the distribution and metabolism of PtdInss and diacylglycerol (DAG) in stochastically migrating Madin-Darby canine kidney (MDCK) cells. The concentrations of phosphatidylinositol (4,5)bisphosphate, phosphatidylinositol (3,4,5)-trisphosphate (PIP3), phosphatidylinositol (3,4)-bisphosphate, and DAG were higher at the plasma membrane in the front of the cell than at the plasma membrane of the rear of the cell. The difference in the concentrations of PtdInss was estimated to be less than twofold between the front and rear of the migrating MDCK cells. To decode the spatial activities of PtdIns metabolic enzymes from the obtained concentration maps of PtdInss, we developed a one-dimensional reaction diffusion model of PtdIns metabolism. In this model, the activities of phosphatidylinositol monophosphate 5-kinase, phosphatidylinositol 3-kinase, phospholipase C, and PIP3 5-phosphatases were higher at the plasma membrane of the front than at the plasma membrane of the rear of the cell. This result suggests that, although the difference in the steady-state level of PtdInss is less than twofold, PtdInss were more rapidly turned over at the front than the rear of the migrating MDCK cells.