Phosphoinositides are phosphorylated derivatives of phosphatidylinositol, a phospholipid that is synthesised at the endoplasmic reticulum. The plasma membrane contains the enzymes to phosphorylate phosphatidylinositol and is therefore rich in the phosphorylated derivatives, PI4P and PI(4,5)P₂. PI(4,5)P₂ is a substrate for phospholipase C and during cell signaling, PI(4,5)P₂ levels are reduced. Here I discuss a family of proteins, phosphatidylinositol transfer proteins (PITPs) that can restore PI(4,5)P₂ levels.

中文翻译：

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PI4P 和 PI(4,5)P2 在质膜上的扩展作用：磷脂酰肌醇转移蛋白的作用

磷脂酰肌醇是磷脂酰肌醇的磷酸化衍生物，磷脂酰肌醇是一种在内质网合成的磷脂。质膜含有磷酸化磷脂酰肌醇的酶，因此富含磷酸化衍生物PI4P和PI(4,5)P ₂。PI(4,5)P ₂是磷脂酶 C 的底物，在细胞信号传导过程中，PI(4,5)P ₂水平会降低。在这里，我讨论了一个蛋白质家族，即磷脂酰肌醇转移蛋白 (PITP)，它可以恢复 PI(4,5)P ₂水平。