6月21日,，Science在線報道了人類對磷酸肌醇4磷酸鹽（PI4P）在細胞質(zhì)膜中重要作用的新認識。
磷脂酰環(huán)己六醇（4,5）- 二磷酸[PI（4,5）P2]是細胞質(zhì)膜（PM）中一種含量很少的磷脂,。但它卻可行使許多細胞質(zhì)膜（PM）的功能,。而其合成的前體，磷酸肌醇4磷酸鹽（PI4P）,，除了合成PI（4,5）P2以外,，此前卻沒有被發(fā)現(xiàn)具有其他PM功能。
研究者將藥理和化學(xué)遺傳學(xué)方法相結(jié)合,，探索PM中PI4P的功能,。研究意外發(fā)現(xiàn)，在細胞PM中,， PI4P具有一些新的重要作用：最重要的是這種功能不依賴于其合成PI（4,5）P2的功能,。相反，PI4P自主性地與PI（4,5）P2一道支持構(gòu)成細胞PM的陰離子脂質(zhì)池,。
研究者認為,，只需要多價陰離子脂質(zhì)的配合，PI4P即可滿足任何PM功能,。這使得PI（4,5）P2可自由進行快速周轉(zhuǎn)并調(diào)節(jié)其大量的特異性效應(yīng)蛋白,。由于PI（4,5）P2的快速周轉(zhuǎn)可能會降低其有效濃度，PI4P的支持無疑保證了PM的獨特靜電性能的穩(wěn)定性,。
這一發(fā)現(xiàn),，加深了人類對細胞質(zhì)膜PI4P功能的認識。對細胞膜相關(guān)疾病的研究和治療都有重要意義,。（生物谷bioon.com）
doi:10.1016/j.cell.2011.10.017
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PI4P and PI(4,5)P2 Are Essential But Independent Lipid Determinants of Membrane Identity
Gerald R. V. Hammond1,3,*, Michael J Fischer1, Karen E Anderson2, Jon Holdich1, Ardita Koteci1, Tamas Balla3, Robin F. Irvine1,*
The quantitatively minor phospholipid phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] fulfils many cellular functions in the plasma membrane (PM), whereas its synthetic precursor, phosphatidylinositol 4-phosphate (PI4P), has no assigned PM roles apart from PI(4,5)P2 synthesis. We used a combination of pharmacological and chemical genetic approaches to probe the function of PM PI4P, most of which was not required for the synthesis or functions of PI(4,5)P2. However, depletion of both lipids was required to prevent PM targeting of proteins that interact with acidic lipids or activation of the transient receptor potential vanilloid 1 cation channel. Therefore, PI4P contributes to the pool of polyanionic lipids that define plasma membrane identity and to some functions previously attributed specifically to PI(4,5)P2, which may be fulfilled by a more general polyanionic lipid requirement
