Raychaudhuri S, Prinz W A
Laboratory of Cell Biochemistry and Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Biochem Soc Trans. 2006 Jun;34(Pt 3):359-62. doi: 10.1042/BST0340359.
The proper distribution of sterols among organelles is critical for numerous cellular functions. How sterols are sorted and moved among membranes remains poorly understood, but they are transported not only in vesicles but also by non-vesicular pathways. One of these pathways moves exogenous sterols from the plasma membrane to the endoplasmic reticulum in the yeast Saccharomyces cerevisiae. We have found that two classes of proteins play critical roles in this transport, ABC transporters (ATP-binding-cassette transporters) and oxysterol-binding protein-related proteins. Transport is also regulated by phosphoinositides and the interactions of sterols with other lipids. Here, we summarize these findings and speculate on the role of non-vesicular sterol transfer in determining intracellular sterol distribution and membrane function.
甾醇在细胞器间的正确分布对众多细胞功能至关重要。甾醇如何在膜之间进行分选和转运仍知之甚少，但它们不仅通过囊泡运输，还通过非囊泡途径运输。其中一条途径将外源甾醇从酵母酿酒酵母的质膜转运到内质网。我们发现两类蛋白质在这种转运中起关键作用，即ABC转运蛋白（ATP结合盒转运蛋白）和氧甾醇结合蛋白相关蛋白。转运也受磷酸肌醇以及甾醇与其他脂质相互作用的调节。在此，我们总结这些发现，并推测非囊泡甾醇转运在决定细胞内甾醇分布和膜功能中的作用。
