Levine Tim, Loewen Chris
Division of Cell Biology, UCL Institute of Ophthalmology, Bath St, London EC1V 9EL, UK.
Curr Opin Cell Biol. 2006 Aug;18(4):371-8. doi: 10.1016/j.ceb.2006.06.011. Epub 2006 Jun 27.
Inter-organelle membrane contact sites are zones where heterologous membranes, usually the endoplasmic reticulum plus a partner organelle, come into close apposition. These sites are very poorly understood because so few of their components have been identified; however, it is clear that they are specialised for traffic of material and information between the two membranes. There have been recent advances in the study of lipid transfer proteins, such as ceramide transfer protein (CERT) and homologues of oxysterol binding protein (OSBP). Not only can these proteins carry lipids across the cytoplasm, but they have been found to target both the endoplasmic reticulum and a partnering organelle, and in some cases have been localised to membrane contact sites. Further work will be needed to test whether these lipid transfer proteins act when anchored at inter-organelle contact sites.
细胞器间膜接触位点是异源膜（通常是内质网与一个伙伴细胞器）紧密并列的区域。由于已鉴定出的此类位点的组分极少，所以对它们的了解非常有限；然而，很明显它们专门用于两种膜之间的物质和信息传递。近期在脂质转运蛋白的研究方面取得了进展，比如神经酰胺转运蛋白（CERT）和氧甾醇结合蛋白（OSBP）的同源物。这些蛋白不仅能携带脂质穿过细胞质，还被发现既靶向内质网又靶向伙伴细胞器，并且在某些情况下定位于膜接触位点。还需要进一步的研究来检验这些脂质转运蛋白在锚定在细胞器间接触位点时是否发挥作用。
