Department of Neurobiology, Max-Planck Institute for Biophysical Chemistry, Göttingen, Germany.
EMBO J. 2011 Apr 6;30(7):1209-20. doi: 10.1038/emboj.2011.53. Epub 2011 Mar 1.
Membrane proteins and membrane lipids are frequently organized in submicron-sized domains within cellular membranes. Factors thought to be responsible for domain formation include lipid-lipid interactions, lipid-protein interactions and protein-protein interactions. However, it is unclear whether the domain structure is regulated by other factors such as divalent cations. Here, we have examined in native plasma membranes and intact cells the role of the second messenger Ca(2+) in membrane protein organization. We find that Ca(2+) at low micromolar concentrations directly redistributes a structurally diverse array of membrane proteins via electrostatic effects. Redistribution results in a more clustered pattern, can be rapid and triggered by Ca(2+) influx through voltage-gated calcium channels and is reversible. In summary, the data demonstrate that the second messenger Ca(2+) strongly influences the organization of membrane proteins, thus adding a novel and unexpected factor that may control the domain structure of biological membranes.
膜蛋白和膜脂经常在细胞内的亚微米大小的区域内组织。被认为负责形成域的因素包括脂质-脂质相互作用、脂质-蛋白质相互作用和蛋白质-蛋白质相互作用。然而，目前尚不清楚域结构是否受其他因素（如二价阳离子）的调节。在这里，我们在天然质膜和完整细胞中研究了第二信使 Ca(2+) 在膜蛋白组织中的作用。我们发现，低微摩尔浓度的 Ca(2+) 通过静电作用直接重新分布结构多样的一系列膜蛋白。再分配导致更聚类的模式，可以快速发生，并通过电压门控钙通道的 Ca(2+) 内流触发，并且是可逆的。总之，数据表明第二信使 Ca(2+) 强烈影响膜蛋白的组织，从而增加了一个新的和意外的因素，可能控制生物膜的域结构。
