Langhorst Matthias F, Solis Gonzalo P, Hannbeck Sylvia, Plattner Helmut, Stuermer Claudia A O
Department of Biology, University of Konstanz, Universitaetsstrasse 10, D-78457 Konstanz, Germany.
FEBS Lett. 2007 Oct 2;581(24):4697-703. doi: 10.1016/j.febslet.2007.08.074. Epub 2007 Sep 6.
The reggies/flotillins are oligomeric scaffolding proteins for membrane microdomains. We show here that reggie-1/flotillin-2 microdomains are organized along cortical F-actin in several cell types. Interaction with F-actin is mediated by the SPFH domain as shown by in vivo co-localization and in vitro binding experiments. Reggie-1/flotillin-2 microdomains form independent of actin, but disruption or stabilization of the actin cytoskeleton modulate the lateral mobility of reggie-1/flotillin-2 as shown by FRAP. Furthermore, reggie/flotillin microdomains can efficiently be immobilized by actin polymerisation, while exchange of reggie-1/flotillin-2 molecules between microdomains is enhanced by actin disruption as shown by tracking of individual microdomains using TIRF microscopy.
瑞吉蛋白/弗洛蒂林蛋白是膜微区的寡聚支架蛋白。我们在此表明，在几种细胞类型中，瑞吉蛋白-1/弗洛蒂林蛋白-2微区沿着皮质F-肌动蛋白排列。体内共定位和体外结合实验表明，与F-肌动蛋白的相互作用由SPFH结构域介导。瑞吉蛋白-1/弗洛蒂林蛋白-2微区的形成不依赖于肌动蛋白，但如荧光漂白恢复实验所示，肌动蛋白细胞骨架的破坏或稳定会调节瑞吉蛋白-1/弗洛蒂林蛋白-2的侧向流动性。此外，如使用全内反射荧光显微镜追踪单个微区所示，瑞吉蛋白/弗洛蒂林蛋白微区可通过肌动蛋白聚合有效固定，而肌动蛋白破坏会增强微区之间瑞吉蛋白-1/弗洛蒂林蛋白-2分子的交换。
