the cytosolic domain of fis1 binds and reversibly clusters lipid vesicles的胞质域fis1可逆地结合集群脂质囊泡.pdfVIP

The Cytosolic Domain of Fis1 Binds and Reversibly Clusters Lipid Vesicles 1 1,2 Robert C. Wells , R. Blake Hill * 1 Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America, 2 Department of Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America Abstract Every lipid membrane fission event involves the association of two apposing bilayers, mediated by proteins that can promote membrane curvature, fusion and fission. We tested the hypothesis that Fis1, a tail-anchored protein involved in mitochondrial and peroxisomal fission, promotes changes in membrane structure. We found that the cytosolic domain of Fis1 alone binds lipid vesicles, which is enhanced upon protonation and increasing concentrations of anionic phospholipids. Fluorescence and circular dichroism data indicate that the cytosolic domain undergoes a membrane-induced conformational change that buries two tryptophan side chains upon membrane binding. Light scattering and electron microscopy data show that membrane binding promotes lipid vesicle clustering. Remarkably, this vesicle clustering is reversible and vesicles largely retain their original shape and size. This raises the possibility that the Fis1 cytosolic domain might act in membrane fission by promoting a reversible membrane association, a necessary step in membrane fission. Citation: Wells RC, Hill RB (2011) The Cytosolic Domain of Fis1 Binds and Reversibly Clusters Lipid Vesicles. PLoS ONE 6(6): e21384. doi:10.1371/ journal.pone.0021384 Editor: Petri Kursula, University of Oulu, Germany Received January 21, 2011; Accepted May 27, 2011; Published June 28, 2011 Copyright: 2011 Wells, Hill. This is an open-access ar