National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
P50 AI150464
米国
National Institutes of Health/Office of the Director
S10OD020054
米国
National Institutes of Health/Office of the Director
S10OD021741
米国
National Institutes of Health/Office of the Director
1S10OD021596-01
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
1DP2GM110772-01
米国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2020 タイトル: Membrane constriction and thinning by sequential ESCRT-III polymerization. 著者: Henry C Nguyen / Nathaniel Talledge / John McCullough / Abhimanyu Sharma / Frank R Moss / Janet H Iwasa / Michael D Vershinin / Wesley I Sundquist / Adam Frost / 要旨: The endosomal sorting complexes required for transport (ESCRTs) mediate diverse membrane remodeling events. These typically require ESCRT-III proteins to stabilize negatively curved membranes; ...The endosomal sorting complexes required for transport (ESCRTs) mediate diverse membrane remodeling events. These typically require ESCRT-III proteins to stabilize negatively curved membranes; however, recent work has indicated that certain ESCRT-IIIs also participate in positive-curvature membrane-shaping reactions. ESCRT-IIIs polymerize into membrane-binding filaments, but the structural basis for negative versus positive membrane remodeling by these proteins remains poorly understood. To learn how certain ESCRT-IIIs shape positively curved membranes, we determined structures of human membrane-bound CHMP1B-only, membrane-bound CHMP1B + IST1, and IST1-only filaments by cryo-EM. Our structures show how CHMP1B first polymerizes into a single-stranded helical filament, shaping membranes into moderate-curvature tubules. Subsequently, IST1 assembles a second strand on CHMP1B, further constricting the membrane tube and reducing its diameter nearly to the fission point. Each step of constriction thins the underlying bilayer, lowering the barrier to membrane fission. Our structures reveal how a two-component, sequential polymerization mechanism drives membrane tubulation, constriction and bilayer thinning.
EMPIAR-10397 (タイトル: CryoEM reconstruction of membrane-bound ESCRT-III filament composed of CHMP1B only Data size: 3.8 Data #1: Processed particle stack and metadata for a cryoEM helical reconstruction of membrane-bound ESCRT-III filament composed of CHMP1B only [picked particles - multiframe - processed])
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 292 K / 装置: FEI VITROBOT MARK III 詳細: Grids were blotted with Whatman No. 1 filter paper for 4-8 seconds with a 0 mm offset at 19C and 100 percent humidity before plunging into liquid ethane.