首页    期刊浏览 2024年11月23日 星期六
登录注册

文章基本信息

  • 标题:Single-molecule dynamics of Dishevelled at the plasma membrane and Wnt pathway activation
  • 本地全文:下载
  • 作者:Wenzhe Ma ; Maorong Chen ; Hong Kang
  • 期刊名称:Proceedings of the National Academy of Sciences
  • 印刷版ISSN:0027-8424
  • 电子版ISSN:1091-6490
  • 出版年度:2020
  • 卷号:117
  • 期号:28
  • 页码:16690-16701
  • DOI:10.1073/pnas.1910547117
  • 出版社:The National Academy of Sciences of the United States of America
  • 摘要:Dvl (Dishevelled) is one of several essential nonenzymatic components of the Wnt signaling pathway. In most current models, Dvl forms complexes with Wnt ligand receptors, Fzd and LRP5/6 at the plasma membrane, which then recruits the destruction complex, eventually leading to inactivation of β-catenin degradation. Although this model is widespread, direct evidence for the individual steps is lacking. In this study, we tagged mEGFP to C terminus of dishevelled2 gene using CRISPR/Cas9-induced homologous recombination and observed its dynamics directly at the single-molecule level with total internal reflection fluorescence (TIRF) microscopy. We focused on two questions: 1) What is the native size and what are the dynamic features of membrane-bound Dvl complexes during Wnt pathway activation? 2) What controls the behavior of these complexes? We found that membrane-bound Dvl2 is predominantly monomer in the absence of Wnt (observed mean size 1.1). Wnt3a stimulation leads to an increase in the total concentration of membrane-bound Dvl2 from 0.12/μm 2 to 0.54/μm 2 . Wnt3a also leads to increased oligomerization which raises the weighted mean size of Dvl2 complexes to 1.5, with 56.1% of Dvl still as monomers. The driving force for Dvl2 oligomerization is the increased concentration of membrane Dvl2 caused by increased affinity of Dvl2 for Fzd, which is independent of LRP5/6. The oligomerized Dvl2 complexes have increased dwell time, 2 ∼ 3 min, compared to less than 1 s for monomeric Dvl2. These properties make Dvl a unique scaffold, dynamically changing its state of assembly and stability at the membrane in response to Wnt ligands.
  • 关键词:Wnt signaling pathway ; Dishevelled ; single molecule ; protein complex size ; fluorescence
国家哲学社会科学文献中心版权所有