Imaging vesicle formation dynamics supports the flexible model of clathrin-mediated endocytosis

• Type of Material: Article
• Authors: Tomasz J Nawara, University of Alabama Birmingham; Yancey D Williams, University of Alabama Birmingham; Tejeshwar C Rao, University of Alabama Birmingham; Yuesong Hu, Emory University; Elizabeth Sztul, University of Alabama Birmingham; Khalid Salaita, Emory University; Alexa L Mattheyses, University of Alabama Birmingham
• Language: English
• Date: 2022-04-01
• Publisher: NATURE PORTFOLIO
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2022
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1038/s41467-022-29317-1
• Title of Journal or Parent Work: NATURE COMMUNICATIONS
• Volume: 13
• Issue: 1
• Start Page: 1732
• End Page: 1732
• Grant/Funding Information: This work was supported by NIH/NIGMS R01GM131099 to K.S. and A.L.M., NSF CAREER 1832100 to A.L.M. and American Heart Association 906086 to T.N.
• Keywords: PITS; Science & Technology - Other Topics; Multidisciplinary Sciences; ACCESSORY PROTEINS; COATED VESICLES; REVEALS; Science & Technology; LATTICES; LIGHT-CHAINS
• Research Categories: Chemistry, General; Biology, Cell

Abstract

Clathrin polymerization and changes in plasma membrane architecture are necessary steps in forming vesicles to internalize cargo during clathrin-mediated endocytosis (CME). Simultaneous analysis of clathrin dynamics and membrane structure is challenging due to the limited axial resolution of fluorescence microscopes and the heterogeneity of CME. This has fueled conflicting models of vesicle assembly and obscured the roles of flat clathrin assemblies. Here, using Simultaneous Two-wavelength Axial Ratiometry (STAR) microscopy, we bridge this critical knowledge gap by quantifying the nanoscale dynamics of clathrin-coat shape change during vesicle assembly. We find that de novo clathrin accumulations generate both flat and curved structures. High-throughput analysis reveals that the initiation of vesicle curvature does not directly correlate with clathrin accumulation. We show clathrin accumulation is preferentially simultaneous with curvature formation at shorter-lived clathrin-coated vesicles (CCVs), but favors a flat-to-curved transition at longer-lived CCVs. The broad spectrum of curvature initiation dynamics revealed by STAR microscopy supports multiple productive mechanisms of vesicle formation and advocates for the flexible model of CME.