The hierarchical assembly of septins revealed by high-speed AFM. Academic Article uri icon

Overview

abstract

  • Septins are GTP-binding proteins involved in diverse cellular processes including division and membrane remodeling. Septins form linear, palindromic heteromeric complexes that can assemble in filaments and higher-order structures. Structural studies revealed various septin architectures, but questions concerning assembly-dynamics and -pathways persist. Here we used high-speed atomic force microscopy (HS-AFM) and kinetic modeling which allowed us to determine that septin filament assembly was a diffusion-driven process, while formation of higher-order structures was complex and involved self-templating. Slightly acidic pH and increased monovalent ion concentrations favor filament-assembly, -alignment and -pairing. Filament-alignment and -pairing further favored diffusion-driven assembly. Pairing is mediated by the septin N-termini face, and may occur symmetrically or staggered, likely important for the formation of higher-order structures of different shapes. Multilayered structures are templated by the morphology of the underlying layers. The septin C-termini face, namely the C-terminal extension of Cdc12, may be involved in membrane binding.

publication date

  • October 8, 2020

Research

keywords

  • Microscopy, Atomic Force
  • Septins

Identity

PubMed Central ID

  • PMC7545167

Scopus Document Identifier

  • 85092329170

Digital Object Identifier (DOI)

  • 10.1002/jmr.2187

PubMed ID

  • 33033254

Additional Document Info

volume

  • 11

issue

  • 1