Ultrastructure of the axonal periodic scaffold reveals a braid-like organization of actin rings.

ABSTRACT: Recent super-resolution microscopy studies have unveiled a periodic scaffold of actin rings regularly spaced by spectrins under the plasma membrane of axons. However, ultrastructural details are unknown, limiting a molecular and mechanistic understanding of these enigmatic structures. Here, we combine platinum-replica electron and optical super-resolution microscopy to investigate the cortical cytoskeleton of axons at the ultrastructural level. Immunogold labeling and correlative super-resolution/electron microscopy allow us to unambiguously resolve actin rings as braids made of two long, intertwined actin filaments connected by a dense mesh of aligned spectrins. This molecular arrangement contrasts with the currently assumed model of actin rings made of short, capped actin filaments. Alon

SUBMITTER: Vassilopoulos S 

PROVIDER: S-EPMC6925202 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature