A cryo-ET survey of microtubules and intracellular compartments in mammalian axons.

Autor: Foster HE; MRC Laboratory of Molecular Biology, Cambridge, UK., Ventura Santos C; MRC Laboratory of Molecular Biology, Cambridge, UK., Carter AP; MRC Laboratory of Molecular Biology, Cambridge, UK.
Jazyk: angličtina
Zdroj: The Journal of cell biology [J Cell Biol] 2022 Feb 07; Vol. 221 (2). Date of Electronic Publication: 2021 Dec 08.
DOI: 10.1083/jcb.202103154
Abstrakt: The neuronal axon is packed with cytoskeletal filaments, membranes, and organelles, many of which move between the cell body and axon tip. Here, we used cryo-electron tomography to survey the internal components of mammalian sensory axons. We determined the polarity of the axonal microtubules (MTs) by combining subtomogram classification and visual inspection, finding MT plus and minus ends are structurally similar. Subtomogram averaging of globular densities in the MT lumen suggests they have a defined structure, which is surprising given they likely contain the disordered protein MAP6. We found the endoplasmic reticulum in axons is tethered to MTs through multiple short linkers. We surveyed membrane-bound cargos and describe unexpected internal features such as granules and broken membranes. In addition, we detected proteinaceous compartments, including numerous virus-like capsid particles. Our observations outline novel features of axonal cargos and MTs, providing a platform for identification of their constituents.
(© 2021 MRC Laboratory of Molecular Biology.)
Databáze: MEDLINE