The membrane periodic skeleton is an actomyosin network that regulates axonal diameter and conduction

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Costa, AR (Author) Other; Sousa, SC (Author) Other; Pinto Costa, R (Author) Other; Mateus, JC (Author) Other; Lopes, CDF (Author) Other; Costa, AC (Author) Other; Rosa, D (Author) Other; Machado, D (Author) Other; Pajuelo, L (Author) Other; Wang, XW (Author) Other; Zhou, FQ (Author) Other; Pereira, AJ (Author) Other; Sampaio, P (Author) Other; Rubinstein, BY (Author) Other; Pinto, IM (Author) Other; Lampe, M (Author) Other; Paulo Aguiar (Author) FMUP; Sousa, MM (Author) Other

Journal

Title: eLife

Vol. 9

ISSN: 2050-084X

Publisher: eLife Sciences Publications

Indexing

ISI Web of Knowledge - 22 Citations

Scopus - 21 Citations

Other information

Authenticus ID: P-00R-Y1J

DOI: 10.7554/elife.55471

Abstract (EN): Neurons have a membrane periodic skeleton (MPS) composed of actin rings interconnected by spectrin. Here, combining chemical and genetic gain- and loss-of-function assays, we show that in rat hippocampal neurons the MPS is an actomyosin network that controls axonal expansion and contraction. Using super-resolution microscopy, we analyzed the localization of axonal non-muscle myosin II (NMII). We show that active NMII light chains are colocalized with actin rings and organized in a circular periodic manner throughout the axon shaft. In contrast, NMII heavy chains are mostly positioned along the longitudinal axonal axis, being able to crosslink adjacent rings. NMII filaments can play contractile or scaffolding roles determined by their position relative to actin rings and activation state. We also show that MPS destabilization through NMII inactivation affects axonal electrophysiology, increasing action potential conduction velocity. In summary, our findings open new perspectives on axon diameter regulation, with important implications in neuronal biology.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 20