Sub-membranous actin rings in the axon initial segment are resistant to the action of latrunculin

Abouelezz, Amr
Micinski, David
Lipponen, Aino
Hotulainen, Pirta

¹ Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland
² HiLIFE - Neuroscience Center, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland

^*Corresponding author: e-mail: [email protected]

Received January 15, 2019; accepted March 06, 2019; previously published online April 05, 2019

Biological Chemistry 400(9):p 1141-1146, September 1, 2019. | DOI: 10.1515/hsz-2019-0111

Abstract:

The axon initial segment (AIS) comprises a sub-membranous lattice containing periodic actin rings. The overall AIS structure is insensitive to actin-disrupting drugs, but the effects of actin-disrupting drugs on actin rings lack consensus. We examined the effect of latrunculin A and B on the actin cytoskeleton of neurons in culture and actin rings in the AIS. Both latrunculin A and B markedly reduced the overall amount of F-actin in treated neurons in a dose-dependent manner, but the periodicity of actin rings remained unaffected. The insensitivity of AIS actin rings to latrunculin suggests they are relatively stable.