Polarized domains of myelinated axons.
The entire length of myelinated axons is organized into a series of polarized domains that center around nodes of Ranvier. These domains, which are crucial for normal saltatory conduction, consist of distinct multiprotein complexes of cell adhesion molecules, ion channels, and scaffolding molecules; they also differ in their diameter, organelle content, and rates of axonal transport. Juxtacrine signals from myelinating glia direct their sequential assembly. The composition, mechanisms of assembly, and function of these molecular domains will be reviewed. I also discuss similarities of this domain organization to that of polarized epithelia and present emerging evidence that disorders of domain organization and function contribute to the axonopathies of myelin and other neurologic disorders.
Salzer
James L
JL
Department of Cell Biology and Neurology, Program in Molecular Neurobiology, Skirball Institute of Biomedical Research, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA. jim.salzer@med.nyu.edu
D000818:Animals; D001369:Axons / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D006801:Humans; D009186:Myelin Sheath / Q000737:chemistry / Q000502:physiology; D009413:Nerve Fibers, Myelinated / Q000502:physiology*