Fast transport of neurofilament protein along microtubules in squid axoplasm

• DOI: 10.1242/jcs.113.22.3939
• Publication Date: 2021-04-25T18:28:18Z
• Authors: Veena Prahlad; Brian T. Helfand; George M. Langford; Ron D. Vale; Robert D. Goldman
• Keywords: Intermediate filament; 0303 health sciences; Time Factors; Molecular Sequence Data; Decapodiformes; Fluorescent Antibody Technique; Kinesins; Microtubule; Neurofilament; Kinesin; Axonal Transport; Microtubules; Axons; Epitopes; Kinetics; Protein Subunits; Protein Transport; 03 medical and health sciences; Neurofilament Proteins; Animals; Amino Acid Sequence; Biology; Cytoskeleton; Axonal transport

ABSTRACT Using squid axoplasm as a model system, we have visualized the fast transport of non-filamentous neurofilament protein particles along axonal microtubules. This transport occurs at speeds of 0.5-1.0 μm/second and the majority of neurofilament particles stain with kinesin antibody. These observations demonstrate, for the first time, that fast (0.5-1.0 μm/second) transport of neurofilament proteins occurs along microtubules. In addition, our studies suggest that neurofilament protein can be transported as non-membrane bound, nonfilamentous subunits along axons, and that the transport is kinesin-dependent. Microtubule-based fast transport might therefore provide a mechanism for the distribution and turnover of neurofilament, and perhaps other cytoskeletal proteins, throughout neurons.