Rapid transport of neural intermediate filament protein.

Peripherin is a neural intermediate filament protein that is expressed in peripheral and enteric neurons, as well as in PC12 cells. A determination of the motile properties of peripherin has been undertaken in PC12 cells during different stages of neurite outgrowth. The results reveal that non-filamentous, non-membrane bound peripherin particles and short peripherin intermediate filaments, termed 'squiggles', are transported at high speed throughout PC12 cell bodies, neurites and growth cones. These movements are bi-directional, and the majority require microtubules along with their associated molecular motors, conventional kinesin and cytoplasmic dynein. Our data demonstrate that peripherin particles and squiggles can move as components of a rapid transport system capable of delivering cytoskeletal subunits to the most distal regions of neurites over relatively short time periods.