Directional change during active diffusion of viral ribonucleoprotein particles through cytoplasm

Kathleen C Smith; Ryan Oglietti; Steven J Moran; Jed C Macosko; Douglas S Lyles; George Holzwarth

doi:10.1016/j.bpj.2024.04.025

Directional change during active diffusion of viral ribonucleoprotein particles through cytoplasm

Biophys J. 2024 Apr 25:S0006-3495(24)00287-X. doi: 10.1016/j.bpj.2024.04.025. Online ahead of print.

Authors

Kathleen C Smith¹, Ryan Oglietti², Steven J Moran³, Jed C Macosko⁴, Douglas S Lyles⁵, George Holzwarth⁴

Affiliations

¹ Department of Chemistry, Wake Forest University, Winston-Salem, North Carolina;; Kathleen C. Smith's current address is National Institute on Aging, Baltimore, Maryland.
² Department of Biology, Wake Forest University, Winston-Salem, North Carolina;; Kathleen C. Smith's current address is National Institute on Aging, Baltimore, Maryland.
³ Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina;; Kathleen C. Smith's current address is National Institute on Aging, Baltimore, Maryland.
⁴ Department of Physics, Wake Forest University, Winston-Salem, North Carolina, North Carolina.
⁵ Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina;. Electronic address: dlyles@wakehealth.edu.

PMID: 38664967
DOI: 10.1016/j.bpj.2024.04.025

Abstract

A mesh of cytoskeletal fibers, consisting of microtubules, intermediate filaments, and fibrous actin, prevents the Brownian diffusion of particles with a diameter larger than 0.10μm, such as vesicular stomatitis virus ribonucleoprotein particles (RNP), in mammalian cells. Nevertheless, RNP particles do move in random directions, but at a lower rate than Brownian diffusion, which is thermally driven. This nonthermal biological transport process is called active diffusion because it is driven by ATP. The ATP powers motor proteins such as myosin II. The motor proteins bend and crosslink actin fibers, causing the mesh to jiggle. Until recently, little was known about how RNP particles get through the mesh.