Direct observation of cytoskeleton-dependent trafficking of miRNA visualized by the introduction of pre-miRNA

Toshinari Ishikawa; Ko Sugawara; Junwei Zhang; Takashi Funatsu; Kohki Okabe

doi:10.1016/j.isci.2024.108811

Direct observation of cytoskeleton-dependent trafficking of miRNA visualized by the introduction of pre-miRNA

iScience. 2024 Jan 5;27(2):108811. doi: 10.1016/j.isci.2024.108811. eCollection 2024 Feb 16.

Authors

Toshinari Ishikawa¹, Ko Sugawara¹, Junwei Zhang¹, Takashi Funatsu¹, Kohki Okabe^{1

2}

Affiliations

¹ Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
² JST, PRESTO, 4-8-1 Honcho, Kawaguchi, Saitama 332-0012, Japan.

Abstract

MicroRNA (miRNA) plays physiologically and pathologically important roles in post-transcriptional regulation. Although miRNA has been suggested to dynamically interact with cellular organelles, the dynamicity of intracellular miRNA behavior has remained unclear. Here, by introducing fluorescently labeled pre-miRNA into living cells, we improved the miRNA visualization method using exogenous miRNA precursors. Through the combination of our miRNA visualization method and single-molecule sensitive fluorescence microscopy, we quantitatively analyzed the process of miRNA maturation. Furthermore, single-particle tracking of fluorescent miRNA in cells revealed the directed movements of miRNA on cytoskeletal components (i.e., microtubules and actin filaments). Our results also suggest that cytoskeleton-dependent miRNA trafficking is associated with the interaction of miRNAs with the nucleus and the endoplasmic reticulum/Golgi apparatus. Our method should facilitate the elucidation of the mechanism and physiological significance of the subcellular localization and organelle interaction of miRNA.

Keywords: Biomechanics; Molecular biology; Molecular physiology; Nucleic acids.