Transport of Drosophila fragile X mental retardation protein-containing ribonucleoprotein granules by kinesin-1 and cytoplasmic dynein

Shuo Chien Ling, Peter S. Fahrner, William T. Greenough, Vladimir I. Gelfand*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

138 Scopus citations

Abstract

Transport and translation of mRMA are tightly coupled to ensure strict temporal and spatial expression of nascent proteins. Fragile X mental retardation protein (FMRP) has been shown to be involved in translational regulation and is found in ribonucleoprotein (RNP) granules that travel along dendrites of neurons. In this study, GFP-tagged Drosophila homologue of FMRP (dFMR) was used to visualize RNP granule movement in Drosophila S2 cells. GFP-dFMR form granules that contain both endogenous dFMR and mRNA. Live fluorescence microscopy revealed that dFMR-containing RNP granules move bidirectionally in thin processes formed by S2 cells in the presence of cytochalasin D. Knocking down the heavy chains of either kinesin-1 (kinesin heavy chain) or cytoplasmic dynein (dynein heavy chain) by RNA interference blocks the movement of the dFMR granules. In contrast, knockdown of kinesin light chain (KLC), which is typically necessary for movement of membrane organelles by kinesin-1, had no effect on the dFMR granule translocation. In immunoprecipitation assays, dFMR associates with both kinesin heavy chain and dynein heavy chain, but not KLC. Based on these findings, we conclude that dFMR-containing RNP granules are moved by both kinesin-1 and cytoplasmic dynein and that KLC is not essential and is likely missing from RNP-transporting kinesin-1.

Original languageEnglish (US)
Pages (from-to)17428-17433
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume101
Issue number50
DOIs
StatePublished - Dec 14 2004

Keywords

  • Cytoskeleton
  • Microtubules
  • Molecular motors
  • RNA transport

ASJC Scopus subject areas

  • General

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