Single-molecule Reconstitution of mRNA Transport by a Class V Myosin

Nat Struct Mol Biol. 2013 Aug;20(8):952-7. doi: 10.1038/nsmb.2614. Epub 2013 Jun 30.

Abstract

Molecular motors are instrumental in mRNA localization, which provides spatial and temporal control of protein expression and function. To obtain mechanistic insight into how a class V myosin transports mRNA, we performed single-molecule in vitro assays on messenger ribonucleoprotein (mRNP) complexes reconstituted from purified proteins and a localizing mRNA found in budding yeast. mRNA is required to form a stable, processive transport complex on actin--an elegant mechanism to ensure that only cargo-bound motors are motile. Increasing the number of localizing elements ('zip codes') on the mRNA, or configuring the track to resemble actin cables, enhanced run length and event frequency. In multi-zip-code mRNPs, motor separation distance varied during a run, thus showing the dynamic nature of the transport complex. Building the complexity of single-molecule in vitro assays is necessary to understand how these complexes function within cells.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Microscopy, Electron, Transmission
  • Microscopy, Fluorescence
  • Models, Molecular
  • Molecular Motor Proteins / physiology*
  • Myosin Heavy Chains / genetics
  • Myosin Heavy Chains / metabolism
  • Myosin Type V / genetics
  • Myosin Type V / metabolism
  • RNA Transport / physiology*
  • RNA, Messenger / metabolism
  • RNA, Messenger / physiology*
  • Ribonucleoproteins / metabolism*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism

Substances

  • Molecular Motor Proteins
  • Myo4 protein, S cerevisiae
  • RNA, Messenger
  • Ribonucleoproteins
  • Saccharomyces cerevisiae Proteins
  • messenger ribonucleoprotein
  • Myosin Type V
  • Myosin Heavy Chains