In vivo single-particle imaging of nuclear mRNA export in budding yeast demonstrates an essential role for Mex67p

J Cell Biol. 2015 Dec 21;211(6):1121-30. doi: 10.1083/jcb.201503135.

Abstract

Many messenger RNA export proteins have been identified; yet the spatial and temporal activities of these proteins and how they determine directionality of messenger ribonucleoprotein (mRNP) complex export from the nucleus remain largely undefined. Here, the bacteriophage PP7 RNA-labeling system was used in Saccharomyces cerevisiae to follow single-particle mRNP export events with high spatial precision and temporal resolution. These data reveal that mRNP export, consisting of nuclear docking, transport, and cytoplasmic release from a nuclear pore complex (NPC), is fast (∼ 200 ms) and that upon arrival in the cytoplasm, mRNPs are frequently confined near the nuclear envelope. Mex67p functions as the principal mRNP export receptor in budding yeast. In a mex67-5 mutant, delayed cytoplasmic release from NPCs and retrograde transport of mRNPs was observed. This proves an essential role for Mex67p in cytoplasmic mRNP release and directionality of transport.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / genetics*
  • Cell Nucleus / metabolism*
  • Nuclear Proteins / metabolism*
  • Nucleocytoplasmic Transport Proteins / metabolism*
  • RNA Transport*
  • RNA, Fungal / metabolism
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins / metabolism*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • MEX67 protein, S cerevisiae
  • Nuclear Proteins
  • Nucleocytoplasmic Transport Proteins
  • RNA, Fungal
  • RNA, Messenger
  • RNA-Binding Proteins
  • Saccharomyces cerevisiae Proteins