Sus1, Sac3, and Thp1 mediate post-transcriptional tethering of active genes to the nuclear rim as well as to non-nascent mRNP

RNA. 2008 Jan;14(1):66-77. doi: 10.1261/rna.764108. Epub 2007 Nov 14.

Abstract

Errors in the mRNP biogenesis pathway can lead to retention of mRNA in discrete, transcription-site-proximal foci. This RNA remains tethered adjacent to the transcription site long after transcriptional shutoff. Here we identify Sus1, Thp1, and Sac3 as factors required for the persistent tethering of such foci (dots) to their cognate genes. We also show that the prolonged association of previously activated GAL genes with the nuclear periphery after transcriptional shutoff is similarly dependent on the Sac3-Thp1-Sus1-Cdc31 complex. We suggest that the complex associates with nuclear mRNP and that mRNP properties influence the association of dot-confined mRNA with its gene of origin as well as the post-transcriptional retention of the cognate gene at the nuclear periphery. These findings indicate a coupling between the mRNA-to-gene and gene-to-nuclear periphery tethering. Taken together with other recent findings, these observations also highlight the importance of nuclear mRNP to the mobilization of active genes to the nuclear rim.

Publication types

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

MeSH terms

  • Cell Nucleus / genetics*
  • In Situ Hybridization, Fluorescence
  • Nuclear Proteins / physiology*
  • Nucleocytoplasmic Transport Proteins
  • Porins
  • RNA Processing, Post-Transcriptional*
  • RNA-Binding Proteins / physiology*
  • Ribonucleoproteins / genetics*
  • Ribonucleoproteins / metabolism
  • Ribonucleoproteins / physiology
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*

Substances

  • Nuclear Proteins
  • Nucleocytoplasmic Transport Proteins
  • Porins
  • RNA-Binding Proteins
  • Ribonucleoproteins
  • SAC3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Sus1 protein, S cerevisiae
  • Thp1 protein, S cerevisiae