Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
EMBO J. 2012 Mar 21;31(6):1440-52. doi: 10.1038/emboj.2011.501. Epub 2012 Feb 14.

PP4 dephosphorylates Maf1 to couple multiple stress conditions to RNA polymerase III repression.

Author information

  • 1HHMI, Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA.

Abstract

Maf1 is the 'master' repressor of RNA polymerase III (Pol III) transcription in yeast, and is conserved in eukaryotes. Maf1 is a phospho-integrator, with unfavourable growth conditions leading to rapid Maf1 dephosphorylation, nuclear accumulation, binding to RNA Pol III at Pol III genes and transcriptional repression. Here, we establish the protein phosphatase 4 (PP4) complex as the main Maf1 phosphatase, and define the involved catalytic (Pph3), scaffold (Psy2) and regulatory subunits (Rrd1, Tip41), as well as uninvolved subunits (Psy4, Rrd2). Multiple approaches support a central role for PP4 in Maf1 dephosphorylation, Maf1 nuclear localization and the rapid repression of Pol III in the nucleus. PP4 action is likely direct, as a portion of PP4 co-precipitates with Maf1, and purified PP4 dephosphorylates Maf1 in vitro. Furthermore, Pph3 mediates (either largely or fully) rapid Maf1 dephosphorylation in response to diverse stresses, suggesting PP4 plays a key role in the integration of cell nutrition and stress conditions by Maf1 to enable Pol III regulation.

PMID:
22333918
[PubMed - indexed for MEDLINE]
PMCID:
PMC3321174
Free PMC Article

Images from this publication.See all images (7)Free text

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk