Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
EMBO J. 2000 Feb 15;19(4):719-28.

On how a transcription factor can avoid its proteolytic activation in the absence of signal transduction.

Author information

  • 1Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas del CSIC, Velázquez 144, Madrid 28006, USA.

Erratum in

  • EMBO J 2000 May 15;19(10):2391.

Abstract

In response to alkaline ambient pH, the Aspergillus nidulans PacC transcription factor mediating pH regulation of gene expression is activated by proteolytic removal of a negative-acting C-terminal domain. We demonstrate interactions involving the approximately 150 C-terminal PacC residues and two regions located immediately downstream of the DNA binding domain. Our data indicate two full-length PacC conformations whose relative amounts depend upon ambient pH: one 'open' and accessible for processing, the other 'closed' and inaccessible. The location of essential determinants for proteolytic processing within the two more upstream interacting regions probably explains why the interactions prevent processing, whereas the direct involvement of the C-terminal region in processing-preventing interactions explains why C-terminal truncating mutations result in alkalinity mimicry and pH-independent processing. A mutant PacC deficient in pH signal response and consequent processing behaves as though locked in the 'closed' form. Single-residue substitutions, obtained as mutations bypassing the need for pH signal transduction, identify crucial residues in each of the three interactive regions and overcome the processing deficiency in the 'permanently closed' mutant.

PMID:
10675341
[PubMed - indexed for MEDLINE]
PMCID:
PMC305610
Free PMC Article

Images from this publication.See all images (9)Free text

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