Search Organism: All OrganismsArabidopsis thalianaBacillus subtilis 168Bos taurusCaenorhabditis elegansCanis familiarisDanio rerioDrosophila melanogasterEquus caballusEscherichia coli K12Gallus gallusHomo sapiensMacaca mulattaMus musculusNematostella vectensisOryza sativaPan troglodytesRattus norvegicusSaccharomyces cerevisiaeSchizosaccharomyces pombeStrongylocentrotus purpuratusTakifugu rubripesXenopus laevis home help / support contribute downloads mirrors about us Nov (2006); 0: SCFCdc4-mediated Degradation of the Hac1p Transcription Factor Regulates the Unfolded Protein Response in Saccharomyces cerevisiae- Pal B, Chan NC, Helfenbaum L, Tan K, Tansey WP, Gething MJ Department of Biochemistry and Molecular Biology, University of Melbourne, Victoria 3010, Australia; Bio21 Molecular Science and Biotechnology Institute, Parkville, Victoria 3010, Australia; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724- Abstract: Monitoring Editor- Jeffrey Brodsky The S- cerevisiae bZIP transcription factor Hac1p is synthesized in response to the accumulation of unfolded polypeptides in the lumen of the endoplasmic reticulum -ER- and is responsible for up-regulation of approximately 5% of all yeast genes, including ER-resident chaperones and protein folding catalysts- Hac1p is one of the most short-lived yeast proteins, having a half-life of approximately 1-5 min- Here we have shown that Hac1p harbors a functional PEST degron and that degradation of Hac1p by the proteasome involves the E2 ubiquitin-conjugating enzyme Ubc3-Cdc34p and the SCF-Cdc4- E3 complex- Consistent with the known nuclear localization of Cdc4p, rapid degradation of Hac1p requires the presence of a functional nuclear localization sequence, which we demonstrated to involve basic residues in the sequence 29RKRAKTK35- Two-hybrid analysis demonstrated that the PEST-dependent interaction of Hac1p with Cdc4p requires Ser146 and Ser149- Turnover of Hac1p may be dependent on transcription since it is inhibited in cell mutants lacking Srb10 kinase, a component of the SRB-mediator module of the RNA polymerase II holoenzyme- Stabilization of Hac1p by point mutation or deletion, or as the consequence of defects in components of the degradation pathway, results in increased UPRE-dependent transcription and-or cell viability under ER stress conditions- [PUBMED: 17108329] Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. terms and conditions - privacy policy - Osprey Network Visualization System BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9.