title: The chaperone-associated ubiquitin ligase CHIP is able to target p53 for proteasomal degradation.
abstract: The cellular level of the tumor suppressor p53 is tightly regulated through induced degradation via the ubiquitin/proteasome system. The ubiquitin ligase Mdm2 plays a pivotal role in stimulating p53 turnover. However, recently additional ubiquitin ligases have been identified that participate in the degradation of the tumor suppressor. Apparently, multiple degradation pathways are employed to ensure proper destruction of p53. Here we show that the chaperone-associated ubiquitin ligase CHIP is able to induce the proteasomal degradation of p53. CHIP-induced degradation was observed for mutant p53, which was previously shown to associate with the chaperones Hsc70 and Hsp90, and for the wild-type form of the tumor suppressor. Our data reveal that mutant and wild-type p53 transiently associate with molecular chaperones and can be diverted onto a degradation pathway through this association.
authors.affiliation: Institute for Cell Biology and Bonner Forum Biomedizin, Rheinische Friedrich-Wilhelms-University Bonn, Ulrich-Haberland-Str. 61a, D-53121 Bonn, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Esser
authors.forename: Martin
authors.initials: M
authors.lastname: Scheffner
authors.forename: Jörg
authors.initials: J
authors.lastname: Höhfeld
mesh_terms: D002460:Cell Line; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D018832:Molecular Chaperones / Q000378:metabolism; D020125:Mutation, Missense; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000494:pharmacology; D014158:Transcription, Genetic; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000502:physiology*
chemical_list: D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; C494371:HSPA8 protein, human; D018832:Molecular Chaperones; D034741:RNA, Small Interfering; D016159:Tumor Suppressor Protein p53; C467728:STUB1 protein, human; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex