title: ATP hydrolysis-dependent disassembly of the 26S proteasome is part of the catalytic cycle.
abstract: ATP hydrolysis is required for degradation of polyubiquitinated proteins by the 26S proteasome but is thought to play no role in proteasomal stability during the catalytic cycle. In contrast to this view, we report that ATP hydrolysis triggers rapid dissociation of the 19S regulatory particles from immunopurified 26S complexes in a manner coincident with release of the bulk of proteasome-interacting proteins. Strikingly, this mechanism leads to quantitative disassembly of the 19S into subcomplexes and free Rpn10, the polyubiquitin binding subunit. Biochemical reconstitution with purified Sic1, a prototype substrate of the Cdc34/SCF ubiquitin ligase, suggests that substrate degradation is essential for triggering the ATP hydrolysis-dependent dissociation and disassembly of the 19S and that this mechanism leads to release of degradation products. This is the first demonstration that a controlled dissociation of the 19S regulatory particles from the 26S proteasome is part of the mechanism of protein degradation.
authors.affiliation: Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
authors.forename: Shalon E
authors.initials: SE
authors.lastname: Babbitt
authors.affiliation: Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
authors.forename: Alexi
authors.initials: A
authors.lastname: Kiss
authors.affiliation: Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Deffenbaugh
authors.affiliation: Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
authors.forename: Yie-Hwa
authors.initials: YH
authors.lastname: Chang
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires-Centre National de la Recherche Scientifique, Marseille Cedex 20, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Bailly
authors.affiliation: Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
authors.forename: Hediye
authors.initials: H
authors.lastname: Erdjument-Bromage
authors.affiliation: Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
authors.forename: Paul
authors.initials: P
authors.lastname: Tempst
authors.affiliation: Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131.
authors.forename: Tione
authors.initials: T
authors.lastname: Buranda
authors.affiliation: Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131.
authors.forename: Larry A
authors.initials: LA
authors.lastname: Sklar
authors.affiliation: School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Baumler
authors.affiliation: School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110.
authors.forename: Edward
authors.initials: E
authors.lastname: Gogol
authors.affiliation: Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104. Electronic address: skowyrad@slu.edu.
authors.forename: Dorota
authors.initials: D
authors.lastname: Skowyra
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism* / Q000648:ultrastructure; D000255:Adenosine Triphosphate / Q000378:metabolism*; D064173:Anaphase-Promoting Complex-Cyclosome; D002352:Carrier Proteins; D002384:Catalysis; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D010450:Endopeptidases / Q000378:metabolism* / Q000648:ultrastructure; D006868:Hydrolysis; D008854:Microscopy, Electron; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D021122:Protein Subunits; C122019:RPN10 protein, S cerevisiae; C086926:SIC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; D000255:Adenosine Triphosphate; C577449:CDC34 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D010450:Endopeptidases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; C119011:26S proteasome non-ATPase regulatory subunit 13; D000251:Adenosine Triphosphatases