ATP hydrolysis-dependent disassembly of the 26S proteasome is part of the catalytic cycle.
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.
Babbitt
Shalon E
SE
Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
Kiss
Alexi
A
Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
Deffenbaugh
Andrew E
AE
Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
Chang
Yie-Hwa
YH
Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104.
Bailly
Eric
E
Laboratoire d'Ingénierie des Systèmes Macromoléculaires-Centre National de la Recherche Scientifique, Marseille Cedex 20, France.
Erdjument-Bromage
Hediye
H
Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Tempst
Paul
P
Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Buranda
Tione
T
Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131.
Sklar
Larry A
LA
Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131.
Baumler
Jennifer
J
School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110.
Gogol
Edward
E
School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110.
Skowyra
Dorota
D
Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104. Electronic address: skowyrad@slu.edu.
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
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