Role of Rpn11 metalloprotease in deubiquitination and degradation by the 26S proteasome.
The 26S proteasome mediates degradation of ubiquitin-conjugated proteins. Although ubiquitin is recycled from proteasome substrates, the molecular basis of deubiquitination at the proteasome and its relation to substrate degradation remain unknown. The Rpn11 subunit of the proteasome lid subcomplex contains a highly conserved Jab1/MPN domain-associated metalloisopeptidase (JAMM) motif-EX(n)HXHX(10)D. Mutation of the predicted active-site histidines to alanine (rpn11AXA) was lethal and stabilized ubiquitin pathway substrates in yeast. Rpn11(AXA) mutant proteasomes assembled normally but failed to either deubiquitinate or degrade ubiquitinated Sic1 in vitro. Our findings reveal an unexpected coupling between substrate deubiquitination and degradation and suggest a unifying rationale for the presence of the lid in eukaryotic proteasomes.
Department of Biology and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA.
Rati
R
Verma
L
L
Aravind
Robert
R
Oania
W Hayes
WH
McDonald
John R
JR
Yates
Eugene V
EV
Koonin
Raymond J
RJ
Deshaies
D000255:Adenosine Triphosphate / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D019759:Carbon-Nitrogen Lyases / Q000737:chemistry / Q000378:metabolism*; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000378:metabolism; D009154:Mutation; D009842:Oligopeptides / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry; D014452:Ubiquitins / Q000378:metabolism*; D015003:Yeasts / Q000378:metabolism; D015032:Zinc / Q000378:metabolism
D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009097:Multienzyme Complexes; D009842:Oligopeptides; C115451:RPN11 protein, S cerevisiae; C086926:SIC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014452:Ubiquitins; D000255:Adenosine Triphosphate; D010450:Endopeptidases; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases; D008666:Metalloendopeptidases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D019759:Carbon-Nitrogen Lyases; C034300:isopeptidase; D015032:Zinc; C078846:epoxomicin