title: The Rbx1 subunit of SCF and VHL E3 ubiquitin ligase activates Rub1 modification of cullins Cdc53 and Cul2.
abstract: The RING-H2 finger protein Rbx1 is a subunit of the related SCF (Skp1-Cdc53/Cul1-F-box protein) and von Hippel-Lindau (VHL) tumor suppressor (elongin BC-Cul2-VHL) E3 ubiquitin ligase complexes, where it functions as a component of Cdc53/Rbx1 and Cul2/Rbx1 modules that activate ubiquitination of target proteins by the E2 ubiquitin-conjugating enzymes Cdc34 and Ubc5. Here we demonstrate that the Cdc53/Rbx1 and Cul2/Rbx1 modules also activate conjugation of the ubiquitin-like protein Rub1 to Cdc53 and Cul2 by the dedicated E2 Rub1 conjugating enzyme Ubc12. Our findings identify Rbx1 as a common component of enzyme systems responsible for ubiquitin and Rub1 modification of target proteins.
authors.affiliation: Howard Hughes Medical Institute (HHMI), Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.
authors.forename: T
authors.initials: T
authors.lastname: Kamura
authors.forename: M N
authors.initials: MN
authors.lastname: Conrad
authors.forename: Q
authors.initials: Q
authors.lastname: Yan
authors.forename: R C
authors.initials: RC
authors.lastname: Conaway
authors.forename: J W
authors.initials: JW
authors.lastname: Conaway
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000378:metabolism* / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D044842:Cullin Proteins; D005656:Fungal Proteins / Q000378:metabolism* / Q000502:physiology; D008025:Ligases; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000502:physiology*; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D014452:Ubiquitins; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D015032:Zinc / Q000378:metabolism
chemical_list: C105153:CUL2 protein, human; D002352:Carrier Proteins; C100988:Cdc53 protein, S cerevisiae; D018797:Cell Cycle Proteins; D044842:Cullin Proteins; D005656:Fungal Proteins; D046911:Macromolecular Substances; D011506:Proteins; C111706:RUB1 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D025521:Tumor Suppressor Proteins; D014452:Ubiquitins; D044843:SKP Cullin F-Box Protein Ligases; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D008025:Ligases; D010453:Peptide Synthases; D015032:Zinc