1. Academic Validation
  2. Targeting of protein ubiquitination by BTB-Cullin 3-Roc1 ubiquitin ligases

Targeting of protein ubiquitination by BTB-Cullin 3-Roc1 ubiquitin ligases

  • Nat Cell Biol. 2003 Nov;5(11):1001-7. doi: 10.1038/ncb1056.
Manabu Furukawa 1 Yizhou Joseph He Christoph Borchers Yue Xiong
Affiliations

Affiliation

  • 1 Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics, and Program in Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, NC 27599-7295, USA.
Abstract

The concentrations and functions of many cellular proteins are regulated by the ubiquitin pathway. Cullin family proteins bind with the RING-finger protein Roc1 to recruit the ubiquitin-conjugating Enzyme (E2) to the ubiquitin Ligase complex (E3). Cul1 and Cul7, but not other cullins, bind to an adaptor protein, Skp1. Cul1 associates with one of many F-box proteins through Skp1 to assemble various SCF-Roc1 E3 Ligases that each selectively ubiquitinate one or more specific substrates. Here, we show that Cul3, but not other cullins, binds directly to multiple BTB domains through a conserved amino-terminal domain. In vitro, Cul3 promoted ubiquitination of Caenorhabditis elegans MEI-1, a katanin-like protein whose degradation requires the function of both Cul3 and BTB protein MEL-26. We suggest that in vivo there exists a potentially large number of BCR3 (BTB-Cul3-Roc1) E3 ubiquitin ligases.

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