Display Settings:

Format

Send to:

Choose Destination
    Cell Signal. 2012 Jan;24(1):290-5. Epub 2011 Sep 16.

    Characterization of the Cullin7 E3 ubiquitin ligase--heterodimerization of cullin substrate receptors as a novel mechanism to regulate cullin E3 ligase activity.

    Source

    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.

    Abstract

    Cul1 and Cul7 are cullin E3 ubiquitin ligase scaffold proteins. Cul1 is known to form a complex with the RING domain protein Rbx1 and one of approximately 70 different F-box proteins. F-box proteins function as substrate receptor subunits and recruit numerous substrates for poly-ubiquitination. Similarly to Cul1, Cul7 interacts with Rbx1, however, only one F-box protein, Fbxw8, has been shown to bind to Cul7. To date only few Cul7 E3 ubiquitin ligase substrates, including cyclin D1, IRS-1 and GRASP65, have been reported, and using Fbxw8 affinity purification, we were unable to identify additional substrate proteins. Here we provide evidence for a model in which Cul7-Rbx1 can promote the ubiquitination of Cul1 substrates by forming high order complexes with Cul1-Rbx1. Binding of Cul1-Rbx1 to Cul7-Rbx1 is mediated via heterodimerization of Fbxw8 with other F-box proteins which function to recruit substrates into the E3 ligase complex. The formation of this high order complex is likely to increase polyubiquitination efficiency.

    Copyright © 2011 Elsevier Inc. All rights reserved.

    PMID:
    21946088
    [PubMed - indexed for MEDLINE]

      Supplemental Content

      Icon for Elsevier Science

      Save items

      loading

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk