Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Nat Struct Mol Biol. 2005 Apr;12(4):294-303. Epub 2005 Mar 20.

The HEAT repeat protein Blm10 regulates the yeast proteasome by capping the core particle.

Author information

  • 1Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.

Abstract

Proteasome activity is fine-tuned by associating the proteolytic core particle (CP) with stimulatory and inhibitory complexes. Although several mammalian regulatory complexes are known, knowledge of yeast proteasome regulators is limited to the 19-subunit regulatory particle (RP), which confers ubiquitin-dependence on proteasomes. Here we describe an alternative proteasome activator from Saccharomyces cerevisiae, Blm10. Synthetic interactions between blm10Delta and other mutations that impair proteasome function show that Blm10 functions together with proteasomes in vivo. This large, internally repetitive protein is found predominantly within hybrid Blm10-CP-RP complexes, representing a distinct pool of mature proteasomes. EM studies show that Blm10 has a highly elongated, curved structure. The near-circular profile of Blm10 adapts it to the end of the CP cylinder, where it is properly positioned to activate the CP by opening the axial channel into its proteolytic chamber.

PMID:
15778719
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Nature Publishing Group Icon for Faculty of 1000
    Loading ...
    Write to the Help Desk