Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2002 Jun 25;99(13):8585-90.

Hsp90 enables Ctf13p/Skp1p to nucleate the budding yeast kinetochore.

Author information

  • 1Biochemie-Zentrum, Ruprecht-Karls Universität, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.

Abstract

Binding of CBF3, a protein complex consisting of Ndc10p, Cep3p, Ctf13p, and Skp1p, to the centromere DNA nucleates kinetochore formation in budding yeast. Here, we investigate how the Ctf13p/Skp1p complex becomes competent to form the CBF3-centromere DNA complex. As revealed by mass spectrometry, Ctf13p and Skp1p carry two and four phosphate groups, respectively. Complete dephosphorylation of Ctf13p and Skp1p does not interfere with the formation of CBF3-centromere DNA complexes in vitro. Furthermore, deletion of corresponding phosphorylation sites results in viable cells. Thus, in contrast to the current view, phosphorylation of Ctf13p and Skp1p is not essential for the formation of CBF3-centromere DNA complexes. Instead, the formation of active Ctf13p/Skp1p requires Hsp90. Several lines of evidence support this conclusion: activation of heterologous Ctf13p/Skp1p by reticulocyte lysate is inhibited by geldanamycin and Hsp90 depletion. skp1 mutants exhibit growth defects on media containing geldanamycin. A skp1 mutation together with Hsp90 mutations exhibits synthetic lethality. An Hsp90 mutant contains decreased levels of active Ctf13p/Skp1p.

PMID:
12084919
[PubMed - indexed for MEDLINE]
PMCID:
PMC124320
Free PMC Article

Images from this publication.See all images (4)Free text

Figure 1
Figure 2
Figure 3
Figure 4
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk