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  • The EMBO Journal (2001) 20, 777 - 791
  • doi:10.1093/emboj/20.4.777

The budding yeast proteins Spc24p and Spc25p interact with Ndc80p and Nuf2p at the kinetochore and are important for kinetochore clustering and checkpoint control

Carsten Janke1, Jennifer Ortiz2, Johannes Lechner2, Anna Shevchenko3, Andrej Shevchenko3, Maria M. Magiera1, Carolin Schramm1 and Elmar Schiebel1

  1. The Beatson Institute for Cancer Research, CRC Beatson Laboratories, Glasgow G61 1BD, UK
  2. Biochemistry Center, Ruprecht-Karls University, 69120 Heidelberg, Germany
  3. Peptide and Protein Group, European Molecular Biology Laboratory, 69012 Heidelberg, Germany

Correspondence to:

Elmar Schiebel, E-mail: eschiebe@udcf.gla.ac.uk

Received 2 November 2000; Accepted 3 January 2001; Revised 28 November 2000

Here, we show that the budding yeast proteins Ndc80p, Nuf2p, Spc24p and Spc25p interact at the kinetochore. Consistently, Ndc80p, Nuf2p, Spc24p and Spc25p associate with centromere DNA in chromatin immunoprecipitation experiments, and SPC24 interacts genetically with MCM21 encoding a kinetochore component. Moreover, although conditional lethal spc24-2 and spc25-7 cells form a mitotic spindle, the kinetochores remain in the mother cell body and fail to segregate the chromosomes. Despite this defect in chromosome segregation, spc24-2 and spc25-7 cells do not arrest in metaphase in response to checkpoint control. Furthermore, spc24-2 cells showed a mitotic checkpoint defect when microtubules were depolymerized with nocodazole, indicating that Spc24p has a function in checkpoint control. Since Ndc80p, Nuf2p and Spc24p are conserved proteins, it is likely that similar complexes are part of the kinetochore in other organisms.

  • Keywords:

    • kinetochore,
    • Ndc80p,
    • Nuf2p,
    • Spc24p,
    • Spc25p