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Mimicking Ndc80 phosphorylation triggers spindle assembly checkpoint signalling.

ABSTRACT: The protein kinase Mps1 is, among others, essential for the spindle assembly checkpoint (SAC). We found that Saccharomyces cerevisiae Mps1 interacts physically with the N-terminal domain of Ndc80 (Ndc80(1-257)), a constituent of the Ndc80 kinetochore complex. Furthermore, Mps1 effectively phosphorylates Ndc80(1-257) in vitro and facilitates Ndc80 phosphorylation in vivo. Mutating 14 of the phosphorylation sites to alanine results in compromised checkpoint signalling upon nocodazole treatment of mutants. Mutating the identical sites to aspartate (to simulate constitutive phosphorylation) causes a metaphase arrest with wild-type-like bipolar kinetochore-microtubule attachment. This arrest is due to a constitutively active SAC and consequently the inviable aspartate mutant can be rescued by disrupting SAC signalling. Therefore, we conclude that a putative Mps1-dependent phosphorylation of Ndc80 is important for SAC activation at kinetochores.

SUBMITTER: Kemmler S

PROVIDER: S-EPMC2683709 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature

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Mimicking Ndc80 phosphorylation triggers spindle assembly checkpoint signalling.

Kemmler Stefan S Stach Manuel M Knapp Maria M Ortiz Jennifer J Pfannstiel Jens J Ruppert Thomas T Lechner Johannes J

The EMBO journal 20090319 8

The protein kinase Mps1 is, among others, essential for the spindle assembly checkpoint (SAC). We found that Saccharomyces cerevisiae Mps1 interacts physically with the N-terminal domain of Ndc80 (Ndc80(1-257)), a constituent of the Ndc80 kinetochore complex. Furthermore, Mps1 effectively phosphorylates Ndc80(1-257) in vitro and facilitates Ndc80 phosphorylation in vivo. Mutating 14 of the phosphorylation sites to alanine results in compromised checkpoint signalling upon nocodazole treatment of ...[more]

PMID: 19300438

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