The spindle assembly checkpoint regulates the phosphorylation state of a subset of DNA checkpoint proteins in Saccharomyces cerevisiae.
The DNA and the spindle assembly checkpoints play key roles in maintaining genomic integrity by coordinating cell responses to DNA lesions and spindle dysfunctions, respectively. These two surveillance pathways seem to operate mostly independently of one another, and little is known about their potential physiological connections. Here, we show that in Saccharomyces cerevisiae, the activation of the spindle assembly checkpoint triggers phosphorylation changes in two components of the DNA checkpoint, Rad53 and Rad9. These modifications are independent of the other DNA checkpoint proteins and are abolished in spindle checkpoint-defective mutants, hinting at specific functions for Rad53 and Rad9 in the spindle damage response. Moreover, we found that after UV irradiation, Rad9 phosphorylation is altered and Rad53 inactivation is accelerated when the spindle checkpoint is activated, which suggests the implication of the spindle checkpoint in the regulation of the DNA damage response.
Clémenson
Céline
C
Service de Biochimie et de Génétique Moléculaire, CEA/Saclay, 91191 Gif-sur-Yvette, France. mcmk@cea.fr.
Marsolier-Kergoat
Marie-Claude
MC
D018797:Cell Cycle Proteins / Q000378:metabolism*; D064447:Checkpoint Kinase 2; D004249:DNA Damage / Q000502:physiology*; D004260:DNA Repair / Q000502:physiology; D004271:DNA, Fungal / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D008941:Spindle Apparatus / Q000502:physiology*
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; C069930:rad9 protein; D064447:Checkpoint Kinase 2; D017346:Protein Serine-Threonine Kinases; C067022:RAD53 protein, S cerevisiae