title: Determinants of robustness in spindle assembly checkpoint signalling.
abstract: The spindle assembly checkpoint is a conserved signalling pathway that protects genome integrity. Given its central importance, this checkpoint should withstand stochastic fluctuations and environmental perturbations, but the extent of and mechanisms underlying its robustness remain unknown. We probed spindle assembly checkpoint signalling by modulating checkpoint protein abundance and nutrient conditions in fission yeast. For core checkpoint proteins, a mere 20% reduction can suffice to impair signalling, revealing a surprising fragility. Quantification of protein abundance in single cells showed little variability (noise) of critical proteins, explaining why the checkpoint normally functions reliably. Checkpoint-mediated stoichiometric inhibition of the anaphase activator Cdc20 (Slp1 in Schizosaccharomyces pombe) can account for the tolerance towards small fluctuations in protein abundance and explains our observation that some perturbations lead to non-genetic variation in the checkpoint response. Our work highlights low gene expression noise as an important determinant of reliable checkpoint signalling.
authors.affiliation: Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Heinrich
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Geissen
authors.forename: Julia
authors.initials: J
authors.lastname: Kamenz
authors.forename: Susanne
authors.initials: S
authors.lastname: Trautmann
authors.forename: Christian
authors.initials: C
authors.lastname: Widmer
authors.forename: Philipp
authors.initials: P
authors.lastname: Drewe
authors.forename: Michael
authors.initials: M
authors.lastname: Knop
authors.forename: Nicole
authors.initials: N
authors.lastname: Radde
authors.forename: Jan
authors.initials: J
authors.lastname: Hasenauer
authors.forename: Silke
authors.identifier: 000000015938721X
authors.initials: S
authors.lastname: Hauf
mesh_terms: D059566:M Phase Cell Cycle Checkpoints; D012568:Schizosaccharomyces / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D015398:Signal Transduction; D008941:Spindle Apparatus
chemical_list: D029702:Schizosaccharomyces pombe Proteins