(a) Scatter plots show relative protein levels of the indicated centriole duplication factors in HEK 293T cells, as determined by PRM mass spectrometry. Cells were treated with either DMSO (control, n = 3) or 0.5 µM MLN4924 (n = 3) for 24 h. To indicate fold-changes in protein levels in response to MLN4924-treatment, the average values measured in DMSO-treated control cells were set to 1.0. Error bars denote s.d., p-values from t-tests (two-tailed, unpaired) are indicated. (b) Western blot analysis shows levels of STIL, CEP135 and Aurora A after 24 h treatment of HEK 293T cells with DMSO (control) or the indicated concentrations of MLN4924. Levels of α-tubulin were analysed for loading control. (c) Western blot analysis shows levels of STIL, CEP135 and Aurora A after treatment of HEK 293T cells with MLN4924 (0.5 µM) for the indicated times (h). Prior to drug addition, cells had been synchronized by a 24 h thymidine treatment. Levels of α-tubulin were analysed for loading control.