Figure 4.

Co-depletion of β-TrCP and Mis18β prevents the mislocalization of CENP-A in MDA-MB-231^Δβ-TrCP cells. (A) Western blots showing the protein levels of β-TrCP and Mis18β in MDA-MB-231^Δβ-TrCP cells transfected with siRNAs as indicated for 72 h and untreated or treated with DOX for 48 h. GAPDH was used as a loading control. (B) Representative images of metaphase chromosome spreads prepared from MDA-MB-231^{Δ β-TrCP} cells transfected with siRNAs as indicated for 72 h and untreated or treated with DOX for 48 h showing the localization of endogenous CENP-A on mitotic chromosomes. Scale bar: 5 µm for main images and 2 µm for insets. (C) Quantification of CENP-A signal intensities (arbitrary units) at centromeric (left) and noncentromeric (right) regions in metaphase chromosome spreads of MDA-MB-231^{Δ β-TrCP} cells treated as in B. Each circle represents one spot quantified on chromosome. “Chr” represents number of chromosomes analyzed in the number of cells denoted. Error bars depict the SD across areas measured in the number of cells from three biological repeats and the P-values were determined using Student’s t test.