CENP-C is a component of the expanded kinetochore. (A) Staining of CCAN proteins (green) in nocodazole-treated extracts costained with BubR1 (magenta, chromosomes not depicted). (B) Quantification of the total kinetochore staining on the chromosome cluster. Mean, standard deviation, and fold change indicated in black (n = 8–10 nuclei). (C) Western blots of chromosomes purified from untreated or nocodazole-treated extracts. Percent values calculated by correcting raw values with the ratio of H3 signal. (D) Schematic of Xenopus CENP-C protein and constructs used in D–I. (E) Mitotic chromosomes assembled in extracts in which the indicated 6×Myc–CENP-C construct was expressed. (F and G) Quantification of data from D, comparing the Myc signal to CENP-A or BubR1 staining. (H–J) Sample preparation and quantification as in E–G. Mann–Whitney test: ns, P > 0.5; *, P < 0.05; **, P < 0.01; ***, P < 0.001. All images are maximum intensity projections of 3D-SIM datasets; bars, 1 µm. A.U., arbitrary unit.