Figure 1. Cenp-F localizes to mitochondria in a cell cycle-dependent manner.

In all panels, mitochondria are shown in red and Cenp-F in green. (a) Cenp-F staining is heterogeneous in a field of unsynchronized cells. Immunofluorescence using an α-Cenp-F antibody (green in lower panel) of KERMIT cells expressing a mitochondrial marker (mtBFP, red in lower panel). Scale bar, 5 μm. (b) As in a. Where indicated, cells were labelled with cell-cycle markers: α-Phosphorylated histone H3 (phospho-H3, blue) α-Aurora-B (Aur-B, blue). Interphase cells were classified as G1 and S/G2 based on Cenp-F levels. Scale bar, 5 μm. (c) Quantification of Cenp-F–mitochondria colocalization in different cell cycle phases. M represents mitosis, from prometaphase to anaphase, *P value <10⁻⁶ from a Mann–Whitney–Wilcoxon U-test. For quantifications, 2–4 regions were selected per cell. Number of selected regions: G1: 14; S/G2: 39, M: 48, cytokinesis: 17. The experiment was repeated at least three times. (d) Cenp-F localizes to mitochondrial tips. As in a. Scale bar, 10 μm. The right panels are higher magnifications of the boxed area. (e) Cenp-F colocalizes with mitochondria and microtubules. Structured-illumination microscopy of U2OS cells stained with mitotracker-red (red), Cenp-F (green) and tubulin-α (white). Scale bars, 5 μm (top panel), 500 nm (bottom).