Fig. 4.

Pontin accumulates in the nucleolar dots during S-phase. Pontin was immunodetected by the anti-Pontin (5G3-11) antibody in a unsynchronized cell population or b cells synchronized to S-phase of the cell cycle. Ninety six percent of cells in S-phase accumulated Pontin in the nucleolus. Scale bar represents 10 μm. c Equivalent amounts of proteins from S-phase cells and from unsynchronized cells were loaded in each line (vimentin antibody used as a loading control). No significant differences in protein levels of Pontin were observed between the unsynchronized and synchronized cell populations