FIG. 4.

The ratio of H4-WT to H4-4A differs in WCEs and nuclear extracts. (A) WCEs (lysates) were prepared from exponentially growing H4-WT (YJB7349), H4-4A (YJB7354), and H4-4A/WT (YJB7348) strains, and extracted nuclear material (pellet) was prepared from the H4-4A/WT strain. Both WCEs and nuclear extracts were separated by SDS-22% PAGE and probed with the anti-H4-17-33 antibody. Note that the H4-4A/WT strain (lane 4) does not contain as much H4-4A protein in the nuclear pellet as in the lysate (lane 3). Quantitation of the amounts of histone H4 present in the nuclear pellet compared to the lysate indicated that 40% of the expected H4-4A is absent in the nuclear pellet. (B) Western blot assay of nucleus-enriched preparations. Lysate, pellet (nuclei), and supernatant (Sup; cytoplasm) material from the nuclear extract protocol were separated by SDS-8% PAGE and probed with either an anti-PGK1 antibody or an anti-RAP1 antibody.