F1-Histone Phosphorylation in Metaphase Chromosomes of Cultured Chinese Hamster Cells

Evidence has accumulated to suggest a relationship between lysine-rich (F1) histone phosphorylation and the overall processes of cell growth and chromosome replication1-4. Augmented F1 phosphorylation has also been found in mitotic Chinese hamster, HeLa S-3, rat nephroma and African green monkey kidney (Vero) cells5,6. These observations suggest a discrete role for F1-histone phosphorylation in events at mitosis which are common to both metaphase (M) and interphase (I) cells. Previous experiments have also shown that the phosphoform of F1 reverts to the dephosphoform upon release of M cells into G15 and that a highly active cAMP-independent Phosphokinase which has a high preference for F1 histone decays with long meta-phase-arrest times6.