The enhancement of histone H4 and H2A serine 1 phosphorylation during mitosis and S-phase is evolutionarily conserved

Abstract

Histone phosphorylation has long been associated with condensed mitotic chromatin; however, the functional roles of these modifications are not yet understood. Histones H1 and H3 are highly phosphorylated from late G2 through telophase in many organisms, and have been implicated in chromatin condensation and sister chromatid segregation. However, mutational analyses in yeast and biochemical experiments with Xenopus extracts have demonstrated that phosphorylation of H1 and H3 is not essential for such processes. In this study, we investigated additional histone phosphorylation events that may have redundant functions to H1 and H3 phosphorylation during mitosis. We developed an antibody to H4 and H2A that are phosphorylated at their respective serine 1 (S1) residues and found that H4S1/H2AS1 are highly phosphorylated in the mitotic chromatin of worm, fly, and mammals. Mitotic H4/H2A phosphorylation has similar timing and localization as H3 phosphorylation, and closely correlates with the chromatin condensation events during mitosis. We also detected a lower level of H4/H2A phosphorylation in 5-bromo-2-deoxyuridine-positive S-phase cells, which corroborates earlier studies that identified H4S1 phosphorylation on newly synthesized histones during S-phase. The evolutionarily conserved phosphorylation of H4/H2A during the cell cycle suggests that they may have a dual purpose in chromatin condensation during mitosis and histone deposition during S-phase.

Granulocytic nuclear differentiation of lamin B receptor–deficient mouse EPRO cells

“…It is clear that me 3 H3K9, me 3 H4K20 and HP1γ are present in all cell states, with no obvious changes in amounts. Also shown are two phosphorylated histone "mitotic" markers, [29][30][31] H3(S10)phos and H4/H2A(S1)phos, which also reveal no significant or systematic changes when comparing the various cell forms.…”

Analysis of Dynamic Changes in Post-translational Modifications of Human Histones during Cell Cycle by Mass Spectrometry

“…In all three analyses, the ion intensities of acetylated peptides were decreased in S phase, and most of these ions were absent in G 2 /M phase. For the monoacetylated H2BJ/N and H2BA variants, MS/MS analysis of the corresponding peptides localized acetylation on Lys 12 , Lys 15 , and Lys 20 (Supplemental Figs. 16 and 18 and Ref.…”

“…Recent reports have shown that H3 is also phosphorylated at Ser28, Thr11, Thr3, and H3.3 Ser 31 during mitosis (11)(12)(13)(14). For histones H4 and H2A, hyperphosphorylation was detected at their respective Ser 1 residues during mitosis in worm, fly, and mammalian cells (15). For histone acetylation, one of the better understood histone modifications, it is now generally accepted that hyperacetylated histones are mostly associated with activated genomic regions, whereas deacetylation mainly results in repression and silencing (16,17).…”

Packing for the germy: the role of histone H4 Ser1 phosphorylation in chromatin compaction and germ cell development: Figure 1.

“…However, mutations altering S10 of H3 do not alter mitosis, meiosis, or cell growth, suggesting a possible redundancy of its function (Hsu et al 2000;Barber et al 2004).…”

“…Although H3 S10 is a common mitotic/meiotic histone phosphorylation mark correlated with chromatin condensation, mutations that alter H3 S10 do not effect either mitosis or meiosis (Barber et al 2004). Therefore, Krishnamoorthy et al (2006) sought to determine whether an H4 S1A mutation demonstrates defects in sporulation.…”