Phosphorylation of histone H3 at serine 10 is correlated with chromosome condensation during mitosis and meiosis in Tetrahymena

Abstract

H3 phosphorylation has been correlated with mitosis temporally in mammalian cells and spatially in ciliated protozoa. In logarithmically growing Tetrahymena thermophila cells, for example, H3 phosphorylation can be detected in germline micronuclei that divide mitotically but not in somatic macronuclei that divide amitotically. Here, we demonstrate that micronuclear H3 phosphorylation occurs at a single site (Ser-10) in the amino-terminal domain of histone H3, the same site phosphorylated during mitosis in mammalian cells. Using an antibody specific for Ser-10 phosphorylated H3, we show that, in Tetrahymena, this modification is correlated with mitotic and meiotic divisions of micronuclei in a fashion that closely coincides with chromosome condensation. Our data suggest that H3 phosphorylation at Ser-10 is a highly conserved event among eukaryotes and is likely involved in both mitotic and meiotic chromosome condensation.In eukaryotic cells, DNA is closely associated with histone proteins in the form of chromatin, packaging DNA in a way that remains only partially understood. Although the structure of the nucleosome core is now known in considerable detail (1), how higher order chromatin structures are folded and unfolded to accommodate processes such as transcription, replication, and chromosome segregation remains unclear. During mitosis, DNA is compacted nearly 10,000-fold to ensure proper segregation of the genetic material to daughter cells. Faithful segregation of sister chromatids requires proper condensation of the chromatin during entry into mitosis and decondensation of the fiber during exit from mitosis and is essential for the viability of the cells.Specific posttranslational modifications of histones, particularly acetylation and phosphorylation, correlate well with dynamic aspects of the folding and unfolding of the chromatin fiber (2). For example, hyperphosphorylation of linker histone H1 is temporally coupled with entry into mitosis and has often been presumed to function in mitotic chromatin condensation (3, 4). However, recent experiments show that chromatin condensation can occur in vivo (5) or in vitro (6, 7) in the absence of H1. Furthermore, H1 hyperphosphorylation does not occur in premature chromatin condensation induced by fostriecin (8) or okadaic acid (9). Therefore, the exact function of H1 hyperphosphorylation in mitosis remains unclear.In contrast to H1 hyperphosphorylation, site-specific phosphorylation of core histone H3 at serine 10 seems to occur exclusively during mitosis in mammalian cells (10, 11). Moreover, fostriecin and okadaic acid, which initiate premature chromatin condensation in cell cultures, also induce H3 phosphorylation (8, 9). Similarly, vanadate-induced dephosphorylation of H3 correlates with chromatin decondensation and the rescue of a mitotic mutant that otherwise fails to initiate postmitotic chromatin decondensation (12). Recent studies, using an antibody selective for the Ser-10 phosphorylated H3 amino terminus, have documented a tight correlation b...

Histone Hyperacetylation in Mitosis Prevents Sister Chromatid Separation and Produces Chromosome Segregation Defects

“…H3 phosphorylation at Ser10 is governed by the activity of aurora/Ipl1 kinases (Speliotes et al, 2000;Giet and Glover 2001;Crosio et al, 2002) in competition with the phosphatase activity of the serine/threonine protein phosphatase 1 (Hsu et al, 2000;Murnion et al, 2001). It has been shown that Ser 10-modified histone colo-calizes with the human condensin complex during G2/ prophase (Schmiesing et al, 2000), suggesting that this modification may have a role in destabilizing local chromatin structure to allow access of condensation factors to DNA or in recruiting the condensation machinery on the modified histone amino-terminal tail (Wei et al, 1998;Schmiesing et al, 2000).…”

“…The presence of this modified histone has been correlated with mitotic chromosome condensation in several eukaryotic systems (Hendzel et al, 1997;Wei et al, 1998). H3 phosphorylation at Ser10 is governed by the activity of aurora/Ipl1 kinases (Speliotes et al, 2000;Giet and Glover 2001;Crosio et al, 2002) in competition with the phosphatase activity of the serine/threonine protein phosphatase 1 (Hsu et al, 2000;Murnion et al, 2001).…”

Inhibition of mixed-lineage kinase (MLK) activity during G2-phase disrupts microtubule formation and mitotic progression in HeLa cells

“…Phosphorylation of histone H3 at serine 10 is commonly used as a marker of mitotic progression [22,23]. HeLa cells were treated with or without CEP-11004 at 5 h after release from G1/S-phase thymidine block and allowed to incubate for an additional 4 h. Cells were then fixed and processed for immunofluorescence of cyclin B1 and phospho-histone H3 (pH3) to identify the mitotic cells.…”

Histone Regulation in the CNS: Basic Principles of Epigenetic Plasticity

“…Despite its longstanding history (Stevely and Stocken, 1966;Gutierrez and Hnilica, 1967) and the presence of numerous serine, threonine, and tyrosine residues speckled throughout the primary sequences of histone proteins. Early work in this area focused primarily on the phosphorylation of linker histones (eg, H1, Sweet and Allis, 1993) and of the core histone H3 (eg, H3S10 phosphorylation (H3S10p)) as universal markers of mitotic and meiotic chromatin condensation (Wei et al, 1998(Wei et al, , 1999. More recently, studies have begun to examine the role of phosphorylation on other core histone proteins, such as H2B, which was only recently demonstrated to function during apoptotic chromatin compaction (Ajiro, 2000;Cheung et al, 2003).…”