Dynamic distribution of Ser-10 phosphorylated histone H3 in cytoplasm of MCF-7 and CHO cells during mitosis

Abstract

The dynamic distribution of phosphorylated Histone H3 on Ser10 (phospho-H3) in cells was investigated to determine its function during mitosis. Human breast adenocarcinoma cells MCF-7, and Chinese hamster cells CHO were analyzed by indirect immunofluorescence staining with an antibody against phospho-H3. We found that the phosphorylation begins at early prophase, and spreads throughout the chromosomes at late prophase. At metaphase, most of the phospho-H3 aggregates at the end of the condensed entity of chromosomes at equatorial plate. During anaphase and telophase, the fluorescent signal of phospho-H3 is detached from chromosomes into cytoplasm. At early anaphase, phospho-H3 shows ladder bands between two sets of separated chromosome, and forms "sandwich-like structure" when the chromosomes condensed. With the cleavage progressing, the "ladders" of the histone contract into a bigger bright dot. Then the histone aggregates and some of compacted microtubules in the midbody region are composed into a "bar-like" complex to separate daughter cells. The daughter cells seal their plasma membrane along with the ends of the "bar", inside which locates microtubules and modified histones, to finish the cytokinesis and keep the "bar complex" out of the cells. The specific distribution and kinetics of phospho-H3 in cytoplasm suggest that the modified histones may take part in the formation of midbody and play a crucial role in cytokinesis.

Arabidopsis thaliana histone deacetylase 1 (AtHD1) is localized in euchromatic regions and demonstrates histone deacetylase activity in vitro

“…Histone deacetylation was shown to correlate with chromatin condensation and subsequent chromatid segregation during mitosis [49][50][51]. It has been demonstrated that the histone acetylation levels in several mammalian cell lines started to decrease as the cells enter prophase, then dramatically reduced as the cells progressed into metaphase through telophase, and restored to normal levels at the late telophase/early interphase boundary [49].…”

“…Moreover, a temporal inhibition of HDACs by trichostatin A (TSA) in human fibroblasts entering mitosis resulted in defective chromatin condensation and impaired chromatid segregation [50]. A similar study in plant also showed that TSA treatment on cultured tobacco cells led to abnormal anaphases and impaired the progression through mitosis [51]. When we examined the subcellular localization of AtHD1-GFP fusion protein, we captured an image of a leaf mesophyll cell entering mitosis.…”

Mapping differentiation kinetics in the mouse retina reveals an extensive period of cell cycle protein expression in post‐mitotic newborn neurons

“…Pax6 (Continues on following page) data indicate that Tubb3 protein is translated just before cell birth in E12.5 progenitors. Occasionally, we observed pairs of PH3 þ cells, likely undergoing anaphase/telophase (Tram and Sullivan, 2002;Li et al, 2005), of which one or both were Tubb3 þ suggesting asymmetric or symmetric division, respectively (Fig. 5B).…”

“…Finally, phosphorylation of histone H3 on Ser 10 (PH3) accompanies chromosome condensation at the beginning of mitosis (Hendzel et al, 1997). In cultured cells, anti-PH3 antibodies detect strong nuclear staining from the beginning of prophase to telophase (Prigent and Dimitrov, 2003;Li et al, 2005) and are widely used to detect mitotic progenitors. Ki67 colocalized with all of four of these markers (30-min BrdU pulse, Ccna2, Ccnb1, and PH3) at multiple time points during retinal development (Fig.…”

Mitotic protein kinase CDK1 phosphorylation of mRNA translation regulator 4E-BP1 Ser83 may contribute to cell transformation

“…3A), U2OS, HeLa, and U87 ( Fig. S4) cells showed p4E-BP1 S83 positivity in all mitotic cells, which were also positive for pH3 S10 , with the exception of telophase cells whose chromosomes are decondensed and hence negative for pH3 S10 (31). In addition to a diffuse staining pattern in mitotic cells, p4E-BP1 S83 also formed two distinct puncta near condensed chromosomes, which colocalized with centrosomal marker γ-tubulin as detected by confocal microscopy (Fig.…”