Phosphorylation of H1 histones

Hohmann, Philip

doi:10.1007/bf00223526

Cited by 73 publications

(37 citation statements)

References 59 publications

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“…Intriguingly, this higher sensitivity is especially pronounced during the progression of the cells from late-G1-phase into early-S-phase. Higher nuclease sensitivity is associated with relaxed chromatin structure, which potentially results from the elevated levels of histone H1 and H3 phosphorylation (Hohmann, 1983;Lu et al, 1994) within pRb-deficient cells at this time of the cell cycle due to deregulated cyclin-dependent kinase 2 (Cdk2) activity (Chadee et al, 1999;Herrera et al, 1996). Similar to the pRbdeficient primary fibroblasts, many transformed cell lines either lack pRb, or express mutant inactive pRb (Nevins, 2001;Niculescu et al, 1998).…”

Section: Journal Of Cell Science 115 (21)mentioning

confidence: 99%

The spatio-temporal organization of DNA replication sites is identical in primary, immortalized and transformed mammalian cells

Dimitrova

Berezney

2002

Journal of Cell Science

207

176

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We investigated the organization of DNA replication sites in primary (young or presenescent), immortalized and transformed mammalian cells. Four different methods were used to visualize replication sites: in vivo pulse-labeling with 5-bromo-2′-deoxyuridine (BrdU), followed by either acid depurination, or incubation in nuclease cocktail to expose single-stranded BrdU-substituted DNA regions for immunolabeling; biotin-dUTP labeling of nascent DNA by run-on replication within intact nuclei and staining with fluorescent streptavidin;and, finally, immunolabeling of the replication fork proteins PCNA and RPA. All methods produced identical results, demonstrating no fundamental differences in the spatio-temporal organization of replication patterns between primary, immortal or transformed mammalian cells. In addition, we did not detect a spatial coincidence between the early firing replicons and nuclear lamin proteins, the retinoblastoma protein or the nucleolus in primary human and rodent cells. The retinoblastoma protein does not colocalize in vivo with members of the Mcm family of proteins (Mcm2, 3 and 7) at any point of the cell cycle and neither in the chromatin-bound nor in the soluble nucleoplasmic fraction. These results argue against a direct role for the retinoblastoma or nuclear lamin proteins in mammalian DNA synthesis under normal physiological conditions.

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Section: Journal Of Cell Science 115 (21)mentioning

confidence: 99%

The spatio-temporal organization of DNA replication sites is identical in primary, immortalized and transformed mammalian cells

Dimitrova

Berezney

2002

Journal of Cell Science

207

176

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“…Although it has been reported that the condensation of chromosomes during mitosis is linked to the phosphorylation of histones HI and H3 (Gurley et al, 1978;Bradbury and Mathews, 1981), the exact connection between these two events remains uncertain (Krystal and Poccia, 1981;Hanks et al, 1983;Hohmann, 1983). It is mentioned, however, that histone phosphorylation influences histone-DNA and histone-histone interactions and that it plays a role in differential gene activity (Allfrey, 1980;Bradbury and Matthews, 1981).…”

Section: Accessibility Of Various Histone Regions In Native or Hj/h5-mentioning

confidence: 99%

Use of histone antibodies for studying chromatin topography and the phosphorylation of chromatin subunits.

Muller¹,

Mazen²,

Martinage³

et al. 1984

The EMBO Journal

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Polyclonal and monoclonal antibodies specific for histones as well as sera directed against synthetic peptides of histones were used to probe the topography of chromatin subunits. In native chromatin, the regions corresponding to residues 130 -135 of H3 and 6-18 of H2B were found to be exposed and able to interact with antibodies whereas the regions 26-35 and 36-43 of H2B and 80-89 and 85-102 of H4 were not. In vitro phosphorylation of H3 and H5 in native chromatin or of H3 in H1/H5-depleted chromatin led to a marked drop in the binding of antibodies specific for residues 130-135 of H3 and 6-18 of H2B. Phosphorylation of H1/H5-depleted chromatin also altered the degree of exposure of certain H2A epitopes but it did not affect the surface accessibility of residues 1-11 of H2B.

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“…The number of phosphorylated residues is small in G 1 phase and starts to increase when the cell progresses through S and G 2 , reaching a maximal level at mitosis (28). Histone H1 phosphorylation is required for DNA replication (24), and protein kinases that activate replication also promote histone H1 phosphorylation (1).…”

mentioning

confidence: 99%

Histone H1 of Trypanosoma cruzi Is Concentrated in the Nucleolus Region and Disperses upon Phosphorylation during Progression to Mitosis

2008

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Phosphorylation of histone H1 is intimately related to the cell cycle progression in higher eukaryotes, reaching maximum levels during mitosis. We have previously shown that in the flagellated protozoan Trypanosoma cruzi, which does not condense chromatin during mitosis, histone H1 is phosphorylated at a single cyclin-dependent kinase site. By using an antibody that recognizes specifically the phosphorylated T. cruzi histone H1 site, we have now confirmed that T. cruzi histone H1 is also phosphorylated in a cell cycle-dependent manner. Differently from core histones, the bulk of nonphosphorylated histone H1 in G 1 and S phases of the cell cycle is concentrated in the central regions of the nucleus, which contains the nucleolus and less densely packed chromatin. When cells pass G 2 , histone H1 becomes phosphorylated and starts to diffuse. At the onset of mitosis, histone H1 phosphorylation is maximal and found in the entire nuclear space. As permeabilized parasites preferentially lose phosphorylated histone H1, we conclude that this modification promotes its release from less condensed and nucleolar chromatin after G 2 .The nucleosome, the basic chromatin unit, is assembled by wrapping DNA around an octamer formed by two copies of histone H2A, H2B, H3, and H4 proteins. A fifth histone, called histone H1, packs the chromatin by contacting internucleosomal DNA and the nucleosome particle (50). Histone H1 is formed by a globular domain flanked by a long unstructured C-terminal portion, comprising almost half of the protein, and by a short and also nonstructured N-terminal domain. The C-terminal domain is enriched in basic amino acids that interact with the negative phosphodiester charges of DNA through S/TPKK motifs (26). The globular portion contacts the core histones and the nucleosomal DNA (3), favoring chromatin compaction, which prevents the access of chromatin remodeling factors and therefore restricts transcription and replication (10). Fluorescence recovery after photobleaching experiments have shown that the chromatin residence time of histone H1 is much shorter than that of other histones, suggesting that histone H1 dynamically associates with the nucleosome particles, contributing to several nuclear processes involving chromatin condensation and decondensation (10, 31, 36). However, when histone H1 is absent, chromatin decondenses (20, 47).Histone H1 is phosphorylated at the N-and C-terminal domains in a cell cycle-dependent manner (22). The number of phosphorylated residues is small in G 1 phase and starts to increase when the cell progresses through S and G 2 , reaching a maximal level at mitosis (28). Histone H1 phosphorylation is required for DNA replication (24), and protein kinases that activate replication also promote histone H1 phosphorylation (1). Histone H1 phosphorylation affects the heterochromatin structure (23), DNA repair, chromatin remodeling, apoptosis, and cell aging (29,49). Histone H1 phosphorylation is also involved in chromosome condensation during mitosis. In the absence of histon...

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Phosphorylation of H1 histones

Cited by 73 publications

References 59 publications

The spatio-temporal organization of DNA replication sites is identical in primary, immortalized and transformed mammalian cells

The spatio-temporal organization of DNA replication sites is identical in primary, immortalized and transformed mammalian cells

Use of histone antibodies for studying chromatin topography and the phosphorylation of chromatin subunits.

Histone H1 of Trypanosoma cruzi Is Concentrated in the Nucleolus Region and Disperses upon Phosphorylation during Progression to Mitosis

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