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Query: UNIPROT:P10412 (H1.4)
 75 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Histone H1 from erythrocytes of Japanese quail was resolved in a sodium dodecyl sulfate (SDS)-polyacrylamide gel into five fractions differing in apparent molecular weights. A polymorphism of histone H1.1, H1.2, and H1.3 bands was detected among quail individuals. While some birds possessed either a high (phenotype .3+) or a low (phenotype .3+/.3-) level of H1.3, at least half of the quail population lacked this H1 band (phenotype .3-). Appropriate genetic crosses demonstrated that H1.3 behaved as though it was coded by a gene with two codominant alleles at an autosomal locus. Using two-dimensional polyacrylamide gel electrophoresis (acid-urea followed by SDS gels), it was found that birds .3+ contained polypeptides H1.b1 and H1.b'1; birds .3-, polypeptides H1.b2 and H1.b'2 with lower apparent molecular weights; and birds .3+/.3-, both types of polypeptides in equal proportions. The H1.b2 + H1.b'2 complement was not discernible in SDS gels, for it migrated together with H1.c' within band H1.4. It was found that a small number of birds lacking the H1.2 band in SDS gels failed to express histone H1.a. Since birds with phenotype .2- with a defective allele of the gene H1.a were simultaneously lacking the H1.3 band, it seems that the imperfect allele of the H1.a gene might be closely linked to the alleles producing H1.b2 + H1.b'2.
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PMID:Genetic polymorphism of erythrocyte histone H1 in Japanese quail. 177

Histones are the major protein constituents of the chromatin of eukaryotic cell nuclei. This group of basic proteins is extremely conserved throughout evolution and includes five classes termed H1, H2A, H2B, H3 and H4. In mammals, each of these classes except H4 is subdivided into several subtypes. The most divergent class of histones is the H1 protein family, which consists of seven different subtypes, termed H1.1-H1.5, H1 degree, and H1t. The subtypes H1.2 and H1.4 are found in most somatic cell nuclei, whereas H1 degree is found in several differentiated tissues, and H1t is restricted to mammalian testicular cells. Similarly, core histone subtypes replacing the major forms of H2A, H2B or H3 have been described. Biochemical analysis of protein and RNA from different tissues and cell lines demonstrates varied patterns of expression of individual histone subtype genes. Moreover, antibodies against specific histone subtypes and in situ hybridization with subtype-specific probes indicate that the expression of histone subtype genes is in several cases modulated in a tissue-specific manner. This is particularly evident at the different stages of spermatogenesis when chromatin undergoes substantial reorganization, which finally results in the highly condensed state of chromatin of the mature sperm head.
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PMID:Histones: genetic diversity and tissue-specific gene expression. 904 36

We have previously located the genes of the five human main type H1 genes and the gene encoding the testicular subtype H1t to the region 21.1 to 22.2 on the short arm of chromosome 6. To investigate the organization of the histone genes in this region, we isolated two YACs from a human YAC library by PCR screening with primers specific for histone H1.1. This screen revealed two YAC clones, YAC Y23 (corresponding to ICRFy901D1223) contains an insert of about 480 kb, whereas the smaller YAC 4A (corresponding to ICRFy900C104) spans about 340 kb and is completely covered by YAC Y23. We have subcloned the YAC inserts in cosmids, determined the linear orientation of the cosmids by cosmid walking, and constructed a restriction map of the entire region by mapping the individual cosmids using partial digests and hybridization with labeled oligonucleotides complementary to the cos site of the vector. Hybridization analysis, subcloning, restriction mapping, and sequencing revealed that most of the previously isolated phage and cosmid clones containing histone genes are part of this YAC including the clones containing the four human main type H1 histone genes H1.1 to H1.4, the H1t gene, and core histone genes. Thirty-five histone genes map within 260 kb of the YAC Y23 insert. All newly identified histone genes were sequenced, and the sequences were deposited with the EMBL nucleotide sequence database. The histone H1.5 gene is not part of this region, and we therefore conclude that the H1.5 gene and the associated core histone genes form a separate subcluster within this chromosomal region.
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PMID:Human histone gene organization: nonregular arrangement within a large cluster. 911 99

Five main type H1 histones have been described in man (H1.1-H1.5) in addition to the testis specific type H1t and the replacement subtype H1 degrees, which is found mainly in highly differentiated cells. We have isolated this whole complement of H1 genes and have studied the expression of the seven human H1 subtype genes in several cell lines. The RNAase protection assay was used to discriminate between the very similar transcripts derived from the seven H1 subtype genes. With the exception of H1.2 and H1.4, we found substantial differences between the H1 mRNA levels in the different cell lines tested. No H1.1 mRNA was detected in most of the cell lines and just a low level of H1.1 mRNA was found in human testis. In contrast to the differential patterns of the other subtypes, H1.2 and H1.4 were in all cells expressed at a high level, indicating a basal function compared with the other H1 histones. Because differences in the timing of H1 protein subtype synthesis have been reported, we have analyzed the kinetics of accumulation of H1 subtypes in synchronized HeLa cells and observed that all H1 subtypes examined (H1 degrees, H1.2-H1.5) were expressed in a replication-dependent manner. The analysis showed a differential rise of mRNA levels during S-phase, from four-fold (H1 degrees) to 15-fold (H1.5). Our results may point at a specific function of each subtype and suggest that expression of the H1 histone subtype genes depends on common S-phase-depent factors as well as on individual regulatory systems. Thus, the data presented here provide a basis for further analysis of the regulation and function of the complex H1 gene and protein family.
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PMID:Varied expression patterns of human H1 histone genes in different cell lines. 932 6

Murine genes encoding the seven H1 histone isoforms H1.1-H1.5, H1(o) and H1t have been isolated and sequenced. We have established expression patterns of these genes in several tissues during postnatal development. For that analysis, RNase protection assay rather than Northern blot hybridization was used, since the sequences of these genes are highly similar and would cross-hybridize under Northern blot conditions. Expression patterns of H1.1 to H1.5 and H1(o) were determined in tissues of animals at days 5, 9 and 20 after birth and of adult mice. In addition, RNA was analyzed in three mouse cell lines (NIH3T3, P19, TM4). Transcription of the subtype genes H1.2 and H1.4 was found in all tissues and cell lines studied. The most varied expression patterns were obtained with the H1.1 subtype. H1.1 mRNA was found at high concentrations in thymus and spleen throughout development and in testis beginning with a low expression in 5-day-old animals and increasing levels in testis RNA from 9- and 20-day-old and adult mice. H1(o) mRNA was found primarily in highly differentiated tissues with concentrations decreasing from 5-day-old to adult animals.
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PMID:Expression of murine H1 histone genes during postnatal development. 965 12

The histone gene H1t is expressed exclusively in pachytene spermatocytes of the testis. In this report we have eliminated the single copy H1t gene by homologous recombination from the mouse genome to analyse the function of the H1t protein during spermatogenesis. Mice homozygous for the mutated H1t gene locus developed normally and showed no anatomic abnormalities until the adult stage. In addition, H1t-deficient mice were fertile and reproduced as wild-type mice. The process of spermatogenesis and the testicular morphology remained unchanged in the absence of H1t. RNase protection analysis demonstrated that H1.1, H1.2 and H1.4 histone gene expression is enhanced during spermatogenesis in H1t-deficient mice.
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PMID:Spermatogenesis proceeds normally in mice without linker histone H1t. 1093 20

We have previously shown a connection between histone H1 phosphorylation and the transcriptional competence of the hormone inducible mouse mammary tumor virus (MMTV) promoter. Prolonged exposure of mouse cells to dexamethasone concurrently dephosphorylated histone H1 and rendered the MMTV promoter refractory to hormonal stimulation and, therefore, transcriptionally unresponsive. Using electrospray mass spectrometry, we demonstrate here that prolonged dexamethasone treatment differentially effects a subset of the six somatic H1 isoforms in mouse cells. H1 isoforms H1.0, H1.1, and H1.2 are non-responsive to hormone whereas prolonged dexamethasone treatment effectively dephosphorylated the H1.3, H1.4, and H1.5 isoforms. The protein kinase inhibitor staurosporine, shown to dephosphorylate histone H1 and down-regulate MMTV in cultured cells, appears only to completely dephosphorylate the H1.3 isoform. These results suggest that dephosphorylation of specific histone H1 isoforms may contribute to the previously observed decrease in transcriptional competence of the MMTV promoter through the modulation of chromatin structure. In a broader sense, this work advances the hypothesis that post-translational modifications of individual histone H1 isoforms directly influence the transcriptional activation/repression of specific genes.
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PMID:Hormone-mediated dephosphorylation of specific histone H1 isoforms. 1147 99

Histone H1 isoforms isolated from asynchronously grown HeLa cells were subjected to enzymatic digestion and analyzed by nano-flow reversed-phase high performance liquid chromatography (RP-HPLC) tandem mass spectrometry (MS/MS) on both quadrupole ion trap and linear quadrupole ion trap-Fourier transform ion cyclotron resonance mass spectrometers. We have observed all five major isoforms of histone H1 (H1.1, H1.2, H1.3, H1.4, and H1.5) as well as a lesser studied H1, isoform H1.X. MS/MS experiments confirmed N-terminal acetylation on all isoforms plus a single internal acetylation site. Immobilized metal affinity chromatography in combination with tandem mass spectrometry was utilized to identify 19 phosphorylation sites on the five major H1 isoforms plus H1.X. Fourteen of these phosphorylation sites were located on peptides containing the cyclin dependent kinase (CDK) consensus motif (S/T)-P-X-Z (where X is any amino acid and Z is a basic amino acid). Five phosphorylation sites were identified in regions that did not fit the consensus CDK motif. One of these phosphorylation sites was found on the serine residue on the H1.4 peptide KARKSAGAAKR. The adjacent lysine residue to the phosphoserine was also shown to be methylated. This finding raises the question of whether the hypothesized "methyl/phos" switch could be extended to linker histones, and not exclusive to core histones.
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PMID:Characterization of phosphorylation sites on histone H1 isoforms by tandem mass spectrometry. 1559 31

In humans, eight types of histone H1 exist (H1.1-H1.5, H1 degrees , H1t and H1oo), all consisting of a highly conserved globular domain and less conserved N- and C-terminal tails. Although the precise functions of these isoforms are not yet understood, and H1 subtypes have been found to be dispensable for mammalian development, it is now clear that specific functions may be assigned to certain individual H1 subtypes. Moreover, microsequence variations within the isoforms, such as polymorphisms or mutations, may have biological significance because of the high degree of sequence conservation of these proteins. This study used a hydrophilic interaction liquid chromatographic method to detect sequence variants within the subtypes. Two deviations from wild-type H1 sequences were found. In K562 erythroleukemic cells, alanine at position 17 in H1.2 was replaced by valine, and, in Raji B lymphoblastoid cells, lysine at position 173 in H1.4 was replaced by arginine. We confirmed these findings by DNA sequencing of the corresponding gene segments. In K562 cells, a homozygous GCC-->GTC shift was found at codon 18, giving rise to H1.2 Ala17Val because the initial methionine is removed in H1 histones. Raji cells showed a heterozygous AAA-->AGA codon change at position 174 in H1.4, corresponding to the Lys173Arg substitution. The allele frequency of these sequence variants in a normal Swedish population was found to be 6.8% for the H1.2 GCC-->GTC shift, indicating that this is a relatively frequent polymorphism. The AAA-->AGA codon change in H1.4 was detected only in Raji cells and was not present in a normal population or in six other cell lines derived from individuals suffering from Burkitt's lymphoma. The significance of these sequence variants is unclear, but increasing evidence indicates that minor sequence variations in linker histones may change their binding characteristics, influence chromatin remodeling, and specifically affect important cellular functions.
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PMID:Characterization of sequence variations in human histone H1.2 and H1.4 subtypes. 1600 66

Although ubiquitously present in chromatin, the function of the linker histone subtypes is partly unknown and contradictory studies on their properties have been published. To explore whether the various H1 subtypes have a differential role in the organization and dynamics of chromatin we have incorporated all of the somatic human H1 subtypes into minichromosomes and compared their influence on nucleosome spacing, chromatin compaction and ATP-dependent remodeling. H1 subtypes exhibit different affinities for chromatin and different abilities to promote chromatin condensation, as studied with the Atomic Force Microscope. According to this criterion, H1 subtypes can be classified as weak condensers (H1.1 and H1.2), intermediate condensers (H1.3) and strong condensers (H1.0, H1.4, H1.5 and H1x). The variable C-terminal domain is required for nucleosome spacing by H1.4 and is likely responsible for the chromatin condensation properties of the various subtypes, as shown using chimeras between H1.4 and H1.2. In contrast to previous reports with isolated nucleosomes or linear nucleosomal arrays, linker histones at a ratio of one per nucleosome do not preclude remodeling of minichromosomes by yeast SWI/SNF or Drosophila NURF. We hypothesize that the linker histone subtypes are differential organizers of chromatin, rather than general repressors.
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PMID:Histone H1 subtypes differentially modulate chromatin condensation without preventing ATP-dependent remodeling by SWI/SNF or NURF. 1979 10


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