Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: HUMANGGP:040116 (histone)
 44,835 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Metaphase plates from tailbuds of Pleurodeles waltlii embryos (stage 34) with or without preceding cold treatment were obtained by squashing followed by quinacrine mustard staining. In both cases, caryograms were established and sites of Q bands located.--Most of the secondary constrictions exhibit very high fluorescence. In general, it is the same for most centromeric parts, but their fluorescence is quenched very strongly by cold treatment.--The proximal part of the long arm of chromosome VII and satellites of chromosomes III and XI exhibit dull fluorescence. All these sites are compared with heterochromatin localization. The relation between banding and base composition or non-histone proteins interactions is discussed.
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PMID:[Localization and significance of the Q bands observed on mitotic chromosomes of the amphibian Pleurodeles waltlii Michah. after coloration by quinacrine mustare (author's transl)]. 5 37

We have identified two classes of in vivo topoisomerase II cleavage sites in the Drosophila histone gene repeat. One class co-localizes with DNase I-hypersensitive regions and another novel class maps to a subset of consecutive nucleosome linker sites in the scaffold-associated region (SAR) of the histone gene loop. Prominent topoisomerase II cleavage is also observed in one of the linker regions of the two nucleosomes spanning satellite III, a centromeric SAR-like DNA sequence with a repeat length of 359 bp. At the sequence level, in vivo topoisomerase II cleavage is highly site specific. Comparison of 10 nucleosome linker sites defines an in vivo cleavage sequence whose major characteristic is a prominent GC-rich core. These GC-rich cleavage sites are flanked by extensive arrays of oligo(dA).oligo(dT) tracts characteristic of SAR sequences. Treatment of cells with distamycin selectively enhances cleavage at nucleosome linker sites of the SAR and satellite regions, suggesting that AT-rich sequences flanking cleavage sites may be involved in determining topoisomerase II activity in the cell. These observations provide evidence for the association of topoisomerase II with SARS in vivo.
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PMID:In vivo topoisomerase II cleavage of the Drosophila histone and satellite III repeats: DNA sequence and structural characteristics. 131 Dec 55

IgM autoantibodies from a subset of patients with undifferentiated rheumatic disease syndromes stained mouse kidney nuclei with a distinctive variable large-speckled (VLS) indirect immunofluorescence (IIF) pattern. However, these antibodies did not stain nuclei of tissue culture cells prepared with conventional fixation. These sera were shown to react with histone H3 by an enzyme-linked immunosorbent assay (ELISA), and adsorption with H3 reduced or eliminated the IIF reaction. Sera yielding a VLS-IIF pattern reacted in ELISA with all three H3 variants as well as the native (H3-H4)2 tetramer, but the reactive determinants were unavailable for binding when chromatin was the substrate. By IIF assay, the epitopes were exposed after treatment of tissue culture cells with 0.5 M NaCl, and were removed by 1.5 M NaCl. These sera also stained the centromeric region of metaphase chromosomes. These observations suggest that the VLS-IIF pattern is due to antibodies that recognize epitopes on constitutive heterochromatin near the centromere. The epitopes are exposed in differentiated cells but hidden in dividing cells. Histone in heterochromatin, or CENP-A, a histone-like protein in the centromere with a sequence similarity to histone H3, are candidates for the target antigen.
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PMID:Anti-histone autoantibodies recognize centromeric heterochromatin in metaphase chromosomes and hidden epitopes in interphase cells. 137 73

Unfixed metaphase chromosome preparations from human lymphocyte cultures were immunofluorescently labelled using antibodies to defined histone epitopes. Both mouse monoclonal antibody HBC-7, raised against the N-terminal region of H2B, and rabbit serum R5/12, which recognizes H4 acetylated at Lys-12, gave non-uniform labelling patterns, whereas control antibodies against total histone fractions H4 and H1 produced homogeneous fluorescence. HBC-7 bound approximately uniformly to the bulk of the chromosomes, but the major heterochromatic domains of chromosomes 1, 9, 15, 16 and the Y showed significantly brighter fluorescence. Serum R5/12 indicated an overall reduction in acetylation of H4 in metaphase chromosomes compared with interphase nuclei, although some specific chromosomal locations had considerably elevated acetylation levels. Acetylation levels in the major heterochromatic domains appeared extremely low. To investigate further the differences noted in heterochromatin labelling, metaphases from cultures grown in the presence of various agents known to induce undercondensation of the major heterochromatic domains were similarly immunolabelled. Decondensed heterochromatin no longer exhibited higher than normal immunofluorescence levels with HBC-7. The higher resolution afforded by "stretching" the centromeric heterochromatin of chromosomes 1, 9 and 16 confirmed the low level of H4 acetylation in these domains. We consider the implications of these observations in relation to chromatin conformation and activity.
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PMID:Antibodies to defined histone epitopes reveal variations in chromatin conformation and underacetylation of centric heterochromatin in human metaphase chromosomes. 137 4

CENP-A, a centromere-specific 17-kDa protein, has histone-like properties. However, in contrast to the common somatic histones, CENP-A is quantitatively retained in bull spermatozoa, and we have exploited this fact to purify CENP-A to apparent homogeneity. Partial sequence analysis of the purified protein indicates that CENP-A is a distinctive gene product. Some CENP-A sequences are highly similar to regions of histone H3. Other segments of CENP-A are not related to H3 or any other histone. These unrelated segments are presumably involved in localizing CENP-A to centromeric DNA or in centromere-specific functions of CENP-A.
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PMID:Purification of the centromere-specific protein CENP-A and demonstration that it is a distinctive histone. 202 23

Saccharomyces cerevisiae centromeric DNA is packaged into a highly nuclease-resistant chromatin core of approximately 200 base pairs of DNA. The structure of the centromere in chromosome III is somewhat larger than a 160-base-pair nucleosomal core and encompasses the conserved centromere DNA elements (CDE I, II, and III). Extensive mutational analysis has revealed the sequence requirements for centromere function. Mutations affecting the segregation properties of centromeres also exhibit altered chromatin structures in vivo. Thus the structure, as delineated by nuclease digestion, correlated with functional centromeres. We have determined the contribution of histone proteins to this unique structural organization. Nucleosome depletion by repression of either histone H2B or H4 rendered the cell incapable of chromosome segregation. Histone repression resulted in increased nuclease sensitivity of centromere DNA, with up to 40% of CEN3 DNA molecules becoming accessible to nucleolytic attack. Nucleosome depletion also resulted in an alteration in the distribution of nuclease cutting sites in the DNA surrounding CEN3. These data provide the first indication that authentic nucleosomal subunits flank the centromere and suggest that nucleosomes may be the central core of the centromere itself.
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PMID:Nucleosome depletion alters the chromatin structure of Saccharomyces cerevisiae centromeres. 223 14

Highly purified centromeric heterochromatin was isolated from mouse liver nuclei and the pattern of core histone variants was analyzed. In comparison with total chromatin, the centromeric heterochromatin of young animals was characterized by (1) enrichment in the replication-dependent variants H2A1, H2B2 and H3(2), (2) reduced amount of the minor variant H2Az and (3) absence of ubiquitinated molecules of H2A. This specific variant pattern changed upon ageing as a result of accumulation of replacement variants so that in adult animals both chromatin preparations exhibited similar pattern for H2A and H2B, while the difference in the profile of H3 variants was preserved.
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PMID:Histone variants in mouse centromeric chromatin. 260 31

Using the immunoblotting technique, sera from 433 patients with rheumatic diseases were screened for the presence of antibodies against several nuclear and cytoplasmic antigens, such as RNP, Sm, Ro(SSA), La(SSB), CR-19 (centromeric antigen), Topo-1 (Scl-70), Jo-1, histone and 56 kD. At the same time clinical data from these patients were collected without prior knowledge of the immunoblotting results. Syndrome-specific autoantibodies were found for mixed connective tissue disease (antibodies against the RNP related 70 kD antigen), for CREST (anti-CR-19 antibodies), for diffuse scleroderma (anti-Topo-1 antibodies) and for polymyositis (anti-Jo-1 antibodies). Almost all specific autoantibodies were present exclusively in patients with a connective tissue disease. Controls were only in a few cases positive for antihistone and anti-56 kD antibodies. Associations of specific autoantibodies with clinical and laboratory features of the patients were mostly as expected. However, some unexpected associations were found, for example polymyositis and calcinosis with anti-Sm antibodies, sicca symptoms with anti-centromere antibodies and leucopenia with Ro(SSA) and La(SSB).
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PMID:The use of immunoblotting to detect antibodies to nuclear and cytoplasmic antigens. Clinical and serological associations in rheumatic diseases. 306 67

In contrast to parental New Zealand Black (NZB) or New Zealand White (NZW) mice, (NZB x NZW)F1 mice exhibit a lupus-like disease characterized by high levels of immunoglobulin G (IgG) antinuclear antibodies in their serum and a fatal immune-complex glomerulonephritis. At least three gene loci have been identified in NZW mice that could potentially contribute to a T cell-dependent autoimmune disease, including the T cell receptor alpha- and beta-chain gene complexes and the major histocompatibility complex (MHC). The NZW T cell receptor beta-chain complex appeared to be particularly unusual in that the C-beta-1, D-beta-2, and J-beta-2 gene segments have been deleted. Approximately one half of (NZB x NZW)F1 x NZB backcross mice developed severe renal disease and elevated levels of IgG antibodies to double-stranded deoxyribonucleic acid and histone, suggesting that only one dominant gene or closely linked group of genes accounts for the NZW genetic contribution to F1 disease. Despite the extremely unusual nature of the NZW T cell receptor beta-chain gene complex, we found no association of disease expression with the presence of this allele in the backcross mice. There was also no correlation of disease incidence with the presence of the NZW T cell receptor alpha-chain allele. In contrast, nearly 90 percent of the backcross mice with the NZW MHC expressed severe autoimmune disease compared with 12 percent of the mice that did not carry this haplotype. Thus, the NZW MHC or gene(s) linked to this locus appears to be the only dominant NZW genetic contribution to F1 disease. Recent preliminary studies mapping genes that are located centromeric and telomeric to the NZW MHC suggest that the disease-associated gene(s) lies within the MHC.
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PMID:Genetic contributions to lupus-like disease in NZB/NZW mice. 326 57

Antibodies directed against centromeric chromatin characteristically occur in the sera of patients with the CREST variant of scleroderma. We have studied the in situ enzymatic sensitivity and solubility of the centromeric antigen and have isolated an antigenic moiety that reacts with anticentromere antibodies. The centromeric antigen in the human epithelial cell line, HEp-2, was sensitive to DNAase I and micrococcal nuclease but not affected by RNAase A, trypsin or amylase. It was insoluble in 0.15-4 M NaCl but was extracted from the HEp-2 cells by 4 M urea/2 M NaCl. Antigenic activity in a 4 M urea/2 M NaCl extract of rabbit thymus was demonstrated by immunoabsorption. Indirect immunofluorescence of the extract separated by polyacrylamide gel electrophoresis revealed a fluorescent band with a mol. wt of 33,000. Calf thymus and trout testis histone preparations were fractionated by gel electrophoresis and transferred by blotting techniques to diazobenzyloxymethyl cellulose paper for autoradiography. Anticentromere antibodies bound to and were absorbed by trout testis histone 1. We propose that the centromeric antigen may be a variant of histone 1 that is associated with condensed chromatin.
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PMID:Anticentromere antibodies bind to trout testis histone 1 and a low molecular weight protein from rabbit thymus. 638 63


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