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A Jerzmanowski

Publications and source records attributed to A Jerzmanowski.

At least 19 recordsLinked to original sources
PubMed2001

Evolutionary correlation between linker histones and microtubular structures.

Histones of the H1 group (linker histones) are abundant components of chromatin in eukaryotes, occurring on average at one molecule per nucleosome. The recent reports on the lack of a clear phenotypic effect of knock-out mutations as well as overexpression of histone H1 genes in different organisms have seriously undermined the long-held view that linker histones are essential for the basic functions of eukaryotic cells. In an attempt to resolve the paradox of an abundant conserved protein without a clear function, we re-examined the molecular and phylogenetic data on linker histones to see if they could reveal any correlation between the features of H1 and the functional or morphological characteristics of cells or organisms. Because of an earlier demonstration that in sea urchin the chromatin-type histone H1 is also found in the flagellar microtubules (Multigner et al. 1992), we focused on the correlation between the features of H1 and those of microtubular structures. A phylogenetic tree based on multiple alignment of over 100 available HI sequences suggests that the first divergence of the globular domain of H1 (GH1) resulted in branching into separate types characteristic for plants/Dictyostelium and for animals/ascomycetes, respectively. The GH1s of these two types differ by a short region (usually 5 amino acids) placed at a specific location within the C-terminal wing subdomain of GH1. Evolutionary analysis of the diversification of H1 mRNA into cell-cycle-dependent (polyA-) and independent (polyA+) forms showed a mosaic occurrence of these two forms in plants and animals, despite the fact that the H1 proteins of plants and animals belong to two well-distinguished groups. However, among organisms from both animal and plant kingdom, only those with H1 mRNA of a polyA- type have flagellated gametes. This correlation as well as the demonstration that in Volvox carteri the accumulation of polyA- mRNA of H1 occurs concurrently with the production of new flagella (Lindauer et al. 1993), suggests a direct link between polyA- phenotype of histone H1 mRNA and flagellogenesis.

Animals↗
PubMed2000

Perturbation in linker histone content has no effect on the cell cycle but affects the cell size of suspension grown tobacco BY-2 cells.

Histone H1, a key structural element of eukaryotic chromosomes can be perturbed in plants in vivo by overexpression or by a change in the proportion of native H1 variants (Prymakowska-Bosak M., Przewloka M., Iwkiewicz J., Egierszdorff S., Kuras M., Chaubert N., Gigot C., Spiker S., Jerzmanowski A., Histone H1 overexpressed to high level in tobacco affects certain developmental programs but has limited effect on basal cellular functions, Proc. Natl. Acad. Sci. U.S.A. 93 (1996) 10250-10255; Prymakowska-Bosak M., Slusarczyk J., Przewloka M., Kuras M., Lichota J., Kilianczyk B., Jerzmanowski A., Linker Histones Play a Role in Male Meiosis and the Development of Pollen Grains in Tobacco, Plant Cell 11 (1999) 2317-2330). In order to analyze the possible causes of the specific phenotypic changes observed in whole plants we employed a simpler system of tobacco BY-2 cell line. We show that the BY-2 cells engineered to overexpress a major variant of Arabidopsis H1 or with the level of native major variants of H1 decreased by antisense strategy maintain the normal ability to grow and the normal length of the cell cycle. In the cells with perturbed H1 histones no change was observed in the organization of mitotic spindle or actin filaments of the cytoskeleton. The only visible phenotypic change occurred in cells overexpressing H1 that showed an increased frequency of cells with unusually large size. This phenotype was correlated with subtle but reproducible changes in the organization of cortical microtubules.

Journal Article↗
PubMed1999

Identification and analysis of the Arabidopsis thaliana BSH gene, a member of the SNF5 gene family.

The multiprotein complexes involved in active dis-ruption of chromatin structure, homologous to yeast SWI/SNF complex, have been described for human and Drosophila cells. In all SWI/SNF-class complexes characterised so far, one of the key components is the SNF5-type protein. Here we describe the isolation of a plant (Arabidopsis thaliana ) cDNA encoding a 27 kDa protein which we named BSH, with high homology to yeast SNF5p and its human (INI1) and Drosophila (SNR1) counterparts as well as to other putative SNF5-type proteins from Caenorhabditis elegans, fish and yeast. With 240 amino acids, the Arabidopsis BSH is the smallest SNF5-type protein so far identified. When expressed in Saccharomyces cerevisiae, the gene for BSH partially complements the snf5 mutation. BSH is, however, unable to activate transcription in yeast when tethered to DNA. The gene for BSH occurs in single copy in the Arabidopsis genome and is ubiquitously expressed in the plant. Analysis of the whole cell and nuclear protein extracts with antibodies against recombinant BSH indicates that the protein is localised in nuclei. Transgenic Arabidopsis plants with markedly decreased physiological level of the BSH mRNA, resulting from the expression of antisense messenger, are viable but exhibit a distinctive phenotype characterised by bushy growth and flowers that are unable to produce seeds.

Amino Acid Sequence↗
PubMed1999

Linker histones play a role in male meiosis and the development of pollen grains in tobacco.

To examine the function of linker histone variants, we produced transgenic tobacco plants in which major somatic histone variants H1A and H1B were present at approximately 25% of their usual amounts in tobacco chromatin. The decrease in these major variants was accompanied by a compensatory increase in the four minor variants, namely, H1C to H1F. These minor variants are smaller and less highly charged than the major variants. This change offered a unique opportunity to examine the consequences to a plant of major remodeling of its chromatin set of linker histones. Plants with markedly altered proportions of H1 variants retained normal nucleosome spacing, but their chromosomes were less tightly packed than those of control plants. The transgenic plants grew normally but showed characteristic aberrations in flower development and were almost completely male sterile. These features correlated with changes in the temporal but not the spatial pattern of expression of developmental genes that could be linked to the abnormal flower phenotypes. Preceding these changes in flower morphology were strong aberrations in male gametogenesis. The earliest symptoms may have resulted from disturbances in correct pairing or segregation of homologous chromosomes during meiosis. No aberrations were observed during mitosis. We conclude that in plants, the physiological stoichiometry and distribution of linker histone variants are crucial for directing male meiosis and the subsequent development of functional pollen grains.

Chromatin↗
PubMed1998

Both the 5S rRNA gene and the AT-rich flanks of xenopus laevis oocyte-type 5S rDNA repeat are required for histone H1-dependent repression of transcription of pol III-type genes in in vitro reconstituted chromatin.

Incorporation of somatic histone H1 into chromatin during embryogenesis of Xenopus laevis results in repression of transcription of the oocyte- but not the somatic-type 5S rRNA genes. We showed earlier that a similar effect of the H1 observed in chromatin reconstituted on circular plasmids in vitro depends on its binding to the AT-rich flanks of the oocyte-type 5S rRNA gene. H1 binding results in stabilization of nucleosomes within the oocyte 5S rDNA repeat comprising the 5S rRNA gene with flanks and in reorganization of chromatin on the entire plasmid DNA. Performing in vitro transcription on reconstituted minichromosome templates carrying the oocyte 5S rRNA gene placed in different arrangements and at different distances from the AT-rich flanks, we now establish that the above effects of H1 observed upon its binding to the AT-rich sequences are absolutely dependent on the presence of the 120 bp oocyte 5S rRNA gene in its native position within the flanks. We also find that with the intact oocyte 5S rDNA repeat, the binding of H1 results in repression of transcription of both pol III- and pol II-type genes and that the transcriptionally inactive chromatin state spreads over a distance of at least a few nucleosomes.

Animals↗
PubMed1998

Binding of SPXK- and APXK-peptide motifs to AT-rich DNA. Experimental and theoretical studies.

The binding properties of the SPXK- and APXK-type peptides to the AT-rich DNA fragments of different length were studied by measuring the competition of peptides with Hoechst 33258 dye for DNA binding and by the gel shift assay analysis. In parallel to the experimental studies, molecular modeling techniques were used to analyze possible binding modes of the SPXZ and APXK motifs to the AT-rich DNA. The results of the competition measurements and gel shift assays suggest that serine at the i-1 position (i is proline) can be replaced by alanine without affecting the binding properties of the motif. Thus, the presence of the conserved serine in this motif in many DNA-binding proteins is probably not dictated by structural requirements. Based on the results of molecular modeling studies we propose that the binding mode of the SPXK-type motifs to the AT-rich DNA resembles closely that between the N-terminal arm of the homeodomain and DNA. This model confirms that serine in the SPXK motifs is not essential for the DNA binding. The model also indicates that if X in the motif is glutamic acid, this residue is probably protonated in the complex with DNA.

Amino Acid Sequence↗
PubMed1997

The AT-rich flanks of the oocyte-type 5S RNA gene of Xenopus laevis act as a strong local signal for histone H1-mediated chromatin reorganization in vitro.

In vivo, histone H1 plays an active role in establishing the transcriptionally repressed chromatin state of the oocyte-type 5S RNA genes in the early stages of Xenopus development. By using fully defined in vitro system of chromatin assembly on plasmids with cloned oocyte- or somatic-type 5S gene repeats we found that the oocyte repeat which comprises a 120 bp oocyte-type 5S RNA gene placed within the few hundred bp long native AT-rich flanks, but not the somatic repeat (a similar 120 bp somatic-type 5S RNA gene placed within native GC-rich flanks) enables histone H1 to realign the nucleosomal core particles densely packed on plasmid DNA. The realignment results in creation of the repeat unit of approximately 240 bp and is achieved through complete removal of several core histone complexes from plasmid template with the oocyte-type repeat. This effect of H1 is independent on the plasmid sequences and seems to be solely due to the presence in the oocyte-repeat of the AT-rich flanks. The effects of H1 are completely suppressed by distamycin A, a drug that specifically recognizes and binds oligo(dA).oligo(dT) runs in DNA. The binding of H1 results in increased protection of DNA sites within the AT-rich oocyte-type 5S repeat. In an in vitro transcription assay performed with reconstituted chromatin templates containing plasmids with the oocyte- or somatic-type repeats only the transcription of the oocyte-type 5S RNA gene was repressed in the presence of physiological concentration of histone H1. These results support the view that the AT-rich flanks of the oocyte-type 5S RNA gene are involved in histone H1-mediated chromatin reorganization that results in the transcriptional repression observed in vivo.

Animals↗
PubMed1997

[Participation of various bacterial species in translocation in intestines of rats subjected to stress].

In the rats, which were treated with impairing factors such as: malnutrition, cooling down and ischaemia, translocation was studied. Aerobes as well as anaerobes which penetrated beyond the intestine into the mesenterium, liver, spleen and kidneys were sought. Bacteria in peripheral blood were not found. The results show that the type of bacterium undergoing translocation does not depend on the factor impairing "intestinal barrier" and translocation mechanisms are most probably the same for all the bacteria found.

Animals↗
PubMed1996

Histone H1 overexpressed to high level in tobacco affects certain developmental programs but has limited effect on basal cellular functions.

Histone H1, a major structural component of chromatin fiber, is believed to act as a general repressor of transcription. To investigate in vivo the role of this protein in transcription regulation during development of a multicellular organism, we made transgenic tobacco plants that overexpress the gene for Arabidopsis histone H1. In all plants that overexpressed H1 the total H1-to-DNA ratio in chromatin increased 2.3-2.8 times compared with the physiological level. This was accompanied by 50-100% decrease of native tobacco H1. The phenotypic changes in H1-overexpressing plants ranged from mild to severe perturbations in morphological appearance and flowering. No correlation was observed between the extent of phenotypic change and the variation in the amount of overexpressed H1 or the presence or absence of the native tobacco H1. However, the severe phenotypic changes were correlated with early occurrence during plant growth of cells with abnormally heterochromatinized nuclei. Such cells occurred considerably later in plants with milder changes. Surprisingly, the ability of cells with highly heterochromatinized nuclei to fulfill basic physiological functions, including differentiation, was not markedly hampered. The results support the suggestion that chromatin structural changes dependent on H1 stoichiometry and on the profile of major H1 variants have limited regulatory effect on the activity of genes that control basal cellular functions. However, the H1-mediated chromatin changes can be of much greater importance for the regulation of genes involved in control of specific developmental programs.

Arabidopsis↗
PubMed1992

Partial displacement of histone H1 from chromatin is required before it can be phosphorylated by mitotic H1 kinase in vitro.

The massive nonselective and reversible phosphorylation of histone H1 during mitosis is a universal phenomenon among eukaryotes. The growth-associated kinase responsible for this phosphorylation is identical to the maturation promoting factor, a key regulator of the cell cycle. Here we showed that growth-associated kinase, isolated from mitotic HeLa cells which were capable of phosphorylating HeLa H1 in vitro with high activity and mostly at the same sites phosphorylated during mitosis in vivo (assayed by two-dimensional analysis of tryptic phosphopeptides), did not significantly phosphorylate chromatin-bound or nuclear H1 in vitro. Its inability to phosphorylate chromatin-bound H1 did not change when the amount of kinase was increased or the incubation was prolonged. The resistance of chromatin-bound H1 to phosphorylation did not result from chromatin aggregation. Rapid phosphorylation of H1 in vitro, as well as in a nuclear system, was restored when NaCl concentrations were raised above 200 mM where H1:DNA interactions are weakened. At 300 mM NaCl, chromatin-bound H1 was phosphorylated in a subset of the sites observed for free H1 phosphorylated in vitro. These results suggest that active displacement of H1 from chromatin DNA may take place before H1 can be fully phosphorylated during mitosis.

Autoradiography↗
PubMed1990

Flanking sequences of Xenopus 5 S RNA genes determine differential inhibition of transcription by H1 histone in vitro. Mitotic phosphorylation of H1 decreases its inhibitory power.

In Xenopus laevis chromatin histone H1 selectively inhibits the transcription of oocyte 5 S RNA genes while not affecting the transcription of somatic 5 S RNA genes (Schlissel, M. S., and Brown, D. D. (1984) Cell 37, 903-913; Wolffe, A. P. (1989) EMBO J. 8, 527-537). To explore possible mechanisms of this specific action of H1 we analyzed the in vitro transcription of H1.DNA complexes. We found that the selective inhibitory effect of H1 in this system depends entirely on the flanking sequences of 5 S RNA genes and not on the coding sequence itself. At an H1:DNA ratio above approximately 0.4, H1 strongly inhibited the transcription of the gene surrounded by the A + T-rich flanks characteristic of oocyte 5 S RNA genes, whereas it did not prevent transcription of the genes surrounded by G + C-rich somatic-type flanks. This was reflected by strongly preferential binding of H1 to isolated 5 S RNA genes contained within A + T-rich flanks. We also showed that superphosphorylation of H1 with growth-associated (mitotic) H1 kinase invariably decreased H1's ability to inhibit transcription in an in vitro system.

Animals↗
PubMed1989

[Properties of bacteriocins of Morganella morganii].

Some properties of Morganella morganii bacteriocins were determined. For this purpose two strains (115 and 137) which after mitomycin C induction produced bacteriocins in high titer were chosen. The influence of several physical and chemical factors such as: heating and storage at various temperatures, a freezing and thawing, an influence of buffered fluid of different pH, and digestion by trypsin, papain and lysozyme were investigated. Range of bacteriocin activity against various microorganisms and the ability to diffuse in agar were also determined. It was found on the basis of the results obtained that two bacteriocins showed different features. Bacteriocin "115" was thermostable, sensitive to proteolytic enzymes, able to diffuse in 1.5% agar. Bacteriocin designated "137" was thermolabile, intensive to proteolytic digestion, and incapable to diffuse in 1.5% agar. Activity of both bacteriocins was reduced after freezing and thawing. They were both insensitive to lysozyme digestion. Storage at room temperature reduced their activity faster than storage at the temperature of refrigerator. Their activity was completely stopped at pH 3.03, and significantly at pH 5.08 while environment of pH ranged from 7.08 to 11.0 did not influence their activity. Both bacteriocins showed narrow range of activity limited to the growth inhibition of sensitive strains belonging to Morganella morganii genus.

Bacterial Typing Techniques↗
PubMed1988

Distribution of postsynthetic methylation sites in Physarum histone H1.

Using limited chymotrypsin and trypsin digestion of isolated Physarum histone H1 labeled in vivo in postsynthetically added N epsilon-methyl groups of lysine we show that: --there is no postsynthetic methylation in the central globular domain of H1, --a moderate number of methylated sites occurs in the N-terminal fragment and the part of the C-terminal fragment directly adjacent to the globular domain (the main site of interphase phosphorylation), --the most intensively methylated region occurs within the sequence located in an extended part of the C-terminal fragment, distant to the globular domain and the main site of interphase phosphorylation.

Binding Sites↗
PubMed1988

Transcriptionally active chromatin can be selectively released by DNase I from Physarum polycephalum genome.

In a simple eukaryote Physarum polycephalum about 13% of the genome is transcribed into abundant cytoplasmic RNA as shown by S1 nuclease digestion of DNA-RNA hybrids. Mild digestion of isolated Physarum nuclei with DNase I liberates a fraction of chromatin 3.5-fold enriched in sequences hybridizing by Physarum poly(A)+ RNA. This fraction is similarly enriched in histone H4 and actin genes known to be actively transcribed in Physarum. High content (about 45%) of actively transcribed sequences in DNase-I-released fraction of Physarum chromatin makes it particularly well suited for studying the structural basis of transcriptional activation in eukaryotes.

Actins↗