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A Jerzmanowski

Publications and source records attributed to A Jerzmanowski.

At least 19 recordsLinked to original sources
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↗
PubMed1983

Immunoglobulins and complement in migraine.

In 54 patients with migraine and 70 persons comprising the control group, the total complement level (CH50) was evaluated together with its C3 and C4 fraction level and the level of IgG, IgA and IgM immunoglobulins. It was found that the average C3 fraction level was significantly decreased, while the C4 fraction level and total complement activity remained in the normal range. The immunoglobulin level did not show any statistically significant alterations except for the IgA level, which was lowered in migraine patients. On this basis, i.e. lowering of the C3 fraction level with normal C4 fraction level and total complement activity and lack of elevation of IgA, it is felt that the alternative pathway of complement system may be activated in migraine.

Adolescent↗
PubMed1980

Some unusual features of Physarum polycephalum chromatin are due to the presence of slime.

Chromatin of lower eukaryote Physarum polycephalum, while showing typical nucleosomal organization, reveals upon digestion with micrococcal nuclease certain features not found in chromatins of higher eukaryotes, the most pronounced of which is the unusual pattern of degradation of core-size DNA, without accumulation of subcore fragments. It has been shown that these peculiarities are not due to intrinsic features of Physarum nucleohistone complex but to the presence of a specific polysaccharide, the main component of Physarum slime, contaminating chromatin preparations.

Animals↗
PubMed1979

Chromatin condensation. Possible dehydrating and stabilizing factors.

The effect of Na+, Mg2+, spermidine and spermine on the dehydration of chromatin gel and precipitation of soluble chromatin has been compared. Considerable differences have been found in the relative ratios within the studied group (Na+, Mg2+, spermidine and spermine) between the ability to dehydrate (1 : 32 : 53 : 67) and to precipitate (1 : 53 : 800 : 2000) chromatin. On the basis of the dependence of precipitation on initial chromatin concentration it has been suggested that the observed effect as contributed considerably by interparticle aggregation is a relatively good measure of the ability of cation to stabilize higher order structures of chromatin through direct crosslinking or induction of hydrophobic associations at selected sites. In contrary to that the method estimating the direct dehydration measures the overall dehydrating effect of a cation exerted on the whole chromatin. It has been suggested on the basis of the above comparative data that the in vivo regulation of the degree of overall chromatin hydration should occur through changes in concentration of free small inorganic cations. Larger organic polycations like polyamines should be mainly involved in stabilization of the higher order chromatin structures. The stabilizing role of large polyanions like RNA has been ruled out. It has also been found that the unwinding of chromatin DNA results in considerable chromatin hydration.

Animals↗