[Phenol biodegradation by a Pseudomonas sp. strain tagged with the gfp gene].

Conjugal transfer of the pAG408 suicide vector from E. coli S 17.1 to Pseudomonas sp. cells able to consume phenol yielded transconjugates brightly luminescing under UV illumination. It was shown that tagging of the Pseudomonas sp. cells with the gfp gene did not affect their ability to consume phenol. The change of the population density of the tagged bacteria after their introduction to soil was studied. The potential of the resulting bacterial strain in remediation of phenol-polluted soils is discussed.

[The effect of thyroid hormones and 5-azacytidine on the gene transcription of malic enzyme and 6-phosphogluconate dehydrogenase]. / Vliianie tireoidnykh gormonov i 5-azatsitidina na transkriptsiiu genov malik-fermenta i 6-fosfogliukonatdegidrogenazy.

The effect of thyroid hormones and the methylation inhibitor 5-azacytidine on the level of expression of thyroid hormone-responsive genes (malic enzyme and 6-phosphogluconate dehydrogenase genes) has been studied. DNA-RNA hybridization has shown there is an inverse correlation between the level of DNA methylation and gene expression of malic enzyme and 6-phosphogluconate dehydrogenase. Thus it suggests that the regulation of thyroid hormone gene expression can take place via DNA methylation blocking and that DNA demethylation is part of structural changes essential to the binding of thyroid hormones with DNA elements recognized by thyroid hormone receptors and to further induction of synthesis of specific mRNA.

[Human thyroid gland DNA methylase in nodular and diffuse goiter]. / DNK-metilazy shchitovidnoi zhelezy cheloveka pri uzlovom i diffuznom zobe.

The heterogeneity and some properties of DNA-methylases isolated from nonmalignant human thyroid formations--nodular and diffuse goiters--have been studied. Isoelectrofocusing of methylase preparations produced 6-7 distinct activity peaks distinguished by pI, activity towards Ca2+ and Mg2+, sensitivity towards dithiothreitol and capacity to methylase cytosine into mono-, di- and tripyrimidine blocks in vitro. The degree of DNA methylation in vivo depended on the origin of of the goiter. Analysis of several methylase fractions by two-dimensional electrophoresis performed according to O'Farrell revealed the presence of major polypeptides having similar molecular masses (approximately 36 kDa). Besides the major component, all the preparations under study contained 6-10 characteristic minor components. The data obtained are suggestive of a structural and functional heterogeneity of human methylases.

[Liver nuclear phospholipids of rats with varying thyroid status]. / Fosfolipidy iader pecheni krys s razlichnym tireoidnym statusom.

Thin-layer chromatography was used for fractionation of rat liver nuclear phospholipids after in vivo administration of 14C-sodium acetate. The administration of T3 to thyroidectomized rats caused a sharp increase in the incorporation of the label in all phospholipids of the nuclear fraction. The action of sphingomyelin and sphingomyelase on RNA-polymerase of nuclei isolated from the liver of thyroidectomized rats was tested. Sphingomyelin was shown to cause stimulation of RNA nuclear synthesis; parallel incubation with sphingomyelinase eliminated a stimulating effect of this phospholipid.

[The effect of thyroid hormones on DNA methylation in rat liver in vivo and in vitro]. / Vliianie tireoidnykh gormonov na metilirovanie DNK pecheni krys in vivo i in vitro.

Methylation of rat liver DNA was studied in vivo and in vitro in presence of various content of thyroid hormones. Both administration of triiodothyronine into intact rats and thyroidectomy led to considerable alterations in activity of endogenous DNA-methylases and in content of m5C in DNA although distinct correlation between these two factors was not detected. Alterations in the acceptor activity of endogenous DNA towards bacterial DNA-methylases of thy Mbu type demonstrated the processes occurring in vivo. The methylase probe 5'...GGA...3' proved to be the universal means for testing of all the types of thyroid status involving either free DNA or whole nuclei.

[Multiple forms of DNA methylases in hepatic cell nuclei of animals in the normal state and in pathology]. / Mnozhestvennye formy DNK-metilaziz iader pechenizhivotnykh v norme i pri patologii.

Using hydrophobic chromatography multiple nature of DNA-methylating enzymes have been revealed. It was established that the most active enzymatic fraction of rats' liver and that of chicken are completely identical.

[Interaction of hormone-receptor complexes of triiodothyronine with DNA and RNA]. / Vzaimodeistvie gormon-retseptornykh kompleksov triiodotironina s DNK i RNK.

Some parameters of triiodothyronine hormone-receptor complexes (HRC) interactions with DNA-cellulose were studied. The competition between DNA and polyribonucleotides for HRC was demonstrated. It was found that in a model system of RNA transport HRC stimulate the 3H-RNA liberation from the nuclei. The functional significance of HRC-RNA interactions is discussed.

[Stimulation with triiodothyronine of the synthesis of DNA, total proteins, nuclear proteins and nuclear matrix proteins in cultured cells of hepatoma Morris 7777]. / Stimuliatsiia triiodtironinom sinteza DNK, total'nykh belkov, belkov iadra i iadernogo matriksa v kul'tiviruemykh kletkakh gepatomy Morrosa 7777.

Intensity of DNA and protein biosynthesis was decreased in Morris hepatoma 7777 cultivated cells in absence of thyroid hormones. Physiological concentrations of triiodothyronine increased synthesis of DNA and total proteins after lag phase within 12-48 hrs, while synthesis of nuclear and nuclear matrix proteins was stimulated already within 2 hrs. This suggests that stimulation of nuclear proteins biosynthesis occurred prior to the hormone effect on proliferation and cell metabolism. Alterations in sensitivity of chromatin to DNAase I were not observed. Response of the Morris hepatoma cells to thyroid hormones may be used in studies of molecular mechanisms of thyroid hormones action.

[The effect of thyroid hormones on structural-functional relations in rat liver chromatin]. / Vliianie tireoidnykh gormonov na strukturno-funktsional'nye vzaimootnosheniia v khromatine pecheni krys.

The effects of thyroid hormones on chromatin structure at different levels of its functional activity were investigated. No differences in the sensitivity of hepatocyte nuclei to DNAase I were found, presumably due to the restriction of acceptor sites for thyroid hormones on DNA.

[Cytoplasmic thyroxine-binding protein: the role of RNA in the interactions between thyroxine receptor and cell nuclei]. / Tsitoplazmaticheskii tiroksinsviazyvaiushchii belok: rol' RNK vo vzaimodeistvii retseptora tiroksina s iadrami.

The presence of 3H-orotic acid in the cytoplasmic receptor fraction isolated in our laboratory, the sensitivity of this fraction to treatment with RNAases accompanied by a shift of the absorption peak of the receptor preparation towards the long-wave region as well as the use of the absorption filter technique point to the existence of ternary thyroxine-thyroxine-binding protein-RNA complex in the cytoplasm. It was found that the cytoplasmic hormone-receptor complex of thyroxine is a genetically active form which can interact with the nuclei and modify the activity of chromatin. The role of RNA in these interactions is discussed.

[Interaction of hormone-receptor complexes from normal and tumorous tissues with DNA and their effect on the RNA polymerase activity of isolated nuclei]. / Vzaimodeistvie gormon-retseptornykh kompleksov iz normal'noi i opukholevoi tkani s DNK i ikh vliianie na RNK-polimeraznuiu aktivnost' izolirovannykh iader.

A study was made of the interaction of the thyroxine hormone-receptor complexes (HRC) from hepatocytes and sarcoma M1 cells with DNA and the involvement of these complexes in the regulation of the RNA-polymerase activity of isolated hepatic cell nuclei. Unlike sarcoma HRC, rat liver HRC showed a weak interaction with DNA. Against a background of considerable stimulation of the incorporation of precursors in RNA under the influence of rat liver HRC (2.64 times), sarcoma HRC increased RNA synthesis in the system by 31.7% only to determine the RNA-polymerase activity of the nuclei. Proceeding from these results the authors have concluded that a thyroxine-binding receptor protein in malignant tissues is devoid of biological activity in the regulation of gene expression by the thyroid hormones, at least in the transcription phase.

[Effect of thyroid hormones on the nuclear-cytoplasmic transport of RNA]. / Vliianie tireoidnykh gormonov na iaderno-tsitoplazmaticheskii transport RNK.

The regulation of gene expression by hormones can be implemented at different levels: mRNA transcription, processing, transport from the nucleus into the cytoplasm, and translation. In the authors' earlier papers it was shown that the thyroxin hormone-receptor complex (HRC) increased chromatin matrix activity and induced new sites of transcription initiation. The present work was concerned with a study of the role of the thyroxin HRC in the regulation of the mechanism of 3H-RNA transport from the nucleus into the cytoplasm. An idea of the involvement of the HRC cytoplasmic thyroxin in RNA transport resulted from the detection in 30-40 S of RNP particles from rat liver nuclear proteins similar to the thyroxin cytoplasmic receptor by the antigen determinants. These data combined with others on the stimulation of 3H-RNA discharge from isolated nuclei under the influence of the thyroxin cytoplasmic HRC led to a conclusion that the thyroxin cytoplasmic HRC was involved in the regulation of gene expression by the thyroid hormones not only at the stage of transcription but also at the post-transcription stage, namely at the stage of RNA nuclear-cytoplasmic transport.

[Binding of triiodothyronine to the nuclear matrix of the rat liver. The effect of thyroid hormones on the phosphorylation of nuclear matrix proteins]. / Sviazyvanie triiodotironina s iadernym matriksom pecheni krys. Vliianie tireoidnykh gormonov na fosforilirovanie belkov iadernogo matriksa.

The interaction of thyroid hormones with rat liver nuclear matrix proteins was studied. It was shown that the nuclear matrix contains the sites which bind triiodothyronine with a high affinity (Ka = 1.07 X 10(9) M-1) and limited capacity (maximal binding capacity--28.5 fmol triiodothyronine/100 micrograms protein). Electrophoretic analysis of triiodothyronine-binding matrix proteins revealed that the molecular mass of the major triiodothyronine-binding fraction is 50 000-52 000 Da. Injections of triiodothyronine to thyroidectomized animals stimulated the phosphorylation of all protein fractions of the nuclear matrix.

[Regulation of genetic activity by thyroid hormones. Effect of purified cytoplasmic hormone-receptor complex on the chromatin template activity]. / Reguliatsiia geneticheskoi aktivnosti tireoidnymi gormonami. 1. Vliianie ochishchennogo tsitoplazmaticheskogo gormon-retseptornogo kompleksa na matrichnuiu aktivnost' khromatina.

This paper continues a work series concerning the investigation of the functional activity of thyroxin receptor isolated from 105000 g fractions of the rat liver cytoplasm. Previously it was shown that the hormone-receptor complex stimulates the RNA-polymerase activity. In this work it was demonstrated that the complex changes the chromatine template activity, determined both under standard conditions and in the absence of transcription reinitiation. It appears that the hormone-receptor complex increases the number of the transcription initiation sites. Thyroxin cytoplasmatic receptor and/or the hormone, tested separately, exert no pronounced activating effect. It was concluded that the primary interaction between the hormone and specific receptor is necessary for participation in the transcription processes.