[Dynamics of the biosynthesis of components of the protein synthesizing apparatus of the rat liver at the stage of restoration of translation, inhibited by cycloheximide]. / Dinamika biosinteza komponentov beloksinteziruiushchego apparata pecheni krys na étape vosstanovleniia transliatsii, ingibirovannoi tsiklogeksimidom.

The biosynthesis of proteins, ribosomal RNA and other components of the rat liver protein-synthesizing system during the reparation and subsequent activation of translation inhibited by a sublethal dose cycloheximide (CHI, 3 mg/kg) was studied. It was found that the incorporation of labeled precursors into proteins and ribosomal rRNA isolated from free and membrane-bound polysomes is repaired already 3 hours after CHI injection. 6-9 hours thereafter, the level of component labeling reaches control values, whereas the total protein biosynthesis is retarded. After 12-24 hours, marked stimulation of ribosome biosynthesis and the integration of ribosomes into polysomes are observed together with an asymmetric accumulation of excessive amounts of newly synthesized 40S subunits into polysomes 12 hours after CHI infection. The putative mechanisms of the activation of expression of the part of the genome responsible for protein and ribosomal rRNA synthesis as well as for the synthesis of other components of the protein-synthesizing system are discussed.

[Characteristics of [3H]cycloheximide distribution, protein and DNA biosynthesis in rat organs after sublethal blocking of translation]. / Osobennosti raspredeleniia [3H]tsiklogeksimida, biosintez belka i DNK v organakh krysy dosle subletal'nogo bloka transliatsii.

The kinetics of accumulation and release of [3H]cycloheximide (CHI) as well as protein and DNA biosyntheses in some organs of the rats injected with sublethal doses of CHI were studied. It was shown that in the majority of organs under study (especially in the liver, kidneys and adrenals) the inhibition is completed within 12 hours after CHI injection followed by the resumption of protein and DNA syntheses. In the thymus and pancreas the levels of these biosyntheses remain below control values up to the 72nd hour. A positive correlation was observed between the decrease of CHI (or its metabolites) concentration and the beginning of protein and DNA syntheses in different organs. However, there was a reverse correlation between the high values of squares below the kinetic curves of CHI release from the liver, kidneys and adrenals and the intensive resumption of protein and DNA biosyntheses in these organs. It was thus assumed that in these particular organs CHI is subjected to intensive biotransformations. The contribution of the endocrine system to the induction of intensive compensatory protein and DNA syntheses in the liver were estimated from the viewpoint of the nature of reconstructive processes occurring in the appropriate organs.

[Activation of nuclear polypeptide synthesis in rat liver cells after inhibition of template protein synthesis. The role of nuclear polypeptide synthesis in the changes of the chromatin structure]. / Aktivatsiia iadernogo polipeptidnogo sinteza v kletkakh pecheni krys pri tormozhenii matrichnogo sinteza belkov. Vklad iadernogo polipeptidnogo sinteza v izmenenie struktury khromatina.

The correlation between the rates of nuclear polypeptide synthesis (NPS) and matrix protein synthesis in rat liver cells was investigated. It was shown that NPS is activated under conditions of protein synthesis inhibition in the cytoplasm. Model experiments revealed that the NPS and ADP ribosylation systems compete for chromatin structure: ADP ribosylation induces condensation, while NPS--decondensation of chromatin.

[Complex nature of the inhibitory effect of the cytosol on transcription in isolated nuclei of rat liver]. / O slozhnoi prirode ingibiruiushchego deistviia tsitozola na transkriptsiiu v izolirovannykh iadrakh pecheni krys.

It was shown that rat liver cytosol contains a factor inhibiting [3H]UTP incorporation into RNA of isolated nuclei. Fractionation of cytosol by Sephadex G-100 chromatography, step-wise increase in ammonium sulfate concentration and electrophoresis in polyacrylamide gel revealed a complex nature of cytosol inhibitory activity. It was suggested that this complex nature can be due to the presence of either non-specific inhibitors of transcription (i.e. phosphatase, RNAase) or a set of virtually specific inhibitors of transcription in the cytosol.

[Suppression of DNA-ligase deficiency and selective breeding of mutants and recombinants of T4 phage with phenotype rII]. / Supressiia nedostatochnosti po DNK-ligase i selektivnyi otbor mutantov i rekombinantov s fenotipom rII u faga T4

A number of methods which greatly simplify the introduction of frame shift mutations in the limited segment of the phage T4 rII genes were developed for studying genetical recombination between closely linked markers. These methods enable to construct multiple rII mutants with relatively small expenditure of labour. Suppression of gene 30 deficiency by rII mutations has been studied for a variety of conditions. The results obtained indicate that rIIB polypeptide is involved in two different activities: rIIB region which is dispensable for growth on lambda-lysogenic Escherichia coli strains behaves as indispensable in phenomenon of suppression of ligase deficiency.