[Synthesis and secretion of recombinant protein--the product of v-sis oncogene in Saccharomyces cerevisiae cells]. / Sintez i sekretsiia rekombinantnogo belka--produkta onkogena v-sis v kletkakh drozhzhei Saccharomyces cerevisiae.

The recombinant plasmid DNA YEp secl-v-sis was constructed. This plasmid was able to code for the synthesis and secretion into the cultural medium of the protein-product of oncogene v-sis. Transcription, copy number and stability of the plasmid DNA were studied under the conditions of galactose induction. The v-sis protein was determined by gel electrophoresis and immunoblotting methods and assayed for cell-proliferation activity in the mammalian cell culture.

[detection of products of reverse transcription in Saccharomyces cells]. / Vyiavlenie produktov obratnoi transkriptsii v kletkakh drozhzhei sakharomitsetov.

Poly(A)-RNA-DNA hybrids complementary to retrotransposons Ty1 have been isolated from baker yeast cells. DNA and RNA in these complexes are represented by perfect hybrids. Reverse transcription enzymatic activity was identified in yeast cells. The results are consistent with the model of reverse transcriptional replication and transposition of Ty elements, similar to that of retroviruses.

[Detection of nucleotide sequences specific for retroviruses in Saccharomyces cells]. / Vyiavlenie posledovatel'nostei nukleotidov, spetsifichnykh dlia retrovirusov, v kletkakh drozhzhei sakharomitsetov.

Restriction endonuclease cleavage analysis and blotting hybridization of nuclear DNA and RNA to cloned avian sarcoma and murine leukemia virus genes (pol, scr and abl) demonstrated the presence and expression in baker's yeast cells of retrovirus-specific sequences. The relationship exists between the pol-specific yeast sequences and Ty cloned fragments. The results obtained are discussed in the light of evolutionary role of retroviral genes in cell division control and transposition.

[Changes in the intracellular localization of pepsinogen-synthesizing polysomes in the gastric mucosa of rats during N-methyl-N'-nitro-N-nitrosoguanidine-induced carcinogenesis]. / Izmenenie vnutrikletochnoi lokalizatsii pepsinogenosinteziruiu-shchikh polisom v slizistoi obolochke zheludka krys pri kantserogeneze, vyzvannom N-metil-N'-nitro-N-nitrozoguanidinom.

A study was made of the distribution of pepsinogen-synthesizing polyribosomes in the rat's stomach mucous membrane, in the process of chemical carcinogenesis induced by N-methyl-N'-nitro-N-nitrozoguanidine. A sharp decrease in the content and proteolytic activity of pepsin is shown in cytosol and membrane-bound polyribosomes of the mucous membrane of the rat stomach due to the inducing substance. The appearance of this enzymatic activity is noted in free polyribosomes isolated from the rat stomach tumours.

[Effect of antiestrogen and antiandrogen derivatives of acylhydrazines on properties of nucleoside triphosphatases and adenyl nucleotide content of nuclei of normal and tumor cells]. / Deistvie antiéstrogenov i antiandrogenov iz klassa atsilgidrazinov na svoistva nukleozidtrifosfataz i na soderzhanie adenilovykh nukleotidov v iadrakh normal'nykh i opukholevykh kletok.

Influence of antiestrogen and antiandrogen derivatives of acylhydrazine, potentiating the antitumoral effect of cytostatics, on properties of nucleoside triphosphatases (NTPases), adenylate content in nuclea of normal and tumoral cells was studied. It was shown that acylhydrazines activated specifically the intranuclear NTPase of normal and tumoral cells. Activity of nuclear membrane-linked NTPases from liver cells was also increased after administration of acylhydrazines, sex hormones or phenobarbital. The increase in activity of intranuclear NTPase (namely ATPase) correlated with decrease of adenylates (ADP, ATP) in nuclea isolated from tumors after simultaneous treatment with acylhydrazines and thiophosphamide. Distinct increase in sensitivity of tumoral cell DNA to the effect of these alkylating preparations appear to be due to noncompensated decrease in content of ATP.

[Characteristics of the organization and expression of individual genes in eukaryotic cells]. / Osobennosti organizatsii i ékspressii individual'nykh genov v kletkakh éukariotov.

The modern views on the organization and expression of single genes in eukaryotic cells, RNA structure and biosynthesis are reviewed. The problems of unstable gene localization ("mobile dispersed genetic elements") of some structural genes of cellular and viral origin are discussed. Peculiarities of transcription and processing of mRNA, pre-mRNA splicing are described. The information on the mechanisms of pre-mRNA splicing in normal and virus-infected eukaryotic cells, the role of low molecular nuclear RNA in the RNA splicing as signals for less than recognition greater than by specific nucleases and RNA synthetases are also regarded.

[Hybridization properties of the 4S RNA of influenza virions]. / Izuchenie gibridizatsionnykh svoistv 4S RNK virionov grippa.

Molecular hybridization of nucleic acids was used to show that 4S RNA from influenza virions cultivated in chick embryos is coded by the chick genome and represented by a group of cellular transport RNA. No complementary nucleotide sequences in 4S RNA molecules or genome RNA from influenza virions were found by means of the procedure used.

[Cytoplasmic RNA biosynthesis in Erlich ascitic carcinoma cells under anaerobic conditions]. / Biosintez tsitoplazmaticheskoi RNK v kletkakh astsitnoi kartsinomy Erlikha v anaérobnykh usloviiakh.

Cells of Ehrlich ascites carcinoma were incubated under aerobic and anaerobic conditions with 3H-uridine, and the amount and radioactivity of poly(A)-containing and poly(A)-non-containing fraction of cytoplasmatic RNA were determined. It is shown that RNA biosynthesis, as judged by the labeled precursor incorporation, is nearly similar to that under oxygen supply conditions. The specific radioactivity of poly(A)-containing fraction of cytoplasmatic RNA of cells incubated under anaerobic conditions was 2 times as much as that under aerobic ones.

[The protein-synthesizing apparatus in chemically- and virus-induced tumors]. / Belok-sinteziruishchii apparat v khimicheski- i virus-indutsirovannykh opukholiakh.

The description is given of the distribution of poly(A)-containing mRNA in different subcellular fractions (nuclei, mitochondria, free- and membrane-bound polyribosomes) from the normal tissues hepatoma MD and chick Rous. The amount of poly(A)-RNA is found to increase in all tumor cell fractions, but free polysomes.

[Hybridization analysis of the viral sequences in the DNA of a hamster Rous sarcoma]. / Gibridizatsionnyi analiz virusnykh posledovatel'nostei v DNK sarkomy Rausa khomiaka.

The nuclear genome of Syrian hamster virrion non-producer tumor contains the Rous sarcoma virus-specific nucleotide sequences. The information complexity of the proviral DNA from its tumor is similar to that for the DNA of Rous chicken sarcoma. The proviral DNA both in the hamster and chicken tumor consists of moderately reiterated and unique sequences. The avian oncornavirus-specific sequences are absent in the DNA of normal hamster tissue.

[Purification and characterization of epidermal G2- and G1-chalones]. / Ochistka i kharakteristika epidermla'nykh G2-i G1-keilonov.

Highly purified epidermal G1- and G2-chalones from rat skin inhibit the entering of epidermocytes to S and M phases of cell cycle respectively. Their biological activity is characterized by tissue-specificity and not by species-specificity. Both of them are tissue-specific glycoproteins as for their antigenic properties. Molecular weight of G1-chlone is 21 000, G2-chalone--34 000, isoelectric point (pH) 5.55 and 5.85 respectively. G2-chalone is the fastest as compared to G1-chalone in 5% acrylamide gel electrophoresis, pH 8.3. When injected in rabbits, G2-chalone produced monospecific antibodies which have no cross-reactivity with G1-chalone. The amino acid composition of both chalones and immunofluorescent localization of G2-chalone in epidermal tisues are given.

[Complementary RNA in the chicken sarcoma cells and Rous sarcoma virus]. / Komplementarnost' ribonulleinovykh kislot v kletkakh sarkomy tsypliat i viruse sarkomy Rausa.

The subcellular localization in chicken Rous sarcoma of nucleotide sequence, complementary to Rous sarcoma virus RNA was examined by RNA/RNA molecular hybridization. The preparations of radioiodinated virion RNA were annealed with RNAs from different fractions (nuclei, mitochondria, free and membrane-bound polyribosomes) isolated from chicken Rous sarcoma. Formation of RNA-ase resistant hybrids between the viral 125I-RNA and RNA from the mitochondria and membrane-bound polyribosomes was revealed. The latter were characterized by a higher relative redundancy of nucleotide sequences complementary to virion RNA than that in the former, by factor 446. The role of complementary ribonucleotide sequences is discussed.

[Change in the hybridization characteristics of rapidly-labelled ribonucleic acids during tumor "progression"]. / Izmenenie gibridizatsionnykh kharakteristik bystro metiashchikhsa ribonukleinovykh kislot v protsesse "progressii" opukholi.

The hybridization properties of in vivo rapidly labeled with 14C-orotate both nuclear and mitochondrial ribonucleic acids from the MD hepatoma were investigated. During tumour progression the repression of nuclear genome found at its early stages (5th to 6th passages) is replaced by the increase of hybridizability of nuclear DNA with a population of 14C-RNA's as well as by the appearance of new classes of pulse labeled RNA's. In other words, at late stages of tumour progression (60th passage) there occur a de-repression of nuclear genome. The hybridizability of mitochondrial RNA with nuclear DNA remains almost the same at different tumour progression stages. The results obtained are discussed in the light of literature data available.