Immunofluorescence localization of the regulatory subunit type II of cAMP-dependent protein kinase in PC12 and 3T3 cells in different proliferative states.

Localization of the regulatory subunit of cAMP-dependent protein kinase type II was studied in proliferating and quiescent fibroblasts 3T3 and in a cell line of neural origin pheochromocytoma PC12. In actively proliferating PC12 cells the regulatory subunit was found to be localized in the nucleus. Transition of these cells into a quiescent state was accompanied by a regulatory subunit translocation to the cytoplasm.

Prognosis of hemolytic anemia in G6PD- subjects. Multifactorial cluster analysis of biochemical characteristics of red cell age groups.

Individual susceptibility of 10 G6PD- hemizygotes to oxidative hemolytic agents was tested on the basis of multifactorial cluster analysis of biochemical indices of erythrocyte populations; the indices related to G6PD activity and glucose metabolism were analyzed under physiological and oxidative stress conditions in very young, exactly adult and very old red cell suspensions. Biochemical images of G6PD- erythrocytes were obtained and compared with the donor (7 subjects) biochemical image on a IBM-PC computer according to a special "taxon" program. As a result, a stable subdivision of 10 Gd- biochemical images into 5 taxons was formed; each taxon included G6PD subjects with a certain form of clinical appearance of G6PD deficiency.

The influence of nerve growth factor on the activities of adenylate cyclase and high-affinity GTPase in pheochromocytoma PC12 cell.

The influence of nerve growth factor (NGF) on the activities of adenylate cyclase and high-affinity GTPase in pheochromocytoma PC12 cells was studied. Incubation of cells with nerve growth factor led to a rapid activation of adenylate cyclase accompanied by an inhibition of high-affinity GTPase. By the 10th min of incubation the activity of adenylate cyclase had been reduced 2-fold when compared to the control.

Production and immunohistochemical characterization of primary cultures of human embryo brain cells.

Primary cultures of human embryo brain cells (9-12 weeks of pregnancy) were obtained. The use of selective substrates (poly-L-lysine, poly-L-ornithine, reconstructed collagen) made it possible to obtain neuron-rich (up to 80%) cultures viable for no less than 30 days. The highest selectivity with respect to neurons was observed when reconstructed collagen was used.

The effect of Staphylococcus aureus enterotoxin A on proliferation of lymphoid and nerve cells.

The effects of Staphylococcus aureus enterotoxin A (SEA) on proliferative activities of human peripheral blood lymphocytes, B-lymphoma cells of the Namalva line, and nerve cells of the PC12 line have been studied. It has been shown that SEA affects these cells in identical ways, producing either a mitogenic or an antiproliferative effect. Studies on the dynamics of cellular responses to the action of SEA have demonstrated that the effects of the toxin are mediated by its interaction with different binding sites on the membranes of target cells.

The ratio of two isozyme groups in microsomal cytochrome P-450 under exogenous influence of carbon tetrachloride and cyclophosphamide.

A method for measuring the content of two groups of microsomal cytochrome P-450 isozymes--cytochromes P-450W and P-450L--with the active sites directed into the water phase and membrane lipids, respectively, has been developed. The method is based on the ability of the xanthine oxidase-menadione complex to reduce microsomal cytochromes b5 and P-450 under anaerobic conditions by transferring electrons to hemoproteins with the active sites directed into the water phase. Cytochrome b5 is completely reduced (to the dithionite level) and cytochrome P-450 is reduced partially (only a group of cytochromes P-450W).

htpR-like gene controls cell division and proteolysis in Pseudomonas aeruginosa.

As shown in hybridization experiments, the genome of Pseudomonas aeruginosa cells contains a htpR-like gene which controls the expression of heat shock genes in cells of Escherichia coli. By means of specially constructed plasmids, the synthesis of htpR antisense RNA has been found to disturb cell division and proteolytic processes in P. aeruginosa, suggesting the functional relationship of htpR genes in E.

Analysis of ligand-receptor binding by the difference method.

A new method has been proposed for analysis of experimental data on ligand-receptor binding at equilibrium. This method makes it possible to detect heterogeneity of a receptor system in cases where the contribution of the high-affinity site to total binding is rather small and the problem of graphic discrimination of a model cannot be solved unambiguously by other methods. The difference method permits us to exclude experiments on measuring nonspecific binding.

Electron microscopic and physico-chemical studies of DNA complexes with synthetic oligopeptides: binding specificity and DNA compact structures.

Binding to DNA of two synthetic peptides, Val-Thr-Thr-Val-Val-NH-NH-Dns and Thr-Val-Thr-Lys-Val-Gly-Thr-Lsy-Val-Gly-Thr-Val-Val-NH-NH-Dns (where Dns is a residue of 5-dimethylaminonaphthalene-1-sulfonic acid), has been studied by circular dichroism, electron microscopy and fluorescence methods. It has been found that these two peptides can self-associate in aqueous solution as follows from the fact that concentration-dependent changes are observed in the UV absorbance and fluorescence spectra. The two peptides can bind to DNA both in self-associated and monomeric forms.

Use of cloned htpR gene of Escherichia coli to introduce htpR mutation into the chromosome.

A deletion htpR mutant of Escherichia coli has been constructed on the basis of site-directed mutagenesis. To this end, the chromosomal allele of htpR gene was substituted by a mutant allele introduced into the cell with a recombinant plasmid. The htpR mutant is characterized by a reduced level of proteolysis and therefore by a decreased rate of proteolytic degradation of RNA polymerase of bacteriophage T7.

Elucidation of conservative elements of calmodulin-dependent enzymes with the use of monoclonal antibodies.

Monoclonal antibodies against human erythrocyte membrane Ca2+-ATPase were obtained. The binding of monoclonal antibodies to the enzyme resulted in a decrease in the enzyme sensitivity to calmodulin (CaM). The effects of monoclonal antibodies on other CaM-dependent enzymes, namely, on the phosphodiesterase of cAMP, phosphorylase kinase, and Ca2+-CaM-dependent protein kinase II (PK II), were studied.

Regulation of proteolysis in Escherichia coli cells by antisense RNA of htpR gene.

A new vector has been constructed on the basis of plasmid pCQV2 containing thermoinducible regulatory elements of bacteriophage lambda. The vector makes it possible to combine an inducible synthesis of foreign proteins with negative control of intracellular proteolysis. The principle employed for the construction of the plasmid implies the regulation of gene expression by antisense RNAs.

Immunochemical studies of human placental alkaline phosphatase in normal and neoplastic tissues.

Human placental alkaline phosphatase (hPLAP) is normally present in plasma membranes of syncytiotrophoblast microvilli. hPLAP is expressed by many malignant tumors and is considered to be useful as a tumor marker. The objective of the work was to develop immunochemical methods for detection of this marker.

Regulation of differentiation of PC12 cells by nerve growth factor.

The effect of NGF from bovine seminal plasma on the adenylate cyclase system of pheochromocytoma PC12 cell line was studied. It was shown that the elevation of the intracellular level of cAMP caused the NGF-like morphological differentiation of PC12 cells cultured in the serum-free medium. This effect was very transitory because of the compensatory action of phosphodiesterase of cAMP, the biosynthesis of which was induced by the elevated level of intracellular cAMP.

Hereditary variability of plants under the action of exogenous DNA.

Injection of exogenous barley donor DNA into grains of barley recipient plants at the milk maturity stage, with a specially designed syringe, led to the appearance of transformed plants. The transformation (in rare cases) was caused by the unsheared DNA since the DNA passing through the syringe needle remained relatively stable (10(6) to 10(7) daltons) as was confirmed by DNA sedimentation analysis.14 plants grown from seeds injected with highly polymeric DNA containing close to 30 per cent protein had transformed pollen grains.

Participation of the intracellular enzymes in the control of mutational processes : Part 4: the role of UV-specific endonuclease and medium composition in the induction of genic mutations in Escherichia coli.

The influence of UV-specific endonuclease and medium composition on the frequency and spectrum of genic mutations in Escherichia coli KI2 uvr (+) (with normal repair enzymes) and urv A6 (defective in UV-specific endonuclease) was studied. Mutations at the locus glu (gene controlling assimilation of glucose) were induced by ultra-violet irradiation and hydroxylamine treatment. To identify mutant colonies, triphenyl tetrazolium chloride (TTC) was added to the medium since it coloured the mutant colonies bright crimson and readily permitted distinction between pure mutant clones (complete mutations) and mixed clones (mosaic or sector mutations).

Linear differentation of cereal chromosomes : III. Rye, triticale and 'Aurora' variety.

The BSG test was used in an investigation of the linear differentiation in rye variety 'Zhitkinskaya', common wheat variety 'Aurora' and two secondary Triticale namely AD-196 and F-1239.Chromosomes of 'Aurora' variety and wheat chromosomes within Triticale may be easily divided into "constant" and 'variable' chromosomes as described previously (lordansky et al. 1977; Zurabishvili et al 1977).

Linear differentiation of cereal chromosomes : I. Common wheat and its supposed ancestors.

Using the Giemsa technique of differential staining (the BSG test), we have studies the karyotypes and constructed the idiograms of T. aestivum L. var.

Participation of the intracellular enzymes in the control of the mutation process : III. Influence of the inhibition of repair and replication on γ-ray induced chromosomal aberrations in barley.

The influence of repair and replication on the frequency of spontaneous chromosome aberrations and of those induced by gamma-irradiation is reported.Using the technique of labelling DNA with radioactive (3)H-thymidine and measuring the radioactivity of DNA isolated from embryos, the time of initiation and the duration of DNA synthesis in barley seeds was studied after the soaking of the seeds had begun. The average duration of each phase of the first DNA synthesis cycle in soaking barley seeds was found to be as follows: pre-DNA synthesis stage, 10-11 hrs; DNA synthesis stage, 8 hrs.

Molecular mechanisms of the origin of chromosome aberrations and the structural organisation of eukaryotic DNA.

A new hypothesis on the appearance of exchange chromosomal aberrations has been suggested. According to this hypothesis, temporal duplex polynucleotide structure should arise during G1 and G2 phases during the correction of DNA. The size of the duplex, as a rule, should be restricted to the size of complementary nucleotide sequences in the regions of repetitions.