Molekulyarnaya Biologiya最新文献

Histone acetyltransferases of the CBP/p300 family are involved in transcriptional regulation and many biological processes (cell proliferation and differentiation, development, and regulation of the stress response and metabolism). Overexpression and knockdown of the nejire (nej) gene (codes for an ortholog of human CBP/p300 proteins) in various tissues (the fat body, intestine, and nervous system) and at various stages of the life cycle (throughout all developmental stages or in adulthood only) were tested for effect on lifespan in the fruit fly Drosophila melanogaster. The activation of nej exerted a positive or a negative effect on the lifespan, depending on the induction mode and the sex. A 6-15% greater lifespan was observed in females with conditional overexpression of nej in the intestine and constitutive overexpression of nej in the nervous system. A decrease (to 44%) or lack of significant changes in lifespan was detected in all other cases observed. In addition, stress response genes (Sod1, Gadd45, Hsp27, Hsp68, and Hif1) were regulated by nej activation. nej knockdown caused a pronounced negative effect on the D. melanogaster lifespan in most variants of the experiment.

Bacillus pumilus ribonuclease (binase) exhibits cytotoxic and oncolytic properties, while causing genotoxic effects at high concentrations. Mutants that have reduced catalytic activity and preserve the antitumor properties of the native enzyme could exert lower toxic side effects. Mutant binase forms with the Lys26Ala and His101Glu single substitutions were obtained by site-directed mutagenesis. A comparative analysis of Escherichia coli- and Bacillus subtilis-based expression systems demonstrated that the latter is better to use to produce the binase mutants. The binase mutants with reduced catalytic activity were isolated and purified to homogeneity by ion exchange chromatography; the maximum yield was 25 mg/L. Catalytic activities of the mutants toward natural RNA-substrates in comparison with those for native binase were estimated at 11% and 0.02%, respectively. Like native binase, the Lys26Ala mutant was found to be cytotoxic to the A549, BT-20, and HuTu 80 tumor cell lines, but did not substantially affect normal WI-38 cells. The His101Glu mutant did not show cytotoxicity.

The marine free-living organism Trichoplax (phylum Placozoa) resembles a unicellular amoeba in shape and type of movement. Trichoplax diverged from the main evolutionary tree in the Neoproterozoic Era. Trichoplax provides one of the simplest models of multicellular animals and a strong example of how cells of an organism interact to form an ensemble during its development and movement. Two orthologs of the mouse Piezo1 protein (6B3R) were found in two Trichoplax haplotypes, H1 and H2, as a result of a search for similar sequences in the NCBI databases. Spatial models of the respective proteins XP_002112008.1 and RDD46920.1 were created via a structural alignment with 6KG7 (mouse Piezo2) template. Their domain structures were analyzed, and a limited graph of protein-protein interactions was constructed for the hypothetical mechanosensor XP_002112008.1. The possibility of signal transduction from the mechanoreceptor to membrane complexes, the cytoplasm, and the cell nucleus was shown. Trichoplax mechanoreceptors were assumed to play a role in perception of force stimuli from neighbor cells and the environment. Based on the results, the primitive Trichoplax organism was proposed as the simplest multicellular model of mechanical and morphogenetic movements.

As an alternative to the classical method of erythrocyte hemagglutination, a latex agglutination assay based on the interaction of influenza viruses with the sialoglycoprotein fetuin immobilized on the surface of polystyrene microspheres has been developed. Twelve influenza A virus strains of different subtypes and two influenza B viruses of different lines were tested. Simultaneous titration of viruses using the classical hemagglutination test and the proposed latex agglutination assay showed similar sensitivity and a high degree of correlation (R = 0.94). The obtained microspheres can be used for titration of viruses that recognize and bind sialylated glycans as receptors. In particular, latex aggregation was also induced by the Newcastle disease virus.

Cancer-associated fibroblasts (CAFs) often form a major component of the tumor microenvironment (TMA), providing conditions for cancer cells to thrive. CAFs may contribute to tumor growth, invasion, metastasis, and resistance to therapy. However, clinical trials of treatment strategies targeting CAFs have largely failed. Moreover, there is evidence that CAFs are capable of inhibiting tumor development. The review considers the current data on the functional heterogeneity of CAFs and their bimodality in tumor development and progression. Understanding the tumor-promoting and tumor-inhibiting activities of CAFs can help to develop new diagnostic and therapeutic approaches.

The vasovagal syncope (VVS) is the most common form of syncope. The mechanisms of VVS development are not entirely clear. It is known that there is a genetic predisposition to this disease, but the data on the roles of individual genes are quite contradictory. Recently, a genome-wide association study identified a locus at chromosome 2q32.1 associated with a united group of diseases, that is, syncope and collapse; among the single nucleotide polymorphisms (SNPs) of this locus, the most significant association was observed for rs12465214. In a homogeneous sample of patients diagnosed with VVS, we analyzed the association of rs12465214, rs12621296, rs17582219 and rs1344706 located on chromosome 2q32.1 with this form of syncope. In the enrolled set, only rs12621296 was associated with VVS by itself, whereas associations of other SNPs were observed only in biallelic combinations. An epistatic interaction between the components of the combination rs12621296*A + rs17582219*A was revealed. The possible involvement of individual genes on the 2q32.1 locus in the genetic architecture of the VVS is discussed.

The constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) are nuclear receptors that are involved in the regulation of gene transcription of enzymes that are responsible for biotransformation and excretion of endo- and xenobiotics. The goal of the work was to study the effect of DL-butyonine sulfoximine (BSO, gamma-glutamylcysteine synthetase inhibitor) on the relative amounts of CAR and PXR in Caco-2 cells and to clarify its mechanisms. BSO was used at concentrations of 1-500 μM for 24 and 72 h. The generation of reactive oxygen species (ROS) has been evaluated using the MitoTracker Red CM-H2 XRos fluorescent probes. Cytotoxicity was analyzed by the MTT test. The relative amount of CAR and PXR was assessed by the Western blot method. It has been shown that BSO caused an increase in ROS formation at concentrations of 10, 50, and 100 μM for 24 h and at concentrations of 50 and 100 μM for 72 h. However, 500 μM BSO reduced the viability of cells during all periods of exposure. The relative amount of CAR increased in 24 h at the BSO concentrations of 50 and 100 μM and in 72 h at its concentrations of 10 and 50 μM. The amount of PXR increased in 72 h during incubation with BSO at the concentration of 50 μM and in 24 and 72 h at its concentrations of 100 and 500 μM. The combined use of BSO (50 μM, 24 h; 10 and 50 μM, 72 h) and glutathione inhibited CAR induction, whereas 50 and 100 μM BSO inhibited PXR formation for 72 h. The addition of 1 mM glutathione to the nutrient medium with BSO (100 and 500 μM, 24 h; 500 μM, 72 h) did not affect the relative amount of PXR. No effect on CAR was observed when 1 mM glutathione was used together with BSO (100 μM, 24 h; 50 and 100 μM, 72 h). Thus, BSO can induce CAR and PXR formation by both increasing the production of free radicals, thus developing oxidative stress, and by acting independently as a xenobiotic.

The PARP1 and PARP2 proteins are members of the poly(ADP-ribose) polymerase family involved in the regulation of DNA repair and replication, RNA processing, ribosome biogenesis, transcription, cell division, and cell death. PARP1 and PARP2 are promising targets for the development of anticancer drugs and can be used in the treatment of cardiovascular, neurodegenerative, and other disorders. The WGR domain has been shown to play a central role in the functioning of PARP1 and PARP2 proteins. This review considers the mechanisms of functioning of WGR domains in the PARP1 and PARP2 proteins, which have several similar and specialized properties. Understanding these processes is of great interest to fundamental science and can contribute to the development of more effective and selective inhibitors of PARP1 and PARP2.

Nucleotide sequence variability of whole mitochondrial genomes (mtDNA) was analyzed and mutation spectra were reconstructed (by L-chain of mtDNA) in four regional groups of indigenous populations representing Northeastern and Southern Siberia, Western Asia, and the Americas. The pyrimidine transitions were found to be predominant in all groups; of these, the T→C substitutions were most frequent. The second most common in all regional groups (except Northeastern Siberia) are A→G substitutions. Of the transversions, in all the populations studied the C→A substitutions dominate. Between-regional differences in the distribution of nucleotide substitutions in mtDNA mutation spectra were not detected. However, a significant (4-fold) decrease in the number of mutations in mitochondrial gene pools was detected in the indigenous population of Northeastern Siberia compared to other regions. This may be due to the increased effect of negative selection on mtDNA in the Far North environment, which prevents the accumulation of new mutations, and genetic drift, which is most pronounced in isolated and small populations of Northeastern Siberia. Because of the lack of between-regional differences in mtDNA mutation spectra, the results we obtained do not allow us to confirm the hypothesis that the T→C substitution frequency is a molecular marker of the level of oxidative stress in mitochondria (at least for germline mutations).

Tomato aspermy virus (TAV, genus Cucumovirus from the family Bromoviridae) is one of the most common and harmful chrysanthemum viruses, causing severe flower distortion, size reduction, and color breaking. Metatranscriptome sequencing of chrysanthemum plants of the Ribonette and Golden Standard cultivars from the collection of the Nikita Botanical Garden (Yalta, Republic of Crimea) generated TAV-related RNA reads. The complete genomes of two Russian isolates of the virus were assembled from the reads. This is the first report of full-length TAV genomes from Russia. Typically of cucumoviruses, the segmented TAV genome is represented by three single-stranded positive-sense linear RNA molecules of 3412 (RNA1), 3097 (RNA2) and 2219 (RNA3) nucleotides. Five open reading frames (ORF) have been identified that encode replicase (ORF1), RNA-dependent RNA polymerase (ORF2a), silencing suppressor protein (OFR2b), movement protein (OFR3a) and the coat protein (ORF3b). The identity of TAV genomes from the two chrysanthemum cultivars was 99.8% for all three viral RNAs; with other TAV isolates from GenBank it was 97.5-99.7% (RNA1), 93.8-99.8% (RNA2), and 89.3-99.3% (RNA3). Phylogenetic analysis showed that RNA1 and RNA3 of the Russian isolates were assigned to heterogeneous groups of TAV isolates found on various plant species in different regions of the world. At the same time, RNA2 clearly clustered with tomato isolates SKO20ST2 from Slovenia and PV-0220 from Bulgaria and, to a lesser extent, with the Iranian isolate Ker.Mah.P from petunia and the Chinese isolate Henan from chrysanthemum. The incongruence of phylogenetic trees reconstructed from different genome segments suggests pseudo-recombination (reassortment) in the Russian TAV isolates.