V A Vakhitov

Ufa Scientific Center of the Russian Academy of Science, Oufa, Bashkortostan, Russia

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Publications (49)18.49 Total impact

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    ABSTRACT: Elevation of intracellular Ca²⁺ in T-lymphocytes as a consequence of T cell antigen receptor activation triggers transcriptional programs resulting in effector cytokine secretion and immune response coordination. Increase of Ca²⁺ concentration in T-lymphocytes follows both the Ins(1,4,5)P(3)-dependent release from an intracellular store and subsequent influx from extracellular milieu. Flow cytometry and the fluorescent dye Fluo-4AM have been used to demonstrate that noncompetitive NMDA receptor antagonist (+)-MK801 inhibits Ca²⁺ influx in T cells induced by thapsigargin. Combination of thapsigargin and (+)-MK801 with following incubation does not affect Ca²⁺ mobilization from intracellular stores, while decreased Ca²⁺ entry was observed. Overall data indicate that the ion channel blocker (+)-MK801 is able to inhibit the Ca²⁺ influx and confirm our suggestion about involvement of NMDA receptor in the store-operated Ca²⁺ entry mechanisms in human T-lymphocytes. To identify the signal transduction pathways associated with NMDA receptors in mitogen-stimulated T-lymphocytes, the cells were incubated with (+)-MK801, then activity of key phosphorylated protein kinases of MAP-activated (pERK1/2, pSAPK/JNK, p-p38), Ca²⁺-dependent (pCaMKII), PI3/Akt-dependent (pGSK-3β), and PKC-activated (pPKCθ) pathways were detected. The data we obtained demonstrate that (+)-MK801 treatment leads to more prominent decrease in Ras-activated protein kinases pERK1/2 and Rac-activated proteins p-p38 and pSAPK/JNK, as compared to DAG-dependent pPKCθ and Ca²⁺-dependent pCaMKII. These results show that NMDA receptors are mainly involved in regulation of Ras/Rac-dependent signaling in T-lymphocytes.
    Biochemistry (Moscow) 11/2011; 76(11):1220-6. · 1.15 Impact Factor
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    ABSTRACT: Under action of growth-stimulating concentrations of bioregulator stifun on wheat plants, an increase of functional activity of nucleoli of meristematic cells; contents of lectin (wheat germ agglutinin); and activity of proteinases, tripsin inhibitors, and ATPase activity was established. The pool of free amino acids was increased under bioregulator use. Levels of methionine, phenylalanine, cysteine, lysine, and tyrosine were increased. It is likely that stifun could activate protein biosynthesis in wheat plants.
    Prikladnaia biokhimiia i mikrobiologiia 01/2011; 47(6):679-84.
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    ABSTRACT: Plant responses to cadmium, whose accumulation may cause various disturbances in metabolic processes, can be represented as a multicomponent integrative response model (in particular, as a gan-shaped response) [1]. In view of this, it is reasonable to use a complex approach to analyzing plant responses to cadmium, which may include studies of plant adaptation, cadmium accumulation, and detoxication. The goal of this work was to study plant responses to cadmium and its accumulation in plants. The study included characterizing the resistance of plants by changes in the proportion of linear sizes and weight; determination of the degree of hydration, phytohormone balance, and the content of free amino acids; establishing the mechanisms of occurrence of chromosome rearrangements on the basis of analysis of the distribution of chromosome aberrations in cells and the aberration index under exposure to cadmium; and assessment of the retaining ability and barrier function of roots during cadmium entry into sprouts. The study was performed with the cibol ( Allium fistulosum L.) cultivars Gribovskii and Russkii zimnii; the spring wheat ( Triticum aestivum L.) cultivars Zhnitsa, Irmenka, and Omskaya-35; the maize ( Zea mays L.) cultivar Zhemchug; and the rice ( Oryza sativa L.) cultivar Rapan. Seeds were sterilized with 70% ethanol. Seedlings were grown in Petri dishes on filter paper wetter with water in a constant-temperature cabinet at 24‐27 ° C. Aligned 48-h-old seedlings were incubated with cadmium acetate for 18, 36, and 54 h (cibol); 24, 48, 72, 96, and 120 h (maize and wheat); and 1, 24, and 48 h (rice). In addition, wheat seeds were allowed to germinate at 24 ° C for 24 h, placed on cork rafts with 4-mm holes, and grown in vessels filled with cadmium acetate for 14 days. During the entire experiment, solutions were aerated and their volume was maintained constant by adding distilled water. Distilled water was used as a control. The resistance index was determined by the ratio between the plant weight in the presence of cadmium and in the control [2]. We studied the effect of cadmium on the intensity of division of apical meristematic cells, the nucleolus characteristics, the level of chromosome aberrations in root meristematic cells (by metaphase and anaphase methods), the content of phytohormones (abscisic acid (ABA), indolylacetic acid (IAA), and cytokinins by enzyme immunoassay), as well as the content of free amino acids by ionexchange chromatography. The content of cadmium was determined by the Experiments were performed in quadruplicate and repeated at least five times. The statistical significance of differences between variants was estimated by Student’s t test. In the presence of cadmium at concentrations of 100, 10, and 1 mg/l, the resistance index of wheat was 0.75, 0.98, and 0.92 (Zhnitsa); 0.69, 1.03, and 1.05 (Omskaya-35); and 0.73, 0.88, and 1.05 (Irmenka), respectively. At these concentrations, the sprout/root ratio obtained after determination of linear sizes was 0.70, 1.31, 0.72, and 0.70 (Zhnitsa); 0.51, 1.06, 0.51, and 0.61 (Omskaya-35); and 0.63, 1.41, 0.70, and 0.60 (Irmenka), respectively. In the presence of 100 mg/l cadmium, the degree of hydration of plants significantly decreased: by 45% (Zhnitsa), 41% (Irmenka), and 41% (Omskaya-35). At concentrations of 10 and 1 mg/l, cadmium had no effect on the degree of hydration. The potential of wheat resistance to cadmium determined at early developmental stages in the Barsukova medium varied from very low (0.21) to very high (1.2) [2]. Thus, we did not reveal significant genotypic differences in plant responses to cadmium at the concentrations used.
    Doklady Biological Sciences 01/2009; 426:274-7.
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    ABSTRACT: New approaches to the detection of impaired nucleotides based on the allele specific ligation of a "C probe" followed by rolling circle amplification have been developed. The detection of amplification products was realized by using enzymatic and deoxyribozyme digestion of fluorescently-labeled DNA-RNA-DNA chimeric oligonucleotide structures in cycling probe technology (CPT) in real-time mode.
    Bioorganicheskaia khimiia 01/2009; 35(5):665-73.
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    ABSTRACT: The physiological activity of the plant growth regulator Epin-extra is investigated under conditions of sodium chloride salinity, cadmium stress, and low temperature. Epin-extra lessens the negative effect of stress factors on growth of spring wheat, Welsh onion, and cabbage: it reduces the level of cadmium-induced chromosome aberrations and concentration of this metal in plants exposed to a cadmium acetate solution. An increase of the level of expression of the cabbage cold shock protein gene (CSP5) under the effect of the bioregulator is established by the real-time PCR method with the use of interprimer fluorescence resonance energy transfer.
    Russian Agricultural Sciences 01/2009; 35(3):163-165.
  • D A Chemeris, Y M Nikonorov, V A Vakhitov
    Doklady Biochemistry and Biophysics 01/2008; 419:53-5. · 0.32 Impact Factor
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    ABSTRACT: The effect of benzyladenine (BA) on the activation of rRNA gene transcription was studied in wheat (Triticum aestivum and T. urartu) as related to the phenomenon of nucleolar dominance and the changes in the extent of methylation of the intergenic spacers in the subgenome A. The method of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to analyze the fragments of rDNA promoter regions amplified with the primers designed to recognize the sites of DNA isolated from BA-treated seedlings of diploid T. urartu and hexaploid T. aestivum and desaminated with metabisulfite. The subsequent genomic bisulfite sequencing of the amplification products was used to evaluate the level of methylation/demethylation of the particular cytosine residues. BA diminished methylation of cytosine residues in rDNA promoter regions to the level, which was different in two wheat species; these data presume that the transcriptional activities of rRNA genes in various wheat subgenomes depend on the extent of their methylation.
    Russian Journal of Plant Physiology 01/2007; 54(2):207-214. · 0.62 Impact Factor
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    ABSTRACT: The effect of stifun on wheat, Welsh onion, and corn plants under the effect of cadmium is investigated. The protective effect of this bioregulator manifested itself in preventing inhibition of growth, stabilizing mitotic phases, and reducing the level of chromosomal aberrations. The results of histochemical investigations permit the assumption that growth regulators can reduce the uptake of cadmium ions into plant tissues.
    Russian Agricultural Sciences 01/2007; 33(4):233-235.
  • Doklady Biochemistry and Biophysics 12/2006; 411:349-50. · 0.32 Impact Factor
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    ABSTRACT: Without Abstract
    Doklady Biochemistry and Biophysics 01/2006; 411:327-30. · 0.32 Impact Factor
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    ABSTRACT: The Atlas Rat cDNA Expression Array (BD Biosciences, United States) has been used to analyze changes in the expression of 588 genes in rat brain cells in response to a single administration of Ladasten, a 2-aminoadamantane derivative that has psychostimulating and anxiolytic effects. The analysis of hybridization on macroarrays, confirmed by the results of real-time quantitative RT-PCR, has demonstrated that Ladasten alters the expression of 12 genes in the rat brain. The GAT3 and CARBH genes are presumed to be pharmacologically important targets of Ladasten. The changes in their activity explain the mechanisms of the anxiolytic and mood-stabilizing effects of the drug. Ladasten has been shown to induce the genes whose products are involved in various signal pathways (APC, Rb, PKCIP, and PMCA), as well as the genes of cytoskeletal proteins (Tub1 and actin), synaptic proteins (SynIA&IB and PLP), and enzymes (Gapdh and NSE). The proteins encoded by these genes are presumably involved in compensatory and/or neuroplastic adaptation to the effects of Ladasten.
    Molecular Biology 02/2005; 39(2):244-252. · 0.64 Impact Factor
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    ABSTRACT: We have used the Rat Atlas cDNA Array ("BD Bioscience") to assess changes in mRNA expression of 588 genes in rat brain after acute treatment of 2-aminoadamantane compound--Ladasten. Drug exhibits the psychostimulating and anxyolitic actions. The analysis of results of hybridization on macrochips and their corroboration by quantitative real-time RT-PCR has allowed to reveal 12 genes, expression of which changes in response to ladasten in rat brain cells. The GAT3 and CARBH genes should be considered as primary pharmacologically significant targets and the changes of their functional conditions allows to explain the distinct mechanisms of anxyolitic properties of the drug. It was shown that Ladasten induced genes are involved in the different signalling pathways (APC, Rb, PKCIP, PMCA), genes encoding the cytosceletal proteins (Tubal, actin), synaptic proteins (Syn IA&IB, PLP) and metabolism enzymes (Gapdh, NSE). It is possible to assume, that proteins, encoded by the given genes participate in the compensatory and/or neuroplastic adaptation to biochemical effects of Ladasten.
    Molekuliarnaia biologiia 01/2005; 39(2):276-85.
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    ABSTRACT: A significant heterogeneity between bacteria Rhizobium galegae bv. officinalis and R. galegae bv. orientalis forming the nitrogen-fixing symbiosis with Galega officinalis and G. orientalis, respectively, and not forming any single cross-inoculation group, was found by means of RAPD and RFEL methods. The high level of sequence similiraty between lectins of these plants indicates at their close relationship. However the sequences of lectin sugar binding peptides (SBP) of G. orientalis (TYCNPGWDPRDR) and G. officinalis (TFYNEEWDLVIKDEH) were highly diverged. Amino acids of SBP which are involved in linkage of Ca2+ and Mn2+ ions responsible for stabilization of spatial structure of carbohydrate-binding "pocket", keep their position in peptide. It suggests that lectins participate in Rhizobium-legume symbiosis and that carbohydrate-binding site plays a key role in this process.
    Molekuliarnaia biologiia 01/2005; 39(1):103-11.
  • Doklady Biochemistry and Biophysics 01/2005; 401:150-3. · 0.32 Impact Factor
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    ABSTRACT: RAPD and RFEL analyses revealed appreciable genetic heterogeneity of Rhizobium galegae bv. officinalis and R. galegae bv. orientalis, which are nitrogen-fixing symbiosis partners of Galega officinalis and G. orientalis, respectively, and do not form a single cross-inoculation group. Comparison of nucleotide and amino acid sequences for their lectins revealed relatively high general homology, testifying again to their close phylogenetic relationships. Yet the lectin region of the carbohydrate-binding peptide (CBP) proved to differ considerably, being TYCNPGWDPRDR in G. orientalis and TFYNEEWDLVIKDEH in G. officinalis. Conserved positions in the CBP were observed for amino acid residues involved in binding Ca2+ and Mn2+ and stabilizing the spatial structure of the carbohydrate-binding pocket. These findings confirm the role in Rhizobium— legume symbiosis for lectins and especially for their carbohydrate-binding domains.
    Molecular Biology 12/2004; 39(1):90-97. · 0.64 Impact Factor
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    ABSTRACT: Some stages of low-temperature signal transduction causing appropriate cold stress response in plants are considered. The effects of Ca2+ chelators, Ca2+ channel blockers, and protein kinase inhibitors on protoplasts and plants of cabbage suggest that the initial stages of cold signal transduction are the change in membrane fluidity followed by the activation of calcium channels and elevation of Ca2+ influx into the cytoplasm. Increased concentration of Ca2+ in cytoplasm activates calcium-dependent protein kinase most likely participating in induction of transcription factors necessary for the expression of cold-regulated genes, in particular csp5. The protein kinase inhibitors staurosporine and wortmannin insignificantly repress the expression of csp5.
    Biochemistry (Moscow) 06/2004; 69(5):575-9. · 1.15 Impact Factor
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    ABSTRACT: This review deals with recent data on the structure and biochemical properties of dehydrins, proteins that are normally synthesized in maturating seeds during their desiccation, and also in vegetative tissues of plants treated with abscisic acid or exposed to environmental stress factors that result in cellular dehydration. The dehydrins are considered as stress proteins involved in formation of plant protective reactions against dehydration. The generally accepted classification of dehydrins is based on their structural features, such as the presence of conserved sequences, designated as Y-, S-, and K-segments. The K-segment representing a highly conserved 15 amino acid motif (EKKGIMDKIKEKLPG) forming amphiphilic alpha-helix has been found in all dehydrins. The pathways of regulation of dehydrin gene expression, putative functions of dehydrins, and molecular mechanisms of their actions are discussed.
    Biochemistry (Moscow) 10/2003; 68(9):945-51. · 1.15 Impact Factor
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    ABSTRACT: The process of accumulation of knowledge on wheat and related wild species during the 20th century is briefly reviewed with special reference to the evidence of the recent years on evolution of polyploid wheats and the role of diploid species. The latter serve as potential donors of the genomes, detection of which is particularly important because of the continuing speciation in the tribe Triticeae and artificial development of synthetic forms. The arguments in favor of the donor role for various diploid wheat species and aegilopses from the section Sitopsis are compared. It is stated that in the formation of the both lines of polyploid wheats turgidum-aestivum and timopheevi, diploid Aegilops speltoides acted as a maternal form. In addition to plasmatic genomes, this aegilops species introduced into them also the B and G nuclear subgenomes. A comparison of nucleotide sequences in the variable part of the promoter of evolutionary conserved rRNA genes in polyploid wheats with their counterparts in diploid wheats and aegilopses confirmed the accepted wheat phylogenies.
    Genetika 02/2003; 39(1):5-17. · 0.37 Impact Factor
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    ABSTRACT: The process of accumulation of knowledge on wheat and related wild species during the 20th century is briefly reviewed with special reference to the evidence of the recent years on evolution of polyploid wheats and the role of diploid species. The latter serve as potential donors of the genomes, detection of which is particularly important because of the continuing speciation in the tribe Triticeae and artificial development of synthetic forms. The arguments in favor of the donor role for various diploid wheat and aegilops species from the section Sitopsis are compared. It is stated that in the formation of the both lines of polyploid wheats turgidum–aestivumand timopheevi,diploid Aegilops speltoides acted as a maternal form. In addition to cytoplasmic genomes, this aegilops species introduced into them also the B and G nuclear subgenomes. A comparison of nucleotide sequences in the variable part of the promoter of evolutionary conserved rRNA genes in polyploid wheats with their counterparts in diploid wheats and aegilops species confirmed the accepted wheat phylogenies.
    Russian Journal of Genetics 12/2002; 39(1):1-11. · 0.43 Impact Factor
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    ABSTRACT: The effects of the phytohormones 6-benzylaminopurine (BAP) and 24-epibrassinolide (EB) on the nucleolar sizes in the interphase nuclei of root meristem were studied using the silver-staining procedure in wheat species with different ploidy levels (a polyploid series). In addition, the effects of the phytohormones on the cell mitotic activity in the roots of 5-day-old seedlings were studied. The higher the wheat species ploidy level, the higher its sensitivities to BAP and EB were. In diploid wheat, the maximum increase in the nucleolar organizing region (NOR) activity was observed after treatment with considerably higher phytohormone concentrations compared to tetra- and hexaploid wheat species. The phytohormone treatment increased both the sizes and the number of nucleoli in meristematic cells of seedling roots in all wheat species studied. It was assumed that the differences between the responses of wheat species with three different ploidy levels to different concentrations of phytohormones were related to their effects on the methylation/demethylation of cytosine residues in the rDNA promoter region.
    Genetika 12/2002; 38(11):1575-9. · 0.37 Impact Factor

Publication Stats

114 Citations
18.49 Total Impact Points

Institutions

  • 1997–2009
    • Ufa Scientific Center of the Russian Academy of Science
      Oufa, Bashkortostan, Russia
  • 2005
    • Russian Academy of Sciences
      • Institute of Biochemistry and Genetics
      Moskva, Moscow, Russia
  • 2002
    • University of California, Davis
      • Department of Plant Sciences
      Davis, CA, United States
  • 2001
    • Institute of Biology, Ufa Research Centre RAS
      Oufa, Bashkortostan, Russia