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V A Vakhitov

Publications and source records attributed to V A Vakhitov.

At least 19 recordsLinked to original sources
PubMed2004

Initial stages of low-temperature induction of cabbage cold shock protein gene csp5.

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.

Brassica↗
PubMed2003

The plant dehydrins: structure and putative functions.

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.

Gene Expression Regulation, Plant↗
PubMed2003

[Phylogeny of Triticum L. and Aegilops L. genuses inferred from a comparative analysis of nucleotide sequences in promoter rDNA regions of individual species].

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.

Base Sequence↗
PubMed2002

[NOR (nucleolar organizer region) activity in wheat species with different ploidy levels treated with phytohormones].

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.

Adenine↗
PubMed2001

Functional analysis of diploid wheat rRNA promoter by transient expression.

The rRNA gene promoter regions of three diploid wheats Triticum boeoticum Boiss, Triticum urartu Tum. ex Gandil, and Triticum monococcum L. have been sequenced and analyzed. It has been found that the rRNA promoter initiation regions of diploid wheats contain the sequences, which differ from the evolutionary conserved TATAGTAGG (+1 is underlined) motif of monocots. The transient expression assay in wheat protoplasts confirmed that cloned sequences are active promoters. Deletion analysis showed that the promoter sequence localized between -113 and +15 (relative to +1) is enough to direct RNA polymerase I-dependent transcription.

Arabidopsis↗
PubMed2001

Childhood peptic ulcer in the Ural area of Russia: clinical status and Helicobacter pylori-associated immune response.

BACKGROUND: The relation of between Helicobacter pylori and the symptoms in children is still controversial. Determination of specific immunoglobulin (Ig) G antibodies to H. pylori may represent a useful test to screen the patients with acid peptic disease in childhood. The aim of this study was to investigate the spectrum of clinical symptoms, endoscopic and histologic lesions, and clinical value of serum IgG response to H. pylori in school-aged children residing in the Ural area of Russia for the identification of Helicobacter -related acid-peptic disease. METHODS: During 1998, 129 pediatric outpatients (mean age, 12.1 +/- 2.3 years; age range, 10-15 years; 41 boys, 88 girls) were undergoing gastroduodenal endoscopy for evaluation of chronic abdominal pain. H. pylori colonization was determined by histology, urease test, and polymerase chain reaction. H. pylori IgG antibodies were found by using an enzyme-linked immunosorbent assay. RESULTS: There was a high prevalence of H. pylori infection (80%) and peptic ulcers (24%) among the study group. Duodenal ulcers were detected in 31 of the children; all of them were H. pylori positive. Family history of peptic ulcers, nighttime pain associated with nocturnal awakening, fasting pain relieved by food, pain associated with meals, postprandial pain, bitter taste, and heartburn were the clinical signs that helped to distinguish the ulcer-positive children from the ulcer-negative H. pylori group. Duodenal ulcer patients had higher anti- H. pylori IgG titers compared with the levels of IgG antibodies in the infected children without ulcers ( P < 0.001). Peptic ulcer disease was a more common finding in the Ural ethnic group of Asians (Bashkirs) compared with the pediatric population of Russian origin. CONCLUSIONS: These results provide further evidence for a causal relation between H. pylori -associated peptic ulcer disease in childhood and relevant clinical symptoms. High titers of anti- H. pylori IgG might serve as a useful noninvasive indicator of ulcer disease.

Abdominal Pain↗
PubMed2001

[Analysis of the primary structure of hantavirus RNA, detected in organs of patients that died from HFKS in the Republic of Bashkortostan].

Fragments of the minor S and middle M segments of Hantavirus genome RNA were isolated by reverse transcription-polymerase chain reaction (RT-PCR) from the organs of patients who died from hemorrhagic fever with the renal syndrome (HFRS) during an epidemic outbreak of this infection in the Bashkortostan Republic in 1997-1998. The sizes of the resultant PCR fragments were 317 p. n. for S segment and 416 p. n. for M segment. Their primary structures (GENBANK registration numbers AJ133581 and AJ133582) were determined and they were compared with the nucleotide sequences of the respective genome sites of Hantavirus strain CG1820/Ufa-83 isolated from Clethrionomys in Bashkortostan in 1983. The homologies of nucleotide sequences of the corresponding sites of S and M segments of RNA isolate of 1997 and CG1820/Ufa-83 were 87.7 and 96.6%, respectively. The authors discuss the probability of circulation of hantaviruses differing by individual features of primary structure of genome RNA in Bashkortostan.

Amino Acid Sequence↗
PubMed2001

[Hydrocarbon-binding peptides from bean plant lectins in connection with various host specific macrosymbionts during development of symbiosis with rhizobium bacteria].

The nucleotide sequences of 280-360-bp domains of lectin genes from 20 legume species belonging to 17 genera have been determined. A computer analysis of the sequences has been performed with the LASERGENE package. Based on this analysis, we constructed the phylogenetic tree of the lectins, which reflects their phylogenetic and evolutionary relationships, and predicted the amino-acid sequences of the corresponding protein domains. Features of the structure of the hydrocarbon-binding lectin domains were elucidated in some species of legume genera from the temperate climatic zone. The domains were highly variable and contained the consensus sequence AspTrePheXxxAsxXxxXxxTrpAspProXxxXxxIns/DelArgHis bearing the bulk of amino acid replacements, insertions, and deletions. An association between legume groups (including species from different genera and tribes) symbiotic with the same rhizobium species and the similarity between the hydrocarbon-binding domains of lectins from these plants was found.

Amino Acid Sequence↗
PubMed1998

[Use of a PCR method for controlling pure-breeding of honeybees Apis mellifera mellifera L. in the southern Urals].

A key problem of honeybee (Apis mellifera mellifera) breeding in the Southern Urals is its cross-breeding with the Caucasian honeybee Apis mellifera caucasica. Mitochondrial DNA (mtDNA) in these subspecies differ in the length of a fragment localized between genes CO-I and CO-II, which can be used as a marker. A pair of 20-mer primers for PCR was chosen by means of computer design in order to determine the fragment size in both of the subspecies. The amplified fragment was shown to have a length of 350 bp in A. m. caucasica and 600 bp in A. m. mellifera. The difference in length results from the different ratio between two main elements P and Q, which comprise a major part of this sequence in these subspecies: a copy of P element and two copies of Q element in A. m. mellifera, and a copy of Q element only in A. m. caucasica. This sharply defined distinction allows us to use PCR for differentiating the subspecies, estimating the heterogeneity in the colonies, and rejecting queens in the selection process because of the maternal inheritance of the studied character. The nucleotide sequence of the amplified mtDNA fragment of A. m. mellifera was determined.

Amino Acid Sequence↗
PubMed1997

[Unusual motifs of the nucleotide sequence adjacent to the putative transcription initiation site in the rDNA intergenic spacer of diploid wheat Triticum urartu Thum. ex Gandil, T. boeoticum Boiss, and T. monococcum L].

In the intergenic spacer (IGS) of rDNA of diploid wheats Triticum urartu, T. boeoticum, and T. monococcum, the uncommon motives adjacent to the site of transcription initiation (TIS) are revealed. They are located in the region from -6 to +1 relative to the putative TIS and are not encountered in cereals studied earlier. In T. urartu and T. boeoticum, the motif TACTATG has been revealed, in T. monococcum--TATTATG, while diploid Aegilops speltoides has the motif TATAGTA, typical of the remaining cereal species. The TIS-surrounding rDNA IGS region of diploid wheats was compared to the correspondent known rDNA IGS regions of different plant and animal species.

Base Sequence↗
PubMed1997

[Nucleotide sequence and genomic organization of repeating units of the AT-rich family or repeats in the diploid wheat Triticum monococcum L].

In diploid wheat Triticum monococcum L., a novel family of AT-rich repeated DNA sequences arranged in clusters of tandem arrays of 560-bp fragments is described. The nucleotide sequence of a 556-bp repeat unit was determined. The basic structural unit of this repeated DNA family contains subrepeats with the main motif AAACATTGTTAC. This type of repetitive DNA sequence could evolve via tandem amplification of short subrepeats with some subsequent divergence, and/or via recombination with unique sequences. Structural organization of homologous sequences, revealed by blot hybridization in other representatives of the Triticeae tribe, suggest that this family of repeated DNA is genome-specific.

Adenine↗
PubMed1989

[Microheterogeneity of the primary structure of the short repeated 5S DNA unit in diploid wheat Triticum monococcum L].

Nucleotide sequences of two 5S rRNA genes located in repeated 327 bp long units were determined in diploid wheat Triticum monococcum. They were compared with sequences of 5S rRNA genes of Tr. monococcum and Tr. aestivum which were earlier determined. The differences were revealed in two localizations of the nucleotide sequence in 5S DNA coding regions of Tr. monococcum and - in nine localizations in nontranscribed spacer. It was established that the nucleotide sequence of 5S rRNA gene cloned in pTm5S9 plasmid and 5S DNA coding region in Tr. aestivum have significant homology. Diploid wheat Tr. monococcum was supposed to have 5S rRNA genes with different functional activity within one multigene family.

Base Sequence↗
PubMedDate not supplied

[Establishment of the phylogenetic relationship between the microbial producers of cyclodextrin glucanotransferases using their complete amino acid sequences].

A phylogenetic tree was constructed on the basis of the amino acid sequences of the known cyclodextrin glucanotransferases (CDGTs), including those deduced from the nucleotide sequences of Bacillus sp. strain 6.6.3 and Paenibacillus macerans IB-7 genes encoding alpha- and beta-CDGTs. The tree clearly demonstrates the existence of distinct phylogenetic groups of CDGT-producing microorganisms and the divergence of the alpha-, beta-, and gamma-CDGT produced by microorganisms from the genera Bacillus, Paenibacillus, Brevibacillus, and Thermoanaerobacter from a common ancestor, whereas the CDGT of Klebsiella pneumoniae is independent and results from the convergence of different ancestors. The degree of homology of the leader peptide sequences of CDGTs may serve as a criterion of intraspecies relatedness between CDGT-producing microorganisms.

Amino Acid Sequence↗
PubMedDate not supplied

[Hormonal transcription regulation in plants].

The review considers the mechanisms of gene transcription regulation by phytohormones, which play an important role in controlling major genetic programs in plants. The focus is cis-regulatory elements, which occur in the phytohormone-responsive gene promoters and, along with trans-acting factors and other proteins, ensure the effective reception of the hormonal signal.

Amino Acid Sequence↗