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101.
Vartapetian B. Crawford R. Sachs M. Hill R. Fagerstedt K. Dolferus R. Kuznetsov Vl. 《Russian Journal of Plant Physiology》2011,58(2):382-385
This paper is dedicated to the 35 year jubilee of the founding and the activity of the International Society for Plant Anaerobiosis
(ISPA). The role of ISPA members in opening new avenues of research is emphasized. Major developments in the study of plant
hypoxic and anoxic stress achieved during subsequent decades are considered. Special attention is given to plant adaptation
and damage under conditions of oxygen deficiency and complete absence of oxygen as well as during the post-anaerobic period.
Plant metabolic adaptation to anaerobic stress and the capacity of some plants to avoid anaerobiosis are discussed. 相似文献
102.
Kuznetsov NA Koval VV Zharkov DO Vorobjev YN Nevinsky GA Douglas KT Fedorova OS 《Biochemistry》2007,46(2):424-435
Formamidopyrimidine-DNA glycosylase (Fpg) is responsible for removal of 8-oxoguanine (8-oxoG) and other oxidized purine lesions from DNA and can also excise some oxidatively modified pyrimidines [such as dihydrouracil (DHU)]. Fpg is also specific for a base opposite the lesion, efficiently excising 8-oxoG paired with C but not with A. We have applied stopped-flow kinetics using intrinsic tryptophan fluorescence of the enzyme and fluorescence of 2-aminopurine-labeled DNA to analyze the conformational dynamics of Escherichia coli Fpg during processing of good substrates (8-oxoG.C), poor substrates (8-oxoG.A), and substrates of unclear specificity (such as DHU and 8-oxoG opposite T or G). The analysis of fluorescence traces allows us to conclude that when the enzyme encounters its true substrate, 8-oxoG.C, the complex enters the productive catalytic reaction after approximately 50 ms, partitioning the substrate away from the competing dissociation process, while poor substrates linger in the initial encounter complex for longer. Several intermediate ES complexes were attributed to different structures that exist along the reaction pathway. A likely sequence of events is that the damaged base is first destabilized by the enzyme binding and then everted from DNA, followed by insertion of several amino acid residues into DNA and isomerization of the enzyme into a pre-excision complex. We conclude that rejection of the incorrect substrates occurs mostly at the early stage of formation of the pre-eversion recognition complex, supporting the role of indirect readout in damage recognition. 相似文献
103.
104.
RAD51C deficiency in mice results in early prophase I arrest in males and sister chromatid separation at metaphase II in females 下载免费PDF全文
Kuznetsov S Pellegrini M Shuda K Fernandez-Capetillo O Liu Y Martin BK Burkett S Southon E Pati D Tessarollo L West SC Donovan PJ Nussenzweig A Sharan SK 《The Journal of cell biology》2007,176(5):581-592
RAD51C is a member of the RecA/RAD51 protein family, which is known to play an important role in DNA repair by homologous recombination. In mice, it is essential for viability. Therefore, we have generated a hypomorphic allele of Rad51c in addition to a null allele. A subset of mice expressing the hypomorphic allele is infertile. This infertility is caused by sexually dimorphic defects in meiotic recombination, revealing its two distinct functions. Spermatocytes undergo a developmental arrest during the early stages of meiotic prophase I, providing evidence for the role of RAD51C in early stages of RAD51-mediated recombination. In contrast, oocytes can progress normally to metaphase I after superovulation but display precocious separation of sister chromatids, aneuploidy, and broken chromosomes at metaphase II. These defects suggest a possible late role of RAD51C in meiotic recombination. Based on the marked reduction in Holliday junction (HJ) resolution activity in Rad51c-null mouse embryonic fibroblasts, we propose that this late function may be associated with HJ resolution. 相似文献
105.
N. L. Radyukina Yu. V. Ivanov A. V. Kartashov N. I. Shevyakova V. Yu. Rakitin V. N. Khryanin Vl. V. Kuznetsov 《Russian Journal of Plant Physiology》2007,54(5):612-618
The avens (Geum urbanum L.) seedlings were grown for 6 weeks until the expansion of five to six leaves and then exposed to salinity shock (300 mM NaCl in the nutrient medium) or to a gradual (within 4 days) increase in NaCl concentration from 100 to 400 mM. The dynamics of stress-dependent accumulation of Na+, Cl?, proline, and polyamines in leaves and roots was measured, together with activities of antioxidant enzymes, namely, superoxide dismutase (SOD) and guaiacol-dependent peroxidase occurring in soluble, ionically bound, and covalently bound forms. It is shown that avens plants can adapt to gradual salinization by mobilizing stressinducible protective mechanisms (accumulation of proline and spermine) and by activating constitutive enzyme systems (SOD and peroxidase). 相似文献
106.
This article describes DP-Bind, a web server for predicting DNA-binding sites in a DNA-binding protein from its amino acid sequence. The web server implements three machine learning methods: support vector machine, kernel logistic regression and penalized logistic regression. Prediction can be performed using either the input sequence alone or an automatically generated profile of evolutionary conservation of the input sequence in the form of PSI-BLAST position-specific scoring matrix (PSSM). PSSM-based kernel logistic regression achieves the accuracy of 77.2%, sensitivity of 76.4% and specificity of 76.6%. The outputs of all three individual methods are combined into a consensus prediction to help identify positions predicted with high level of confidence. AVAILABILITY: Freely available at http://lcg.rit.albany.edu/dp-bind. SUPPLEMENTARY INFORMATION: http://lcg.rit.albany.edu/dp-bind/dpbind_supplement.html. 相似文献
107.
Iakovleva KE Kurzeev SA Stepanova EV Fedorova TV Kuznetsov BA Koroleva OV 《Prikladnaia biokhimiia i mikrobiologiia》2007,43(6):730-739
Phenolic acids and flavonoids were characterized by cyclic voltammetry and total antioxidant activity in the reaction with the ABTS cation radical. Anode peak voltages (Eap) and their pH dependences were determined for the studied phenolic acids and flavonoids. The Eap and Trolox equivalent antioxidant capacity (TEAC) values were found to correlate for polyphenols, which react with the ABTS cation radical in two steps. Correlation between the half-wave potential (Ep/2) and TEAC was determined for electrochemically irreversible compounds. Mechanisms of the reaction of phenolics on the electrode involving one- and two-electron oxidation are proposed. 相似文献
108.
Roland Schwarz Chunguang Liang Christoph Kaleta Mark Kühnel Eik Hoffmann Sergei Kuznetsov Michael Hecker Gareth Griffiths Stefan Schuster Thomas Dandekar 《BMC bioinformatics》2007,8(1):313
Background
Modeling of metabolic networks includes tasks such as network assembly, network overview, calculation of metabolic fluxes and testing the robustness of the network. 相似文献109.
Cameron C Scott Stefania Vossio Fabrizio Vacca Berend Snijder Jorge Larios Olivier Schaad Nicolas Guex Dmitry Kuznetsov Olivier Martin Marc Chambon Gerardo Turcatti Lucas Pelkmans Jean Gruenberg 《EMBO reports》2015,16(6):741-752
The Wnt pathway, which controls crucial steps of the development and differentiation programs, has been proposed to influence lipid storage and homeostasis. In this paper, using an unbiased strategy based on high-content genome-wide RNAi screens that monitored lipid distribution and amounts, we find that Wnt3a regulates cellular cholesterol. We show that Wnt3a stimulates the production of lipid droplets and that this stimulation strictly depends on endocytosed, LDL-derived cholesterol and on functional early and late endosomes. We also show that Wnt signaling itself controls cholesterol endocytosis and flux along the endosomal pathway, which in turn modulates cellular lipid homeostasis. These results underscore the importance of endosome functions for LD formation and reveal a previously unknown regulatory mechanism of the cellular programs controlling lipid storage and endosome transport under the control of Wnt signaling. 相似文献
110.
Guzun R Timohhina N Tepp K Gonzalez-Granillo M Shevchuk I Chekulayev V Kuznetsov AV Kaambre T Saks VA 《Amino acids》2011,40(5):1333-1348
Physiological role of creatine (Cr) became first evident in the experiments of Belitzer and Tsybakova in 1939, who showed
that oxygen consumption in a well-washed skeletal muscle homogenate increases strongly in the presence of creatine and with
this results in phosphocreatine (PCr) production with PCr/O2 ratio of about 5–6. This was the beginning of quantitative analysis in bioenergetics. It was also observed in many physiological
experiments that the contractile force changes in parallel with the alteration in the PCr content. On the other hand, it was
shown that when heart function is governed by Frank–Starling law, work performance and oxygen consumption rate increase in
parallel without any changes in PCr and ATP tissue contents (metabolic homeostasis). Studies of cellular mechanisms of all
these important phenomena helped in shaping new approach to bioenergetics, Molecular System Bioenergetics, a part of Systems
Biology. This approach takes into consideration intracellular interactions that lead to novel mechanisms of regulation of
energy fluxes. In particular, interactions between mitochondria and cytoskeleton resulting in selective restriction of permeability
of outer mitochondrial membrane anion channel (VDAC) for adenine nucleotides and thus their recycling in mitochondria coupled
to effective synthesis of PCr by mitochondrial creatine kinase, MtCK. Therefore, Cr concentration and the PCr/Cr ratio became
important kinetic parameters in the regulation of respiration and energy fluxes in muscle cells. Decrease in the intracellular
contents of Cr and PCr results in a hypodynamic state of muscle and muscle pathology. Many experimental studies have revealed
that PCr may play two important roles in the regulation of muscle energetics: first by maintaining local ATP pools via compartmentalized
creatine kinase reactions, and secondly by stabilizing cellular membranes due to electrostatic interactions with phospholipids.
The second mechanism decreases the production of lysophosphoglycerides in hypoxic heart, protects the cardiac cells sarcolemma
against ischemic damage, decreases the frequency of arrhythmias and increases the post-ischemic recovery of contractile function.
PCr is used as a pharmacological product Neoton in cardiac surgery as one of the components of cardioplegic solutions for
protection of the heart against intraoperational injury and injected intravenously in acute myocardial ischemic conditions
for improving the hemodynamic response and clinical conditions of patients with heart failure. 相似文献