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51.
52.
Mariya V. Kovaleva Evgeniya I. Sukhanova Tatyana A. Trendeleva Marina V. Zyl’kova Ludmila A. Ural’skaya Kristina M. Popova Nils-Erik L. Saris Renata A. Zvyagilskaya 《Journal of bioenergetics and biomembranes》2009,41(3):239-249
In this study we used tightly-coupled mitochondria from Yarrowia lipolytica and Dipodascus (Endomyces) magnusii yeasts, possessing a respiratory chain with the usual three points of energy conservation. High-amplitude swelling and collapse
of the membrane potential were used as parameters for demonstrating induction of the mitochondrial permeability transition
due to opening of a pore (mPTP). Mitochondria from Y. lipolytica, lacking a natural mitochondrial Ca2+ uptake pathway, and from D. magnusii, harboring a high-capacitive, regulated mitochondrial Ca2+ transport system (Bazhenova et al. J Biol Chem 273:4372–4377, 1998a; Bazhenova et al. Biochim Biophys Acta 1371:96–100, 1998b; Deryabina and Zvyagilskaya Biochemistry (Moscow) 65:1352–1356, 2000; Deryabina et al. J Biol Chem 276:47801–47806, 2001) were very resistant to Ca2+ overload. However, exposure of yeast mitochondria to 50–100 μM Ca2+ in the presence of the Ca2+ ionophore ETH129 induced collapse of the membrane potential, possibly due to activation of the fatty acid-dependent Ca2+/nH+-antiporter, with no classical mPTP induction. The absence of response in yeast mitochondria was not simply due to structural
limitations, since large-amplitude swelling occurred in the presence of alamethicin, a hydrophobic, helical peptide, forming
voltage-sensitive ion channels in lipid membranes. Ca2+- ETH129-induced activation of the Ca2+/H+-antiport system was inhibited and prevented by bovine serum albumin, and partially by inorganic phosphate and ATP. We subjected
yeast mitochondria to other conditions known to induce the permeability transition in animal mitochondria, i.e., Ca2+ overload (in the presence of ETH129) combined with palmitic acid (Mironova et al. J Bioenerg Biomembr 33:319–331, 2001; Sultan and Sokolove Arch Biochem Biophys 386:37–51, 2001), SH-reagents, carboxyatractyloside (an inhibitor of the ADP/ATP translocator), depletion of intramitochondrial adenine nucleotide
pools, deenergization of mitochondria, and shifting to acidic pH values in the presence of high phosphate concentrations.
None of the above-mentioned substances or conditions induced a mPTP-like pore. It is thus evident that the permeability transition
in yeast mitochondria is not coupled with Ca2+ uptake and is differently regulated compared to the mPTP of animal mitochondria. 相似文献
53.
A. A. Dobrovol’skaya G. B. Rodionova A. S. Voronkov L. V. Kovaleva 《Russian Journal of Plant Physiology》2009,56(3):394-401
Sporophyte-gametophyte interactions between anther and male gametophyte were investigated in two (fertile and sterile) clones of petunia (Petunia hybrida L.) with different reproductive strategies. Structural and functional reorganization of sporophyte tissues in the developing anther of fertile clone is closely coordinated with each of the successive stages of male gametophyte development (from meiosis to the formation of binuclear pollen) and comprises not only destruction of tapetum and three middle layers of the wall but also an activation of gas exchange and a rise in the content of sugars (sucrose, fructose, and glucose). In sterile clone, degradation of tapetum and anomalies in the development of sporogenic tissue were simultaneously observed in the prophase of meiosis. The death of microsporocytes and degeneration of tapetum were accompanied by a decrease in the level of sucrose delivered to the anther tissues and changes in the ratio between sucrose and hexoses in favor of glucose. 相似文献
54.
Kovaleva TA Belenova AS Bitiutskaia LA Trofimova OD Grechkina MV Bagno OP Artiukhov VG 《Biofizika》2011,56(4):617-622
It has been shown by classical biophysical and biochemical methods in combination with atomic microscopy that lipase from Rhizopus niveus exists in a water solution as a dimer with a molecular weight of 96 kDa. The rate of splitting of triglycerides by a dimeric molecules is twice that of monomers. The heat stability of the monomeric form of lipase at temperatures of 20-60 degrees C is significantly higher than that of the native molecule. 相似文献
55.
Starch gel electrophoresis was performed to study polymorphism of hordeins encoded by the Hrd A, Hrd B, and Hrd Floci in 366 local old barley accessions from Iran and Central Asian countries, including Turkmenistan, Uzbekistan, Tajikistan (Mountain Badahsan), and Kirgizia. In total, 60 alleles with frequencies of 0.0003-0.2818 were observed for the Hrd A locus, 106 alleles with frequencies of 0.0003-0.1603 were observed for the Hrd B locus, and five alleles with frequencies of 0.0164-0.4131 were observed for the Hrd Flocus. The alleles and allele frequencies displayed irregular distributions in barley populations of the above countries. Cluster analysis of the matrix of allele frequencies in populations from known collection sites revealed a cluster structure of local barley populations within each country. Local populations formed five differently sized clusters in Iran, six in Turkmenistan, three in Uzbekistan, and three in Kirgizia. The variation and allele frequency distribution of the hordein-coding loci in Iran and Central Asian countries were assumed to result from the introduction and spreading of barley forms via migrations of husbandmen. 相似文献
56.
Knizhnik AV Kovaleva OB Laktionov KK Mochal'nikova VV Komel'kov AV Chevkina EM Zborovskaia IB 《Molekuliarnaia biologiia》2011,45(2):307-315
Evaluation of tumor markers expression pattern which determines individual progression parameters is one of the major topics in molecular oncopathology research. This work presents research on expression analysis of several Ras-Ral associated signal transduction pathway proteins (Arf6, RalA and BIRC5) in accordance with clinical criteria in non small cell lung cancer patients. Using Western-blot analysis and RT-PCR Arf6, RalA and BIRC5 expression has been analyzed in parallel in 53 non small cell lung cancer samples of different origin. Arf6 protein expression was elevated in 55% non small cell lung cancer tumor samples in comparison with normal tissue. In the group of squamous cell lung cancer Arf6 expression elevation was observed more often. RalA protein expression was decreased in comparison to normal tissue samples in 64% of non small cell lung cancer regardless to morphological structure. Correlation between RalA protein expression decrease and absence of regional metastases was revealed for squamous cell lung cancer. BIRC5 protein expression in tumor samples versus corresponding normal tissue was 1.3 times more often elevated in the squamous cell lung cancer group (in 76% tumor samples). At the same time elevation of BIRC5 expression was fixed only in 63% of adenocarcinoma tumor samples. A statistically significant decrease (p = 0.0158) of RalA protein expression and increase (p = 0.0498) of Arf6 protein expression in comparison with normal tissue was found for T1-2N0M0 and T1-2N1-2M0 groups of squamous cell lung cancer correspondingly. 相似文献
57.
T. P. Tourova O. L. Kovaleva B. K. Bumazhkin E. O. Patutina B. B. Kuznetsov I. A. Bryantseva V. M. Gorlenko D. Yu. Sorokin 《Microbiology》2011,80(6):812-825
The genes encoding the key metabolic reactions are often used as functional markers for phylogenetic analysis and microbial
ecology studies. The composition and structure of the genes encoding ribulose-1,5-bisphosphate carboxylase (RuBisCO) of various
photoautotrophic bacteria, representatives of the order Chromatiales, including collection strains and the strains isolated from saline and soda lakes, were studied in detail. The green-like
form I RuBisCO was detected in the majority of the studied strains. In some strains, the genes encoding both form I and form
II RuBisCO were present, which has not been previously known for the representatives of this group of bacteria. Moreover,
RuBisCO genes were used as functional markers to investigate the autotrophic microbial community inhabiting the upper horizons
of bottom sediments of two saline soda lakes and two hypersaline neutral lakes of the Kulunda Steppe. In general, the diversity
of autotrophic bacteria in the studied sediment horizons was low. In soda lakes, haloalkaliphilic cyanobacteria and sulfuroxidizing
bacteria (SOB) of the genus Halorhodospira were predominant. In saline lakes, halophilic chemoautotrophic SOB Halothiobacillus and Thioalkalivibrio were found, as well as photoautotrophic bacteria of the genus Ectothiorhodosinus and cyanobacteria. Many phylotypes remained unidentified, which indicates the presence of groups of microorganisms with an
unknown type of metabolism. 相似文献
58.
T. P. Tourova O. I. Keppen O. L. Kovaleva N. V. Slobodova I. A. Berg R. N. Ivanovsky 《Microbiology》2009,78(3):339-349
Strain BBS, the purple sulfur bacterium assigned initially to the species Thiocapsa roseopersicina, is the best studied representative of this species. However, no molecular phylogenetic analysis has been performed to confirm
its systematic position. Based on the results of analysis of the sequences of 16S rRNA, cbbL, and nifH genes, DNA-DNA hybridization with the T. roseopersicina type strain, and comparative analysis of the phenotypic characteristics of various species belonging to the genus Thiocapsa, we suggest that strain BBS should be assigned to a new species of the genus Thiocapsa, Thiocapsa bogorovii sp. nov.
Original Russian Text ? T.P. Tourova, O.I. Keppen, O.L. Kovaleva, N.V. Slobodova, I.A. Berg, R.N. Ivanovsky, 2009, published
in Mikrobiologiya, 2009, Vol. 78, No. 3, pp. 381–392. 相似文献
59.
It has earlier been shown that CYP11A1 (cytochrome P450scc precursor), synthesized in yeast cells, is imported into yeast mitochondria. However, in large part the foreign protein undergoes degradation or aggregates. In this work, we tried to prevent aggregation of CYP11A1 and stimulate its insertion into the mitochondrial inner membrane by substituting cholesterol (a substrate for cytochrome P450scc) for ergosterol in yeast cells. To this end, an ergosterol-deficient Saccharomyces cerevisiae mutant, growing in the presence of cholesterol and expressing a modified bovine CYP11A1 gene, was used. Under defined conditions, the mitochondrial respiratory system developed in this yeast and CYP11A1 with the CoxIV targeting presequence was imported into the mitochondria, being then proteolytically processed. However, substitution of cholesterol for ergosterol did not result in lowered aggregation of the imported CYP11A1 and its increased content in the SMP fraction. Hence, the presence of cholesterol is not instrumental in proper intramitochondrial compartmentalization and folding of CYP11A1. 相似文献
60.