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71.
On autocorrelation in a Poisson regression model 总被引:3,自引:0,他引:3
72.
Pimenov N. V. Savvichev A. S. Rusanov I. I. Lein A. Yu. Ivanov M. V. 《Microbiology》2000,69(6):709-720
Functioning of microbial communities in surface sediments of the Haakon Mosby underwater mud volcano (lat. 72°N) and in gas seepage fields of the Vestnesa Ridge was investigated using Mir-1 and Mir-2 deep-sea submersibles during the 40th voyage of the research vessel Academician Mstislav Keldysh. Large areas of sedimentary deposits of the Haakon Mosby mud volcano (HMMV) and pockmarks of the Vestnesa Ridge (VR) are covered with bacterial mats 0.1 to 0.5 cm thick. The microbial community making up bacterial mats of the HMMV was dominated by large filamentous bacteria with filaments measuring up to 100 m in length and 2 to 8 m in width. The occurrence of rosettes allowed the observed filamentous bacteria to be referred to the morphologically similar genera Leucothrix or Thiothrix. Three morphological types of filamentous bacteria were identified in bacterial mats covering VR pockmarks. Filaments of type one are morphologically similar with representatives of the genera Thioploca or Desmanthos. Type two filaments had numerous inclusions of sulfur and resembled representatives of the genus Thiothrix. The third morphological type was constituted by single filaments made up of tightly connected disk-like cells and can be assigned to the genus Beggiatoa. The rates of methane oxidation (up to 1570 l C/(dm3 day)) and sulfate reduction (up to 17 mg S/(dm3day)) measured in the surface sediments of HMMV and VR were close to the maximum rates of these processes observed in heavily polluted regions of the northwestern shelf of the Black Sea. High rates of microbiological processes correlated with the high number of bacteria. The rate of methane production in sediments studied was notably lower and ranged from 0.1 to 3.5 CH4/(dm3 day). Large areas of the HMMV caldera were populated by pogonophoras, represented by the two species Sclerolinum sp. and Oligobrachia sp. The mass development of Sclerolinum sp. in the HMMV caldera was by the activity of aerobic methane-oxidizing bacteria localized inside the cells of these animals. Bacterial cells were also found in the trophosome tissue of Oligobrachia sp., but in cells of these bacteria, we did not observe the membrane structures typical of methanotrophs. The localization pattern of pogonophoras on the surface of reduced sediments suggests that the predominant bacteria in Oligobrachia tissues are sulfur-oxidizing endosymbionts. 相似文献
73.
Seung Kyoon Woo Min Seong Kwon Alexander Ivanov Volodymyr Gerzanich J. Marc Simard 《The Journal of biological chemistry》2013,288(5):3655-3667
The sulfonylurea receptor 1 (Sur1)-NCCa-ATP channel plays a central role in necrotic cell death in central nervous system (CNS) injury, including ischemic stroke, and traumatic brain and spinal cord injury. Here, we show that Sur1-NCCa-ATP channels are formed by co-assembly of Sur1 and transient receptor potential melastatin 4 (Trpm4). Co-expression of Sur1 and Trpm4 yielded Sur1-Trpm4 heteromers, as shown in experiments with Förster resonance energy transfer (FRET) and co-immunoprecipitation. Co-expression of Sur1 and Trpm4 also yielded functional Sur1-Trpm4 channels with biophysical properties of Trpm4 and pharmacological properties of Sur1. Co-assembly with Sur1 doubled the affinity of Trpm4 for calmodulin and doubled its sensitivity to intracellular calcium. Experiments with FRET and co-immunoprecipitation showed de novo appearance of Sur1-Trpm4 heteromers after spinal cord injury in rats. Our findings depart from the long-held view of an exclusive association between Sur1 and KATP channels and reveal an unexpected molecular partnership with far-ranging implications for CNS injury. 相似文献
74.
MARIA JOSÉ ASINS IRENE VILLALTA MOHAMED M. ALY RAQUEL OLÍAS PAZ ÁLVAREZ DE MORALES RAÚL HUERTAS JUN LI NOELIA JAIME‐PÉREZ ROSARIO HARO VERÓNICA RAGA EMILIO A. CARBONELL ANDRÉS BELVER 《Plant, cell & environment》2013,36(6):1171-1191
The location of major quantitative trait loci (QTL) contributing to stem and leaf [Na+] and [K+] was previously reported in chromosome 7 using two connected populations of recombinant inbred lines (RILs) of tomato. HKT1;1 and HKT1;2, two tomato Na+‐selective class I‐HKT transporters, were found to be closely linked, where the maximum logarithm of odds (LOD) score for these QTLs located. When a chromosome 7 linkage map based on 278 single‐nucleotide polymorphisms (SNPs) was used, the maximum LOD score position was only 35 kb from HKT1;1 and HKT1;2. Their expression patterns and phenotypic effects were further investigated in two near‐isogenic lines (NILs): 157‐14 (double homozygote for the cheesmaniae alleles) and 157‐17 (double homozygote for the lycopersicum alleles). The expression pattern for the HKT1;1 and HKT1;2 alleles was complex, possibly because of differences in their promoter sequences. High salinity had very little effect on root dry and fresh weight and consequently on the plant dry weight of NIL 157‐14 in comparison with 157‐17. A significant difference between NILs was also found for [K+] and the [Na+]/[K+] ratio in leaf and stem but not for [Na+] arising a disagreement with the corresponding RIL population. Their association with leaf [Na+] and salt tolerance in tomato is also discussed. 相似文献
75.
76.
Vasil Georgiev Ivan Ivanov Strahil Berkov Mladenka Ilieva Milen Georgiev Tatiana Gocheva Atanas Pavlov 《Engineering in Life Science》2012,12(5):534-543
Shoot culture of summer snowflake (Leucojum aestivum L.) was successfully cultivated in an advanced modified glass‐column bioreactor with internal sections for production of Amaryllidaceae alkaloids. The highest amounts of dry biomass (20.8 g/L) and galanthamine (1.7 mg/L) were achieved when shoots were cultured at 22°C and 18 L/(L·h) flow rate of inlet air. At these conditions, the L. aestivum shoot culture possessed mixotrophic‐type nutrition, synthesizing the highest amounts of chlorophyll (0.24 mg/g DW (dry weight) chlorophyll A and 0.13 mg/g DW chlorophyll B). The alkaloids extract of shoot biomass showed high acetylcholinesterase inhibitory activity (IC50 = 4.6 mg). The gas chromatography–mass spectrometry (GC/MS) profiling of biosynthesized alkaloids revealed that galanthamine and related compounds were presented in higher extracellular proportions while lycorine and hemanthamine‐type compounds had higher intracellular proportions. The developed modified bubble‐column bioreactor with internal sections provided conditions ensuring the growth and galanthamine production by L. aestivum shoot culture. 相似文献
77.
78.
Carbonic anhydrase (CA) activity of pea thylakoids, thylakoid membranes enriched with photosystem I (PSI-membranes), or photosystem
II (PSII-membranes) as well as both supernatant and pellet after precipitation of thylakoids treated with detergent Triton
X-100 were studied. CA activity of thylakoids in the presence of varying concentrations of Triton X-100 had two maxima, at
Triton/chlorophyll (triton/Chl) ratios of 0.3 and 1.0. CA activities of PSI-membranes and PSII-membranes had only one maximum
each, at Triton/Chl ratio 0.3 or 1.0, respectively. Two CAs with characteristics of the membrane-bound proteins and one CA
with characteristics of the soluble proteins were found in the medium after thylakoids were incubated with Triton. One of
the first two CAs had mobility in PAAG after native electrophoresis the same as that of CA residing in PSI-membranes, and
the other CA had mobility the same as the mobility of CA residing in PSII-membranes, but the latter was different from CA
situated in PSII core-complex (Ignatova et al. 2006 Biochemistry (Moscow) 71:525–532). The properties of the “soluble” CA removed from thylakoids were different from the properties
of the known soluble CAs of plant cell: apparent molecular mass was about 262 kD and it was three orders more sensitive to
the specific CA inhibitor, ethoxyzolamide, than soluble stromal CA. The data are discussed as indicating the presence of,
at least, four CAs in pea thylakoids. 相似文献
79.
Na/K-ATPase tethers phospholipase C and IP3 receptor into a calcium-regulatory complex 总被引:8,自引:0,他引:8 下载免费PDF全文
Yuan Z Cai T Tian J Ivanov AV Giovannucci DR Xie Z 《Molecular biology of the cell》2005,16(9):4034-4045
We have shown that the caveolar Na/K-ATPase transmits ouabain signals via multiple signalplexes. To obtain the information on the composition of such complexes, we separated the Na/K-ATPase from the outer medulla of rat kidney into two different fractions by detergent treatment and density gradient centrifugation. Analysis of the light fraction indicated that both PLC-gamma1 and IP3 receptors (isoforms 2 and 3, IP3R2 and IP3R3) were coenriched with the Na/K-ATPase, caveolin-1 and Src. GST pulldown assays revealed that the central loop of the Na/K-ATPase alpha1 subunit interacts with PLC-gamma1, whereas the N-terminus binds IP3R2 and IP3R3, suggesting that the signaling Na/K-ATPase may tether PLC-gamma1 and IP3 receptors together to form a Ca(2+)-regulatory complex. This notion is supported by the following findings. First, both PLC-gamma1 and IP3R2 coimmunoprecipitated with the Na/K-ATPase and ouabain increased this interaction in a dose- and time-dependent manner in LLC-PK1 cells. Depletion of cholesterol abolished the effects of ouabain on this interaction. Second, ouabain induced phosphorylation of PLC-gamma1 at Tyr(783) and activated PLC-gamma1 in a Src-dependent manner, resulting in increased hydrolysis of PIP2. It also stimulated Src-dependent tyrosine phosphorylation of the IP3R2. Finally, ouabain induced Ca(2+) release from the intracellular stores via the activation of IP3 receptors in LLC-PK1 cells. This effect required the ouabain-induced activation of PLC-gamma1. Inhibition of Src or depletion of cholesterol also abolished the effect of ouabain on intracellular Ca(2+). 相似文献
80.