排序方式: 共有50条查询结果,搜索用时 343 毫秒
21.
Ahan Dalal Abhaypratap Vishwakarma Naveen Kumar Singh Triveni Gudla Mrinal Kanti Bhattacharyya Kollipara Padmasree Andrea Viehhauser Karl-Josef Dietz Pulugurtha Bharadwaja Kirti 《FEBS letters》2014
Brassica juncea annexin-3 (BjAnn3) was functionally characterized for its ability to modulate H2O2-mediated oxidative stress in Saccharomyces cerevisiae. BjAnn3 showed a significant protective role in cellular-defense against oxidative stress and partially alleviated inhibition of mitochondrial respiration in presence of exogenously applied H2O2. Heterologous expression of BjAnn3 protected membranes from oxidative stress-mediated damage and positively regulated antioxidant gene expression for ROS detoxification. We conclude that, BjAnn3 partially counteracts the effects of thioredoxin peroxidase 1 (TSA1) deficiency and aids in cellular-protection across kingdoms. Despite partial compensation of TSA1 by BjAnn3 in cell-viability tests, the over-complementation in ROS-related features suggests the existence of both redundant (e.g. ROS detoxification) and distinct features (e.g. membrane protection versus proximity-based redox regulator) of both proteins. 相似文献
22.
Thalidomide attenuates nitric oxide mediated angiogenesis by blocking migration of endothelial cells
KP Tamilarasan Gopi Krishna Kolluru Megha Rajaram M Indhumathy R Saranya Suvro Chatterjee 《BMC cell biology》2006,7(1):17-13
Background
Thalidomide is an immunomodulatory agent, which arrests angiogenesis. The mechanism of anti-angiogenic activity of thalidomide is not fully understood. As nitric oxide is involved in angiogenesis, we speculate a cross-talk between thalidomide and nitric oxide signaling pathway to define angiogenesis. The aim of present study is to understand the mechanistic aspects of thalidomide-mediated attenuation of angiogenesis induced by nitric oxide at the cellular level. 相似文献23.
24.
Challabathula Dinakar Vishwakarma Abhaypratap Srinivasa Rao Yearla Agepati S. Raghavendra Kollipara Padmasree 《Planta》2010,231(2):461-474
The present study suggests the importance of reactive oxygen species (ROS) and antioxidant metabolites as biochemical signals
during the beneficial interactions of mitochondrial metabolism with photosynthetic carbon assimilation at saturating light
and optimal CO2. Changes in steady-state photosynthesis of pea mesophyll protoplasts monitored in the presence of antimycin A [AA, inhibitor
of cytochrome oxidase (COX) pathway] and salicylhydroxamic acid [SHAM, inhibitor of alternative oxidase (AOX) pathway] were
correlated with total cellular ROS and its scavenging system. Along with superoxide dismutase (SOD) and catalase (CAT), responses
of enzymatic components—ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), glutathione reductase (GR) and
non-enzymatic redox components of ascorbate–glutathione (Asc–GSH) cycle, which play a significant role in scavenging cellular
ROS, were examined in the presence of mitochondrial inhibitors. Both AA and SHAM caused marked reduction in photosynthetic
carbon assimilation with concomitant rise in total cellular ROS. Restriction of electron transport through COX or AOX pathway
had differential effect on ROS generating (SOD), ROS scavenging (CAT and APX) and antioxidant (Asc and GSH) regenerating (MDAR
and GR) enzymes. Further, restriction of mitochondrial electron transport decreased redox ratios of both Asc and GSH. However,
while decrease in redox ratio of Asc was more prominent in the presence of SHAM in light compared with dark, decrease in redox
ratio of GSH was similar in both dark and light. These results suggest that the maintenance of cellular ROS at optimal levels
is a prerequisite to sustain high photosynthetic rates which in turn is regulated by respiratory capacities of COX and AOX
pathways. 相似文献
25.
Substitution reaction of chloro η6-arene ruthenium N∩O-base complexes [(η6-arene)Ru(N∩O)Cl] [N∩O = pyrazine-2-carboxylic acid (pca-H), 8-hydroxyquinoline (hq-H); arene = p-iPrC6H4Me, N∩O = hq (1); arene = C6Me6, N∩O = hq (2)] with NaN3 yield the neutral arene ruthenium azido complexes of the general formula [(η6-arene)Ru(N∩O)N3] [N∩O = pca, arene = p-iPrC6H4Me (3), arene = C6Me6 (4); N∩O = hq, arene = p-iPrC6H4Me (5), arene = C6Me6 (6)]. These complexes undergo [3 + 2] dipolar cycloaddition reaction with activated alkynes dimethyl and diethyl acetylenedicarboxylates to yield the arene triazole complexes [(η6-arene)Ru(N∩O){N3C2(CO2R)2}] [N∩O = pca, R = Me, arene = p-iPrC6H4Me (7), C6Me6 (8); R = Et, arene = p-iPrC6H4Me (9), C6Me6 (10); N∩O = hq, R = Me, arene = p-iPrC6H4Me (11) C6Me6 (12); R = Et, arene = p-iPrC6H4Me (13), C6Me6 (14)]. On the bases of proton NMR study, in the above triazole complexes N(2) isomers are assigned with dimethylacetylenedicarboxylate whereas N(1) isomers with diethylacetylenedicarboxylate. All complexes have been characterized by IR and NMR spectroscopy as well as by elemental analysis. The molecular structures of the azido complexes [(η6-p-iPrC6H4Me)Ru(pca)N3] (3), [(η6-p-iPrC6H4Me)Ru(hq)N3] (5) and [(η6-C6Me6)Ru(hq)N3] (6) have been established by single crystal X-ray diffraction studies. 相似文献
26.
The fruit fly, Drosophila melanogaster, innately avoids even low levels of CO2. CO2 is part of the so-called Drosophila stress odor produced by stressed flies, but also a byproduct of fermenting fruit, a main food source, making the strong avoidance behavior somewhat surprising. Therefore, we addressed whether feeding states might influence the fly’s behavior and processing of CO2. In a recent report, we showed that this innate behavior is differentially processed and modified according to the feeding state of the fly. Interestingly, we found that hungry flies require the function of the mushroom body, a higher brain center required for olfactory learning and memory, but thought to be dispensable for innate olfactory behaviors. In addition, we anatomically and functionally characterized a novel bilateral projection neuron connecting the CO2 sensory input to the mushroom body. This neuron was essential for processing of CO2 in the starved fly but not in the fed fly. In this Extra View article, we provide evidence for the potential involvement of the neuromodulator dopamine in state-dependent CO2 avoidance behavior. Taken together, our work demonstrates that CO2 avoidance behavior is mediated by alternative neural pathways in a context-dependent manner. Furthermore, it shows that the mushroom body is not only involved in processing of learned olfactory behavior, as previously suggested, but also in context-dependent innate olfaction. 相似文献
27.
The cyclopentadienyl osmium(II) complexes [(η5-C5H5)Os(PPh3)2X] [X = Br (1), CH3CN (2)] reacts with sodium azide (NaN3) to yield the corresponding azido complex [(η5-C5H5)Os(PPh3)2N3] (3). This undergoes [3+2] dipolar cycloaddition reaction with activated alkynes like dimethyl and diethyl acetylenedicarboxylate to yield triazolato complexes [(η5-C5H5)Os(PPh3)2{N3C2(CO2R)2}] [R = –CH2CH3 (4) and –CH3 (5)]. The complex 3 also reacts with nitriles such as tetracyanoethylene (TCE), fumaronitrile and p-nitrobenzonitrile to yield complexes of the type [(η5-C5H5)Os(PPh3)2{N4C2(CN)C(CN)2}] (6), [(η5-C5H5)Os(PPh3)2{N3C2HCN}] (7) and [(η5-C5H5)Os(PPh3)2{N4C(C6H4–p-NO2)}] (8). These complexes were fully characterized on the basis of microanalyses, FT-IR and NMR spectroscopic data. The molecular structure of the representative complex [(η5-C5H5)Os(PPh3)2{N3C2(CO2CH2CH3)2}] (4) was determined by single crystal X-ray analysis. 相似文献
28.
29.
A Ca(2+)-dependent cysteine protease is associated with anoxia-induced root tip death in maize 总被引:3,自引:0,他引:3
Imposition of anoxia on maize (Zea mays cv. B73) seedlings for 48 h or longer led to the death of the root tip. The necrosis extended into the root axis during postanoxic treatment, leading to the mortality of 30-50% of the seedlings. Using zymography, protease profiles in the root tissues of anoxic seedlings were studied. O2 deprivation for 24 h or longer repressed pre-existing protease activities and induced a novel soluble enzyme in the roots. The anoxia-induced protease (AIP) activity was predominant in the root apex at 24 h of anoxia and, subsequently, became the most abundant soluble activity in the root axis as well. The induction of AIP and its in vitro renaturation were Ca(2+)-dependent. Inhibitor sensitivity studies indicated that AIP is a cysteine protease. In SDS-acrylamide gels, the enzyme activity migrated as a 23.5 kDa polypeptide. The anoxic induction of the activity was repressed by cycloheximide treatment, suggesting that new protein synthesis was required for the AIP appearance. Excision of the root tip (de-tipping) before anoxia led to a superior recovery of seedlings from stress injury. De-tipped seedlings showed lesser root damage and an increased production of lateral roots compared to intact seedlings. Furthermore, the superior anoxia tolerance of de-tipped seedlings was associated with a decreased AIP activity. Thus, the appearance of AIP activity in the root tip at 24 h of anoxia was spatially and temporally associated with the root tissue death. These studies further indicate that the root tip elimination early during anoxia may provide an adaptive advantage. 相似文献
30.
Iain Beehuat Tan Simeen Malik Kalpana Ramnarayanan John R McPherson Dan Liang Ho Yuka Suzuki Sarah Boonhsui Ng Su Yan Kiat Hon Lim Dennis Koh Chew Min Hoe Chung Yip Chan Rachel Ten Brian KP Goh Alexander YF Chung Joanna Tan Cheryl Xueli Chan Su Ting Tay Lezhava Alexander Niranjan Nagarajan Axel M Hillmer Choon Leong Tang Clarinda Chua Bin Tean Teh Steve Rozen Patrick Tan 《Genome biology》2015,16(1)
BackgroundColorectal cancer with metastases limited to the liver (liver-limited mCRC) is a distinct clinical subset characterized by possible cure with surgery. We performed high-depth sequencing of over 750 cancer-associated genes and copy number profiling in matched primary, metastasis and normal tissues to characterize genomic progression in 18 patients with liver-limited mCRC.ResultsHigh depth Illumina sequencing and use of three different variant callers enable comprehensive and accurate identification of somatic variants down to 2.5% variant allele frequency. We identify a median of 11 somatic single nucleotide variants (SNVs) per tumor. Across patients, a median of 79.3% of somatic SNVs present in the primary are present in the metastasis and 81.7% of all alterations present in the metastasis are present in the primary. Private alterations are found at lower allele frequencies; a different mutational signature characterized shared and private variants, suggesting distinct mutational processes. Using B-allele frequencies of heterozygous germline SNPs and copy number profiling, we find that broad regions of allelic imbalance and focal copy number changes, respectively, are generally shared between the primary tumor and metastasis.ConclusionsOur analyses point to high genomic concordance of primary tumor and metastasis, with a thick common trunk and smaller genomic branches in general support of the linear progression model in most patients with liver-limited mCRC. More extensive studies are warranted to further characterize genomic progression in this important clinical population.