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71.
Mathivanan Ashokkumar Geetha Irudayaraj Nandakumar Yellapu Arulsamy Mary Manonmani 《World journal of microbiology & biotechnology》2018,34(8):116
A strain of Bacillus amyloliquefaciens (VCRC B483) exhibiting mosquito pupicidal, keratinase and antimicrobial activities was isolated from mangrove forest ecosystem of Andaman and Nicobar Islands. Molecular characterization of the strain showed the presence of lipopeptide encoding bmyC gene. Phylogenetic tree based on protein sequence of this gene exhibited homology with mycosubtilin synthetase of Bacilus atropheus and Iturin synthetase of Bacillus subtilis and B. amyloliquefaciens. This is the first report on the evolutionary conservation of amino acids concerned with the function and structure of bmyC protein of B. amyloliquefaciens. The presence of valine at the 1197th position in our strain was found to be unique and different from the existing strains of B. subtilis and B. amyloliquefaciens. Molecular modelling studies revealed significant changes in the structure of epimerization domain of the bmyC protein with A1197V variation. Crude metabolite of this strain exhibited antifungal activity against Fusarium sp. and Carvularia sp. 相似文献
72.
Olivia L. McGovern Yolanda Rivera‐Cuevas Geetha Kannan Andrew J. Narwold Jr Vern B. Carruthers 《Traffic (Copenhagen, Denmark)》2018,19(5):336-353
Host cytosolic proteins are endocytosed by Toxoplasma gondii and degraded in its lysosome‐like compartment, the vacuolar compartment (VAC), but the dynamics and route of endocytic trafficking remain undefined. Conserved endocytic components and plant‐like features suggest T. gondii endocytic trafficking involves transit through early and late endosome‐like compartments (ELCs) and potentially the trans‐Golgi network (TGN) as in plants. However, exocytic trafficking to regulated secretory organelles, micronemes and rhoptries, also proceeds through ELCs and requires classical endocytic components, including a dynamin‐related protein, DrpB. Here, we show that host cytosolic proteins are endocytosed within 7 minutes post‐invasion, trafficked through ELCs en route to the VAC, and degraded within 30 minutes. We could not definitively interpret if ingested protein is trafficked through the TGN. We also found that parasites ingest material from the host cytosol throughout the parasite cell cycle. Ingested host proteins colocalize with immature microneme proteins, proM2AP and proMIC5, in transit to the micronemes, but not with the immature rhoptry protein proRON4, indicating that endocytic trafficking of ingested protein intersects with exocytic trafficking of microneme proteins. Finally, we show that conditional expression of a DrpB dominant negative mutant increases T. gondii ingestion of host‐derived proteins, suggesting that DrpB is not required for parasite endocytosis. 相似文献
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74.
Asymmetric distribution of muscarinic acetylcholine receptors in Madin-Darby canine kidney cells 总被引:1,自引:0,他引:1
Nadler Laurie S.; Kumar Geetha; Hinds Thomas R.; Migeon Jacques C.; Nathanson Neil M. 《American journal of physiology. Cell physiology》1999,277(6):C1220
We have characterized the muscarinic AChreceptors (mAChRs) expressed in Madin- Darby canine kidney (MDCK)strain II epithelial cells. Binding studies with themembrane-impermeable antagonist N-[3H]methylscopolaminedemonstrated that mAChRs are ~2.5 times more abundant on thebasolateral than on the apical surface. Apical, but not basolateral,mAChRs inhibited forskolin-stimulated adenylyl cyclase activity inresponse to the agonist carbachol. Neither apical nor basolateralmAChRs exhibited detectable carbachol-stimulated phospholipase Cactivity. Carbachol application to the apical or the basolateralmembrane resulted in a threefold increase in intracellularCa2+ concentration, which wascompletely inhibited by pertussis toxin on the apical side andpartially inhibited on the basolateral side. RT-PCR analysis showedthat MDCK cells express the M4 and M5 receptor mRNAs. These datasuggest that M4 receptors reside on the apical and basolateral membranes of polarized MDCK strain IIcells and that the M5 receptor mayreside in the basolateral membrane of a subset of cells. 相似文献
75.
Arumugam Geetha Panneerselvam Saranya Sam Annie Jeyachristy Rajagopal Surendran Arunachalam Sundaram 《Biological trace element research》2009,130(3):229-240
Altered copper homeostasis and oxidative stress have been observed in patients with hepatocellular carcinoma. Non-ceruloplasmin
copper, the free form, is a potent pro-oxidant than the protein bound copper. The aim of the present study was to evaluate
which form of copper can be correlated with the oxidative stress in the circulation and in the malignant liver tissues of
hepatocellular carcinoma patients. Hepatocellular carcinoma patients (grades II and III, n = 18) were enrolled in this study. Serum levels of total, free and bound copper, ceruloplasmin, iron, iron-binding capacity,
lipid peroxidation products, and enzymatic and non-enzymatic antioxidants were quantified in serum and in malignant liver
tissues and compared with those of normal samples (n = 20). A significant positive correlation between the serum non-ceruloplasmin copper and lipid peroxidation products and
negative correlation with antioxidants were observed in hepatocellular carcinoma patients. In liver tissue, glutathione peroxidase,
superoxide dismutase, and catalase activity were significantly decreased with concomitant elevation in oxidative stress markers.
Our experiment revealed that the elevation in non-ceruloplasmin copper has high relevance with the oxidative stress than the
bound copper. 相似文献
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78.
Bhattacharyya A Thakur AK Chellgren VM Thiagarajan G Williams AD Chellgren BW Creamer TP Wetzel R 《Journal of molecular biology》2006,355(3):524-535
There are nine known expanded CAG repeat neurological diseases, including Huntington's disease (HD), each involving the repeat expansion of polyglutamine (polyGln) in a different protein. Similar conditions can be induced in animal models by expression of the polyGln sequence alone or in other protein contexts. Besides the polyGln sequence, the cellular context of the disease protein, and the sequence context of the polyGln within the disease protein, are both likely to contribute to polyGln physical behavior and to pathology. In HD, the N-terminal, exon-1 segment of the protein huntingtin contains the polyGln sequence immediately followed by an oligoproline region. We show here that introduction of a P10 sequence C-terminal to polyGln in synthetic peptides decreases both the rate of formation and the apparent stability of the amyloid-like aggregates associated with this family of diseases. The sequence can be trimmed to P6 without altering the suppression, but a P3 sequence is ineffective. Spacers up to at least three amino acid residues in length can be inserted between polyGln and P10 without altering this effect. There is no suppression, however, when the P10 sequence is either placed on the N-terminal side of polyGln or attached to polyGln via a side-chain tether. The nucleation mechanism of a Q40 sequence is unchanged upon addition of a P10 C-terminal extension, yielding a critical nucleus of one. The effects of oligoPro length and structural context on polyGln aggregation are correlated strongly with alterations in the circular dichroism spectra of the monomeric peptides. For example, the P10 sequence eliminates the small amount of alpha helical content otherwise exhibited by the Q40 sequence. The P10 sequence may suppress aggregation by stabilizing an aggregation-incompetent conformation of the monomer. The effect is transportable: a P10 sequence fixed to the C terminus of the sequence Abeta similarly modulates amyloid fibril formation. 相似文献
79.
Dispersal is an important ecological process that affects plant population structure and community composition. Invasive plants with fleshy fruits rapidly form associations with native and invasive dispersers, and may affect existing native plant-disperser associations. We asked whether frugivore visitation rate and fruit removal was associated with plant characteristics in a community of fleshy-fruited plants and whether an invasive plant receives more visitation and greater fruit removal than native plants in a semi-arid habitat of Andhra Pradesh, India. Tree-watches were undertaken at individuals of nine native and one invasive shrub species to assess the identity, number and fruit removal by avian frugivores. Network analyses and generalised linear mixed-effects models were used to understand species and community-level patterns. All plants received most number of visits from abundant, generalist avian frugivores. Number of frugivore visits and time spent by frugivores at individual plants was positively associated with fruit crop size, while fruit removal was positively associated with number of frugivore visits and their mean foraging time at individual plants. The invasive shrub, Lantana camara L. (Lantana), had lower average frugivore visit rate than the community of fleshy-fruited plants and received similar average frugivore visits but greater average per-hour fruit removal than two other concurrently fruiting native species. Based on the results of our study, we infer that there is little evidence of competition between native plants and Lantana for the dispersal services of native frugivores and that more data are required to assess the nature of these interactions over the long term. We speculate that plant associations with generalist frugivores may increase the functional redundancy of this frugivory network, buffering it against loss of participating species. 相似文献
80.
Genetic interplay between human longevity and metabolic pathways — a large‐scale eQTL study
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