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941.
942.
Marie L. Antony Joomin Lee Eun-Ryeong Hahm Su-Hyeong Kim Adam I. Marcus Vandana Kumari Xinhua Ji Zhen Yang Courtney L. Vowell Peter Wipf Guy T. Uechi Nathan A. Yates Guillermo Romero Saumendra N. Sarkar Shivendra V. Singh 《The Journal of biological chemistry》2014,289(3):1852-1865
Withaferin A (WA), a C5,C6-epoxy steroidal lactone derived from a medicinal plant (Withania somnifera), inhibits growth of human breast cancer cells in vitro and in vivo and prevents mammary cancer development in a transgenic mouse model. However, the mechanisms underlying the anticancer effect of WA are not fully understood. Herein, we report that tubulin is a novel target of WA-mediated growth arrest in human breast cancer cells. The G2 and mitotic arrest resulting from WA exposure in MCF-7, SUM159, and SK-BR-3 cells was associated with a marked decrease in protein levels of β-tubulin. These effects were not observed with the naturally occurring C6,C7-epoxy analogs of WA (withanone and withanolide A). A non-tumorigenic normal mammary epithelial cell line (MCF-10A) was markedly more resistant to mitotic arrest by WA compared with breast cancer cells. Vehicle-treated control cells exhibited a normal bipolar spindle with chromosomes aligned along the metaphase plate. In contrast, WA treatment led to a severe disruption of normal spindle morphology. NMR analyses revealed that the A-ring enone in WA, but not in withanone or withanolide A, was highly reactive with cysteamine and rapidly succumbed to irreversible nucleophilic addition. Mass spectrometry demonstrated direct covalent binding of WA to Cys303 of β-tubulin in MCF-7 cells. Molecular docking indicated that the WA-binding pocket is located on the surface of β-tubulin and characterized by a hydrophobic floor, a hydrophobic wall, and a charge-balanced hydrophilic entrance. These results provide novel insights into the mechanism of growth arrest by WA in breast cancer cells. 相似文献
943.
Abimbola M. Enitan Sheena Kumari Feroz M. Swalaha J. Adeyemo Nishani Ramdhani Faizal Bux 《Microbial ecology》2014,67(2):358-368
The performance of a full-scale upflow anaerobic sludge blanket (UASB) reactor treating brewery wastewater was investigated by microbial analysis and kinetic modelling. The microbial community present in the granular sludge was detected using fluorescent in situ hybridization (FISH) and further confirmed using polymerase chain reaction. A group of 16S rRNA based fluorescent probes and primers targeting Archaea and Eubacteria were selected for microbial analysis. FISH results indicated the presence and dominance of a significant amount of Eubacteria and diverse group of methanogenic Archaea belonging to the order Methanococcales, Methanobacteriales, and Methanomicrobiales within in the UASB reactor. The influent brewery wastewater had a relatively high amount of volatile fatty acids chemical oxygen demand (COD), 2005 mg/l and the final COD concentration of the reactor was 457 mg/l. The biogas analysis showed 60–69 % of methane, confirming the presence and activities of methanogens within the reactor. Biokinetics of the degradable organic substrate present in the brewery wastewater was further explored using Stover and Kincannon kinetic model, with the aim of predicting the final effluent quality. The maximum utilization rate constant U max and the saturation constant (K B) in the model were estimated as 18.51 and 13.64 g/l/day, respectively. The model showed an excellent fit between the predicted and the observed effluent COD concentrations. Applicability of this model to predict the effluent quality of the UASB reactor treating brewery wastewater was evident from the regression analysis (R 2?=?0.957) which could be used for optimizing the reactor performance. 相似文献
944.
Silpi Chatterjee Minti Kumari Anurag Rai Tanoj Kumar Akash Tripathi Shruti Gupta 《Bioinformation》2021,17(1):53
It is of interest to report data on periodontal Health among elderly people in Bushland, Jharkhand, Magadha and Patna, India. The sample comprised of a 130 elderly people. The studies device comprised of a semi-structured survey with thirteen questions. Data shows that old people in Jharkhand suffered from advanced periodontal ailment (47.6%) with easy gingivitis (33.8%). Data also shows that grownups (88.2% grownup males, 64.5% girls in Jharkhand and 34.5% grownup males and 88.9% girls in Bihar) used toothpaste and toothbrush as their primary style for tooth cleansing. These data help in providing improved dental service to rural population in India. 相似文献
945.
Ras GTPase controls the normal cell growth through binding with an array of effector molecules, such as Raf and PI3-kinase in a GTP-dependent manner. RASSF2, a member of the Ras association domain family, is known to be involved in the suppression of cell growth and is frequently down-regulated in various tumor tissues by promoter hypermethylation. In the present study, we demonstrate that RASSF2 shuttles between nucleus and cytoplasm by a signal-mediated process and its export from the nucleus is sensitive to leptomycin B. Amino acids between 240 to 260 in the C-terminus of RASSF2 harbor a functional nuclear export signal (NES), which is necessary and sufficient for efficient export of RASSF2 from the nucleus. Substitution of conserved Ile254, Val257 and Leu259 within the minimal NES impaired RASSF2 export from the nucleus. In addition, wild type but not the nuclear export defective RASSF2 mutant interacts with export receptor, CRM-1 and exported from the nucleus. Surprisingly, we observed nucleolar localization for the nuclear export defective mutant suggesting the possibility that RASSF2 may localize in different cellular compartments transiently in a cell cycle dependent manner and the observed nuclear localization for wild type protein may be due to faster export kinetics from the nucleolus. Furthermore, our data suggest that RASSF2 is specifically phosphorylated by MAPK/ERK-2 and the inhibitors of MAPK pathway impair the phosphorylation and subsequently block the export of RASSF2 from the nucleus. These data clearly suggest that ERK-2 mediated phosphorylation plays an important role in regulating the nucleo-cytoplasmic shuttling of RASSF2. Interestingly, nuclear import defective mutant of RASSF2 failed to induce cell cycle arrest at G1/S phase and apoptosis suggesting that RASSF2 regulates cell growth in a nuclear localization dependent manner. Collectively, these data provided evidence for the first time that MAPK/ERK-2 mediated phosphorylation regulates nucleo-cytoplasmic transport and cell growth arrest activity of RASSF2. Taken together, the present study suggests that active transport between nucleus and cytoplasm may constitute an important regulatory mechanism for RASSF2 function. 相似文献
946.
Arf6-independent GPI-anchored protein-enriched early endosomal compartments fuse with sorting endosomes via a Rab5/phosphatidylinositol-3'-kinase-dependent machinery
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Kalia M Kumari S Chadda R Hill MM Parton RG Mayor S 《Molecular biology of the cell》2006,17(8):3689-3704
In the process of internalization of molecules from the extracellular milieu, a cell uses multiple endocytic pathways, consequently generating different endocytic vesicles. These primary endocytic vesicles are targeted to specific destinations inside the cell. Here, we show that GPI-anchored proteins are internalized by an Arf6-independent mechanism into GPI-anchored protein-enriched early endosomal compartments (GEECs). Internalized GPI-anchored proteins and the fluid phase are first visualized in GEECs that are acidic, primary endocytic structures, negative for early endosomal markers, Rab4, Rab5, and early endosome antigen (EEA)1. They subsequently acquire Rab5 and EEA1 before homotypic fusion with other GEECs, and heterotypic fusion with endosomes containing cargo from the clathrin-dependent endocytic pathway. Although, the formation of GEECs is unaffected by inhibition of Rab5 GTPase and phosphatidylinositol-3'-kinase (PI3K) activity, their fusion with sorting endosomes is dependent on both activities. Overexpression of Rab5 reverts PI3K inhibition of fusion, providing evidence that Rab5 effectors play important roles in heterotypic fusion between the dynamin-independent GEECs and clathrin- and dynamin-dependent sorting endosomes. 相似文献
947.
T. R. Shamala M. S. Divyashree Reeta Davis K. S. Latha Kumari S. V. N. Vijayendra Baldev Raj 《Indian journal of microbiology》2009,49(3):251-258
Rhizobium meliloti produced a copolymer of short chain length polyhydroxyalkanoate (scl-PHA) on sucrose and rice bran oil as carbon substrates.
Recombinant Escherichia coli (JC7623ABC1J4), bearing PHA synthesis genes, was used to synthesize short chain length-co-medium chain length PHA (scl-co-mcl-PHA)
on glucose and decanoic acid. Fourier transform infrared spectroscopy (FTIR) spectra of the PHAs indicated strong characteristic
bands at 1282, 1723, and 2934 cm−1 for scl-PHA and at 2933 and 2976 cm−1 for scl-co-mcl-PHA polymer. Differentiation of polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-hydroxyvalerate-P(HB-co-HV)
copolymer was obseverd using FTIR, with absorption bands at 1723 and 1281 for PHB, and at 1738, 1134, 1215 cm−1 for HV-copolymer. The copolymers were analyzed by GC and 1H NMR spectroscopy. Films of polymer blends of PHA produced by R. meliloti and recombinant E. coli were prepared using glycerol, polyethylene glycol, polyvinyl acetate, individually (1:1 ratio), to modify the mechanical
properties of the films and these films were evaluated by FTIR and scanning electron microscopy. 相似文献
948.
R. Radhakrishnan A. Ramachandran B. D. Ranjitha Kumari 《Acta Physiologiae Plantarum》2009,31(6):1213-1217
Thidiazuron (TDZ), primarily a cotton defoliant, has been later accepted as a plant growth regulator. In spite of extensive
studies, the physiological function of TDZ is still uncertain. The aim of the present experiment was to study the activity
of TDZ in in vitro regeneration of soybean. The seeds of soybean were cultured separately on MS and B5 medium supplemented
with TDZ. The hypocotyls, cotyledons, cotyledonary nodes without axillary buds and cotyledonary nodes with axillary buds were
used as explants and their capacity to direct regeneration was tested on both MS and B5 media containing TDZ (0.9–5.4 μM).
Shoot formation was observed only on cotyledonary nodes with axillary buds cultured on MS and B5 basal media with TDZ (0.9–5.4 μM).
All tested explants cultured on B5 medium with TDZ produced roots. Root formation was not observed on MS basal media supplemented
with TDZ. Results show that TDZ functions as cytokinin (to produce the shoots) and auxin (to produce the roots) on various
explants depending on the basal medium used. 相似文献
949.
Anuradha Kumari Irina G. Minko Rebecca L. Smith R. Stephen Lloyd Amanda K. McCullough 《The Journal of biological chemistry》2010,285(28):21313-21322
UvrD (DNA helicase II) has been implicated in DNA replication, DNA recombination, nucleotide excision repair, and methyl-directed mismatch repair. The enzymatic function of UvrD is to translocate along a DNA strand in a 3′ to 5′ direction and unwind duplex DNA utilizing a DNA-dependent ATPase activity. In addition, UvrD interacts with many other proteins involved in the above processes and is hypothesized to facilitate protein turnover, thus promoting further DNA processing. Although UvrD interactions with proteins bound to DNA have significant biological implications, the effects of covalent DNA-protein cross-links on UvrD helicase activity have not been characterized. Herein, we demonstrate that UvrD-catalyzed strand separation was inhibited on a DNA strand to which a 16-kDa protein was covalently bound. Our sequestration studies suggest that the inhibition of UvrD activity is most likely due to a translocation block and not helicase sequestration on the cross-link-containing DNA substrate. In contrast, no inhibition of UvrD-catalyzed strand separation was apparent when the protein was linked to the complementary strand. The latter result is surprising given the earlier observations that the DNA in this covalent complex is severely bent (∼70°), with both DNA strands making multiple contacts with the cross-linked protein. In addition, UvrD was shown to be required for replication of plasmid DNAs containing covalent DNA-protein complexes. Combined, these data suggest a critical role for UvrD in the processing of DNA-protein cross-links. 相似文献
950.
An efficient in vitro propagation is described for Spondias mangifera Willd., a medicinally important tree, using nodal explants obtained from 4-week-old seedlings. The frequency of shoot regeneration
from seedling node was affected by various concentrations of BAP and successive transfer of mother explant. MS (Murashige
and Skoog, Physiol Plant 15:473–497, 1962) medium supplemented with 1.0 mg l−1 of 6-benzylaminopurine (BAP) was optimal for shoot multiplication. Upon this medium, highest number of shoots (about 10.6)
per explants was obtained after fourth subculture of mother explants. Half-strength MS medium containing IAA (1.0 mg l−1) was most effective for rooting of shoots. Regenerated plantlets were successfully acclimatized and transferred into soil
with 80–90% survival rate. The regenerated plants were morphologically uniform and exhibited similar growth characteristics
and vegetative morphology to the mother plants. This is the first report on micropropagation of S. mangifera, which can be applied for further genetic transformation assays and pharmaceutical purposes. 相似文献