排序方式: 共有150条查询结果,搜索用时 15 毫秒
81.
Purification of the simian virus 40 (SV40) T antigen DNA-binding domain and characterization of its interactions with the SV40 origin. 总被引:3,自引:1,他引:2 下载免费PDF全文
W S Joo X Luo D Denis H Y Kim G J Rainey C Jones K R Sreekumar P A Bullock 《Journal of virology》1997,71(5):3972-3985
To better define protein-DNA interactions at a eukaryotic origin, the domain of simian virus 40 (SV40) large T antigen that specifically interacts with the SV40 origin has been purified and its binding to DNA has been characterized. Evidence is presented that the affinity of the purified T antigen DNA-binding domain for the SV40 origin is comparable to that of the full-length T antigen. Furthermore, stable binding of the T antigen DNA-binding domain to the SV40 origin requires pairs of pentanucleotide recognition sites separated by approximately one turn of a DNA double helix and positioned in a head-to-head orientation. Although two pairs of pentanucleotides are present in the SV40 origin, footprinting and band shift experiments indicate that binding is limited to dimer formation on a single pair of pentanucleotides. Finally, it is demonstrated that the T antigen DNA-binding domain interacts poorly with single-stranded DNA. 相似文献
82.
Phytophthora palmivora causes bud rot, fruit and immature nut fall in India, and causes significant coconut yield losses. Genetic variability was estimated in 70 isolates representing seven populations from the Kerala and Karnataka regions using random amplified polymorphic DNA (RAPD) markers. RAPDs generated a total of 163 markers with 15 decamer primers, of which 92% were found to be polymorphic. The number of polymorphic loci within a single population varied from 45 to 92 with estimated hetrozygosities ranging from 0.08 to 0.23. The majority of the genetic diversity was distributed within populations (68.25%) and only 31.75% were among populations. Genetic relationships estimated by the unweighted pair‐group method with arithmatic averaging (UPGMA) revealed clear separation of Kerala and Karnataka populations. 相似文献
83.
84.
Seema Dharni Sanchita SreeKuttan M. Unni Sreekumar Kurungot Abdul Samad Ashok Sharma 《Journal of biomolecular structure & dynamics》2016,34(1):152-162
We have investigated in vitro antifungal efficiency of nitrogen-doped carbon nanohorn (NCNH) against Rhizoctonia solani (R. solani) plant pathogenic fungi. NCNH with size of 50–60 nm and concentrations of 10, 50, 100, and 150 μg mL?1 were used. The results showed that growth of fungi in the presence of NCNH was significantly (p > .05) inhibited at 150 μg mL?1 (85.13 ± .97) after 72 h. The results were validated through computational approaches. Molecular docking analysis of NCNH with endochitinase protein of R. solani was performed to validate the potential of antifungal activity of NCNH. Docking results showed different conformations of interaction of NCNH with endochitinase enzyme. The conformation with least binding energy ?13.54 kcal/mol was considered further. It is likely that NCNH interacts with the pathogens by mechanically wrapping, which may be one of the major toxicity actions of NCNH against R. solani. The analysis showed that NCNH might interwinds to endochitinase of R. solani leading to the deactivation of the enzyme. To best of our knowledge, this is the first report of antifungal efficacy of NCNH against R. solani and provides useful information about the application of NCNH in resisting crop disease. 相似文献
85.
Vareed SK Bhat VB Thompson C Vasu VT Fermin D Choi H Creighton CJ Gayatri S Lan L Putluri N Thangjam GS Kaur P Shabahang M Giri JG Nesvizhskii AI Asea AA Cashikar AG Rao A McLoughlin J Sreekumar A 《PloS one》2011,6(3):e17177
Pancreatic Adenocarcinoma (PDAC), the fourth highest cause of cancer related deaths in the United States, has the most aggressive presentation resulting in a very short median survival time for the affected patients. Early detection of PDAC is confounded by lack of specific markers that has motivated the use of high throughput molecular approaches to delineate potential biomarkers. To pursue identification of a distinct marker, this study profiled the secretory proteome in 16 PDAC, 2 carcinoma in situ (CIS) and 7 benign patients using label-free mass spectrometry coupled to 1D-SDS-PAGE and Strong Cation-Exchange Chromatography (SCX). A total of 431 proteins were detected of which 56 were found to be significantly elevated in PDAC. Included in this differential set were Parkinson disease autosomal recessive, early onset 7 (PARK 7) and Alpha Synuclein (aSyn), both of which are known to be pathognomonic to Parkinson's disease as well as metabolic enzymes like Purine Nucleoside Phosphorylase (NP) which has been exploited as therapeutic target in cancers. Tissue Microarray analysis confirmed higher expression of aSyn and NP in ductal epithelia of pancreatic tumors compared to benign ducts. Furthermore, extent of both aSyn and NP staining positively correlated with tumor stage and perineural invasion while their intensity of staining correlated with the existence of metastatic lesions in the PDAC tissues. From the biomarker perspective, NP protein levels were higher in PDAC sera and furthermore serum levels of its downstream metabolites guanosine and adenosine were able to distinguish PDAC from benign in an unsupervised hierarchical classification model. Overall, this study for the first time describes elevated levels of aSyn in PDAC as well as highlights the potential of evaluating NP protein expression and levels of its downstream metabolites to develop a multiplex panel for non-invasive detection of PDAC. 相似文献
86.
Nallusamy Kalaivanan Ragothaman Venkataramanan Chirukandoth Sreekumar Alagarsamy Saravanan Rajeev K. Srivastava 《European Journal of Wildlife Research》2011,57(1):191-194
India, with its huge human population and fragmented wildlife habitat, is plagued with human–animal conflicts. In conflict
areas, large carnivores are often primary targets for malicious poisoning. The effects of certain poisons do not stop with
the target animal but also affects other species of wildlife in the form of secondary poisoning. This paper describes incidences
of secondary poisoning of a tiger (Panthera tigris) and a black panther (melanistic Panthera pardus) in the Nilgiri Biosphere Reserve. Wild boars (Sus scrofa), which are considered pests in horticultural plantations, were the primary targets in both cases and were poisoned using
phorate, a highly toxic organophosphorus compound. Tigers and leopards hold significant position in the upper most trophic
level of the ecological pyramid and are grouped in schedule I of the Wildlife Protection Act of India. The tiger, as a species,
is currently waging a grim battle of survival in the wild. The world over, leopard populations are also dwindling. The implications
of the death of these endangered apex predators due to the increase in population of the ubiquitous wild boars are analysed.
The merits of introducing a policy of selective culling of wild boars in conflict areas are discussed. 相似文献
87.
88.
Ramakrishna Kommagani Maria M. Szwarc Ertug Kovanci William E. Gibbons Nagireddy Putluri Suman Maity Chad J. Creighton Arun Sreekumar Francesco J. DeMayo John P. Lydon Bert W. O'Malley 《PLoS genetics》2013,9(10)
Early embryo miscarriage is linked to inadequate endometrial decidualization, a cellular transformation process that enables deep blastocyst invasion into the maternal compartment. Although much of the cellular events that underpin endometrial stromal cell (ESC) decidualization are well recognized, the individual gene(s) and molecular pathways that drive the initiation and progression of this process remain elusive. Using a genetic mouse model and a primary human ESC culture model, we demonstrate that steroid receptor coactivator-2 (SRC-2) is indispensable for rapid steroid hormone-dependent proliferation of ESCs, a critical cell-division step which precedes ESC terminal differentiation into decidual cells. We reveal that SRC-2 is required for increasing the glycolytic flux in human ESCs, which enables rapid proliferation to occur during the early stages of the decidualization program. Specifically, SRC-2 increases the glycolytic flux through induction of 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3), a major rate-limiting glycolytic enzyme. Similarly, acute treatment of mice with a small molecule inhibitor of PFKFB3 significantly suppressed the ability of these animals to exhibit an endometrial decidual response. Together, these data strongly support a conserved mechanism of action by which SRC-2 accelerates the glycolytic flux through PFKFB3 induction to provide the necessary bioenergy and biomass to meet the demands of a high proliferation rate observed in ESCs prior to their differentiation into decidual cells. Because deregulation of endometrial SRC-2 expression has been associated with common gynecological disorders of reproductive-age women, this signaling pathway, involving SRC-2 and PFKFB3, promises to offer new clinical approaches in the diagnosis and/or treatment of a non-receptive uterus in patients presenting idiopathic infertility, recurrent early pregnancy loss, or increased time to pregnancy. 相似文献
89.
Sanjib Bhattacharyya Sounik Saha Karuna Giri Ian R. Lanza K. Sreekumar Nair Nicholas B. Jennings Cristian Rodriguez-Aguayo Gabriel Lopez-Berestein Eati Basal Amy L. Weaver Daniel W. Visscher William Cliby Anil K. Sood Resham Bhattacharya Priyabrata Mukherjee 《PloS one》2013,8(11)
Background
Epithelial ovarian cancer is the leading cause of gynecologic cancer deaths. Most patients respond initially to platinum-based chemotherapy after surgical debulking, however relapse is very common and ultimately platinum resistance emerges. Understanding the mechanism of tumor growth, metastasis and drug resistant relapse will profoundly impact the therapeutic management of ovarian cancer.Methods/Principal Findings
Using patient tissue microarray (TMA), in vitro and in vivo studies we report a role of of cystathionine-beta-synthase (CBS), a sulfur metabolism enzyme in ovarian carcinoma. We report here that the expression of cystathionine-beta-synthase (CBS), a sulfur metabolism enzyme, is common in primary serous ovarian carcinoma. The in vitro effects of CBS silencing can be reversed by exogenous supplementation with the GSH and H2S producing chemical Na2S. Silencing CBS in a cisplatin resistant orthotopic model in vivo by nanoliposomal delivery of CBS siRNA inhibits tumor growth, reduces nodule formation and sensitizes ovarian cancer cells to cisplatin. The effects were further corroborated by immunohistochemistry that demonstrates a reduction of H&E, Ki-67 and CD31 positive cells in si-RNA treated as compared to scrambled-RNA treated animals. Furthermore, CBS also regulates bioenergetics of ovarian cancer cells by regulating mitochondrial ROS production, oxygen consumption and ATP generation. This study reports an important role of CBS in promoting ovarian tumor growth and maintaining drug resistant phenotype by controlling cellular redox behavior and regulating mitochondrial bioenergetics.Conclusion
The present investigation highlights CBS as a potential therapeutic target in relapsed and platinum resistant ovarian cancer. 相似文献90.
Sabyasachi Sutradhar Vikas Yadav Shreyas Sridhar Lakshmi Sreekumar Dibyendu Bhattacharyya Santanu Kumar Ghosh Raja Paul Kaustuv Sanyal 《Molecular biology of the cell》2015,26(22):3954-3965
High-fidelity chromosome segregation during cell division depends on a series of concerted interdependent interactions. Using a systems biology approach, we built a robust minimal computational model to comprehend mitotic events in dividing budding yeasts of two major phyla: Ascomycota and Basidiomycota. This model accurately reproduces experimental observations related to spindle alignment, nuclear migration, and microtubule (MT) dynamics during cell division in these yeasts. The model converges to the conclusion that biased nucleation of cytoplasmic microtubules (cMTs) is essential for directional nuclear migration. Two distinct pathways, based on the population of cMTs and cortical dyneins, differentiate nuclear migration and spindle orientation in these two phyla. In addition, the model accurately predicts the contribution of specific classes of MTs in chromosome segregation. Thus we present a model that offers a wider applicability to simulate the effects of perturbation of an event on the concerted process of the mitotic cell division. 相似文献