Search Results - (Author, Cooperation:V. K. Rajasekhar)
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1Latest Papers from Table of Contents or Articles in PressA. L. Wolfe ; K. Singh ; Y. Zhong ; P. Drewe ; V. K. Rajasekhar ; V. R. Sanghvi ; K. J. Mavrakis ; M. Jiang ; J. E. Roderick ; J. Van der Meulen ; J. H. Schatz ; C. M. Rodrigo ; C. Zhao ; P. Rondou ; E. de Stanchina ; J. Teruya-Feldstein ; M. A. Kelliher ; F. Speleman ; J. A. Porco, Jr. ; J. Pelletier ; G. Ratsch ; H. G. Wendel
Nature Publishing Group (NPG)
Published 2014Staff ViewPublication Date: 2014-08-01Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: 5' Untranslated Regions/*genetics ; Animals ; Antineoplastic Agents, Phytogenic/pharmacology/therapeutic use ; Base Sequence ; Cell Line, Tumor ; Epigenesis, Genetic ; Eukaryotic Initiation Factor-4A/*metabolism ; Female ; *G-Quadruplexes ; Humans ; Mice ; Mice, Inbred C57BL ; Nucleotide Motifs ; Oncogene Proteins/*biosynthesis/*genetics ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/drug ; therapy/genetics/*metabolism ; *Protein Biosynthesis/drug effects ; Ribosomes/metabolism ; Transcription Factors/metabolism ; Transcription, Genetic/drug effects/genetics ; Triterpenes/pharmacologyPublished by: -
2Latest Papers from Table of Contents or Articles in PressA. Hoshino ; B. Costa-Silva ; T. L. Shen ; G. Rodrigues ; A. Hashimoto ; M. Tesic Mark ; H. Molina ; S. Kohsaka ; A. Di Giannatale ; S. Ceder ; S. Singh ; C. Williams ; N. Soplop ; K. Uryu ; L. Pharmer ; T. King ; L. Bojmar ; A. E. Davies ; Y. Ararso ; T. Zhang ; H. Zhang ; J. Hernandez ; J. M. Weiss ; V. D. Dumont-Cole ; K. Kramer ; L. H. Wexler ; A. Narendran ; G. K. Schwartz ; J. H. Healey ; P. Sandstrom ; K. J. Labori ; E. H. Kure ; P. M. Grandgenett ; M. A. Hollingsworth ; M. de Sousa ; S. Kaur ; M. Jain ; K. Mallya ; S. K. Batra ; W. R. Jarnagin ; M. S. Brady ; O. Fodstad ; V. Muller ; K. Pantel ; A. J. Minn ; M. J. Bissell ; B. A. Garcia ; Y. Kang ; V. K. Rajasekhar ; C. M. Ghajar ; I. Matei ; H. Peinado ; J. Bromberg ; D. Lyden
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-11-03Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Biomarkers/metabolism ; Brain/cytology/*metabolism ; Cell Line, Tumor ; Endothelial Cells/cytology/metabolism ; Epithelial Cells/cytology/metabolism ; Exosomes/*metabolism ; Female ; Fibroblasts/cytology/metabolism ; Genes, src ; Humans ; Integrin alpha6beta1/metabolism ; Integrin alpha6beta4/antagonists & inhibitors/metabolism ; Integrin beta Chains/metabolism ; Integrin beta4/metabolism ; Integrins/antagonists & inhibitors/*metabolism ; Kupffer Cells/cytology/metabolism ; Liver/cytology/*metabolism ; Lung/cytology/*metabolism ; Mice ; Mice, Inbred C57BL ; Neoplasm Metastasis/*pathology/*prevention & control ; Organ Specificity ; Phosphorylation ; Receptors, Vitronectin/antagonists & inhibitors/metabolism ; S100 Proteins/genetics ; *TropismPublished by: -
3Articles: DFG German National LicensesStaff View
ISSN: 1399-3054Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyType of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1432-2048Keywords: Nitrate assimilation ; Nitrate reductase ; Nitrite reductase ; Phytochrome ; Plastidic signal ; SinapisSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract Nitrite reductase (NIR; EC 1.7.7.1) is a central enzyme in nitrate assimilation and is localized in plastids. The present study concerns the regulation of the appearance of NIR in cotyledons of the mustard (Sinapis alba L.) seedling. It was shown that light exerts its positive control over the nitrate-mediated induction of NIR via the farred-absorbing form of phytochrome. Without nitrate the light effect cannot express itself; even though the light signal is accumulated in the cotyledons it remains totally cryptic in the absence of nitrate. Moreover, it was recognised that ‘intact plastids’ are important in the control of the appearance of NIR. If the plastids are damaged by photooxidation the action of nitrate and phytochrome on NIR appearance is abolished. The appearance of nitrate reductase (NR; EC 1.6.6.1) responds similarly to photooxidative damage even though this enzyme is cytosolic. While the data strongly indicate that some ‘plastidic signal’ is a prerequisite for the nitrate-induced and phytochrome-modulated appearance of NIR and NR, the possibility could not be ruled out that photooxidative damage affects the accumulation of NIR in the organelle.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1573-5028Keywords: chloroplasts ; DNA primase ; DNA replication ; Pisum sativumSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract A DNA primase activity was isolated from pea chloroplasts and examined for its role in replication. The DNA primase activity was separated from the majority of the chloroplast RNA polymerase activity by linear salt gradient elution from a DEAE-cellulose column, and the two enzyme activities were separately purified through heparin-Sepharose columns. The primase activity was not inhibited by tagetitoxin, a specific inhibitor of chloroplast RNA polymerase, or by polyclonal antibodies prepared against purified pea chloroplast RNA polymerase, while the RNA polymerase activity was inhibited completely by either tagetitoxin or the polyclonal antibodies. The DNA primase activity was capable of priming DNA replication on single-stranded templates including poly(dT), poly(dC), M13mp19, and M13mp19_+ 2.1, which contains the AT-rich pea chloroplast origin of replication. The RNA polymerase fraction was incapable of supporting incorporation of 3H-TTP in in vitro replication reactions using any of these single-stranded DNA templates. Glycerol gradient analysis indicated that the pea chloroplast DNA primase (115–120 kDa) separated from the pea chloroplast DNA polymerase (90 kDa), but is much smaller than chloroplast RNA polymerase. Because of these differences in size, template specificity, sensitivity to inhibitors, and elution characteristics, it is clear that the pea chloroplast DNA primase is an distinct enzyme form RNA polymerase. In vitro replication activity using the DNA primase fraction required all four rNTPs for optimum activity. The chloroplast DNA primase was capable of priming DNA replication activity on any single-stranded M13 template, but shows a strong preference for M13mp19+2.1. Primers synthesized using M13mp19+2.1 are resistant to DNase I, and range in size from 4 to about 60 nucleotides.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1432-2048Keywords: Nuclear gene expression ; Photooxidation of chloroplast ; Phytochrome ; SinapisSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract In a preceding paper (Oelmüller and Mohr 1986, Planta 167, 106–113) it was shown that in the cotyledons of the mustard (Sinapis alba L.) seedling the integrity of the plastid is a necessary prerequisite for phytochrome-controlled appearance of translatable mRNA for the nuclear-encoded small subunit (SSU) of ribulose-1,5-bisphosphate carboxylase and the light-harvesting chlorophyll a/b-binding protein of photosystem II (LHCP). It was concluded that a signal from the plastid is essential for the expression of nuclear genes involved in plastidogenesis. The present study was undertaken to characterize this postulated signal. Chloramphenicol, an inhibitor of intraplastidic protein synthesis and Norflurazon, an inhibitor of carotenoid synthesis (to bring about photooxidative sensitivity of the plastids) were applied. We obtained the following major results. (i) After a brief period of photooxidative damage a rapid decrease of the above translatable mRNAs was observed. Conclusion: the signal is short-lived and thus required continually. (ii) Once the plastids became damaged by photooxidation, no recovery with regard to nuclear gene expression was observed after a transfer to non-damaging light conditions. Conclusion: even a brief period of damage suffices to prevent production of the signal. (iii) Chloramphenicol inhibited nuclear gene expression (SSU, LHCP) and plastidic development when applied during the early stages of plastidogenesis. Once a certain stage had been reached (between 36–48 h after sowing at 25° C) nuclear gene expression became remarkably insensitive toward inhibition of intraplastidic translation. Conclusion: a certain developmental stage of the plastid must be reached before the signal is released by the plastid. (iv) Under the growth conditions we adopted in our experiments the plastids in the mesophyll cells of mustard cotyledons developed essentially between 36 and 120 (-144) h after sowing. Only during this period could translatable mRNAs for SSU and LHCP be detected. Conclusion: the signal is released by the plastids only during this time span.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1432-2048Keywords: NH 4 + -toxicity ; Nitrate assimilation ; Nitrate reductase ; Nitrite reductase ; Phytochrome ; SinapisSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract Nitrate-induced and phytochrome-modulated appearance of nitrate reductase (NR; EC 1.6.6.1) and nitrite reductase (NIR; EC 1.7.7.1) in the cotyledons of the mustard (Sinapis alba L.) seedling is strongly affected by externally supplied ammonium (NH 4 + ). In short-term experiments between 60 and 78 h after sowing it was found that in darkness NH 4 + —simultaneously given with NO 3 - —strongly inhibits appearance of nitrate-inducible NR and NIR whereas in continuous far-red light—which operates exclusively via phytochrome without significant chlorophyll formation —NH 4 + (simultaneously given with NO 3 - ) strongly stimulates appearance of NR. The NIR levels are not affected. This indicates that NR and NIR levels are regulated differently. In the absence of external NO 3 - appearance of NR is induced by NH4 in darkness as well as in continuous far-red light whereas NIR levels are not affected. On the other hand, in the absence of external NO 3 - , exogenous NH 4 + strongly inhibits growth of the mustard seedling in darkness as well as in continuous far-red light. This effect can be abolished by simultaneously supplying NO 3 - . The adverse effect of NH 4 + on growth (‘NH 4 + -toxicity’) cannot be attributed to pH-changes in the medium since it was shown that neither the growth responses nor the changes of the enzyme levels are related to pH changes in the medium. Non-specific osmotic effects are not involved either.Type of Medium: Electronic ResourceURL: