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71.
The deubiquitylation activity of Ubp8 is dependent upon Sgf11 and its association with the SAGA complex 下载免费PDF全文
Lee KK Florens L Swanson SK Washburn MP Workman JL 《Molecular and cellular biology》2005,25(3):1173-1182
Covalent modifications of the histone tails and the cross talk between these modifications are hallmark features of gene regulation. The SAGA histone acetyltransferase complex is one of the most well-characterized complexes involved in these covalent modifications. The recent finding that the removal of the ubiquitin group from H2B is performed by a component of SAGA, Ubp8, is intriguing as it assigns two posttranslation modification processes to one complex. In this work, we characterize the association of Ubp8 with SAGA and the effect that acetylation and deubiquitylation have on one another in vitro and in vivo. We found not only that Ubp8 is a part of the SAGA complex, but also that its deubiquitylation activity requires Ubp8's association with SAGA. Furthermore, we found that the Ubp8 association with SAGA requires Sgf11 and that this requirement is reciprocal. We also found that the acetylation and deubiquitylation activities of SAGA are independent of one another. However, we found that preacetylating histone H2B inhibited subsequent deubiquitylation. Additionally, we found that increasing the ubiquitylation state of H2B inhibited the expression of the ARG1 gene, whose repression was previously shown to require the RAD6 ubiquitin ligase. Taken together, these data indicate that the expression of some genes, including ARG1, is regulated by a balance of histone H2B ubiquitylation in the cell. 相似文献
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Shia WJ Osada S Florens L Swanson SK Washburn MP Workman JL 《The Journal of biological chemistry》2005,280(12):11987-11994
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Metal contaminations impact archaeal community composition,abundance and function in remote alpine lakes 下载免费PDF全文
Sergi Compte‐Port Carles M. Borrego Hélène Moussard Mathilde Jeanbille Claudia Ximena Restrepo‐Ortiz Alberto de Diego Azibar Rodriguez‐Iruretagoiena Ainara Gredilla Silvia Fdez‐Ortiz de Vallejuelo Pierre E. Galand Dimitri Kalenitchenko Jean‐Luc Rols Oleg S. Pokrovsky Aridane G. Gonzalez Lluis Camarero Selene Muñiz Enrique Navarro‐Navarro Jean‐Christophe Auguet 《Environmental microbiology》2018,20(7):2422-2437
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Jo?o Tavares Calixto Júnior Selene Maia de Morais Celeste Vega Gomez Cathia Coronel Molas Miriam Rolon Aline Augusti Boligon Margareth Linde Athayde Cícera Datiane de Morais Oliveira Saulo Relison Tintino Melo Coutinho Henrique Douglas 《Saudi Journal of Biological Sciences》2016,23(3):434-440
This work describes the antiparasitic and cytotoxic activities of three plant species from the Cerrado biome, Northeastern Brazil. Significant antiparasitic inhibition was observed against Trypanosoma cruzi (63.86%), Leishmania brasiliensis (92.20%) and Leishmania infantum (95.23%) when using ethanol extract from leaves of Guazuma ulmifolia Lam. (Malvaceae), at a concentration of 500 μg/mL. However, low levels of inhibition were observed when assessing leishmanicidal and trypanocidal (Clone CL-B5) activities of crude ethanol extracts from leaves and bast tissue of Luehea paniculata (Malvaceae) and leaves and bark of Prockia crucis (Salicaceae) at a concentration of 500 μg/mL. The extracts revealed the presence of phenolic acids such as gallic acid, chlorogenic acid, caffeic acid and rosmarinic acid, as well as flavonoids such as rutin, luteolin, apigenin and quercetin – the latter detected only in G. ulmifolia. G. ulmifolia extract displayed higher leishmanicidal activity probably due to the presence of quercetin, a potent known leishmanicidal compound. A cytotoxicity test indicated values over 50% at the highest concentration (1000 μg/mL) for all natural products, which were considered cytotoxic. This points out the need for further tests to enable future in vivo trials, including antineoplastic activity on human tumor cells. 相似文献
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Juan Manuel Bello-López Yendi E. Navarro-Noya Selene Gómez-Acata Zahuiti Hernández-Montañez Luc Dendooven 《Folia microbiologica》2014,59(3):235-240
The alkaline α-amylase produced by Texcoconibacillus texcoconensis 13CCT strain was identified by random mutagenesis and confirmed by directed mutagenesis. A transposon mutagenesis approach was taken to identify the gene responsible for the degradation of starch in T. texcoconensis 13CCT strain. The deduced amino acids of the amy gene had a 99 % similarity with those of Bacillus selenitireducens MLS10 and 97 % with those of Paenibacillus curdlanolyticus YK9. The enzyme showed a maximum activity of 131.1 U/mL at 37 °C and pH 9.5 to 10.5. In situ activity of the enzyme determined by polyacrylamide gel electrophoresis showed only one band with amylolytic activity. This is the first report of a bacterium isolated from the extreme alkaline–saline soil of the former Lake Texcoco (Mexico) with amylolytic activity in alkaline conditions while its potential as a source of amylases for the industry is discussed. 相似文献
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Selene Nunez-Cruz Denise C. Connolly Nathalie Scholler 《Journal of visualized experiments : JoVE》2010,(45)
Background: Ovarian cancer is generally diagnosed at an advanced stage where the case/fatality ratio is high and thus remains the most lethal of all gynecologic malignancies among US women 1,2,3. Serous tumors are the most widespread forms of ovarian cancer and 4,5 the Tg-MISIIR-TAg transgenic represents the only mouse model that spontaneously develops this type of tumors. Tg-MISIIR-TAg mice express SV40 transforming region under control of the Mullerian Inhibitory Substance type II Receptor (MISIIR) gene promoter 6. Additional transgenic lines have been identified that express the SV40 TAg transgene, but do not develop ovarian tumors. Non-tumor prone mice exhibit typical lifespan for C57Bl/6 mice and are fertile. These mice can be used as syngeneic allograft recipients for tumor cells isolated from Tg-MISIIR-TAg-DR26 mice.
Objective: Although tumor imaging is possible 7, early detection of deep tumors is challenging in small living animals. To enable preclinical studies in an immunologically intact animal model for serous ovarian cancer, we describe a syngeneic mouse model for this type of ovarian cancer that permits in vivo imaging, studies of the tumor microenvironment and tumor immune responses.
Methods: We first derived a TAg+ mouse cancer cell line (MOV1) from a spontaneous ovarian tumor harvested in a 26 week-old DR26 Tg-MISIIR-TAg female. Then, we stably transduced MOV1 cells with TurboFP635 Lentivirus mammalian vector that encodes Katushka, a far-red mutant of the red fluorescent protein from sea anemone Entacmaea quadricolor with excitation/emission maxima at 588/635 nm 8,9,10. We orthotopically implanted MOV1Kat in the ovary 11,12,13,14 of non-tumor prone Tg-MISIIR-TAg female mice. Tumor progression was followed by in vivo optical imaging and tumor microenvironment was analyzed by immunohistochemistry.
Results: Orthotopically implanted MOV1Kat cells developed serous ovarian tumors. MOV1Kat tumors could be visualized by in vivo imaging up to three weeks after implantation (fig. 1) and were infiltrated with leukocytes, as observed in human ovarian cancers 15 (fig. 2).
Conclusions: We describe an orthotopic model of ovarian cancer suitable for in vivo imaging of early tumors due to the high pH-stability and photostability of Katushka in deep tissues. We propose the use of this novel syngeneic model of serous ovarian cancer for in vivo imaging studies and monitoring of tumor immune responses and immunotherapies.Download video file.(63M, mov) 相似文献
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Dubrovsky JG Guttenberger M Saralegui A Napsucialy-Mendivil S Voigt B Baluska F Menzel D 《Annals of botany》2006,97(6):1127-1138
BACKGROUND AND AIMS: Neutral red (NR), a lipophilic phenazine dye, has been widely used in various biological systems as a vital stain for bright-field microscopy. In its unprotonated form it penetrates the plasma membrane and tonoplast of viable plant cells, then due to protonation it becomes trapped in acidic compartments. The possible applications of NR for confocal laser scanning microscopy (CLSM) studies were examined in various aspects of plant root biology. METHODS: NR was used as a fluorochrome for living roots of Phaseolus vulgaris, Allium cepa, A. porrum and Arabidopsis thaliana (wild-type and transgenic GFP-carrying lines). The tissues were visualized using CLSM. The effect of NR on the integrity of the cytoskeleton and the growth rate of arabidopsis primary roots was analysed to judge potential toxic effects of the dye. KEY RESULTS: The main advantages of the use of NR are related to the fact that NR rapidly penetrates root tissues, has affinity to suberin and lignin, and accumulates in the vacuoles. It is shown that NR is a suitable probe for visualization of proto- and metaxylem elements, Casparian bands in the endodermis, and vacuoles in cells of living roots. The actin cytoskeleton and the microtubule system of the cells, as well as the dynamics of root growth, remain unchanged after short-term application of NR, indicating a relatively low toxicity of this chemical. It was also found that NR is a useful probe for the observation of the internal structures of root nodules and of fungal hyphae in vesicular-arbuscular mycorrhizas. CONCLUSIONS: Ease, low cost and absence of tissue processing make NR a useful probe for structural, developmental and vacuole-biogenetic studies of plant roots with CLSM. 相似文献
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Naryshkina T Liu J Florens L Swanson SK Pavlov AR Pavlova NV Inman R Minakhin L Kozyavkin SA Washburn M Mushegian A Severinov K 《Journal of molecular biology》2006,364(4):667-677
We determined the sequence of the 152,372 bp genome of phiYS40, a lytic tailed bacteriophage of Thermus thermophilus. The genome contains 170 putative open reading frames and three tRNA genes. Functions for 25% of phiYS40 gene products were predicted on the basis of similarity to proteins of known function from diverse phages and bacteria. phiYS40 encodes a cluster of proteins involved in nucleotide salvage, such as flavin-dependent thymidylate synthase, thymidylate kinase, ribonucleotide reductase, and deoxycytidylate deaminase, and in DNA replication, such as DNA primase, helicase, type A DNA polymerase, and predicted terminal protein involved in initiation of DNA synthesis. The structural genes of phiYS40, most of which have no similarity to sequences in public databases, were identified by mass spectrometric analysis of purified virions. Various phiYS40 proteins have different phylogenetic neighbors, including myovirus, podovirus, and siphovirus gene products, bacterial genes and, in one case, a dUTPase from a eukaryotic virus. phiYS40 has apparently arisen through multiple acts of recombination between different phage genomes as well as through acquisition of bacterial genes. 相似文献