1,720,973 research outputs found
Integrative gene transfer in the truffleTuber borchii by Agrobacterium tumefaciens-mediated transformation
Get PDFAgrobacterium tumefaciens-mediated transformation is a powerful tool for reverse genetics and functional genomic analysis in a wide variety of plants and fungi. Tuber spp. are ecologically important and gastronomically prized fungi ("truffles") with a cryptic life cycle, a subterranean habitat and a symbiotic, but also facultative saprophytic lifestyle. The genome of a representative member of this group of fungi has recently been sequenced. However, because of their poor genetic tractability, including transformation, truffles have so far eluded in-depth functional genomic investigations. Here we report that A. tumefaciens can infect Tuber borchii mycelia, thereby conveying its transfer DNA with the production of stably integrated transformants. We constructed two new binary plasmids (pABr1 and pABr3) and tested them as improved transformation vectors using the green fluorescent protein as reporter gene and hygromycin phosphotransferase as selection marker. Transformants were stable for at least 12 months of in vitro culture propagation and, as revealed by TAIL- PCR analysis, integration sites appear to be heterogeneous, with a preference for repeat element-containing genome sites
SAGA complex and Gcn5 are necessary for respiration in budding yeast
Get PDFIn budding yeast, growth through fermentation and/or respiration is dependent on the type of carbon source
present in the medium. SAGA complex is themain acetylation complex and is required, togetherwith Rtg factors,
for nucleus-mitochondria communication and transcriptional activation of specific nuclear genes. Even though
acetylation is necessary formitochondria activity and respiratory pathways the direct role of histone acetyltransferases
and SAGA complex has never been investigated directly. In this study we demonstrate, for the first time,
that Gcn5 and SAGA are needed for respiratory metabolismand oxygen consumption. According to a central role
for acetylation in respirationwe find that the Gcn5 inhibitor CPTH2 had higher efficacy on cells grown in glycerol
containing media. We also demonstrated that the opposing activities of Gcn5 and Hda1 modify selectively H3-
AcK18 and are essential for respiration. Taken together our results suggest a novel paradigm coupling
acetyltransferase activity to respiratory metabolism. Correspondingly we propose the selective utilization of
KAT inhibitor CPTH2, combined to the modulation of the respiratory metabolism of the cell, as a promising
novel tool of intervention in cancer cell
A novel Gcn5p inhibitor represses cell growth, gene transcription and histone acetylation in budding yeast
No full textHistone acetyltransferases are key chromatin regulators responsible for transcriptional activation and cell cycle progression. We propose a simple yeast-based assay to determine the specificity and targets of novel Gcn5p inhibitors. Here, we report the finding of a novel, small molecule, MC1626, which is able to inhibit yeast cell growth, Gcn5p-dependent gene transcription and acetylation of the histone H3 N-terminal tail in vivo. Because HATs misregulation is invariably associated with human diseases, the identification of MC1626 as a novel cell-permeable Gcn5p inhibitor suggests that it may be a very useful starting tool for the further development of new molecules to be applied to expression profiling of genes regulated by histone H3 acetylation. In addition, our results demonstrate that MC1626 is a Gcn5p-dependent yeast growth inhibitor
Treatment of kidney clear cell carcinoma, lung adenocarcinoma and glioblastoma cell lines with hydrogels made of DNA nanostars
No full textOvercoming the systemic administration of chemotherapy to reduce drug toxicity and the application of personalised medicine are two of the major challenges in the treatment of cancer. To this aim, efforts are focused on finding novel nanomaterials for the targeted administration of drugs and bioactive molecules in the tumor sites. DNA-based hydrogels are promising candidates for these applications. However, while such materials are fairly known from a structural and physical standpoint, their effects on cell cultures are far less investigated. Here, we studied the biological response of three different cell lines (clear cell renal cell carcinoma 786-O, lung adenocarcinoma H1975 and glioblastoma U87MG) to the treatment with DNA-GEL - a DNA-based hydrogel composed of interacting DNA nanostars. Additionally, we investigated the structural modification of DNA-GELs under cell culture conditions. The results we collected show a cell type specificity of the response, with interesting implications for future applications
The structural basis for the recognition of acetylated histone H4 by the bromodomain of histone acetyltransferase Gcn5p
No full textGcn5 histone acetyltransferase is present in the mitoplasts
Get PDFIn Saccharomyces cerevisiae the Lysine-acetyltransferase Gcn5 (KAT2) is part of the SAGA complex and is responsible for histone acetylation widely or at specific lysines. In this paper we report that GCN5 deletion differently affects the growth of two strains. The defective mitochondrial phenotype is related to a marked decrease in mtDNA content, which also involves the deletion of specific regions of the molecule. We also show that in wild-type mitochondria the Gcn5 protein is present in the mitoplasts, suggesting a new mitochondrial function independent from the SAGA complex and possibly a new function for this protein connecting epigenetics and metabolism
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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