1,720,987 research outputs found
The interacting RNA polymerase II subunits, hRPB11 and hRPB3, are coordinately expressed in adult human tissues and down regulated by doxorubicin
No full textEnergy Metabolism of Human LoVo Colon Carcinoma Cells: Correlation to Drug Resistance and Influence of Lonidamine
No full textEffect of local anesthetic ropivacaine on the energy metabolism of Ehrlich ascites tumor cells
No full textThe RNA polymerase II core subunit 11 interacts with keratin 19, a component of the intermediate filament proteins
No full textMyod acetylation influences temporal patterns of skeletal muscle gene expression
No full textMyoD is sufficient to initiate the skeletal muscle gene expression program. Transcription of certain MyoD target genes occurs in the early phases, whereas that of others is induced only at later stages, although MyoD is present throughout the differentiation process. MyoD acetylation regulates transcriptional competency, yet whether this post-translational modification is equally relevant for activation of all the MyoD targets is unknown. Moreover, the molecular mechanisms through which acetylation ensures that MyoD achieves its optimal activity remain unexplored. To address these two outstanding issues, we have coupled genome-wide expression profiling and chromatin immunoprecipitation in a model system in which MyoD or its nonacetylatable version was inducibly activated in mouse embryonic fibroblasts derived from MyoD(-/-)/Myf5(-/-) mice. Our results reveal that MyoD acetylation influences transcription of selected genes expressed at defined stages of the muscle program by regulating chromatin access of MyoD, histone acetylation, and RNA polymerase II recruitment
The Polycomb Ezh2 Methyltransferase regulates muscle gene expression and skeletal muscle differentiation
No full textThe Ezh2 protein endows the Polycomb PRC2 and PRC3 complexes with histone lysine methyltransferase (HKMT) activity that is associated with transcriptional repression. We report that Ezh2 expression was developmentally regulated in the myotome compartment of mouse somites and that its down-regulation coincided with activation of muscle gene expression and differentiation of satellite-cell-derived myoblasts. Increased Ezh2 expression inhibited muscle differentiation, and this property was conferred by its SET domain, required for the HKMT activity. In undifferentiated myoblasts, endogenous Ezh2 was associated with the transcriptional regulator YY1. Both Ezh2 and YY1 were detected, with the deacetylase HDAC1, at genomic regions of silent muscle-specific genes. Their presence correlated with methylation of K27 of histone H3. YY1 was required for Ezh2 binding because RNA interference of YY1 abrogated chromatin recruitment of Ezh2 and prevented H3-K27 methylation. Upon gene activation, Ezh2, HDAC1, and YY1 dissociated from muscle loci, H3-K27 became hypomethylated and MyoD and SRF were recruited to the chromatin. These findings suggest the existence of a two-step activation mechanism whereby removal of H3-K27 methylation, conferred by an active Ezh2-containing protein complex, followed by recruitment of positive transcriptional regulators at discrete genomic loci are required to promote muscle gene expression and cell differentiation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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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