Search results for "ROMA"
showing 10 items of 13919 documents
Customised next-generation sequencing multigene panel to screen a large cohort of individuals with chromatin-related disorder
2020
BackgroundThe regulation of the chromatin state by epigenetic mechanisms plays a central role in gene expression, cell function, and maintenance of cell identity. Hereditary disorders of chromatin regulation are a group of conditions caused by abnormalities of the various components of the epigenetic machinery, namely writers, erasers, readers, and chromatin remodelers. Although neurological dysfunction is almost ubiquitous in these disorders, the constellation of additional features characterizing many of these genes and the emerging clinical overlap among them indicate the existence of a community of syndromes. The introduction of high-throughput next generation sequencing (NGS) methods f…
Regulation of ISWI chromatin remodelling activity.
2013
The packaging of the eukaryotic genome into chromatin facilitates the storage of the genetic information within the nucleus, but prevents the access to the underlying DNA sequences. Structural changes in chromatin are mediated by several mechanisms. Among them, ATP-dependent remodelling complexes belonging to ISWI family provides one of the best examples that eukaryotic cells evolved to finely regulate these changes. ISWI-containing complexes use the energy derived from ATP hydrolysis to rearrange nucleosomes on chromatin in order to favour specific nuclear reactions. The combination of regulatory nuclear factors associated with the ATPase subunit as well as its modulation by specific histo…
Genome-wide characterization of chromatin binding and nucleosome spacing activity of the nucleosome remodelling ATPase ISWI.
2010
The evolutionarily conserved ATP-dependent nucleosome remodelling factor ISWI can space nucleosomes affecting a variety of nuclear processes. In Drosophila, loss of ISWI leads to global transcriptional defects and to dramatic alterations in higher-order chromatin structure, especially on the male X chromosome. In order to understand if chromatin condensation and gene expression defects, observed in ISWI mutants, are directly correlated with ISWI nucleosome spacing activity, we conducted a genome-wide survey of ISWI binding and nucleosome positioning in wild-type and ISWI mutant chromatin. Our analysis revealed that ISWI binds both genic and intergenic regions. Remarkably, we found that ISWI…
Membrane-Bound F1 ATPase from Micrococcus Sp. ATCC 398E. Purification and Characterization by Affinity Chromatography
1976
A chemically reactive ATP analogue, 6-[(3-carboxy-4-nitrophenyl)thio]-9-β-D-ribofuranosylpurine 5′-triphosphate (Nbs6ITP) has been synthesized. It has the ability to form stable thioether bonds between the 6-position of the purine ring and aliphatic mercapto groups. The nucleotide moiety of the reagent has been covalently bound to agarose, via iminobispropylamine and N-acetyl-homocysteine as spacer with the purpose of producing an affinity chromatography material. The affinity matrix binds solubilized F1 ATPase from a crude extract of Micrococcus sp. membranes. Afterwards the enzyme can be selectively eluted from the column at a defined ATP concentration. This method is superior to the conv…
F1-ATPase from Micrococcus sp. ATCC 398. Purification by Ion-Exchange Chromatography and Further Characterization. (Auto)proteolysis and Dissociative…
1977
The preparation of highly purified F1-ATPase from Micrococcus sp. ATCC 398 by application of DEAE-Sepharose CL-6B chromatography as final step is described. This enzyme consists of five subunits of different molecular weight: alpha (65000), beta (55000),gamma (35000), delta (20000), and epsilon (17000). Disc electrophoresis on 5% polyacrylamide gels removes the epsilon-polypeptide yielding an active ATPase complex with four different subunits: alpha, beta, gamma, delta. Additionally, by variation of the ionic strength delta can (partly) removed allowing the isolation by disc electrophoresis of an active ATPase complex which consists only of three different subunits alpha, beta, and gamma. I…
m6A RNA methylation of major satellite repeat transcripts facilitates chromatin association and RNA:DNA hybrid formation in mouse heterochromatin
2021
Abstract Heterochromatin has essential functions in maintaining chromosome structure, in protecting genome integrity and in stabilizing gene expression programs. Heterochromatin is often nucleated by underlying DNA repeat sequences, such as major satellite repeats (MSR) and long interspersed nuclear elements (LINE). In order to establish heterochromatin, MSR and LINE elements need to be transcriptionally competent and generate non-coding repeat RNA that remain chromatin associated. We explored whether these heterochromatic RNA, similar to DNA and histones, may be methylated, particularly for 5-methylcytosine (5mC) or methyl-6-adenosine (m6A). Our analysis in mouse ES cells identifies only b…
NOseq: amplicon sequencing evaluation method for RNA m6A sites after chemical deamination
2020
Abstract Methods for the detection of m6A by RNA-Seq technologies are increasingly sought after. We here present NOseq, a method to detect m6A residues in defined amplicons by virtue of their resistance to chemical deamination, effected by nitrous acid. Partial deamination in NOseq affects all exocyclic amino groups present in nucleobases and thus also changes sequence information. The method uses a mapping algorithm specifically adapted to the sequence degeneration caused by deamination events. Thus, m6A sites with partial modification levels of ∼50% were detected in defined amplicons, and this threshold can be lowered to ∼10% by combination with m6A immunoprecipitation. NOseq faithfully d…
Production of Adenosine by Ectonucleotidases: A Key Factor in Tumor Immunoescape
2012
It is now well known that tumor immunosurveillance contributes to the control of cancer growth. Many mechanisms can be used by cancer cells to avoid the antitumor immune response. One such mechanism relies on the capacity of cancer cells or more generally of the tumor microenvironment to generate adenosine, a major molecule involved in antitumor T cell response suppression. Adenosine is generated by the dephosphorylation of extracellular ATP released by dying tumor cells. The conversion of ATP into adenosine is mediated by ectonucleotidase molecules, namely, CD73 and CD39. These molecules are frequently expressed in the tumor bed by a wide range of cells including tumor cells, regulatory T …
The Affective Geography of Paris in the 19th Century Romanian Novel: Between Admiration and Aversion
2020
Based on “The Emotions of London”, a research project initiated at the Stanford Literary Lab, my article focuses on two relevant issues. First of all, I aim to demonstrate, as the “geography of emotions” experiment has already proved, that distant reading approaches and big data interpretation do not necessarily have to replace traditional methods of analysis. In other words, by using a corpus of 157 texts, I intend to outline the affective image of Paris as presented in the nineteenth century Romanian novel. Secondly, the aspect that makes my article different from “The Emotions of London” is that my purpose does not lie in analysing emotions associated with certain place-names in Paris, b…
Emotional and Sexual Development in Adolescence: From Puberty to the Formation of Emotional Bonds
2014
The physiological processes, which occur during adolescence and often so abruptly, can threaten the continuity of the previously constructed sense of identity. They do this by questioning the patterns and representations that had previously governed the relations of the teenager with regards to his body and his relational systems. Although puberty is not just about sexual transformations, definitions centered mainly on this aspect can be found in literature. In fact, pubertal development is the acquisition disclosure index of the adult reproductive capacity. The aim of this task is to explore the process of increasing involvement of the adolescent in an emotional and sexual relationship wit…