Search results for "CHROMATIN"

ICIL: a new ISWI Complex In D.melanogaster Larvae

2008

Role of epigenetic factors in the selection of the alternative splicing isoforms of human

2017

Mutation-driven activation of KRAS is crucial to cancer development. The human gene yields four mRNA splicing isoforms, 4A and 4B being translated to protein. Their different properties and oncogenic potential have been studied, but the mechanisms deciding the ratio 4A/4B are not known. To address this issue, the expression of the four KRAS isoforms was determined in 9 human colorectal cancer cell lines. HCT116 and SW48 were further selected because they present the highest difference in the ratio 4A/4B (twice as much in HCT116 than in SW48). Chromatin structure was analysed at the exon 4A, characteristic of isoform 4A, at its intronic borders and at the two flanking exons. The low nucleoso…

Role for Chromatin Remodeling Factor Chd1 in Learning and Memory

2019

Precise temporal and spatial regulation of gene expression in the brain is a prerequisite for cognitive processes such as learning and memory. Epigenetic mechanisms that modulate the chromatin structure have emerged as important regulators in this context. While posttranslational modification of histones or the modification of DNA bases have been examined in detail in many studies, the role of ATP-dependent chromatin remodeling factors (ChRFs) in learning- and memory-associated gene regulation has largely remained obscure. Here we present data that implicate the highly conserved chromatin assembly and remodeling factor Chd1 in memory formation and the control of immediate early gene (IEG) r…

Pluripotent stem cells to model Hutchinson-Gilford progeria syndrome (HGPS): Current trends and future perspectives for drug discovery

2015

Progeria, or Hutchinson-Gilford progeria syndrome (HGPS), is a rare, fatal genetic disease characterized by an appearance of accelerated aging in children. This syndrome is typically caused by mutations in codon 608 (p.G608G) of the LMNA, leading to the production of a mutated form of lamin A precursor called progerin. In HGPS, progerin accumulates in cells causing progressive molecular defects, including nuclear shape abnormalities, chromatin disorganization, damage to DNA and delays in cell proliferation. Here we report how, over the past five years, pluripotent stem cells have provided new insights into the study of HGPS and opened new original therapeutic perspectives to treat the disea…

Epigenetic involvement in Hutchinson-Gilford progeria syndrome: a mini-review.

2013

Hutchinson-Gilford progeria syndrome (HGPS) is a rare human genetic disease that leads to a severe premature ageing phenotype, caused by mutations in the <i>LMNA</i> gene. The <i>LMNA</i> gene codes for lamin-A and lamin-C proteins, which are structural components of the nuclear lamina. HGPS is usually caused by a de novo <i>C1824T</i> mutation that leads to the accumulation of a dominant negative form of lamin-A called progerin. Progerin also accumulates physiologically in normal ageing cells as a rare splicing form of lamin-A transcripts. From this perspective, HGPS cells seem to be good candidates for the study of the physiological mechanisms of ageing…

On the ubiquitous presence of histone acetyltransferase B in eukaryotes

1985

AbstractHistone acetyltransferase B activity has been found in pea (Pisun sativum) seedlings. The enzyme has been partially purified and it has been found that it is highly specific for H4. The results confirm that histone acetyltransferase B occurs in 3 eukaryotic kingdoms.

Resveratrol post-transcriptionally regulates pro-inflammatory gene expression via regulation of KSRP RNA binding activity

2014

Resveratrol shows beneficial effects in inflammation-based diseases like cancer, cardiovascular and chronic inflammatory diseases. Therefore, the molecular mechanisms of the anti-inflammatory resveratrol effects deserve more attention. In human epithelial DLD-1 and monocytic Mono Mac 6 cells resveratrol decreased the expression of iNOS, IL-8 and TNF-α by reducing mRNA stability without inhibition of the promoter activity. Shown by pharmacological and siRNA-mediated inhibition, the observed effects are SIRT1-independent. Target-fishing and drug responsive target stability experiments showed selective binding of resveratrol to the RNA-binding protein KSRP, a central post-transcriptional regul…

Extensive nuclear gyration and pervasive non-genic transcription during primordial germ cell development in zebrafish.

2020

ABSTRACT Primordial germ cells (PGCs) are the precursors of germ cells, which migrate to the genital ridge during early development. Relatively little is known about PGCs after their migration. We studied this post-migratory stage using microscopy and sequencing techniques, and found that many PGC-specific genes, including genes known to induce PGC fate in the mouse, are only activated several days after migration. At this same time point, PGC nuclei become extremely gyrated, displaying general broad opening of chromatin and high levels of intergenic transcription. This is accompanied by changes in nuage morphology, expression of large loci (PGC-expressed non-coding RNA loci, PERLs) that ar…

The distributions of protein coding genes within chromatin domains in relation to human disease.

2019

Abstract Background Our understanding of the nuclear chromatin structure has increased hugely during the last years mainly as a consequence of the advances in chromatin conformation capture methods like Hi-C. The unprecedented resolution of genome-wide interaction maps shows functional consequences that extend the initial thought of an efficient DNA packaging mechanism: gene regulation, DNA repair, chromosomal translocations and evolutionary rearrangements seem to be only the peak of the iceberg. One key concept emerging from this research is the topologically associating domains (TADs) whose functional role in gene regulation and their association with disease is not fully untangled. Resul…

Xrn1 influence on gene transcription results from the combination of general effects on elongating RNA pol II and gene-specific chromatin configurati…

2020

mRNA homoeostasis is favoured by crosstalk between transcription and degradation machineries. Both the Ccr4-Not and the Xrn1-decaysome complexes have been described to influence transcription. While Ccr4-Not has been shown to directly stimulate transcription elongation, the information available on how Xrn1 influences transcription is scarce and contradictory. In this study we have addressed this issue by mapping RNA polymerase II (RNA pol II) at high resolution, using CRAC and BioGRO-seq techniques in Saccharomyces cerevisiae. We found significant effects of Xrn1 perturbation on RNA pol II profiles across the genome. RNA pol II profiles at 5ʹ exhibited significant alterations that were com…