Search results for "chromatin remodeling"

Deciphering the histone code to build the genome structure

2017

Histones are punctuated with small chemical modifications that alter their interaction with DNA. One attractive hypothesis stipulates that certain combinations of these histone modifications may function, alone or together, as a part of a predictive histone code to provide ground rules for chromatin folding. We consider four features that relate histone modifications to chromatin folding: charge neutralisation, molecular specificity, robustness and evolvability. Next, we present evidence for the association among different histone modifications at various levels of chromatin organisation and show how these relationships relate to function such as transcription, replication and cell division…

Abstract 4479: Unveiling the relationship between the SWI/SNF chromatin remodeling complex and noncoding RNAs

2016

Abstract Chromatin remodeling complexes are crucial for the viability of the cells due to their role in regulating interactions between DNA and histones and, therefore, modifying the accessibility of the genetic information to the transcriptional machinery. This relevance can also been seen in the SWI/SNF complex that has been associated with cancer in the last deep-sequencing efforts on tumoral genomes. BRG1 is the helicase/ATPase catalytic subunit of the SWI/SNF complex and it is frequently lost in NSCLC cell lines with a high mutation rate. In primary tumors, the loss of expression of BRG1 is also frequent, however it cannot be explained by mutations or by promoter hypermethylation. In t…

Genetic and Cytological Analysis of Drosophila Chromatin-Remodeling Factors

2003

RNA-based regulation of transposon expression

2015

Throughout the domains of life, transposon activity represents a serious threat to genome integrity and evolution has realized different molecular mechanisms that aim to inhibit the transposition of mobile DNA. Small noncoding RNAs that function as guides for Argonaute effector proteins represent a key feature of so-called RNA interference (RNAi) pathways and specialized RNAi pathways exist to repress transposon activity on the transcriptional and posttranscriptional level. Transposon transcription can be diminished by targeted DNA methylation or chromatin remodeling via repressive Histone modifications. Posttranscriptional transposon silencing bases on degradation of transposon transcripts…

Histone Code and Higher-Order Chromatin Folding: A Hypothesis

2016

AbstractHistone modifications alone or in combination are thought to modulate chromatin structure and function; a concept termed histone code. By combining evidence from several studies, we investigated if the histone code can play a role in higher-order folding of chromatin. Firstly using genomic data, we analyzed associations between histone modifications at the nucleosome level. We could dissect the composition of individual nucleosomes into five predicted clusters of histone modifications. Secondly, by assembling the raw reads of histone modifications at various length scales, we noticed that the histone mark relationships that exist at nucleosome level tend to be maintained at the high…

Redox signaling and histone acetylation in acute pancreatitis

2011

Histone acetylation via CBP/p300 coordinates the expression of proinflammatory cytokines in the activation phase of inflammation, particularly through mitogen-activated protein kinases (MAPKs), nuclear factor-κB (NF-κB), and signal transducers and activators of transcription (STAT) pathways. In contrast, histone deacetylases (HDACs) and protein phosphatases are mainly involved in the attenuation phase of inflammation. The role of reactive oxygen species (ROS) in the inflammatory cascade is much more important than expected. Mitochondrial ROS act as signal-transducing molecules that trigger proinflammatory cytokine production via inflammasome-independent and inflammasome-dependent pathways. …

Protein phosphatases and chromatin modifying complexes in the inflammatory cascade in acute pancreatitis

2010

Acute pancreatitis is an inflammation of the pancreas that may lead to systemic inflammatory response syndrome and death due to multiple organ failure. Acinar cells, together with leukocytes, trigger the inflammatory cascade in response to local damage of the pancreas. Amplification of the inflammatory cascade requires up-regulation of pro-inflammatory cytokines and this process is mediated not only by nuclear factor κB but also by chromatin modifying complexes and chromatin remodeling. Among the different families of histone acetyltransferases, the p300/CBP family seems to be particularly associated with the inflammatory process. cAMP activates gene expression via the cAMP-responsive eleme…

IL-17A induces chromatin remodeling promoting IL-8 and TSLP release in bronchial epithelial cells. Effect of Tiotropium.

Regulation of ISWI-family of chromatin remodelling Complexes

2013

The packaging of DNA into chromatin facilitates the storage of the genetic information within the nucleus but prevents the access to the underlying sequences. The evolutionarily conserved ISWI family of ATP-dependent chromatin remodelling complexes provide one of the regulatory mechanisms that eukaryotic cells have evolved to induce structural changes to chromatin. All ISWI-containing complexes use the energy derived from ATP hydrolysis in order to rearrange nucleosomes on chromatin to carry specific nuclear reactions. The combination of associated proteins with the ATPase subunit as well as specific histone modifications specialize the nuclear function of each ISWI-containing complex. Here…

The ISWI chromatin remodeler organizes the hsrω ncRNA-containing omega speckle nuclear compartments.

2011

The complexity in composition and function of the eukaryotic nucleus is achieved through its organization in specialized nuclear compartments. The Drosophila chromatin remodeling ATPase ISWI plays evolutionarily conserved roles in chromatin organization. Interestingly, ISWI genetically interacts with the hsrω gene, encoding multiple non-coding RNAs (ncRNA) essential, among other functions, for the assembly and organization of the omega speckles. The nucleoplasmic omega speckles play important functions in RNA metabolism, in normal and stressed cells, by regulating availability of hnRNPs and some other RNA processing proteins. Chromatin remodelers, as well as nuclear speckles and their assoc…