Sentences with phrase «a nucleosome»

In this way the binding of the DNA to the corresponding nucleosome is changed so that the DNA for example becomes accessible for transcription enzymes and activates a particular gene.

Nucleosome: Eight histone proteins form the core of a nucleosome, around which the 147 base pairs of a DNA strand are coiled.

The researchers found that the binding of auranofin takes place through an allosteric, «action - over-a-distance» mechanism within the nucleosome, which is the component that contains the cell's packaged DNA.

The authors conclude that this newly discovered allosteric mechanism «suggests that allosteric modulation in nucleosomes may have biological relevance and potential for therapeutic interventions.»

Differentially methylated regions are hypomethylated and enriched in nucleosome - retaining regions.

The researchers found that the nucleosomes within chromatin fibers form short stacks that quickly fall apart and reform within a matter of milliseconds.

In order to fit inside cells, DNA is wrapped around small protein spindles, forming strings of molecules called nucleosomes.

ASF1 in fact «chaperones» a histone protein, which when coiled in a complex with DNA, forms the basic structural building block of DNA called a nucleosome.

O'Sullivan came to the Karlseder lab seven years ago to explore whether histone / DNA interactions in nucleosomes altered telomere function.

«Our paper shows that suppressing ASF1 induces ALT by affecting nucleosome assembly,» he says.

The team observed a relative scarcity of nucleosomes at telomeres from ASF1 - depleted cells, as one might expect once a histone chaperone is lost.

In January, a team at the University of Washington, Seattle, described in Cell a test that relies on tissue - specific differences in how DNA is packaged in structures called nucleosomes.

«Our cryo - EM images help us understand how the complex can recognize the presence of a histone modification in one nucleosome and place the same tag onto a neighboring nucleosome.»

«PRC2 can simultaneously engage two nucleosomes,» said Poepsel, first author of this study.

Researchers now plan to test the nucleosome and methylation approaches in larger groups of people.

The helix winds onto nucleosomes to form chromatin, which winds and winds in its turn into formations similar to what you get when you keep twisting the two ends of a string.

Genomic DNA is packaged into nucleosomes, which are formed by histone proteins that have DNA wrapped around them.

In three out of five people with advanced cancers, the team could use those nucleosome fingerprints to trace circulating DNA to the cancerous tissue.

scNMT - seq uniquely allows scientists to directly examine the connections between nucleosomes, methylation and transcription.

Our genes are packaged into cells by wrapping them around protein structures called nucleosomes.

Put simply, nucleosomes and methylation can affect transcription leading to changes in cells.

Made up of nucleosomes — roll - shaped bundles of DNA and protein — the heterochromatin is connected by a velcro - like feature called «Heterochromatin Protein 1 (HP1).»

«Currently, the nucleosome is often portrayed as a stable, inert structure, or a tiny ball,» Tulin says.

They found that the addition of a phosphate group to a histone — called H2Av — triggered the entire nucleosome to change shape, exposing previously hidden parts of the nucleosome that began to interact with and activate PARP1.

Together, nucleosomes and DNA form chromatin, which is the primary substance of chromosomes.

The ability of PARP1 to control cellular processes is regulated by nucleosomes — the basic unit of DNA packaging, consisting of a segment of DNA wound in sequence around eight histone protein cores, similar to a thread wrapped around a spool.

When we modified one histone, we changed the whole nucleosome.»

In a study published in Molecular Cell this month, Alexei V. Tulin, PhD, Associate Professor at Fox Chase Cancer Center, and colleagues reported that chemical modification of one type of histone — called H2Av — leads to substantial changes in nucleosome shape.

In the new study, Tulin and his colleagues reevaluated how PARP1 is activated by changes in the nucleosome.

In this system, the DNA strand, with its genes, is coiled around molecules known as histones, which themselves are assembled into larger entities called nucleosomes.

As a consequence, a previously hidden portion of the nucleosome becomes exposed.

We believe that the presence of dynamic nucleosomes at highly expressed genes helps to unwind this spring rapidly and as often as necessary,» comments David Shore.

Nagaki et al. [6] used anti-CenH3 antibodies to immunoprecipitate chromatin (ChIP) comprising DNA bound to CenH3 - containing nucleosomes, confirming that CenH3 is associated with both the CentO repeats and the CRR family of retrotransposons.

These nucleosomes remain a part of the chromatin throughout the cell cycle and are essential to both meiotic and mitotic cell divisions [12].

Since many of the genes containing «fragile» nucleosomes are controlled in a continuous manner by nutrient availability, modulation of promoter nucleosome stability may be a strategy used to coordinate growth - related transcription on a genome - wide level.

The scientists also found out that the type of promoter containing «fragile» nucleosomes is strongly associated with high levels of transcription.

Although it has not been established that CenH3 alone determines centromere identity, the sequence of a complete centromere should at the least include the entire region that is wound around nucleosomes containing CenH3.

«The genome probably stays in a very compact state most of the time, with nucleosomes winding the DNA like a tight spring.

«It is important to understand how nucleosomes are moved, ejected or restructured, as this will affect the accessibility of promoter DNA, which in turn influences the expression of the corresponding genes,» explains David Shore, professor at the Department of Molecular Biology of the Faculty of Science at UNIGE.

They speculate that the dynamic nature of the «fragile» nucleosome plays an important role in increasing access of the proteins initiating the transcription to the promoter.

«It's the packing density that could change and limit the accessibility of chromatin, providing a local and global structural basis through which different combinations of DNA sequences, nucleosome variations and modifications could be integrated in the nucleus to exquisitely fine - tune the functional activity and accessibility of our genomes.»

The dynamics of nucleosome formation and positioning in promoters may, for example, help to understand why some genes are highly expressed, such as those involved in normal or malignant growth, while others, such as stress - induced genes, are only rarely expressed under normal conditions.

As do human cells, yeast also possesses so - called «fragile» nucleosomes.

This is done with the help of nucleosomes, basic units made of proteins around which a segment of DNA is wound.

When a given gene needs to be transcribed to create new proteins, its promoter region must be unwrapped from the nucleosome so that it can be accessed by the factors involved in initiating the transcription process.

X-rays and microscopy showed that the primary level of chromatin organization involves 147 bases of DNA spooling around proteins to form particles approximately 11 nanometers (nm) in diameter called nucleosomes.

In collaboration with researchers at the Department of Computer Science (UNIGE) and the Swiss Institute of Bioinformatics at EPFL, David Shore's team has undertaken to characterize nucleosomes present in every gene promoter of yeast DNA.

Researchers from the University of Geneva (UNIGE) and the Ecole polytechnique fédérale de Lausanne (EPFL), Switzerland, are studying the mechanisms controlling nucleosome dynamics and how this affects gene expression.

One type, characterized by the presence of dynamic, unstable, nucleosomes, is found at highly expressed genes, such as those involved in the control of cell growth and division.

Because this region covers the entire CenHs - binding region (around 750 kb), the authors [6] postulated that CenH3 - containing and dimethyl - K9 H3 - containing nucleosomes are interspersed and that the position of these nucleosomes is dynamic, so that a population of cells may have the same DNA sequence interacting with both types of nucleosome.