chromatin

Man and mouse share genome structures

...Chemical tags placed on the histones alter the way chromatin is organized, thus allowing the right combination ... on. In their study, the researchers analyzed the chromatin structure of the two shortest human chromosomes, numbers 21 and 22, containing about two percent of ...

An HIV Protein Plays a Surprising Role in Gene Activation

...living human cells, Green and colleagues turned to chromatin immunoprecipitation, a technique that detects proteins bound (directly or indirectly) to DNA. Working with three well-known effectors of transcription—an activator (Gal4-VP16), a transcriptional enhancer, and another viral activator called E1a—the au...

Protein Packages Found To Activate Genes; May Be What Regulates Development And Disease

...e and identified the DNA sequences associated with chromatin that contains "on" tags. DNA is the same in all th... are turned on and off remain unknown, the tags in chromatin are believed to play a major role. Until now, however, it had not even been known which regions of t...

Study of genomic DNA leads to new advances in cancer diagnostics

...urrounding the cell, influenced whether the cell's chromatin was sensitive or resistant to Alu I. The group als...hers could alter the Alu I sensitivity of a cell's chromatin by exposing the cell to a single extracellular matrix molecule or by disrupting any of three cytoske...

Gene keeps neural cells on correct developmental path

...ing of neural genes in other cells, REST keeps the chromatin in embryonic stem and precursor neurons open and poised for gene activity. "REST keeps the brake on lightly until a trigger tells embryonic stem cells it's time to make a neuron," Mandel said. The cell then triggers the expression of an ensemble of ...

UCR chemist part of team identifying new areas of gene regulation

...attracting the protein string known as the SWI/SNI chromatin remodeling complex to the location of acetylation. "In this paper, we used mass spectrometry to identify a novel acetylation site at the lysine 56 of yeast histone H3," said Zhang, referring to the previously unknown location of a chemical opening t...

'Punctuated' evolution in the human genome

...may have been changes in transcriptional status or chromatin conformation. "Other regions may show different temporal biases," explains Eichler. "The important implication here is that episodic bursts of activity challenge the concept of gradual clock-like changes during the course of genome evolution. Since ...

NYU chemists use computer simulation to enhance understanding of DNA transcription

...lly, chains of nucleosomes, the building blocks of chromatin that appear as bead-like structures along DNA, fol... increases. This folding and the interplay between chromatin structures regulate fundamental gene expression. However, the molecular mechanism underlying this pr...

Scientists unpick genetics of first 15 minutes of life

...rm a proper male pro-nucleus. By highlighting the chromatin and watching the changes it goes through at different stages of the fertilisation process, the scientists found that the pro-nucleus in s�same mutant is wound into a tight ball that could not interact with its female counterpart, the egg pro-nucleus....

Novel molecular 'signature' marks DNA of embryonic stem cells

...ical tags joined to its backbone. By examining the chromatin in mouse ES cells across the genome, the scientist... unusual pair of overlapping molecular tags in the chromatin structure, which together comprise what they called a "bivalent domain," reflecting the dual nature ...

Researchers uncover new mechanism of tumor suppressor

... inhibitor of growth 2 tumor suppressor recognizes chromatin and regulates cell growth, proliferation, stress responses and aging. We hope this discovery opens up new opportunities to establish novel targets to prevent and treat cancer," said Kutateladze, a NARSAD Young Investigator and an American Cancer Soci...

Pathway toward gene silencing described in plants

...uences that match the siRNAs. At these sites, the chromatin remodeler DRD1 presumably bulldozes histones and other proteins out of the way to make the DNA accessible for methylation by the de novo cytosine methyltransferase, DRM2. A paradoxical aspect of the pathway is that siRNAs direct DNA methylation but...

Promising cell protein may play role in infection and dry eye

...he researchers, this interaction with Rb2/p130 and chromatin modeling enzymes may affect how PAI-2 is expressed. "There is a different expression of the protein between the epithelium of the cornea and conjunctiva cells," says Massaro-Giordano, an assistant professor of ophthalmology, cataract and refractive...

Loosen up, DNA: Leukemia gene changes genetic packaging

...lecular mechanisms to be identified as controlling chromatin remodeling. Its work resembles that of a criminal ...DAC (histone deacetylase) inhibitors, which affect chromatin structure and play a role in turning on or off whole swaths of DNA. Such drugs are under investigati...

Activation of microRNA inhibits cancer gene in human cancer cells

... be controlled by epigenetic alterations linked to chromatin remodeling. Cancer cells and normal cells were treated with chromatin-remodeling drugs to simultaneously inhibit DNA methylation and histone deacetylation. A subset of miRNAs was upregulated in the cancer cells but not the normal cells. Importantly, ...

Single molecular 'mark' seen as pivotal for genome compaction in spores and sperm

...r experiments showed that the molecule "marks" the chromatin just prior to compaction and that its presence is mandatory for successful compaction. Additionally, after first noting the molecule's activity during the production of yeast spores, the scientists saw the same activity during the creation of sperm i...

Regulating the nuclear architecture of the cell

...s of a chromosome, where it abuts the telomeres -- chromatin structures best known for limiting, by their dimin...omere in the central region of the chromosome, the chromatin structure that plays a crucial role in chromosome segregation during cell division. What other funct...

Detailed 3-D image catches a key regulator of neural stem cell differentiation in action

.... "In the past there has been a lot of emphasis on chromatin modifications and physical access to genes, but Scp1 regulates the activity of the enzyme that transcribes genes directly," he adds. Scp1 is not the only protein that directly influences the activity of RNA polymerase II. A constantly fluctuating ...

Molecular atlas provides new tool for understanding estrogen-fueled breast cancer

...on-chip. Researchers first used a technique called chromatin immunoprecipitation (ChIP) to purify the regions of genes that take orders from the ER. They then placed these pieces of DNA on "microarray chips" containing the entire human genome sequence. This allowed the researchers to identify all the points in...

Beyond the DNA: Chemical signatures reveal genetic switches in the genome

...m. "We used genome-scale approaches to analyze the chromatin architecture in human cells and discovered distinct signatures of modified histones that correspond to known promoters and enhancers. These findings enabled us to generate computational algorithms that identified hundreds of novel genomic regions wit...

DNA repair proteins monitored at double-strand break

... The team then used a biochemical technique called chromatin immunoprecipitation to collect and identify repair proteins and show where each one bound to the DNA. ...

'Insulator' helps silence genes in dormant herpes virus

...c material that forms chromosomes. By establishing chromatin boundaries, insulators can limit the range of acti...we were able to identify this element as a kind of chromatin insulator that helps HSV-1 maintain a balance in its life cycle." The study also showed that HSV-...