Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Enzyme shown to help protect genomic stability

18.02.2005


Findings may provide insights into aging and cancer

Genomes throughout the animal kingdom and beyond are characterized by extensive segments that are inactive, lengthy stretches of DNA containing multiple genes that are closed to gene transcription. Scientists believe one reason for this broad gene silencing is the vital need for genomic stability, for protection against unwanted recombinations of genetic material or other disruptions of the genome’s integrity.

Genomic instability, particularly in the regions at the ends of the chromosomes known as telomeres, has been linked to aging in humans and an elevated risk for aging-related diseases, the most prominent of which is cancer. For this reason, insights into the mechanisms of gene silencing could provide important guideposts for new approaches to retarding aging or treating cancer.



Now, an investigation led by researchers at The Wistar Institute has shown that an enzyme known as Ubp10 plays a vital role in protecting the telomeric regions of the genome from potential destabilizing molecular events. The enzyme helps to keep the genome structurally closed, unavailable for transcription and possibly protected from dangerous genetic recombinations with other regions of the genome. A report on the research, which was conducted in yeast, appears in the February 18 issue of Molecular Cell.

"There are regions of the genome that have to be inaccessible," says Shelley L. Berger, Ph.D., the Hilary Koprowski Professor in the gene expression and regulation program at Wistar and senior author on the study. "Otherwise, they can recombine with themselves or with other DNA segments. In the telomeres, such events may accelerate aging or trigger cancer in humans."

"We have identified a molecular mechanism to explain how this enzyme helps keep telomeric DNA silenced and potentially protects the genome from destabilizing activity," says N.C. Tolga Emre, a graduate student in Berger’s laboratory and lead author on the study.

The Ubp10 enzyme acts on histones, molecules that have attracted increasing attention from scientists as they move beyond sequencing the human genome to trying to better understand how DNA is managed and its activity regulated. Histones are small proteins around which DNA is coiled to create structures called nucleosomes. Compact strings of nucleosomes, then, form into chromatin, the substructure of chromosomes. In many cases, when the DNA is tightly wrapped around the histones, the genes cannot be accessed and their expression is repressed. When the coils of DNA around the histones are loosened or the histone molecules are altered, the genes become available for expression.

It is the complex activity governing this process to which Ubp10 contributes. Enzymatic modifications to histones control DNA activation or silencing through the addition or removal of acetyl, methyl, and ubiquitin molecules in prescribed sequences and patterns. One job of Ubp10, as identified in this study, is to remove ubiquitin from certain histones where ubiquitin is associated with gene activation and to maintain low levels of the ubiquitin molecule at those sites.

Interestingly, Ubp10 appears to work similarly and in concert with another enzyme called Sir2, which removes acetyl molecules from histones. Sir2 has also been associated with promoting genomic stability, and some studies have linked it intriguingly to the aging process. Some studies, for example, have suggested that low-calorie diets that extend life also boost Sir2 activity dramatically.

Franklin Hoke | EurekAlert!
Further information:
http://www.wistar.upenn.edu

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>