How DNA alarm-system works
Researcher from Lomonosov Moscow State University managed to clarify how DNA damage signaling works
2015-03-30
(Press-News.org) The DNA molecule is chemically unstable giving rise to DNA lesions of different nature. That is why DNA damage detection, signaling and repair, collectively known as the DNA damage response, are needed. The DNA damage response is immensely important, for example, for ensuring the highest possible quality of the DNA before replication - duplication of the DNA prior to cell division. If the damaged DNA is replicated, the risk of cancer and other diseases increases significantly due to mutations. All in all this may lead to the death of a cell itself.
DNA repair consists of enzymes which find the damaged DNA and repair it before the replication. These enzymes work differently. Some of them recognize the damaged bases and give signals to the other enzymes, which repair the DNA.
Ataxia-telangiectasia mutated (ATM) is a kinase that transmits the signal from damaged DNA to cellular repair systems. Scientists used to think that ATM exclusively recognizes DNA double-strand breaks (DSBs). These breaks are extremely dangerous because they may lead to the loss of genetic information.
Svetlana V. Khoronenkova who is a Postdoctoral Researcher at Lomonosov Moscow State University and at the University of Oxford was among the scientists who managed to discover a novel role for ATM. She designed the project, controlled its experimental part and prepared the results for the publication. The article written by Svetlana V. Khoronenkova and her colleague Grigory L. Dianov was published in PNAS.
"Endogenous double-strand breaks are rarely formed in the DNA. The concept of the cellular function lies in the prevention of DNA double-strand break's formation", -- Svetlana V. Khoronenkova said, -- "We now understand that ATM recognizes and is activated in response to DNA single-strand breaks (SSBs)".
Svetlana V. Khoronenkova mentioned that about 15 to 20 thousand endogenous DNA single-strand breaks form per day. On the other hand, only 10-20 DNA double-strand breaks are formed during this period. This highlights the importance of signaling the presence of unrepaired DNA single-strand breaks to repair systems.
In response to DNA single-strand breaks ATM self- activates and transmits the signal about the damage.
This leads to a delay in the DNA replication, giving a cell more time to repair.
If timely repair does not occur, replication over the SSB-containing DNA results in the formation of deleterious DSBs, thus increasing the risk of cancer and other diseases.
In particular, mutations in the ATM gene are associated with Ataxia telangiectasia (A-T), a rare inherited disease with symptoms in early childhood and a short life span. Overall, there is about one documented case in 40,000-100,000 births worldwide, and about 1% of the world's population carry mutations in ATM. In addition to immunodeficiency and neurodegeneration, A-T is characterised by extreme sensitivity and predisposition to cancer.
"Now we want to understand how ATM is activated in response to SSBs. This future work will ultimately help with the development of new therapies, and in an attempt to improve the lives of those who suffer from A-T and diseases with the similar phenotype", -- Svetlana V. Khoronenkova summarized.
INFORMATION:
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2015-03-30
Fasting in combination with chemotherapy has already been shown to kill cancer cells, but a pair of new studies in mice suggests that a less-toxic class of drugs combined with fasting may kill breast, colorectal and lung cancer cells equally well.
If shown to work in humans, this combination could replace chemotherapy and make fasting a potent component of a long-term strategy to treat cancer, according to senior author Valter Longo of USC.
Human clinical trials in the United States and Europe are already studying the effectiveness and safety of Longo's strategy of ...
2015-03-30
TORONTO, March 30, 2015 - In their latest brain imaging study on women at risk for Alzheimer's disease, York University researchers have found deterioration in the pathways that serve to communicate signals between different brain regions needed for performing everyday activities such as driving a car or using a computer.
"We observed a relationship between the levels of deterioration in the brain wiring and their performance on our task that required simultaneous thinking and moving; what we see here is a result of communication failure," explains Professor Lauren Sergio ...
2015-03-30
March 30, 2015 - New estimates suggest that 20 to 30 percent of opioid analgesic drugs prescribed for chronic pain are misused, while the rate of opioid addiction is approximately 10 percent, reports a study in the April issue of END ...
2015-03-30
New guidelines from the Canadian Task Force on Preventive Health Care to help prevent and manage obesity in children and youth recommend regular growth monitoring at routine health care visits as well as a focus on family lifestyles and health behaviours. The guidelines, published in CMAJ (Canadian Medical Association Journal), are aimed at helping primary care practitioners address this major public health issue.
Growth monitoring includes measuring weight, height or length, calculating body mass index and plotting these according to age using the measures on the WHO ...
2015-03-30
SAN FRANCISCO--Located in the Marmara Sea, major earthquakes along the North Anatolian Fault (NAF) system have repeatedly struck what is current-day Istanbul and the surrounding region, but determining the recurrence rate has proven difficult since the faults are offshore. Cores of marine sediment reveal an earthquake history of the Cinarcik Segment, a main branch of NAF, and suggest a seismic gap where the next earthquake is likely to rupture, as detailed in a new study published in the Bulletin of the Seismological Society of America (BSSA).
The area has experienced ...
2015-03-30
Researchers have been fascinated for a long time by learning and memory formation, and many questions are still open. Bochum-based neuroscientists Prof Dr Denise Manahan-Vaughan and Dr Hardy Hagena have discovered a key building block for this complex process. A particular neurotransmitter receptor, namely the metabotropic glutamate receptor 5, is a switch for activating opposing forms of plasticity in the hippocampus, a brain region vital for memory forming. They reported in the current edition of "The Journal of Neuroscience".
Synapses between neurons process different ...
2015-03-30
While the body of evidence for feeding recommendations for children continues to evolve, one constant remains: Children do not eat enough vegetables. In fact, more than 90% of young children fail to meet vegetable recommendations, and these patterns often persist into adolescence and adulthood, making it important to understand the factors involved in establishing feeding patterns in early childhood. Are children not eating their vegetables because of texture, lack of role modeling, negative sensory experience, delayed introduction, bitter taste, infrequent exposure, rejection ...
2015-03-30
A new star rating system can help hockey players to know just how well each helmet on the market can protect them from suffering head injuries and concussions during the course of a season. The "Hockey STAR" (Summation of Tests for the Analysis of Risk) rating is an extension of a similar rating system developed for football helmets. It was developed by researchers from Virginia Tech in the US, led by Bethany Rowson, and reported on in Springer's journal Annals of Biomedical Engineering.
More ice hockey players suffer concussion while playing hockey than their counterparts ...
2015-03-30
Researchers at MIT and Northwestern University have developed a new peer-to-peer networking tool that enables sufferers of anxiety and depression to build online support communities and practice therapeutic techniques.
In a study involving 166 subjects who had exhibited symptoms of depression, the researchers compared their tool with an established technique known as expressive writing. The new tool yielded better outcomes across the board, but it had particular advantages in two areas: One was in training subjects to use a therapeutic technique called cognitive reappraisal, ...
2015-03-30
PHILADELPHIA -- Intensive care units across the United States vary widely in how they manage the care of patients who have set preexisting limits on life-sustaining therapies, such as authorizing do-not-resuscitate (DNR) orders and prohibiting interventions such as feeding tubes or dialysis, according to new research from the Perelman School of Medicine at the University of Pennsylvania. Their work is published in the current issue of JAMA Internal Medicine.
"We've long known that end-of-life and critical care varies across nations, regions and centers, whether from ...
LAST 30 PRESS RELEASES:
[Press-News.org] How DNA alarm-system works
Researcher from Lomonosov Moscow State University managed to clarify how DNA damage signaling works
