Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The proteins ensuring genome protection

13.02.2012
Researchers from the University of Geneva, Switzerland, discover how enzymatic onslaughts at the ends of our chromosomes are countered

Researchers from the University of Geneva (UNIGE), Switzerland, have discovered the crucial role of two proteins in developing a cell 'anti-enzyme shield'. This protection system, which operates at the level of molecular 'caps' named telomeres, prevents cells from treating chromosome ends like accidental DNA breaks and 'repairing' them.

Joining chromosome ends would, indeed, lead to tumor formation. This study, carried out by Cyril Ribeyre and led by David Shore, professor of molecular biology, is published in the revue Nature Structural & Molecular Biology.

Each of our cells contains two huge DNA strands, segmented into parts that are packaged within chromosomes. Each chromosome end, however, becomes vulnerable to specific enzymes that target accidental DNA breaks in need of repair. The cell is, indeed, equipped with a sensitive surveillance system that recognizes and corrects abnormalities occurring within our genome. This system includes patrolling proteins, molecules that set off an alarm, as well as damage-repairing enzymes.

In order to escape the cellular mechanisms that detect and repair damaged DNA, the ends of our chromosomes are covered by molecular 'caps' called telomeres. These complexes, formed of proteins and repetitive DNA, constitute an 'anti-enzyme shield' that protects chromosome ends. Inadvertent end joining would indeed lead to chromosome breakage and rearrangement during cell division, processes that are known to drive tumor formation.

Restraining the zeal of repair enzymes

Cyril Ribeyre and David Shore, from the Department of Molecular biology of the UNIGE, have discovered that Rif1 and Rif2, two related proteins that bind telomeres, deactivate the alarm of the DNA repair surveillance system. 'Telomeres interact with many molecules. We had identified several biochemical players, but we didn't know how they functioned', says Professor Shore, member of the National Center of Competence in Research Frontiers in Genetics. 'We have now established that Rif1 and Rif2 prevent the binding of specific proteins involved in setting off this alarm, which inhibits an enzymatic cascade at an early stage in the process'.

This local 'anti-enzyme shield' seems to extend to neighboring regions. 'Telomeres of adjacent chromosomes probably benefit from this protective system, in case they undergo severe damage', suggests Professor Shore.

These two related molecules had already been analyzed and part of their functions uncovered by the researcher's team. 'We knew that Rif1 and Rif2 were involved in regulating telomere length, which determines the life span of the cell. Both of them were also suspected to take part in the telomeric cap formation', details Cyril Ribeyre.

The multiple activities of Rif1 and Rif2 thus contribute to ensure the optimal functioning of telomeres with respect to their roles –all essential- within the cell.

David Shore | EurekAlert!
Further information:
http://www.unige.ch

More articles from Life Sciences:

nachricht Cancer cachexia: Extracellular ligand helps to prevent muscle loss
25.02.2020 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

nachricht The genetic secret of night vision
25.02.2020 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: High-pressure scientists in Bayreuth discover promising material for information technology

Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.

The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...

Im Focus: From China to the South Pole: Joining forces to solve the neutrino mass puzzle

Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics

Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...

Im Focus: Therapies without drugs

Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.

A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Turbomachine expander offers efficient, safe strategy for heating, cooling

25.02.2020 | Power and Electrical Engineering

The seismicity of Mars

25.02.2020 | Earth Sciences

Cancer cachexia: Extracellular ligand helps to prevent muscle loss

25.02.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>