PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Degrading proteins to divide cells

Researchers at IRB Barcelona discover a crucial mechanism controlling the segregation of genetic material from parent to daughter cells

2011-08-27
(Press-News.org) From bacteria to humans, all forms of life are based on the capacity of one cell to divide into two or more identical daughter cells. In doing so, cells have to produce a copy of their genetic material (DNA) and separate it into two identical sets, one for each daughter cell. Immediately after duplication and before its segregation, DNA is packed in chromosomes that consist of two identical strands joined at a point along their length, called centromeres. Centromeres ensure accurate separation of the chromosomes between daughter cells by directing the assembly of the molecular scaffolding that helps separate cells. The group of scientists led by the IBMB-CSIC Professor and IRB Barcelona researcher Ferran Azorín has identified the main instrument that Drosophila cells use to control the levels of the CenH3 protein, a key element for defining the identity and function of the centromere in the fruit fly.

CenH3 is a unique variant of conventional histones —proteins responsible for DNA packaging— found exclusively in the centromeres of all eukaryotes studied to date. "The presence of CenH3 in chromosome regions other than the centromere is sufficient to cause defects in chromosome separation in Drosophila and in budding yeast", explains Azorín. In yeast and Drosophila, the controlled degradation of CenH3 is known to be one of the mechanisms that regulate its location in the centromere. How this mechanism works, however, has been a mystery until now. The study, led by Azorín and published online on August 25 in Current Biology, shows that CenH3 interacts specifically with the protein partner of pair (Ppa), involved in directing proteins toward degradation. "We have demonstrated that degradation of CenH3 is essential for limiting its presence at the centromeres and that this degradation is mediated by the protein Ppa, which targets CenH3 to one of the cell's degradation mechanisms, the proteasome", explains Azorín. The proteasome is a barrel-shape protein structure that breaks down and disposes of unfunctional or unnecessary proteins in the cell. When a protein has to be degraded it needs to be somehow 'tagged' for degradation so it can be detected efficiently and directed to the proteasome. Ppa is part of a 'degradation labelling complex' that marks proteins such as CenH3 with a molecule called ubiquitin for destruction in the proteasome.

"The split between insects and humans during evolution must have occurred about 5 hundred millions years ago. However, most of the molecular components of the centromere have remained practically unchanged in all eukaryotic organisms: CenH3, for example is found in all eukaryotic centromeres", says Azorín. In Drosophila and also in humans impairment of chromosome segregation during cell division may contribute to disease and birth defects. Thus, errors in centromere function can lead to chromosome instability and aberrant cell division, both of which are often observed in cancer cells. Given the essential roles of the centromeric CenH3 during cell division and the similarities in centromeric structure and function observed among all eukaryotes, the insights into Drosophila centromere stability provided by Azorín's group may contribute to our understanding of the genetic basis of cancer.

INFORMATION:

END



ELSE PRESS RELEASES FROM THIS DATE:

Benefits of Prenuptial Agreements in Virginia

2011-08-27
Even though it is not very romantic to consider death or divorce on the eve of beginning a new life together, there are various situations where couples about to wed should consider prenuptial agreements. A prenuptial agreement is a contract that couples sign prior to marriage which details the rights and obligations of each party in the event of death or divorce. A well-drafted prenuptial agreement can make things easier during difficult times that may arise in the future. Requirements of a Valid Prenuptial Agreement A prenuptial agreement is a legally binding contract, ...

40-year-old Mariner 5 solar wind problem finds answer -- turbulence doesn't go with the flow

40-year-old Mariner 5 solar wind problem finds answer -- turbulence doesnt go with the flow
2011-08-27
Research led by astrophysicists at the University of Warwick has resolved a 40 year old problem with observations of turbulence in the solar wind first made by the probe Mariner Five. The research resolves an issue with what is by far the largest and most interesting natural turbulence lab accessible to researchers today. Our current understanding tells us that turbulence in the solar wind should not be affected by the speed and direction of travel of that solar wind. However when the first space probes attempted to measure that turbulence they found their observations ...

Relocation for Ex-Spouses With Children In California

2011-08-27
It is increasingly common for parents to relocate in today's mobile society. Some do so because of military deployment orders. Others move to pursue professional opportunities. Some people relocate to care for ailing family members. Under California law, a parent who has been awarded primary custody of a child may change his or her residence, even if the parent has previously agreed not to do so. However, a move is subject to approval by the court. Essentially, a court will not allow a move if it is not in the best interests of the child. This is especially important ...

Facebook Profiles Could Jeopardize Disability Benefits

2011-08-27
Through social networking websites like Facebook and MySpace, more and more of our personal lives are ending up flashed across the Internet. While many thoroughly enjoy social networking and its many benefits, being careless with your profile can have grave financial consequences: disability insurers and even the Social Security Administration are increasingly turning to sites like Facebook to dig up evidence that can be used to deny a disability claim. Photos, Posts Can Be Problematic The issue at question in most Social Security Disability cases is whether or not ...

Lack of free play among children is causing harm, say experts in American Journal of Play

2011-08-27
CHESTNUT HILL, MA (8-26-11) -- Hovering helicopter parents who restrict their kids' unstructured play may actually harm, rather than help, children according to the latest issue of the American Journal of Play, a scholarly journal which has gathered a distinguished group of experts to probe the near-extinction of free play and its effects on children and society. "Remarkably, over the last 50 years, opportunities for children to play freely have declined continuously and dramatically in the United States and other developed nations; and that decline continues, with serious ...

Sensor chip for monitoring tumors

2011-08-27
A surgery is usually one of the first therapy options in cancer treatment. However, some tumors, such as brain tumors, can be difficult to operate on if there is a risk of damaging surrounding nerve tissue. Other cancerous tumors, such as prostate carcinoma, grow at a very slow rate and primarily affect older patients. Operating in these cases often lowers patients' quality of life without significantly extending their life expectancy. A team of medical engineers headed by Prof. Bernhard Wolf at the TUM Heinz Nixdorf Chair of Medical Electronics have now developed a ...

The Debt Ceiling Deal: How Will it Impact You?

2011-08-27
Each year, the U.S. Congress sets a budget to determine how the country will spend its money. However, the U.S. does not raise enough revenue to cover every dollar that is being spent. Therefore, the budget includes revenues that need to be borrowed from other sources. This part of the process does not necessarily include discussion about where the borrowed money will come from, or if Congress will okay borrowing these additional funds. Back in April, U.S. Treasury Secretary Timothy Geithner stated that the U.S. would be in default on August 2nd of this year if the debt ...

New study finds no nutritional difference between free-range and cage-produced eggs

2011-08-27
CHAMPAIGN, IL (August 26, 2011) – Eggs produced by free-range hens are often perceived by the public to be nutritionally superior to eggs obtained from layers kept in traditional battery cages. However, a recent scientific study has called this popular perception into question by finding essentially no differences in the nutritional quality of eggs produced by hens from both management systems, said the Poultry Science Association (PSA).The findings also showed that cholesterol levels in all eggs were lower than U.S. Department of Agriculture guidelines, prompting the USDA ...

Hand-held unit to detect cancer in poorer countries

2011-08-27
EAST LANSING, Mich. — An engineering researcher and a global health expert from Michigan State University are working on bringing a low-cost, hand-held device to nations with limited resources to help physicians detect and diagnose cancer. Syed Hashsham, a professor of civil and environmental engineering at MSU, is developing the Gene-Z device, which is operated using an iPod Touch or Android-based tablet and performs genetic analysis on microRNAs and other genetic markers. MicroRNAs are single-stranded molecules that regulate genes; changes in certain microRNAs have ...

Colorado's Harsh Penalties for Sex Crime Convictions

2011-08-27
There are few things as eye-opening as being charged with a crime. Just knowing that you could be facing prison time can be a scary thought to someone who has no experience with the criminal justice system. Not knowing what to do next or where to turn can leave a person completely unprepared to protect their rights. But not all crimes are created equal, as certain charges by their very nature carry serious potential consequences. Most sex crimes fit into this category, as the Colorado legislature has created very specific sentences that must be imposed if someone is ...

LAST 30 PRESS RELEASES:

Exercise as an anti-ageing intervention to avoid detrimental impact of mental fatigue

UMass Amherst Nursing Professor Emerita honored as ‘Living Legend’

New guidelines aim to improve cystic fibrosis screening

Picky eaters by day, buffet by night: Butterfly, moth diets sync to plant aromas

Pennington Biomedical’s Dr. Leanne Redman honored with the E. V. McCollum Award from the American Society for Nutrition

CCNY physicists uncover electronic interactions mediated via spin waves

Researchers’ 3D-printing formula may transform future of foam

Nurture more important than nature for robotic hand

Drug-delivering aptamers target leukemia stem cells for one-two knockout punch

New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New sea grant report helps great lakes fish farmers navigate aquaculture regulations

Strain “trick” improves perovskite solar cells’ efficiency

How GPS helps older drivers stay on the roads

Estrogen and progesterone stimulate the body to make opioids

Dancing with the cells – how acoustically levitating a diamond led to a breakthrough in biotech automation

Machine learning helps construct an evolutionary timeline of bacteria

Cellular regulator of mRNA vaccine revealed... offering new therapeutic options

Animal behavioral diversity at risk in the face of declining biodiversity

Finding their way: GPS ignites independence in older adult drivers

Antibiotic resistance among key bacterial species plateaus over time

‘Some insects are declining but what’s happening to the other 99%?’

Powerful new software platform could reshape biomedical research by making data analysis more accessible

Revealing capillaries and cells in living organs with ultrasound

American College of Physicians awards $260,000 in grants to address equity challenges in obesity care

Researchers from MARE ULisboa discover that the European catfish, an invasive species in Portugal, has a prolonged breeding season, enhancing its invasive potential

Rakesh K. Jain, PhD, FAACR, honored with the 2025 AACR Award for Lifetime Achievement in Cancer Research

Solar cells made of moon dust could power future space exploration

Deporting immigrants may further shrink the health care workforce

Border region emergency medical services in migrant emergency care

Resident physician intentions regarding unionization

[Press-News.org] Degrading proteins to divide cells
Researchers at IRB Barcelona discover a crucial mechanism controlling the segregation of genetic material from parent to daughter cells