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

The role of the cellular entry point of anthrax identified

Researchers at the University of Geneva, Switzerland, demonstrate that the receptors that bind the toxin of this bacterium control how cell division is oriented

2012-12-03
(Press-News.org) Anthrax uses a receptor on the surface of cells to inject its lethal toxins. However, the physiological function of this receptor, named Anthrax Toxin Receptor 2a (Antxr2a), remained unknown until now. A team led by Marcos Gonzalez-Gaitan, a professor at the University of Geneva (UNIGE), Switzerland, in collaboration with Gisou van der Goot at EPFL (École Polytechnique Fédérale de Lausanne), reveals that Antxr2a actually plays a role in embryonic development, orienting cell division along a specific plane, which is a prelude to the formation of future tissues and organs. At the cellular level, this receptor exerts traction on the system that allows chromosomes to separate to opposite poles, the mitotic spindle, to position it along the plane of division. These results are presented in the journal Nature Cell Biology. Anthrax is a particularly virulent germ once a person is infected by inhaling its spores. The severity of symptoms, which affect various organs, is mainly due to bacterial toxins which are lethal to cells. It is by attempting to understand how the bacillus' toxins enter cells that the Antxr2a receptor was discovered. Otherwise, its physiological role would not have been identified at present. A cap of proteins indicates the plane of division During animal development, the orientation of cell division along a specific plane is important for the organization of the different tissues and the generation of cellular diversity. This orientation is provided by the position of the mitotic spindle in the cell that is about to divide. This temporary assembly of microtubules forms an actual spindle between opposite poles of the cell in order to guide the migration of each set of chromosomes. "When the cell receives an external signal to initiate its division, a cascade of biochemical events is launched to transmit the message to the interior of the cell and have it carried out. We knew that an external signal, a protein called Wnt, was necessary to properly position the mitotic spindle, but knew nothing of the intracellular messengers involved," explains Marcos Gonzalez-Gaitan, Professor in the Departments of Biochemistry and Molecular Biology at the University of Geneva. This has now been accomplished. The scientist and his group have established the complete sequence of intracellular events allowing the mitotic spindle to align itself along the general plane of division. They conducted their experiments on zebrafish embryos, a model system in developmental studies. "Once Wnt binds to the cell membrane, different molecular agents prompt the formation of a layer of filamentous proteins along the cell membrane, at the site of the future plane of division," explains Irinka Castanon, first author of the article. The anthrax receptor used as a control lever This internal 'cap' associates itself in turn with the Antxr2a receptors, known to bind the anthrax toxin. The accumulation of these receptors will thus form a second layer, superimposed on the first. Everything is now in place for the final phase: "The Antxr2a receptors recruit in turn 'motor' proteins capable of attaching themselves to the mitotic spindle and pulling it towards the internal cap," states Marcos Gonzalez-Gaitan. Motor proteins probably act by travelling back up along the cap's filaments, allowing the alignment of the spindle with the plane of cell division. In mammals, the Antxr2a receptor is also involved in the formation and proliferation of blood vessels. "It is therefore possible that the role of this receptor in the orientation of cell division is not restricted solely to embryonic development," states the professor, who is a member of two Swiss National Research Programs: Frontiers in Genetics, and Chemical Biology.

### END


ELSE PRESS RELEASES FROM THIS DATE:

New gene-sequencing tools offer clues to highest-risk form of a childhood cancer

2012-12-03
Using powerful gene-analysis tools, researchers have discovered mutations in two related genes, ARID1A and ARID1B, that are involved in the most aggressive form of the childhood cancer neuroblastoma. While these findings do not immediately improve clinical treatments, they identify a novel pathway that is defective in these cancers, a pathway that scientists can now study to develop potential new therapies. "These gene alterations were not previously known to be mutated in neuroblastoma, and they may significantly advance our knowledge of the underlying biological pathways ...

Genes linked to low birth weight, adult shortness and later diabetes risk

2012-12-03
An international team of genetics researchers has discovered four new gene regions that contribute to low birth weight. Three of those regions influence adult metabolism, and appear to affect longer-term outcomes such as adult height, risk of type 2 diabetes and adult blood pressure. "This large study adds to the evidence that genes have a strong influence on fetal growth," said one of the co-authors, Struan F.A. Grant, Ph.D., associate director of the Center for Applied Genomics at The Children's Hospital of Philadelphia. "The cumulative effect of the genes is surprisingly ...

Scientists at Scripps Research Institute discover how 2 proteins help keep cells healthy

Scientists at Scripps Research Institute discover how 2 proteins help keep cells healthy
2012-12-03
LA JOLLA, CA – December 2, 2012 – Scientists at The Scripps Research Institute (TSRI) have determined how two proteins help create organelles, or specialized subunits within a cell, that play a vital role in maintaining cell health. This discovery opens the door for research on substances that could interfere with the formation of these organelles and lead to new therapies for cancer. The study, published online ahead of print on December 2, 2012, by the journal Nature Structural & Molecular Biology, focuses on the structure and function of the two proteins, ATG12 and ...

Scientists find 'bully' genes in common childhood tumor

2012-12-03
In a genome sequencing study of 74 neuroblastoma tumors in children, scientists at the Johns Hopkins Kimmel Cancer Center and the Children's Hospital of Philadelphia (CHOP) found that patients with changes in two genes, ARID1A and ARID1B, survive only a quarter as long as patients without the changes. The discovery could eventually lead to early identification of patients with aggressive neuroblastomas who may need additional treatments. Neuroblastomas affect nerve tissue throughout the body and are the most common, non-blood cancer in children. "These cancers have a ...

Origin of intelligence and mental illness linked to ancient genetic accident

2012-12-03
Scientists have discovered for the first time how humans – and other mammals – have evolved to have intelligence. Researchers have identified the moment in history when the genes that enabled us to think and reason evolved. This point 500 million years ago provided our ability to learn complex skills, analyse situations and have flexibility in the way in which we think. Professor Seth Grant, of the University of Edinburgh, who led the research, said: "One of the greatest scientific problems is to explain how intelligence and complex behaviours arose during evolution." ...

Childhood trauma leaves mark on DNA of some victims

Childhood trauma leaves mark on DNA of some victims
2012-12-03
This press release is available in German. Abused children are at high risk of anxiety and mood disorders, as traumatic experience induces lasting changes to their gene regulation. Scientists from the Max Planck Institute of Psychiatry in Munich have now documented for the first time that genetic variants of the FKBP5 gene can influence epigenetic alterations in this gene induced by early trauma. In individuals with a genetic predisposition, trauma causes long-term changes in DNA methylation leading to a lasting dysregulation of the stress hormone system. As a result, ...

A shock to pollution in chemistry

A shock to pollution in chemistry
2012-12-03
Solvents are omnipresent in the chemical industry, and are a major environmental and safety concern. Therefore the large interest in mechanochemistry: an energy-efficient alternative that avoids using bulk solvents and uses high-frequency milling to drive reactions. Milling is achieved by the intense impact of steel balls in a rapidly moving jar, which hinders the direct observation of underlying chemistry. Scientists have now for the first time studied a milling reaction in real time, using highly penetrating X-rays to observe the surprisingly rapid transformations as ...

Cell surface transporters exploited for cancer drug delivery

2012-12-03
CAMBRIDGE, Mass. (December 2, 2012) –Whitehead Institute scientists report that certain molecules present in high concentrations on the surfaces of many cancer cells could be exploited to funnel lethal toxic molecules into the malignant cells. In such an approach, the overexpression of specific transporters could be exploited to deliver toxic substances into cancer cells. Although this finding emerges from the study of a single toxic molecule and the protein that it transports, Whitehead Member David Sabatini says this phenomenon could be leveraged more broadly. "Our ...

Surprising results from study of non-epileptic seizures

2012-12-03
MAYWOOD, Il. - A Loyola University Medical Center neurologist is reporting surprising results of a study of patients who experience both epileptic and non-epileptic seizures. Non-epileptic seizures resemble epileptic seizures, but are not accompanied by abnormal electrical discharges. Rather, these seizures are believed to be brought on by psychological stresses. Dr. Diane Thomas reported that 15.7 percent of hospital patients who experienced non-epileptic seizures also had epileptic seizures during the same hospital stay. Previous studies found the percentage of such ...

A better way to make chemicals?

A better way to make chemicals?
2012-12-03
Bulk solvents, widely used in the chemical industry, pose a serious threat to human health and the environment. As a result, there is growing interest in avoiding their use by relying on "mechanochemistry" – an energy-efficient alternative that uses high-frequency milling to drive reactions. Because milling involves the intense impact of steel balls in rapidly moving jars, however, the underlying chemistry is difficult to observe. Now, for the first time, scientists have studied a milling reaction in real time, using highly penetrating X-rays to observe the surprisingly ...

LAST 30 PRESS RELEASES:

Underserved youth less likely to visit emergency department for concussion in Ontario, study finds

‘Molecular shield’ placed in the nose may soon treat common hay fever trigger

Beetles under climate stress lay larger male eggs: Wolbachia infection drives adaptive reproduction strategy in response to rising temperature and CO₂

Groundbreaking quantum study puts wave-particle duality to work

Weekly injection could be life changing for Parkinson’s patients

Toxic metals linked to impaired growth in infants in Guatemala

Being consistently physically active in adulthood linked to 30–40% lower risk of death

Nerve pain drug gabapentin linked to increased dementia, cognitive impairment risks

Children’s social care involvement common to nearly third of UK mums who died during perinatal period

‘Support, not judgement’: Study explores links between children’s social care involvement and maternal deaths

Ethnic minority and poorer children more likely to die in intensive care

Major progress in fertility preservation after treatment for cancer of the lymphatic system

Fewer complications after additional ultrasound in pregnant women who feel less fetal movement

Environmental impact of common pesticides seriously underestimated

The Milky Way could be teeming with more satellite galaxies than previously thought

New study reveals surprising reproductive secrets of a cricket-hunting parasitoid fly

Media Tip Sheet: Symposia at ESA2025

NSF CAREER Award will power UVA engineer’s research to improve drug purification

Tiny parasitoid flies show how early-life competition shapes adult success

New coating for glass promises energy-saving windows

Green spaces boost children’s cognitive skills and strengthen family well-being

Ancient trees dying faster than expected in Eastern Oregon

Study findings help hone precision of proven CVD risk tool

Most patients with advanced melanoma who received pre-surgical immunotherapy remain alive and disease free four years later

Introducing BioEmu: A generative AI Model that enables high-speed and accurate prediction of protein structural ensembles

Replacing mutated microglia with healthy microglia halts progression of genetic neurological disease in mice and humans

New research shows how tropical plants manage rival insect tenants by giving them separate ‘flats’

Condo-style living helps keep the peace inside these ant plants

Climate change action could dramatically limit rising UK heatwave deaths

Annual heat-related deaths projected to increase significantly due to climate and population change

[Press-News.org] The role of the cellular entry point of anthrax identified
Researchers at the University of Geneva, Switzerland, demonstrate that the receptors that bind the toxin of this bacterium control how cell division is oriented