Biology News Net
Molecular & Cell Biology

Category: Molecular & Cell Biology

A key question in the origin of biological molecules like RNA and DNA is how they first came together billions of years ago from simple precursors. Now, in a study appearing in this week's JBC, researchers in Italy have reconstructed one of the earliest evolutionary steps yet: generating long chains of RNA from individual subunits using nothing but warm water.

Until recently, scientists believed that, following a stroke, a patient had about six months to regain any lost function. After that, patients would be forced to compensate for the lost function by focusing on their remaining abilities. Although this belief has been refuted, a University of Missouri occupational therapy professor believes that the current health system is still not giving patients enough time to recover and underestimating what the human brain can do given the right conditions.

Cancer researchers of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch have gained new insights into how cells react to DNA damage. Dr. Michael Stilmann, Dr. Michael Hinz and Professor Claus Scheidereit have shown that the protein PARP-1, which detects DNA damage within seconds, activates the transcription factor NF-kappaB, a well-known regulator of gene expression. NF-kappaB triggers a survival program, which blocks programmed cell death. The activation of NF-kappaB is thought to be one of the potential causes for tumor cell resistance to chemo and radiation therapy. (Molecular Cell, online, doi 10.1016/j.molcel.2009.09.032; Preview: doi 10.1016/j.molcel.2009.10.022)*.

Meiosis – the pairing and recombination of chromosomes, followed by segregation of half to each egg or sperm cell – is a major crossroads in all organisms reproducing sexually. Yet, how the cell precisely choreographs these chromosomal interactions is a long-standing question.

Short-term memory may depend in a surprising way on the ability of newly formed neurons to erase older connections. That's the conclusion of a report in the November 13th issue of the journal Cell, a Cell Press publication, that provides some of the first evidence in mice and rats that new neurons sprouted in the hippocampus cause the decay of short-term fear memories in that brain region, without an overall memory loss.

University of California, Berkeley, chemists have discovered the secret to the success of a jellyfish protein whose green glow has made it the darling of biologists and the subject of the 2008 Nobel Prize in Physiology or Medicine.

A team led by researchers at Albert Einstein College of Medicine of Yeshiva University has found a clear link between living to 100 and inheriting a hyperactive version of an enzyme that rebuilds telomeres – the tip ends of chromosomes. The findings appear in the latest issue of the Proceedings of the National Academy of Sciences.

Researchers Researchers at the Swedish medical university Karolinska Institutet have discovered a mechanism that controls the brain's ability to create lasting memories. In experiments on genetically manipulated mice, they were able to switch on and off the animals' ability to form lasting memories by adding a substance to their drinking water. The findings, which are published in the scientific journal PNAS, are of potential significance to the future treatment of Alzheimer's and stroke.

A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist calls a "cascade of advances."

A chemical culprit responsible for the rapid, mysterious death of phytoplankton in the North Atlantic Ocean has been found by collaborating scientists at Rutgers University and the Woods Hole Oceanographic Institution (WHOI). This same chemical may hold unexpected promise in cancer research.

Designers of anti-cancer drugs are aiming their arrows at mysterious chunks of the genetic material DNA that may play a key role in preventing the growth and spread of cancer cells, according to an article in the current issue of Chemical & Engineering News, ACS' weekly newsmagazine.

New research reveals how proteins that are critical for the transparency of the eye lens are properly sorted and localized in membrane bilayers. The study, published by Cell Press in the November 3rd issue of Biophysical Journal, analyzes how interactions between lipid and protein molecules can selectively concentrate proteins in certain regions of the cell membrane.

Scientists at the University of Bonn have discovered a previously unknown fruit fly gene that controls the metabolism of fat. Larvae in which this gene is defective lose their entire fat reserves. Therefore the researchers called the gene 'schlank' (German for 'slim'). Mammals carry a group of genes that are structurally very similar to 'schlank'. They possibly take on a similar function in the energy metabolism. The scientists therefore have hopes in new medicines with which obesity could be fought. Their research bas been published in 'The EMBO Journal' (doi: 10.1038/emboj.2009.305).

Trophoblast stem cells (TSCs), cells found in the layer of peripheral embryonic stem cells from which the placenta is formed, are thought to exhibit "immune privilege" that aids cell survivability and is potentially beneficial for cell and gene therapies. Further, the survivability of TSCs has been thought to require the presence of ovarian hormones. However, none of these assumptions has ever been verified. This study, published in the current issue of the journal Cell Transplantation (18:7) - now freely available on-line at http://www.ingentaconnect.com/content/cog/ct - has demonstrated that it is the absence of male hormones, rather than the presence of female hormones, that allows extended transplanted cell survivability.

Since the completion of the human genome sequence, a question has baffled researchers studying gene control: How is it that humans, being far more complex than the lowly yeast, do not proportionally contain in our genome significantly more gene-control proteins?

Prozac works wonders for some depressed people, but not for others. In some cases, patients derive little benefit and at worst, it can lead to bizarre hallucinations and fits of rage. Researchers and doctors remain puzzled as to what causes the wide range of reaction to Prozac and similar antidepressants.

Fragile X tremor/ataxia syndrome (FXTAS) is a recently recognized condition, which is actually one of the most prevalent heritable neurodegenerative diseases. It is assumed that the condition is caused by deficiency for the protein Pur-alpha, which is essential for normal neural function. Structural studies undertaken by a team under the leadership of Dr. Dierk Niessing of the Helmholtz Zentrum München and the Gene Center at Ludwigs-Maximilians-University (LMU) have now determined the three-dimensional structure of Pur-alpha, and gained insights into the molecular function of the protein. The findings provide a possible basis for the development of an effective therapy for the disease.(PNAS Early Edition, 21. Oktober 2009)

Perilous and polluting industrial processes can be made safer with enzymes. But only a short range of enzymes have been available for the chemical industry.

Groups of neurons that precisely keep time have been discovered in the primate brain by a team of researchers that includes Dezhe Jin, assistant professor of physics at Penn State University and two neuroscientists from the RIKEN Brain Science Institute in Japan and the Massachusetts Institute of Technology (MIT). "This research is the first time that precise time-keeping activities have been identified in recordings of neuron activity," Jin said. The time-keeping neurons are in two interconnected brain regions, the prefrontal cortex and the striatum, both of which are known to play critical roles in learning, movement, and thought control.

A study from the University of North Carolina at Chapel Hill has identified a key player in a molecular process essential for DNA replication within cells.

Tsuruta et al. find that a lipid kinase directs a voltage-gated calcium channel's degradation to save neurons from a lethal dose of overexcitement. The study appears in the October 19, 2009 issue of the Journal of Cell Biology (www.jcb.org).

A new cancer gene has been discovered by a research group at the Sahlgrenska Academy at the University of Gothenburg, Sweden. The gene causes an insidious form of glandular cancer usually in the head and neck and in women also in the breast. The discovery could lead to quicker and better diagnosis and more effective treatment.

In new papers appearing this month in Science and the Proceedings of the National Academy of Sciences, University of Illinois biochemistry professor Raven H. Huang and his colleagues describe the first RNA repair system to be discovered in bacteria. This is only the second RNA repair system discovered to date (with two proteins from T4 phage, a virus that attacks bacteria, as the first).

One hundred years ago, Kikunae Ikeda discovered the flavour-giving properties of glutamate, a non essential amino acid traditionally used to enhance the taste of many fermented or ripe foods, such as ripe tomatoes or cheese. New research now reveals that the tongue has a receptor that is exclusively activated by glutamate.

Infectious diseases currently cause about one-third of all human deaths worldwide, more than all forms of cancer combined. Advances in cell biology and microbial genetics have greatly enhanced understanding of the cause and mechanisms of infectious diseases. Researchers from Thomas Jefferson University, the Pasteur Institute in Paris, and Yale University reported in PLoS ONE, a way in which intracellular pathogens exploit the biological attributes of their hosts in order to escape destruction.

Researchers have fresh insight into an evolutionarily ancient way that cells cope when oxygen levels decline, according to a new study in the October 7th issue of Cell Metabolism, a Cell Press publication. In studies of cells taken from the lining of human pulmonary arteries, they show that a microRNA – a tiny bit of RNA that regulates the activity of particular genes and thus the availability of certain proteins – allows cells to shift their metabolic gears, in a process known as the Pasteur effect.

Multiple myeloma cancer cells thwart many of the drugs used against them by causing nearby cells to turn traitor – to switch from defending the body against disease to shielding the myeloma cells from harm – Dana-Farber Cancer Institute scientists report in the October issue of Cancer Cell.

A new drug designed to "seek and destroy" common cancers such as breast, prostate, endometrial, pancreatic, ovarian, skin and testicular cancers is being tested at TGen Clinical Research Services (TCRS) at Scottsdale Healthcare.

A derivative of cholesterol is necessary for the formation of brain cells, according to a study from the Swedish medical university Karolinska Institutet. The results, which are published in the journal Cell Stem Cell, can help scientists to cultivate dopamine-producing cells outside the body.

Natural killer, or NK cells, are part of our innate immune system. A healthy body produces them to respond early during infection. They are activated and they kill cells infected with a given virus.

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