machinery
The new study, which was published on April 12, 2009, in an advanced online edition of the journal Nature Structural & Molecular Biology, draws new parallels between the Rad60 DNA repair factor and SUMO, a small ubiquitin-like modifier, which are both essential for maintaining genome stability during replication.
When cells undergo potentially catastrophic damage, for example as a result of exposure to ionizing radiation, they must make a decision: either to fix the damage or program themselves for death, a process called apoptosis.
The DNA in the 23 pairs of chromosomes in each of the billions of cells of the human body is so tightly packed that it would measure six feet in length if stretched end to end. A genome of this size can squeeze into a cell's tiny nucleus because it is compressed into highly condensed chromatin fibers by proteins called histones.
March 31, 2009, New York, NY--Scientists at Columbia University Mailman School of Public Health have discovered that astrocytes, supportive cells in the brain that are not derived from an immune cell lineage, respond to a molecule that mimics a viral infection using cellular machinery similar to that used by classical immune cells in the blood.
Researchers have identified a new cancer gene - one that is common to many cancers and affects the most basic regulation of our genes. The new example - a gene on the X chromosome called UTX - is found in 10% of cases of multiple myeloma and 8% of esophageal cancers.
Biofilms are everywhere - in dental plaque and ear canals, on contact lenses and in water pipelines - and the bacteria that make them get more resilient with age, finds a new study in FEMS Microbiology Letters.
A new study provides insight into how a short burst in nitrite can exert lasting beneficial effects on the heart, protecting it from stress and assaults such as heart attacks.
An antimicrobial agent found in many shampoos and hand lotions and widely used in industrial settings inhibits the development of particular neuron structures that are essential for transmitting signals between cells, according to a University of Pittsburgh study. Prolonged exposure to low levels of methylisothiazolinone (MIT) restricted growth of axons and dendrites of immature rat nerve cells in culture, apparently by disengaging the machinery of a key enzyme that is activated in response to cell-to-cell contact, and may have potentially damaging consequences to a developing nervous system, the researchers report.
A new approach to outwit resistance to antibiotics has been discovered by researchers. By inserting a naturally occurring molecule into an antibiotic-resistant bacterium, the team was able to gradually destroy the machinery responsible for the resistance. ''Multidrug-resistant bacteria are now ubiquitous in both hospital settings and the larger community... Clearly, new strategies and targets are needed to combat drug-resistant bacteria.''
Biologists studying the development of plant roots, a general basic model for tissue development, are uncovering new pieces of the puzzle of how one root cell sends its molecular instructions to another in the development process. Researchers have found hints that the channels by which such molecules move between plant cells may also be mirrored in animal cells. Thus, discoveries about plant development may be more broadly applicable to understanding the fundamental processes of how complex tissues develop from a few cells -- one of the central mysteries in biology.
Neuroscientists at Duke University have figured out how to study with rigorous experimental control how the brain recalls autobiographical memories -- the memories of a person's past experiences. Their new ''photo paradigm'' involves having subjects take photographs that they later recall in the laboratory while their brains are being scanned. The researchers said their study revealed that the brain uses much of the same machinery for both autobiographical memory and the type of memory elicited in previous laboratory studies. However, the new technique also disclosed significant brain function differences between laboratory memory and autobiographical memory.
Neurobiologists have pinpointed the molecular storehouse that supplies the neurotransmitter receptor proteins used for learning-related changes in the brain. They also found hints that the same storage compartments, called recycling endosomes, might be more general transporters for 'memory molecules' used to remodel the neuron to strengthen its connections with its neighbors.
By mimicking a molecular switch that triggers cell death, researchers have killed cells grown in the laboratory from one of the most resilient and aggressive cancers -- a virulent brain cancer known as glioblastoma. The new approach to tricking the cell-death machinery could be applied to a wide range of cancers where this pathway, known as apoptosis, has been inactivated.
Researchers are proposing that the first battle for survival-of-the-fittest might have played out as a simple physical duel between fatty bubbles stuffed with genetic material. The scientists suggest that genetic material that replicated quickly may have been all the bubbles needed to edge out their competitors and begin evolving into more sophisticated cells. This possibility, revealed by laboratory experiments with artificial fatty acid sacs, is in sharp contrast to a current theory of the earliest evolution of cells, which suggests that cellular evolution was driven by primordial genetic machinery that actively synthesized cell membranes or otherwise influenced cell stability or division.
Researchers have discovered a new component of the machinery immune cells use to generate a remarkably diverse array of antibodies from a relatively small number of genes. The discovery reveals important links in the molecular pathway by which complex genetic alterations arm the immune system to target myriad potential bacterial and viral invaders with swiftness and precision. The discovery may also provide welcome new information about lymphoma, a form of leukemia in which certain cells of the immune system proliferate uncontrollably.
