When Ralph Waldo Emerson said that nature pardons no mistakes, he wasn’t thinking about RNA polymerase (RNAP) – the versatile enzyme that copies genes from DNA onto strands of RNA, which then serve as templates for all of the proteins that make life possible.
Emerson’s comment notwithstanding, RNAP makes plenty of mistakes but also proofreads and corrects them before they have a chance to create abnormal proteins. The error-prone nature of RNAP is not surprising given the size of its task.
Since their discovery, cytokines have provided biomedical researchers with a tangled web of immune-system pathways to unknot. While most known cytokines have a role in stimulating immunity, one cytokine, IL-27, may actually suppress CD4 T cells, the helper T cells that orchestrate the immune system response to infections, according to researchers at the University of Pennsylvania School of Veterinary Medicine.
Their findings could provide researchers with a way to clamp down on dozens of
Children usually spill if trying to drink from a full cup, but adults rarely do. How we learn to almost automatically complete complex movements — like how to lift a cup and tip it so the liquid is right at the edge when we’re ready to drink — is one of our brain’s mysterious abilities.
Now, by conducting experiments with robots and humans, scientists at Johns Hopkins have solved part of this mystery and created a new computer model that accurately reflects how the brain uses ex
When a cell needs a protein to function, it sometimes uses molecule-sized fishing poles to “catch” one and “cast” it across the cell membrane, reports a research team of Purdue University biologists.
Using high-resolution X-ray crystallography, a team including William A. Cramer has determined the structure and surprising behavior of a protein receptor complex, or “gate,” found in the outer membrane of an E. coli bacterium. The complex is one of thousands of such tiny gates that the cell us
Australian scientists have had their first view of the habitats and ecosystem that support Australia’s largest commercial crab – the “giant crab”.
A series of five surveys are planned in waters of 150-350 metres depth to assess the seabed habitats of the giant crab (Pseudocarcinus gigas) at the edge of the continental shelf around Tasmania.
The pilot survey was completed on the State’s east coast earlier this month in a collaborative project between CSIRO Marine Research
UT Southwestern Medical Center at Dallas researchers have shown that the absence of a key oxygen-sensing molecule can lead to multiple developmental defects – from an enlarged heart to eye problems.
The researchers generated the first mouse model that lacks entirely a member of an important family of proteins involved in sensing hypoxia, a state of reduced oxygen in the body’s cells that is associated with conditions such as heart attacks, stroke and lung disease.
This new mode
While breathalyzers help police crack down on drunk driving, a similar new device is helping a University of Rhode Island graduate student analyze the dietary changes of migrating songbirds.
Just as human breathalyzers measure an individual’s blood-alcohol level, David Podlesak says that his bird breathalyzer measures the “carbon signature” of a bird’s last meal.
“We measure the ratio of the isotopes of carbon 12 to carbon 13, and this carbon signature in their breath can
Black bears living in and around urban areas are up to a third less active and weigh up to thirty percent more than bears living in wild areas, according to a recent study by scientists from the Bronx Zoo-based Wildlife Conservation Society (WCS).
The study, published in the latest issue of the Journal of Zoology says that black bears are spending less time hunting for natural food, which can consist of everything from berries up to adult deer. Instead, they are choosing to forage in dumpste
Almost 150 different genomes have been sequenced to date, including the human genome. But sequencing needs are growing faster than ever: In March 2003, the Bush administration announced it will spend $1 billion over five years to increase forensic analysis of DNA, including a backlog of up to 300,000 samples. And the success of the growing field of genomic medicine, which promises to deliver better therapies and diagnostics, depends on faster sequencing technology.
This fall, researchers at
A recent Purdue University study has uncovered the processes responsible for shutting down scent production in certain flowers once they’ve been pollinated – a finding that may help the horticulture industry enhance floral scent.
Natalia Dudareva, associate professor of horticulture, and her colleagues have recently identified the molecular mechanisms that cause petunias and snapdragons to decrease scent production after they’ve been visited by pollinators such as bees or moths. Th
Researchers have discovered that a specific type of calcium channel — a pore-like protein that nestles in the cell membrane and controls the flow of calcium into the cell — regulates the relaxation of coronary arteries.
The studies showed that mice engineered to lack these calcium channels had constricted coronary arteries and had fibrous tissue in their hearts, which was evident when the animals’ hearts reacted to chronic blood restriction. The researchers hypothesize that drugs tar
Scientists at the Emory Vaccine Center and The Scripps Research Institute have found a way to identify which of the T cells generated after a viral infection can persist and confer protective immunity. Because these long-lived cells protect against reinfection by “remembering” the prior pathogen, they are called memory T cells. This discovery about the specific mechanisms of long-term immunity could help scientists develop more effective vaccines against challenging infections.
The research
Protein discovery in Chlamydomonas
A new protein discovery sheds light on how chemical information is transported within cells. A group of researchers, which includes Dartmouth Professor of Biological Sciences Roger Sloboda, have found the protein EB1 in Chlamydomonas, a single-celled organism commonly used to study cell biology. Previous research has implicated EB1 in the progression of many colon cancers.
Published in the November 11 edition of the journal Current Biology,
A research team at The University of Texas M. D. Anderson Cancer Center has found that a single protein known as ARF helps coordinate both growth and division within a cell — the functions that are often perturbed in cancer development.
Many proteins have been found in cancer research that are associated with either errant cell division or with uncontrolled growth, but ARF is the first “master molecule” that seems to be involved in both crucial aspects of the cell cycle, say the researcher
Chemists at the University of Toronto have captured atom-scale images of the melting process-revealing the first images of the transition of a solid into a liquid at the timescale of femtoseconds, or millionths of a billionth of a second.
The result is an unprecedented “movie” detailing the melting process as solid aluminum becomes a liquid. This new study, led by Professor R. J. Dwayne Miller of the Departments of Chemistry and Physics, received the prestigious cover position of the Nov.
The explosion of “junk” DNA in animals, plants and fungi may be the simple result of their ancestors’ reduced population sizes, according to a new hypothesis proposed by Indiana University Bloomington and University of Oregon scientists in the Nov. 21 issue of Science.
The hypothesis explains a mysterious genetic difference between bacteria and eukaryotes, a giant group of organisms that includes animals, plants, fungi, algae and other protists. Bacteria tend to have extremely lean gen
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