Life Sciences and Chemistry

Regulating cells under stress

An article published this week in the journal Nature provides the first experimental evidence for an unusual molecular bonding mechanism that could explain how certain cells adhere to surfaces such as blood vessel walls under conditions of mechanical stress.
Known as “catch bonds,” the adhesion mechanism displays surprising behavior, prolonging rather than shortening the lifetimes of bonds between specific molecules as increasing force is applied. Pr

Dartmouth researchers have found evidence of two circadian clocks working within the same tissue of the plant Arabidopsis thaliana, a flowering plant often used in genetic studies. Their results suggest that plants can integrate information from at least two environmental signals, light and temperature, which is important in order to respond to seasonal changes.

The study, published this week, appears in the online edition of the Proceedings of the National Academy of Sciences.

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To carry out their functions, proteins must first fold into particular structures. How rapidly this process can occur has been both a source of debate and a roadblock to comparing protein folding theory and experiment.

Now, researchers at the University of Illinois at Urbana-Champaign have observed a protein that hit a speed limit when folding into its native state.

“Some of our proteins were folding as fast as they possibly could — in only one or two microseconds,” said Martin G

May explain life extension via calorie restriction

Researchers at Harvard Medical School (HMS) have discovered that a gene in yeast is a key regulator of lifespan. The gene, PNC1, is the first that has been shown to respond specifically to environmental factors known to affect lifespan in many organisms. A team led by David Sinclair, assistant professor of pathology at HMS, found that PNC1 is required for the lifespan extension that yeast experience under calorie restriction. A yeast

Duke University Medical Center biochemists have developed a computational method to design proteins that can specifically detect a wide array of chemicals from TNT to brain chemicals involved in neurological disorders. In a paper in the May 8, 2003, issue of the journal Nature, they demonstrate the breadth of their design method, and also that such sensor proteins can be re-incorporated into cells to activate cellular signaling and genetic pathways.

The researchers said their achievement c

For nine months before birth, infants soak in a watery, urine-filled environment. Just hours after birth, however, they have near-perfect skin. How is it that nature enables infants to develop ideal skin in such seemingly unsuitable surroundings?

A new study by researchers at the Skin Sciences Institute of Cincinnati Children’s Hospital Medical Center shows that the answer may be vernix — the white, cheesy substance that coats infants for weeks before they are born, then is wiped off and d