For humans, living as we do in an atmosphere with a rich and stable supply of oxygen, maintaining the correct levels in our bodies is a relatively routine task. For organisms that live in soil or water, however, where oxygen levels can fluctuate wildly, the task is far more challenging -- and pretty much of a mystery, until now.

A multi-institutional collaboration of researchers that includes a scientist with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has learned how one soil dweller, the nematode Caenorhabditis elegans, is able to sense oxygen levels in its environment and feed in areas where the concentration of oxygen is just right.

"It's surprising that more than 200 years after Antoine Laurent Lavoisier and Joseph Priestly discovered oxygen, we're still finding out how organisms sense and use it," says Michael Marletta, a chemist who holds a joint appointment with Berkeley Lab's Physical Biosciences Division and the University of California at Berkeley.

Marletta is one of the co-authors of a paper on the oxygen-sensing system, which appears in the July 15 issue of the journal Nature. Other authors are Cornelia Bargmann, who holds a joint appointment with the University of California at San Francisco and the Howard Hughes Medical Institute, plus David Karow of UC Berkeley, Jesse Gray, Hang Lu, and Andy Chang of UCSF, Jennifer Chang of the University of Michigan, and Ronald Ellis of the University of Medicine and Dentistry of New Jersey.

An enzyme points the way:

The discovery of the oxygen-sensing mechanism in nematodes actually began as an investigation into a human enzyme, guanylate cyclase, which performs signaling interactions with nitric oxide molecules critical to regulating blood pressure. When nitric oxide enters a human cell it activates guanylate cyclase, whic
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Contact: Lynn Yarris
lcyarris@lbl.gov
510-486-5375
DOE/Lawrence Berkeley National Laboratory
14-Jul-2004