Scientists map first structure in important family o...( An international team including scien...)

An international team including scientists from the University of Washington has mapped the first crystal structure of a G protein-coupled receptor (GPCR), one of a family of proteins that are crucial to everything from vision to the development of the human embryo, according to a paper published in the Aug. 4 issue of Science.

A model of the protein is featured on the cover of the journal, which is published by the American Association for the Advancement of Science.

The particular GPCR that the scientists mapped is rhodopsin, a light receptor protein that resides inside cell membranes of retinal rod cells that carry out the first step in vision. It converts an environmental signal -- light -- into a biological action -- a nerve signal to the brain. The process is called phototransduction. But GPCRs do more than this. They are one of the largest families of proteins encoded in the human genome, representing roughly 3 percent of the genome.

Work based on this model "should have far-reaching implications," write Henry R. Bourne and Elaine C. Meng of the University of California, San Francisco, in an article accompanying the paper. "New insights gained will help us to understand how GPCRs transduce the signals that regulate embryonic development and control the heart, blood vessels, synaptic traffic in the brain and, indeed, the functions of virtually every eukaryotic cell."

While genomes have been rightfully getting a lot of attention lately, the proteins that the genomes produce are what actually function inside the cell. For example, GPCRs are involved in the receptors found in the tongue -- responsible for taste -- and in the nose -- responsible for detecting odors. Other GPCRs are involved in the regulation of the heartbeat. They are even found in the brain, in the opiate receptors that bind someone to a life of drug addiction. In other words, GPCRs participate in almost every physiological process. "Because the underlying structure is simil
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Contact: Walter Neary
wneary@u.washington.edu
206-685-3841
University of Washington
3-Aug-2000