How cells move gas

In the cover story of the September 10 issue of Science, scientists report the first high-resolution structural details of a protein that shuttles gas across cell membranes.

The research team says the mechanism of ammonia permeation they find in bacteria is likely similar in eukaryotic cells. "The findings uncover a whole new biology of how this and orthologous proteins work, including Rh factors in humans," researcher Robert Stroud of the University of California, San Francisco, told The Scientist, because the shuttle proteins are genetically related to the structural components of the Rh blood group antigens of mammalian blood cells, which facilitate the transport of ammonia and carbon dioxide across eukaryotic cell membranes.

Nobel laureate Peter Agre at Johns Hopkins University School of Medicine, Baltimore, who was not involved in this study, called the findings "a quantum leap forward" in the scientific understanding of gas transport. "It takes membrane gas permeation ...