Biomedical Beat - A monthly digest of research news from NIGMS

IN THIS ISSUE . . .
July 19, 2005

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The National Institute of General Medical Sciences (NIGMS), one of the National Institutes of Health, supports all research featured in this digest. Although only the lead scientists are named, coworkers and other collaborators also contributed to the findings. To read additional news items, visit NIGMS Research Around the Nation.

Cool Image: Modeling Disease Spread

A network of social interactions within a community
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What looks like a Native American dream catcher is really a network of social interactions within a community. The red dots along the inner and outer circles represent people, while the different colored lines represent direct contact between them. All connections originate from four individuals near the center of the graph. Modeling social networks can help researchers understand how diseases spread. Courtesy of Stephen Eubank, a physicist at the Virginia Bioinformatics Institute.

Virginia Bioinformatics Institute home page

microRNAs: A New Class of Cancer Genes

Add microRNAs to the list of things that contribute to cancer. These still-mysterious, small bits of genetic material make up far less than 1 percent of our genome and don't code for proteins. Yet, according to new work by geneticist Gregory Hannon of Cold Spring Harbor Laboratory, a few microRNAs—together with a known cancer-causing genetic mutation (c-myc)—can cause lymphoma in mice and humans to develop faster, spread farther, and be more deadly. Research by others suggests that analysis of microRNAs one day may help doctors classify cancer in a patient and point to the best way to treat it.

Full story
Hannon home page
Article abstract (from the June 9, 2005, issue of Nature)

Algae Offer Clue to Understanding Human Protein

Rh proteins act as gas channels that help speed the transfer of carbon dioxide (CO2) in and out of red blood cells.
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People with Rh-positive blood have a protein called the Rh protein on the surface of their red blood cells. This molecular distinction matters when a pregnant woman delivers her child—a mismatch between the Rh status of mom and baby may require a life-saving blood transfusion. While scientists know very little about the Rh protein, new research from microbiologist Sydney Kustu offers a clue. Kustu, of the University of California, Berkeley, discovered that green algae use the Rh protein to take in carbon dioxide. These organisms transport the carbon dioxide inside cells where it's used to generate energy through photosynthesis. Although humans don't perform photosynthesis, we do exhale carbon dioxide with each breath, requiring our lung cells to quickly recycle this gas. Since Rh proteins appear to be very similar in algae and humans, the findings should help clarify the biological function of these proteins.

“This work shows the powerful capacity of basic research to reveal nature's secrets. Understanding how Rh proteins function has important implications for human health, including preventing certain pregnancy complications.”

—Laurie Tompkins, NIGMS program director in genetics and developmental biology



Image caption: Rh proteins act as gas channels that help speed the transfer of carbon dioxide (CO2) in and out of red blood cells. CO2 can also pass through the cell membrane unaided (above right). Courtesy of Barbara Alonso

Full story
Kustu lab
Article abstract (from the June 2005 issue of Genetics)

Cell Death Regulator Discovered

Our cells come armed with a set of weapons they can use to shred their contents and commit suicide. This process, called apoptosis, is normal and often beneficial, helping shape developing embryos and killing off diseased cells. But sometimes the proteins that control the process fail to trigger it when they should, and cancer could ensue. Now, scientists led by Xiaodong Wang, a biochemist at the University of Texas Southwestern Medical Center, have discovered one of these control proteins they called Mule. Wang speculates that a more detailed biochemical understanding of how Mule works eventually could lead to new cancer treatments.

Full story
Wang home page
Article abstract (from the July 1, 2005, issue of Cell)

On Your Mark, Get Set, Solve Protein Structures

Crystal structure of a protein with unknown function from Pseudomonas aeruginosa, a disease-causing bacterium.
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With the announcement of 10 new research centers, the Protein Structure Initiative (PSI) launches the second phase of its national effort to find the three-dimensional shapes of a wide range of proteins. While four large-scale centers plan to churn out 3,000 to 4,000 protein structures over the next 5 years, six specialized centers will develop the technology needed to quickly and cheaply determine the shapes of proteins not amenable to high-throughput methods. Adding to the information gained during the first PSI phase started in 2000, these structural details will help reveal the roles that proteins play in health and disease and point the way to designing new medicines.

Image caption: Crystal structure of a protein with unknown function from Pseudomonas aeruginosa, a disease-causing bacterium.

Full story
PSI home page