Biomedical Beat - A monthly digest of research news from NIGMS

Fenruary 20, 2008

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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 News. To check out free NIGMS publications, go to the order form.

Cool Image: Golden Gene Chips

Courtesy of nanotechnologist Hao Yan and Ph.D. candidate Yonggang Ke, Arizona State University.
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A team of chemists and physicists used nanotechnology and DNA's ability to self-assemble with matching RNA to create a new kind of chip for measuring gene activity. When RNA of a gene of interest binds to a DNA tile (gold squares), it creates a raised surface (white areas) that can be detected by a powerful microscope. This nanochip approach offers manufacturing and usage advantages over existing gene chips and is a key step toward detecting gene activity in a single cell. Courtesy of nanotechnologist Hao Yan and Ph.D. candidate Yonggang Ke, Arizona State University.

Full story
Yan lab home page
Article abstract (from the January 11 issue of Science)

Tracking Maize DNA May Aid Nutrition

Vitamin A is an important ingredient for health, but it's often deficient in the maize-based diets of children living in sub-Saharan Africa and South and Central America. Lack of this essential nutrient leads to eye disease, malnutrition, and death. Now, a multi-institution team of researchers in the United States and Mexico, including plant geneticist Eleanore Wurtzel of Lehman College and students in her Minority Biomedical Research Support program, has identified genetic markers for breeding maize rich in provitamin A. The finding ultimately could help farmers produce crops containing high levels of this important vitamin, improving human nutrition and reducing disease worldwide.

Full story and video
Wurtzel lab home page
Article abstract (from the January 18 issue of Science)

Networking Technique Enables Gene Discovery

Like friends linked together through social networking sites, an organism's genes are intricately connected to each other. Drawing on data from about 20 million experiments worldwide, computational biologist Edward Marcotte at the University of Texas at Austin mapped the roundworm’s network of 16,000 genes. He and colleagues used the network to identify genes involved in tumor formation and lifespan. Later experiments showed that inactivating some of those genes reversed the onset of tumors and prolonged lifespan. This network sets the stage for developing ones for other organisms, even humans, and pinpointing medically relevant genes.

Full story
Marcotte home page
Article abstract (from the January 27 online issue of Nature Genetics)

Alzheimer's Protein Linked to Nerve Cell Transport

The segrosome, a molecular complex central to plasmid distribution during bacterial cell division.
Tau binds microtubule tracks and impedes the passage of the cell's molecular shuttles, kinesin and dynein. Courtesy of Ram Dixit, University of Pennsylvania School of Medicine.
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Nerve cells shuttle cargo, such as proteins and nutrients, around the cell using a system of tracks called microtubules. Now, Erika Holzbaur, a cell biologist at the University of Pennsylvania School of Medicine, has revealed that a protein implicated in Alzheimer's disease, helps regulate traffic along these tracks. For cargo traveling toward the outside of the cell, the tau protein helps ensure that it's offloaded at the right destination. Tau has less of an effect on inbound traffic, so cargo headed for the cell center arrives efficiently. The findings suggest that disruptions in this transport network could contribute to the cellular damage characteristic of Alzheimer's.

NIH's National Institute of Arthritis and Musculoskeletal and Skin Diseases also supported this work.

Full story
Holzbaur lab home page
Article abstract (from the January 17 online issue of Science)

How Cells Prevent Hydrogen Peroxide Damage

Many people use hydrogen peroxide to kill microbes on contact. So do our cells. But the substance is so highly reactive that it can cause cellular damage if levels aren’t tightly controlled. Scientists led by biochemist W. Todd Lowther at Wake Forest University School of Medicine just revealed the molecular gymnastics that two proteins perform to keep hydrogen peroxide at safe levels. A deeper understanding of this protective process may help scientists discover how it can break down, causing damage associated with cancer, diabetes, and other diseases.

Full story
Lowther lab home page
Article abstract (from the January 3 issue of Nature)