Zhijian (James) Chen, PhD ’91 (biochemistry), has been elected to the National Academy of Sciences, one of the highest honors in American science.
Chen is the George L. MacGregor Distinguished Chair in Biomedical Science and a Howard Hughes Medical Institute investigator at UT Southwestern Medical Center.
He is also a member of UT Southwestern’s Center for the Genetics of Host Defense, where he collaborates with Bruce Beutler, MD, who shared the 2011 Nobel Prize in Physiology or Medicine for his groundbreaking work in innate immunity.
“In the effort to understand how viruses and other microbes are detected by the immune system once they get inside our cells, James has dominated the field," says Beutler, who directs the center. "He is an immunologist and a biochemist of the very top echelon. In fact, he really has no peers.”
Chen’s accomplishments are considered important for understanding the fundamental mechanisms of cancer and immunity. Early in his career, he uncovered a new, unexpected role for ubiquitin, a small protein, showing that it activates other proteins important to growth regulation and other essential cellular functions.
In other work, Chen found that the cell’s energy-producing bodies, the mitochondria, contribute to the body’s immune response, and he identified MAVS, the first beneficial prion found in humans. MAVS proteins, located on the mitochondria, function in an innate immune pathway that defends against viruses by misfolding and causing nearby proteins to misfold in a domino effect. Whereas other prions can cause deadly brain-wasting diseases as infectious proteins, Chen showed that MAVS use the mechanism as a force for good by helping the cell quickly amplify its immune response to invasion by pathogens.
At UB, Chen studied in the laboratory of the late Cecile Pickart, PhD, professor of biochemistry, where he researched mechanisms of protein degradation. In addition to Pickart’s tutelage, Chen credits Ed Niles, PhD, emeritus professor of biochemistry, with teaching him molecular biology.
In 2012, Chen received the Distinguished Biomedical Alumnus Award from the UB School of Medicine and Biomedical Sciences.