One of the greatest achievements of modern biology is the remarkable progress that has been made in understanding how genes work. Research by Robert Tjian has contributed substantially to this body of knowledge. Tjian studies the biochemical steps that control the way genes are turned on, and then turned off when their jobs are finished. For nearly 30 years, his research has helped scientists piece together a picture—one that is substantially advanced—detailing the molecular machinery used by human cells to "decode" the genome and control the switches that turn genes on and off. This machinery is involved in every facet of human life, including embryogenesis, cellular differentiation, cell growth and development, and the initiation of disease.
Armed with a Ph.D. degree in biochemistry and molecular biology in 1976, Tjian began his scientific career studying how cells live and what happens when cell growth goes awry. At the time, little was understood about how genes are turned on and off. "The field was wide open and promised to be of fundamental importance," recalled Tjian.
Specifically, Tjian studies how genetic information stored in DNA is copied (transcribed) into RNA, which directs the production of proteins inside cells that are essential to life. He has devised a way to isolate the individual components of the cell involved in transcription and recreate this complex, highly regulated process in a test tube and even to observe these reactions at the single-molecule resolution. Advances in technology have also enabled Tjian to purify rare sequence-specific transcription factors, which bind to DNA at specific sites and regulate the expression of genes, and to isolate the genes that encode these important transcription factors.
His work has provided new insights into the molecular mechanisms that underlie various human diseases and conditions, including Huntington's disease, cancer, diabetes, and infertility.
Tjian has been actively involved in training new generations of molecular biologists and biochemists who are poised to answer new questions generated by today's scientists. "It gives me great pride to have guided so many students into medical careers, and to watch my students and postdoctoral fellows develop into first-rate scientists," said Tjian.
Dr. Tjian was an HHMI investigator at the University of California, Berkeley from 1987 to 2009. In April 2009, he became president of HHMI. Dr. Tjian continues his research on the biochemistry of gene regulation at HHMI's Janelia Farm Research Campus and at the University of California, Berkeley.
RESEARCH ABSTRACT SUMMARY:
Robert Tjian is interested in the biochemistry of gene regulation in humans and animals. In particular, what is the nature of the molecular machinery that controls the turning up and down of gene expression in human cells, and how does disruption of this highly regulated process lead to various disease states?
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Photo: Barbara Ries