Biochemistry, Molecular Biology
University of California, Berkeley
*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 continued his research on the biochemistry of gene regulation at HHMI's Janelia Research Campus and at the University of California, Berkeley. He resumed his Investigator status after stepping down from the presidency in 2016.
Mechanisms of Gene Regulation
Robert Tjian wants to understand the molecular machinery that controls gene activity in human and animal cells. His research is helping to decipher exactly how animal cells retrieve the genetic information stored in DNA molecules during transcription – the biochemical process that leads to the production of proteins.
Tjian’s lab team has devised methods to isolate the individual cellular components that carry out transcription, and used those components to recreate the complex reaction in a test tube. This allows the team to study the detailed molecular mechanisms that direct the exquisitely sensitive process of gene expression in humans and other animals. Tjian’s team complements these in vitro investigations with studies in cells and whole organisms, such as flies and mice, in which they explore how transcription is regulated in physiological situations that require the switching on and off of specific genes, such as cell growth, development, and differentiation.
In recent years, much of Tjian’s research has focused on key transcription events in embryonic stem cells (ESCs), as well as various terminally differentiated cell types, including adipocytes (fat cells), hepatocytes (liver cells), myotubes (muscle fibers), and motor neurons. The lab has been developing single-molecule imaging technologies and exploiting powerful new microscopes that make it possible to watch the dynamic movement of transcription factors as they control gene expression, both in living cells and in “test tube” assays using purified transcription factor proteins. Observing individual transcription factor molecules allows scientists, for the first time, to measure the kinetics and three-dimensional distribution of key gene regulatory proteins as they search for and bind to target DNA sites.
Robert Tjian was president of the Howard Hughes Medical Institute from April 2009 through August 2016. Trained as a biochemist, he has made major contributions to the understanding of how genes work during his three decades on the faculty of the University of California, Berkeley.
Tjian studies the biochemical steps involved in controlling how genes are turned on and off – information that is key to decoding the human genome. He discovered proteins called transcription factors that bind to specific sections of DNA and play a critical role in controlling how genetic information is transcribed and translated into the thousands of biomolecules that keep cells, tissues, and organisms alive. Findings from Tjian's laboratory have illuminated the relationship between disruptions in the transcription process and disorders such as cancer, diabetes, and Huntington's disease. More recently, his team has begun studying how transcription factors control the differentiation of embryonic stem cells into muscle, liver, and neurons.
Tjian received a bachelor's degree in biochemistry from UC Berkeley in 1971 and a PhD from Harvard University in 1976. After completing a postdoctoral fellowship at the Cold Spring Harbor Laboratory with James Watson, he joined the Berkeley faculty in 1979. He was named an HHMI investigator in 1987. Five years later, he cofounded the start-up company Tularik.
At Berkeley, Tjian assumed a variety of leadership roles, including spearheading a major campus initiative to support and implement new paradigms for bioscience teaching and research. He served as the director of the Berkeley Stem Cell Center, and the faculty director of the Li Ka Shing Center for Biomedical and Health Sciences. Currently he serves on the board of the Lasker Foundation and the journal eLife, and in the past, served on the scientific boards of Genentech, Chiron, and Amgen.
Tjian is a member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society. He has received many awards honoring his scientific contributions, including the Alfred P. Sloan Prize from the General Motors Cancer Research Foundation and the Louisa Gross Horwitz Prize from Columbia University. He was named California Scientist of the Year in 1994.
Tjian remains an active scientist. He maintains a research laboratory at UC Berkeley, where he is a professor of biochemistry and molecular biology.