Robert T. Simpson (1938–2004)

The field of chromatin research lost one of its long-standing and respected members recently, Robert T. Simpson. Bob died suddenly in late April after a fall in his home near the Penn State University campus. Bob began his scientific career just as the modern era of molecular biology was maturing. He graduated from Swarthmore College in 1959 with high honors, Phi Beta Kappa. He completed his M.D. at Harvard in 1963, graduating cum laude with Alpha Omega Alpha honors, and received his Ph.D. in Biological Chemistry from Harvard in 1969. Bob joined the Public Health Service and took a position at the National Institutes of Health that same year. He remained at the NIH throughout most of his career, rising to the rank of Lab Chief at the Laboratory of Cell and Developmental Biology. In 1995 he joined the faculty at Penn State as the Verne Williman Professor in the Department of Biochemistry and Molecular Biology.Figure 1Figure 1Figure 1Robert T. SimpsonView Large Image | View Hi-Res Image | Download PowerPoint SlideBob made seminal contributions to the resurgence of chromatin research in the 1980s. The nucleosome concept had emerged in the early 70s, but most molecular biologists at the time still viewed chromatin as simply a means to package the very large DNA content in eukaryotic cells. In a series of elegant papers, Bob demonstrated several important properties of chromatin structure. He showed that nucleosomes containing H1 manifested a unique nuclease digestion product and coined the term “chromatosome” to distinguish nucleosomes that contain histone H1 from nucleosomes that contained only the core histones. In a 1983 PNAS paper with D. Stafford, Bob demonstrated that Lytechinus variegatus 5S DNA would support deposition of a nucleosome in a specific position. This finding contravened the prevailing opinion that nucleosomes were unlikely to occupy unique positions on DNA and provided the basis for the subsequent discoveries of positioning in other systems. Bob went on to exploit this finding in developing the famous “5S array” of positioned nucleosomes (Cell, 1985). This system has been widely exploited by many investigators as an in vitro model of higher-order chromatin structure. The 5S system reflects three fundamental features that characterized Bob's work throughout his career: simplicity, cleverness, and the integration of structure and activity. In more recent years, he studied the importance of nucleosome positioning in the regulation of transcription and was in the process of devising methods to define in vivo chromatin structures on a genomic scale.In addition to his significant research contributions, Bob provided extensive service to the scientific community. He was regularly involved in NIH study section reviews and was a leader in the Foundation for Advanced Education in the Intramural Program. He served on the editorial board of the Journal of Biological Chemistry and was an executive editor of Nucleic Acids Research. After moving to Penn State, he took on a leadership role in both the undergraduate and graduate training programs and was active in mentoring junior faculty in Biochemistry and Molecular Biology.Bob was a quiet person, and his reserve was something of a trademark. However, anyone who spent time with him quickly realized that his quiet ways were balanced with a keen wit and a wonderful sense of humor. Bob was also known for his ability to “cut to the chase” in any discussion, whether it be a faculty meeting, a study section meeting, or a lab meeting. He managed to say in a few well-chosen words what others might not convey in a half-hour speech.One of Bob's greatest enjoyments was the achievements of his students and post-docs. He was a legend at the NIH because he encouraged his post-docs to pursue independent research and to publish on their own. His policy, very unusual in today's competitive environment, was to only put his name on papers to which he felt he made a real intellectual or “hands-on” contribution. He was generous with his time, his talents, and his resources, and he considered the success of those he mentored as a great reward itself.Although he directed an active and widely recognized research program, Bob managed to fit in a rich and active life outside of science. He took special pride in his family at home and his family in the lab. He enjoyed camping, fishing, and sailing with his family, and spent many hours on the Chesapeake in his historic draketail boat. He loved to cook and to share his latest experiment in the kitchen, and he and his wife Kathy opened their home for many a celebration.Bob's work will continue in the labs of the many fellows and students who developed their skills under his direction. He will be remembered for his high standards, his sharp intellect, his attention to careful and well-designed experiments, and above all his dedication to the development and success of those who passed through his lab.