|Excellence in Research|
Professor of Biochemistry
Every morning Clyde Denis enters his laboratory in Rudman Hall with the expectation that, before the day is through, he might learn something that nobody ever knew before. Thats why hes a molecular biologist, he says: because we know so little about life, and there is so much more to discover.
For the past 19 years,
Denis, a professor of biochemistry and molecular biology, has been investigating
how cells function and why cancerous cells grow uncontrollably. Most recently,
he has focused on two proteins manufactured by cells that appear to turn
off that growth. In the past 19 years, the National Science Foundation
and National Institutes of Health have given him more than $5.6 million
to continue this promising line of inquiry.
Denis became intrigued by the possibility of discovery in a high school biology class, but it wasnt until he took organic chemistry and microbiology at the University of Illinois in the early 1970s that he abandoned his plan to become a physicist. As an undergraduate he was strongly inuenced by Carl Woese, one of his professors. Woese studied bacteria living in extreme environments at the bottom of the deep ocean, for example and found what many scientists now agree is a whole new kingdom of living things.
He was always thinking, creating questions, formulating hypotheses, Denis says. Thats what I liked about the scientific process.
Denis has spent his own career figuring out how cells know what proteins to produce, when to produce them, and when to stop. Thats critical because most cell functions are carried out by proteins.
The proteins that a cell produces are determined by the genetic coding stored in the double helix of DNA in the cells nucleus. DNA provides the original template for the production of messenger RNA which, in turn, serves as a template for the production of proteins. Ordinarily, the cell keeps producing a particular protein as long as it needs it and then stops. Denis has been looking for the mechanism that turns off the protein production. Working with a colleague at the University of Arizona, he has recently shown that two proteins, CCR4 and CAF1, act together to trigger the breakdown of RNA and stop production. Both proteins occur in human cells, so this discovery could ultimately lead to a new method of tumor suppression in humans.
Research is painstakingly slow and often takes decades to lead to a breakthrough. Denis first isolated CCR4 in 1981 and is still investigating exactly how it is regulated. Yet he remains as excited about the opportunities for generating new knowledge today as he was when he started studying biology as a teenager. Science is all about making those connections, he says. All were limited by in science is our imagination.