Study of primitive life form expected to provide clues to biological processes in higher organisms
November 10, 2003
Primitive microorganisms provide important clues as to how all creatures employ a basic regulatory mechanism to conduct the business of life. Peter Kennelly, professor of biochemistry at Virginia Tech, is studying a primitive organism discovered in acidic hot springs at Yellowstone National Park to find clues about that mechanism in higher organisms.
A $400,000 grant from the National Science Foundation is allowing Kennelly to continue his investigations into the process of protein phosphorylation.
That is a process by which nature controls the structure, functions and interactions of the proteins that carry out the chemistry of life. In higher organisms, thousands of phosphorylated proteins are linked together into sophisticated networks. These networks are responsible for coordinating the multiple chemical events that take place inside each cell and modifying these processes in response to changes in the environment.
While the great size of these networks provides them with a high capacity to process a broad spectrum of environmental factors and select appropriate responses, it also renders them difficult to study, Kennelly said. Microorganisms carry out many of the same basic processes as higher organisms, but they do so with a much smaller set of molecular machinery.
"If you consider living cells to be a molecular puzzle, a microorganism puzzle contains from 10 to as many as 100 times fewer pieces than the human puzzle," Kennelly said. "Solving the first puzzle will be much faster than the second. More importantly, the parallels between microbial and human puzzles mean that completing the first puzzle will make solving the second one easier and faster."
The organism the Kennelly lab is studying is called Sulfolobus solfataricus, an extremophile from the "third domain of life" known as the Archaea. Extremophiles live in conditions far more stressful than other life forms can endure.
"The process of protein phosphorylation is so basic to controlling life's chemistry, that it occurs in organisms of all types, from even the most extreme corners of the biosphere," Kennelly said.
Specifically, Kennelly and his students will identify the proteins that are controlled by phosphorylation in Sulfolobus solfataricus, the protein kinases that are responsible for phosphorylating them, and the protein phosphatases that remove the phosphate groups. Ultimately, he hopes to not only identify all the pieces in the phosphorylation network, but to also dissect the functional relationships between them.
The end product will be a molecular map describing how such a network functions. This map can be used by other scientists as a guide to the solving the more complex systems that have developed in more biologically complicated organisms.
Eventually, Kennelly hopes to use simple models to understand the origins of this regulatory mechanism. He also hopes to identify the processes first targeted for regulation in this manner, and learn how other organisms built upon this foundation to create complex information processing networks.
The project will utilize a variety of approaches, including genomics, enzymology, molecular biology and mass spectroscopy.
"The variety of organisms found in nature provides us with a library of information and tools for answering important questions about how the chemistry of life works," Kennelly said. "The basic principles are universal, so work on primitive organisms can help lead us to an understanding of the rules governing the processes that take place in plants, animals and ourselves."
Kennelly, a resident of Blacksburg, Va., is a professor of biochemistry in the university's College of Agriculture and Life Sciences. He received his Ph.D. from Purdue University.
This release was written by Amy Mortensen, an intern with Virginia Tech’s Department of University Relations