Searching for Answers in the Stuff of Life

If DNA is the blueprint of life, the basic proteins known as “histones” work for the architectural firm, overseeing and protecting the blueprints. Histone proteins interact directly with DNA to organize and maintain the inheritable genetic blueprint of an organism. Histones were once thought of as mere structural props to package the long strands of DNA into the nucleus of cells, like a canister for storing blueprints. However, research on histones over the past several decades has made it clear that they play a much more substantial and active role in the management of DNA.
 Over in the Samson Talbot Hall of Biological Sciences, biology professor Jeff Thompson is working with students to gain an understanding of how histone proteins participate in the process of repairing damage to DNA that comes with the wear and tear of everyday life. This mundane maintenance process within the cell sounds unremarkable, until you realize that out-of-control repair and rebuilding processes can lead to clinical problems like cancer. Thompson and his students are particularly interested in how histones can turn the course of DNA damage caused by ultraviolet light.
 Using the simple features of the yeast Saccharomyces cerevisiae, Thompson and student research assistants Ashley Albrecht ’07, Arzu Arat ’08, Lindsey Bostelman ’05, and Andrew Keller ’06 looked at how the impact of ultraviolet light, which damages DNA (and is why you need to use your sunscreen), is repaired by processes tied back into those histones. Their work, published in a journal aptly named DNA Repair, suggests that the histones oversee a complex “molecular origami,” unfolding the DNA for repairs to occur, and subsequently refolding the DNA to restore its shape, much like an architect would do to correct an error in the blueprints. In other studies, Thompson and assistants Margery Evans ’07, Ariel Lee ’08, and Natasha Strande ’08 are attempting to understand precisely how the histones participate in this process.
As molecular biologists and genetic researchers successfully sequence genomes of plant and animal species, including humans, they’re realizing that the complexity of the genetic code in DNA still isn’t enough to build the entire living being. Just as a building has a blueprint, there also are reams of documents specifying materials, colors, and how many gallons per flush that are printed alongside the drawings. That’s where histones and other proteins draw out the details that may fit into the broader strokes sketched by DNA.
This is current, exciting research in molecular biology, and students under Thompson’s guidance look forward to packing their bags for opportunities in other labs, and medical and graduate research programs. We feel good knowing that their first steps into unfolding the mysteries of these cellular processes began here at Denison.