The scientists showed for the first time that when certain parts of a protein molecule are modified ?flexible, randomly structured regions believed to be only minor players in the protein world ?they become important in turning genes on and off, but in a way that resembles a dimmer switch rather than an on-off switch.
Genes carry the code that produces proteins to carry out almost all functions in a living organism. But some of these proteins also help control when and where genes do their jobs. The new study deals with how one such protein, named Ets-1, turns genes on or off.
Huntsman Cancer Institute scientists, led by Barbara Graves, Ph.D., professor and chair of the Department of Oncological Sciences at the University of Utah School of Medicine, and doctoral student Miles Pufall, studied Ets-1, a protein known as a transcription factor that helps read genetic information. This factor serves as a cell's librarian, helping find the right genetic instructions.
How much information the librarian provides, and how accurate that information is, must be tightly controlled. Without the right information, cells can't behave properly, and may, as in the case of cancer, grow out of control. The connection between factors such as Ets-1 and a number of cancers prompted the study of how it works.
One way proteins are controlled occurs after a cell creates a protein. Graves illustrates this process by comparing protein structure with beads on a string. "After the protein is made, it can acquire what we call post-translational modifications, which are like decorations on a beaded necklace. In this analogy, one person creates a necklace using similar beads and then a committee comes along and decorates i
Source:Huntsman Cancer Institute/University of Utah Health Sciences Center