CLEVELAND August 23, 2009 Case Western Reserve University School of Medicine assistant professor in the Center for RNA Molecular Biology, Jeff Coller, Ph.D., and his team discovered that messenger RNA (mRNA) predominately degrade on ribosomes, fundamentally altering a common understanding of how gene expression is controlled within the cell. The study, "Co-translational mRNA decay in Saccharomyces cerevisiae", is published in the latest issue of Nature.
"Many genetic diseases are linked to mutations that can cause mis-regulation of RNA destruction so it's important to know the when, where and how the cell normally controls the process of mRNA decay," said Dr. Coller.
mRNA communicates genetic information from DNA to ribosomes where the information is converted to proteins. Proteins catalyze the reactions of life and how much protein is made is critical to fine tune the function of the cell. This means that the amount of mRNA present within the cell is vital for overall cellular health.
The rates of RNA synthesis and destruction determine the overall levels of mRNA. While the details of mRNA synthesis have been studied intensely over the years, the mechanism(s) controlling mRNA decay remain unclear. Prior to Dr. Coller's study it had been thought that once an mRNA had ended its utility it was removed from ribosomes and possibly transported to specialized structures within the cell, called P-bodies, where they are eventually destroyed.
Contrary to this prediction, Dr. Coller's research demonstrates that decay takes place while mRNAs are associated with actively translating ribosomes.
"The data clearly indicate that sequestration into a ribosome-free state (like a P-body) is not a prerequisite for initiation of mRNA decay," said Dr. Coller. Moreover, Dr. Coller and colleagues believe that this new understanding provides an evolutionary explanation for the nature of the decay pathway and may lea
|Contact: Christina DeAngelis|
Case Western Reserve University