"It's not all of any particular message that's uncapped, just a portion of a message," Schoenberg said. "We wanted to show that we have uncapped RNAs in the cell and they are not degraded. It means they're stored that way."
This finding offered hints that there is a higher order to this phenomenon, and that some mRNAs purposefully rest in an uncapped state without being degraded by enzymes within the cell whose job is to remove them. It also suggested that as the capping circumstances change inside the cell body, signals from genes might undergo change that allows for two or more proteins, one being shorter than the other, to be made from the same mRNA.
"We have always thought that one gene would give an mRNA for one kind of protein. But what we have found makes us wonder if multiple proteins could be made from each of the messenger RNAs that undergo decapping and recapping in the cytoplasm," Schoenberg said.
The researchers used bioinformatics technology to determine which genes were manufacturing mRNAs that could exist in this uncapped and recapped state in the cytoplasm. These genes included those that control some of the most basic elements of cell survival: They determine the location of proteins and RNAs within the cell and, perhaps most significantly, the mitotic cell cycle - part of the process of cell division.
"It wasn't random. It was very specific," Schoenberg said. "There are specific families of mRNAs that are regulated in this way, and that has ramifications for how proteins are expressed and regulated."
As an example, he cited how neurons communicate messages across vast distances to other nerve cells. It is known that mRNAs are deliberately kept in a silent state while they travel from, for example, the spinal cord to the fi
|Contact: Daniel Schoenberg|
Ohio State University