Cells use that mechanism to control the production of proteins such as growth factors, which activate genes in response to a hormone or other signal.
PMR1 also plays a key role in Cooley's anemia, which causes the loss of red blood cells in infants and children.
For the present study, Schoenberg and coauthor Yong Peng, a research associate in Schoenberg's laboratory, wanted to learn how PMR1 is activated to attach to mRNAs.
They found that activation occurs when PMR1 is momentarily joined by an unidentified enzyme. Contact with this enzyme changes the properties of PMR1, and this enables it to join with, or bind to, its target mRNA.
Peng then used monoclonal antibodies to isolate PMR1 and the enzyme while the two were bound together, capturing both. After separating the two, the investigators identified the enzyme as Src, which is a member of a large family of molecules called tyrosine kinases. These molecules act like switches that turn other molecules on and off, including PMR1.
“That's the real excitement about this paper,?Schoenberg says. “We came at this with an interest in mRNA decay, and we may have stumbled across a fundamental mechanism of cancer.?
Next, Schoenberg and his associates Xiaoqiang Liu and Elizabeth Murray will use three cancer-cell lines to try to identify what messenger RNAs ?which will also tell them what proteins ?are targeted and destroyed by PMR1.
“That will help tell us whether Src works through PMR1 to contribute to cancer,?Schoenberg says.
Funding from the National Institute for General Medical Sciences supported this research.
Source:Ohio State University