Charité scientists identify new function of 'microRNAs'
The precise amount of a protein that is produced by a cell is controlled and regulated by way of small RNA molecules. This phenomenon was discovered by scientists at the Charité – Universitätsmedizin Berlin. The mechanism by which accuracy of protein production is controlled is significant in terms of gaining a deeper understanding of cancer genes. The results of the study are being published in the journal Science*.
Ribonucleic acid (RNA) transforms the genetic information stored in desoxyribonucleic acid (DNA) into proteins. This process is called 'translation'. However, RNA is not – as has long been assumed – merely a kind of 'RAM memory' for DNA, it is also responsible for numerous regulatory tasks in the cells. Accordingly, microRNAs constitute a class of short RNA molecules that can control the production of important proteins in the cell. On the one hand they serve to limit the translation, while on the other they lead to accelerated degradation of messenger RNAs. In this way they limit the amount of protein produced by the cell. Many proteins, which if not properly regulated can cause disease, are controlled by many different microRNAs. Until now it was thought that these molecules acted to limit the production of a protein to specific cell types or organs.
Scientists of the research group Computational Modeling in Medicine, in close cooperation with colleagues from the Harvard Medical School and the Massachusetts Institute of Technology, have now demonstrated that microRNAs are able to control the accuracy of the produced quantity of protein. The researchers initially simulated the protein production process using a mathematical model. These models were then analyzed in the computer, and the findings showed that microRNAs can improve the precision of protein production. The results of these simulations were confirmed experimentally by measuring protein production in the individual cells.
"Our results can be particularly interesting in terms of improving our understanding of oncogenes and tumor suppressors as these genes require precise regulation and are often regulated by many microRNAs", Prof. Nils Blüthgen explained. He added: "For example, tumors can be initiated if there is to much of an oncogenic protein present. With this study we have laid a cornerstone for further dedicated research in order to better understand the complex regulation of individual proteins by a large number of microRNAs and perhaps how we can best utilize this discovery."
*Schmiedel JM, Klemm SL, Zheng Y, Sahay A, Blüthgen N, Marks DS, van Oudenaarden A. Gene expression. MicroRNA control of protein expression noise. Science. 2015 Apr 3; 348(6230):128-32. doi: 10.1126/science.aaa1738.
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Arbeitsgruppe Computational Modelling in Medicine des Instituts für Pathologie
Contact
Prof. Dr. Nils Blüthgen
Institute of Pathology
Charité – Universitätsmedizin Berlin
t: +49 30 2093 8924
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