In a paper entitled “General properties of transcriptional time series in Escherichia coli” published at the beginning of May in Nature Genetics, a research group in collaboration with Dr. Anandamohan Ghosh and Dr. Ronen Segev from the Department of Life Sciences and the Zlotowski Center for Neuroscience has shown that the production of mRNA in E. Coli is universal and does not depend on the gene identity. In fact the group has found that the degree of burstiness in production depends on the total number of proteins in the cell alone. In fact, the production process behavior is explained by an underlying modulation of a single parameter which depends solely on the number of molecules being produced.
As Dr. Segev explains, “Every living cell depends on the ability to express different genes that create the essential proteins for cellular function. This process takes place by translating the information which is encoded in the DNA to an mRNA molecule which then allows the production of a new protein. This production process does not proceed at a constant rate but is rather characterized by bursts or pulses of production followed by periods of inactivity. Due to the complexity of this production process, the cell can in principle modify the process by adjusting a large number of parameters.
For example the cell can adjust the number of proteins it produces in each burst or the number of bursts per minutes - both will lead to differences in the number of proteins in the cell. Furthermore, due to the large number of genes in the living cell, one could imagine that there are many ways in which this production process can be tuned to obtain the right production level in a way that is specific to each gene. Clearly, due to the centrality of this process in biology it is critical for us to understand how exactly the protein production process is controlled. This work, which at this stage is specific to E. Coli, elucidates an important aspect of cell biology.”