Genetic information is mainly stored in human genomic DNA, which can be transcribed to form mRNA, which in turn directs the translation of proteins.
This process is a key component of the “Law of Center”.
In a recent study published in Science, scientists measured in detail a dataset of changes in gene expression and mRNA concentrations of thousands of genes in Escherichia coli (E. coli) during rapid growth.
Based on this, they analyzed in detail the interactions between the activity of the gene expression machinery, the activity of individual promoters and the concentration of the resulting proteins.
They found that for most genes, the protein concentration in the cytoplasm depends largely on the intrinsic size of their promoters.
In contrast, cell growth conditions have a much smaller effect on the concentration of synthesized proteins.
It showed that the protein concentration in gene regulation in E. coli is mainly determined by the transcriptional process and is less influenced by the translation process of mRNA and the growth conditions.
In addition, transcription and translation processes are closely coordinated, and this coordination is achieved by a class of anti-σ factors in E. coli, Rsd, that regulate the availability of RNA polymerase required for transcription under different growth conditions.
These two principles can link mRNA and protein concentrations to the regulatory activity of the corresponding promoters.
These relationships provide the basis for understanding the behavior of more complex genetic circuits under different conditions.