AbstractCell survival requires the control of biomolecule concentration, i.e. biomolecules should approach homeostasis. With information-carrying macromolecules, the particular concentration variation ranges depend on each type: DNA is not buffered, but mRNA and protein concentrations are homeostatically controlled, which leads to the ribostasis and proteostasis concepts. In recent years, we have studied the particular features of mRNA ribostasis and proteostasis in the model organismS. cerevisiae. Here we extend this study by comparing published data from three other model organisms:E. coli, S. pombeand cultured human cells. We describe how mRNA ribostasis is less strict than proteostasis. A constant ratio appears between the average decay and dilution rates during cell growth for mRNA, but not for proteins. We postulate that this is due to a trade-off between the cost of synthesis and the response capacity. This compromise takes place at the transcription level, but is not possible at the translation level as the high stability of proteins,versusthat of mRNAs, precludes it. We hypothesize that the middle-place role of mRNA in theCentral Dogmaof Molecular Biology and its chemical instability make it more suitable than proteins for the fast changes needed for gene regulation.Graphical Abstract
120 Role of dynamic base pair polymorphism in the central dogma of molecular biology