Mechanisms of specificity in mRNA degradation: autoregulation and cognate interactions.

Autoregulation of gene expression is a common control mechanism for a large number of transcriptional units. Cases of self-regulation of the stability of various messenger RNAs (mRNAs) are re-evaluated here, and a general hypothesis for the origins and the mechanism of this process is presented. It is proposed that post-transcriptional autoregulation and mRNA stability are closely associated processes that might represent a general class of gene regulation mechanisms, with special regard to mRNA-protein cognate interactions. Generalizing from known examples, autoregulation is here considered to induce the decay of certain messenger RNAs through a yet undiscovered mechanism. Autoregulation via cognate interactions might be the vestigial process of a primitive world, where protein-nucleic acid interactions originated. The model can therefore serve as a framework to study the origins of the genetic code in particular, and gene expression in general.