<p>The stability of beta-tubulin mRNAs are autoregulated by their own translation product [<cite idref="PUB00005335"/>]. Unpolymerised tubulin subunits bind directly (or activate a factor(s) which binds co-translationally) to the nascent N terminus of beta-tubulin. This binding is transduced through the adjacent ribosomes to activate an RNAse that degrades the polysome-bound mRNA. The recognition element has been shown to be the first four amino acids of beta-tubulin: Met-Arg-Glu-Ile. Mutations to this sequence abolish the autoregulation effect (except for the replacement of Glu by Asp); transposition of this sequence to an internal region of a polypeptide also suppresses the autoregulatory effect.</p>