{PDOC00200}
{PS00228; TUBULIN_B_AUTOREG}
{BEGIN}
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* Tubulin-beta mRNA autoregulation signal *
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The stability of beta-tubulin mRNAs are autoregulated by their own translation
product [1].  Unpolymerized  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.

-Consensus pattern: <M-R-[DE]-[IL]
-Sequences known to belong to this class detected by the pattern: ALL,  except
 for soybean beta-2 tubulin which has Ser in the last position of the pattern.
-Other sequence(s) detected in Swiss-Prot: a number of alpha-tubulins, as well
 as 26 other proteins.
-Last update: May 1991 / Pattern and text revised.

[ 1] Cleveland D.W.
     "Autoregulated instability of tubulin mRNAs: a novel eukaryotic
     regulatory mechanism."
     Trends Biochem. Sci. 13:339-343(1988).
     PubMed=3072712
{END}