= AAUAAA signal
{c}
The <AAUAAA signal> is a six-nucleotide <RNA> sequence involved in cleavage and <polyadenylation> of many eukaryotic pre-mRNAs. Recognition of the signal helps organize processing downstream, after which a <poly(A) tail> is added. The signal itself is an encoded part of the <RNA>; the tail is subsequently synthesized and is not simply a copied run of genomic adenines. <The AAUAAA sequence is required both for cleavage and for polyadenylation of simian virus 40 pre-mRNA in vitro by David Zarkower and others>[1986, in-vitro processing of altered signal sequences]{ref}
Mutating the signal and comparing processing of defined <RNA> <substrates> supplied a direct functional test. The result concerns a particular processing context: other surrounding sequences and <protein> factors also contribute, and biological <polyadenylation> sites can use signal variants. Sequence recognition, cleavage position and final tail length are separate features of the mature transcript.
Back to article page
