A sequence downstream of AAUAAA is required for rabbit β-globin mRNA 3′-end formation

Abstract

The sequence AAUAAA, found 11–30 base pairs (bp) upstream of the poly(A) site of most non-histone eukaryotic messenger RNAs (mRNAs)1 forms an essential part of the recognition site for 3′-end processing of the primary transcript2–4. However, the sequence AATAAA is found in transcribed regions of genes5–8 and is differentially utilized in genes containing multiple copies of the sequence within the 3′-noncoding region8–18, suggesting that the hexanucleotide alone does not comprise a complete recognition site. Therefore, it seems likely that additional sequences are required to form a complete recognition site for 3′-end formation. We have investigated the sequence requirements for mRNA 3′-end formation using the rabbit β-globin gene as a model system. Here we demonstrate that an additional sequence 3′ to AAUAAA is required for the correct 3′-end formation of rabbit β-globin mRNA.