Definition of an efficient synthetic poly(A) site.

Journal article

We constructed and analyzed a synthetic poly(A) (SPA) site that was based on the highly efficient poly(A) signal of the rabbit beta-globin gene. By use of the SPA, we demonstrate that the minimum sequences required for efficient polyadenylation are the AATAAA sequence and a GT/T-rich sequence with the correct spacing of 22-23 nucleotides between them. When placed downstream of the poly(A) site of the human alpha 2-globin gene, the SPA is used exclusively. We predict that the SPA, with its more extensive GT/T-rich sequence, is a more efficient poly(A) site than alpha-globin. Also, we compared the use of the SPA when it is placed either in the exon 3 or intron 2 of the rabbit beta-globin gene. When in the exonic position, SPA is used 10-fold more than the regular poly(A) site of rabbit beta-globin. In contrast, when it is in the intronic location, no detectable use of SPA is observed; however, the deletion of the donor site of intron 2 reactivates the intronic positioned SPA. These results indicate that the splicing of intron 2 in the rabbit beta-globin gene occurs ahead of polyadenylation and have important implications for termination of transcription. Polyadenylation, although required for termination of transcription, is not sufficient; therefore, additional termination signals for RNA polymerase II must exist.

Authors: Levitt, N; Briggs, D; Gil, A; Proudfoot, N

• Publication status: Published
• Journal: Genes and development
• Volume: 3
• Issue: 7
• Pages: 1019-1025
• Publication date: 1989-07-01
• DOI: 10.1101/gad.3.7.1019
• EISSN: 1549-5477
• ISSN: 0890-9369
• Language: English
• Keywords: Restriction Mapping; Transcription, Genetic; Globins; Rabbits; DNA; Introns; Animals; Humans; Poly A; RNA Splicing; Molecular Sequence Data; Exonucleases; Exons; Nucleic Acid Hybridization; Base Sequence; RNA, Messenger