In vitro polyadenylation is stimulated by the presence of an upstream intron

• Published in: Genes & development Vol. 4; no. 9; pp. 1552 - 1559
• Main Authors: NIWA, M, ROSE, S. D, BERGET, S. M
• Format: Journal Article
• Language: English
• Published: Cold Spring Harbor, NY Cold Spring Harbor Laboratory 01.09.1990
• Subjects: Base Sequence; Biological and medical sciences; Cell Nucleus - metabolism; Cell-Free System; Exons - physiology; Fundamental and applied biological sciences. Psychology; HeLa Cells; Humans; Introns - genetics; Introns - physiology; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Poly A - biosynthesis; Regulatory Sequences, Nucleic Acid - genetics; RNA - genetics; RNA Precursors - metabolism; RNA Processing, Post-Transcriptional - genetics; RNA Splicing - genetics; RNA, Messenger - biosynthesis; Transcription. Transcription factor. Splicing. Rna processing; Vertebrata; Messenger RNA; Splicing; Radiolabelling; Gel electrophoresis; Polyadenylation; Activation; Biosynthesis precursor; Mechanism of action; In vitro; Intervening sequence; Chimera
• ISSN: 0890-9369; 1549-5477
• DOI: 10.1101/gad.4.9.1552

The majority of vertebrate pre-mRNAs are both spliced and polyadenylated. To investigate the mechanism whereby processing factors recognize last exons containing both splicing and polyadenylation consensus elements, chimeric precursor RNAs containing a single intron and a poly(A) site were constructed and assayed for in vitro splicing and polyadenylation. Chimeric RNAs underwent splicing and polyadenylation. Both reactions occurred in a single RNA. The presence of an intron enhanced the rate of polyadenylation at a downstream poly(A) site. The extent of stimulation varied from two- to fivefold, depending on the magnesium concentration. Maximal stimulation of polyadenylation by an upstream intron required a 3' splice site but not a 5' splice site, suggesting that the structure of the terminal exon was more important than the presence of a complete upstream intron. We suggest that splicing and polyadenylation factors interact to recognize terminal, poly(A) site-containing exons. Such interaction may explain why all known intron-containing eukaryotic pre-mRNAs generate their 3' ends by polyadenylation.