Adenovirus Early Region 4 Stimulates mRNA Accumulation Via 5' Introns

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 87; no. 24; pp. 9543 - 9547
• Main Authors: Nordqvist, Katarina, Akusjarvi, Goran
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.12.1990; National Acad Sciences
• Subjects: Adenoviruses; Adenoviruses, Human - genetics; Animals; Biological and medical sciences; Cell Line; DNA; Fundamental and applied biological sciences. Psychology; Genes, Viral; Introns; Messenger RNA; Molecular and cellular biology; Molecular genetics; Nuclear RNA; Nucleotides; Plasmids; RNA; RNA Processing, Post-Transcriptional; RNA, Messenger - genetics; RNA, Messenger - metabolism; Transcription, Genetic; Transcription. Transcription factor. Splicing. Rna processing; Transfection; Untranslated regions; Viruses; Virus; Molecular hybridization; Enhancer sequence; Adenoviridae; Messenger RNA; Transfection; Intron; Transcription; Stimulation; Molecular cloning; Mechanism of action
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.87.24.9543

The adenovirus major late transcription unit accounts for most virus-specific transcription late after infection. All mRNAs expressed from this unit carry a short spliced leader, the so-called tripartite leader, attached to their 5' ends. Here we describe a function for an adenovirus gene product in the control of major late mRNA abundance. We show that early region 4 (E4) stimulates mRNA accumulation from tripartite leader intron-containing transcription units ≈ 10-fold in short-term transfection assays. The effect was already detectable in nuclear RNA and was not due to a transcriptional activation through any of the major late promoter elements or through an effect at nuclear to cytoplasmic mRNA transport. A surprising positional effect of the intron was noted. To be E4 responsive, the intron had to be placed close to the pre-mRNA 5' end. The same intron located far downstream in the 3' untranslated region of the mRNA was not E4 responsive. The E4 enhancement was not dependent on specific virus exon or intron sequences. These results suggest that E4 modulates a general pathway in mammalian mRNA formation.