Assembly of pre-mRNA splicing complex is cap dependent

• Published in: Nucleic acids research Vol. 15; no. 4; pp. 1387 - 1399
• Main Authors: PATZELT, E, THALMANN, E, HARTMUTH, K, BLAAS, D, KUECHLER, E
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 25.02.1987
• Subjects: Biological and medical sciences; Exons; Fundamental and applied biological sciences. Psychology; Gene expression; Genes; Humans; Introns; Metallothionein - genetics; Molecular and cellular biology; Molecular genetics; Nucleic Acid Precursors - genetics; RNA Caps; RNA Precursors; RNA Splicing; RNA, Messenger - genetics; Transcription, Genetic; Human; Messenger RNA; Splicing; Molecular assembly; Cap structure; Complexes; In vitro; Metallothionein
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/15.4.1387

To study the influence of the ubiquitous cap structure of nuclear pre-mRNAs on the assembly of a functional splicing complex, the in vitro splicing of a truncated human metallothionein pre-mRNA was examined in the presence of the cap analogue m7GTP. Significant inhibition of splicing was observed at a concentration as low as 5 microM m7GTP. Analysis of the splicing reaction on glycerol density gradients showed two complexes sedimenting at 45S and 22S. When the reaction was carried out in presence of m7GTP a marked decrease of the material sedimenting at 45S, representing the active splicing complex, was observed. When capped pre-mRNA was replaced by uncapped pre-mRNA, complex formation was significantly reduced. These data indicate that the cap structure plays an important yet unknown role in the assembly of spliceosomes.