Efficient 3'-end formation of human ß-globin mRNA in vivo requires sequences within the last intron but occurs independently of the splicing reaction
| Autor: | Finola Geraghty, Michael Antoniou, J. Hurst, Frank Grosveld |
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| Přispěvatelé: | Cell biology |
| Rok vydání: | 1998 |
| Předmět: |
Polyadenylation
RNA Splicing Molecular Sequence Data Biology Exon Mice Genetics Tumor Cells Cultured Animals Humans Point Mutation RNA Messenger Gene Splice site mutation Base Sequence Intron Group II intron Exons Molecular biology Exon skipping Introns Globins Gene Expression Regulation RNA splicing Mutation Leukemia Erythroblastic Acute Research Article |
| Zdroj: | Nucleic Acids Research, 26(3), 721-729. Oxford University Press |
| ISSN: | 0305-1048 |
| Popis: | The second intron (betaIVS-II) of the human beta-globin gene is essential for the accumulation of stable cytoplasmic mRNA and is implicated in promoting efficient 3'-end formation. This report presents quantitative comparisons between betaIVS-II mutants at physiological levels of expression from within a natural chromatin context in vivo which further defines it's function. In marked contrast to a beta-globin gene lacking a second intron, two mutants defective in splicing (small size or a splice donor mutation), still undergo essentially normal levels of 3'-end formation and in the absence of exon skipping. Therefore, 3' cleavage of beta-globin transcripts requires the presence of betaIVS-II sequences, but not the splicing reaction. The placement of betaIVS-II in the IVS-I position did not reduce the efficiency of 3' cleavage indicating that the distance between the necessary element(s) in this intron and the polyadenylation recognition site is not a crucial factor. Subsequent placement of betaIVS-I in the intron II position, reduced the efficiency of 3'-end formation to only 16% of normal. A direct replacement of intron II by the heterologous introns betaIVS-I or alpha-globin IVS-II, only partially substitute (16 and 30% respectively) for betaIVS-II. Hybrid introns show that efficient 3'-end formation is strongly enhanced by the presence of the terminal 60 nt of betaIVS-II. These data imply that the last intervening sequence of multiple intron containing genes is a principal determinant of the efficiency of 3'-end formation and may act as a post-transcriptional regulatory step in gene expression. |
| Databáze: | OpenAIRE |
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