IGF1 Alternate splicing paper(rev2) with Figs.pdf (716.25 kB)
Characterization of a novel alternatively-spliced 5' exon in the human insulin-like growth factor I (IGF-I) gene, expressed in liver and some cancers
journal contribution
posted on 2023-06-09, 18:10 authored by Michael WallisIn mammals, the large IGF-I gene comprises 6 exons, which are subject to alternative splicing. All transcripts contain exons 3 and 4, encoding mature IGF-I, but the other exons are included in various combinations, giving at least 6 possible mature mRNAs. At the 5' end, exons 1 and 2 are spliced alternatively to exon 3, giving different leader/signal sequences. It is shown in this study that in human an additional exon (designated exon 0) is present, upstream of exon 1. This can be spliced directly to exon 3 or, less frequently, into exon 1. Exon 0 is utilised in liver, in about 24% of IGF-I transcripts, to a minor extent in prostate and endometrium (<1% of transcripts), but not in any of 29 other normal human tissues examined. The exon 0 sequence includes an in-frame ATG/AUG, potentially providing a translation start point giving an IGF-I precursor with a very long signal peptide. However, this ATG is very close to the 5' end, and may not be included in all transcripts; an in-frame ATG in exon 3 could provide an alternative start point. Utilization of exon 0 was detected in other apes, and to a small extent in Old World monkeys, but not in New World monkeys, prosimians or various non-primate mammals. Exon 0 was not expressed in most human tumours, but was utilized in many prostate tumours, at levels much greater than seen in normal prostate, and in liver tumours, at a lower level than in normal liver.
History
Publication status
- Published
File Version
- Accepted version
Journal
Growth Hormone and IGF ResearchISSN
1096-6374Publisher
ElsevierExternal DOI
Volume
46-47Page range
36-43Department affiliated with
- Biochemistry Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2019-06-25First Open Access (FOA) Date
2020-06-10First Compliant Deposit (FCD) Date
2019-06-25Usage metrics
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