| First Author | Rotwein P | Year | 1990 |
| Journal | DNA Cell Biol | Volume | 9 |
| Issue | 10 | Pages | 725-35 |
| PubMed ID | 1702294 | Mgi Jnum | J:10904 |
| Mgi Id | MGI:59348 | Doi | 10.1089/dna.1990.9.725 |
| Citation | Rotwein P, et al. (1990) Evolution of insulin-like growth factor II: characterization of the mouse IGF-II gene and identification of two pseudo-exons. DNA Cell Biol 9(10):725-35 |
| abstractText | We have cloned the mouse insulin-like growth factor II (IGF-II) gene as a series of overlapping cosmid and lambda recombinants and have characterized its six exons. The gene extends over approximately 12 kb of mouse chromosome 7 and is located 18 kb 3' to the insulin 2 gene and in the same transcriptional polarity. Exons 1-3 encode distinct 5' untranslated regions and are transcribed by three different promoters, P1, P2, and P3, into three IGF-II mRNAs sharing common coding and 3' untranslated sequences. Promoters P2 and P3 each contain a TATA box and appear to direct transcription from single initiation sites. By contrast, exon 1 has three major transcriptional start sites distributed over 556 nucleotides, and P1 lacks a TATA region and other typical transcriptional control sequences. Exons 4-6 code for the 180-amino-acid IGF-II precursor, and exon 6 also contains a 3,045-nucleotide 3' untranslated region which ends at a single polyadenylation site. In addition to six functional IGF-II exons, we identified two 5' pseudo-exons, which appear to be evolutionarily retained remnants of an alternative promoter-exon cassette that is active in human IGF-II. Loss of the homolog of this promoter, which directs adult-specific expression of the IGF-II gene in some human tissues, may explain the disappearance of this growth factor from most murine tissues in the early postnatal period. |
