| First Author | Le HT | Year | 2012 |
| Journal | PLoS One | Volume | 7 |
| Issue | 3 | Pages | e33140 |
| PubMed ID | 22427968 | Mgi Jnum | J:186917 |
| Mgi Id | MGI:5433780 | Doi | 10.1371/journal.pone.0033140 |
| Citation | Le HT, et al. (2012) Two isoforms of the mRNA binding protein IGF2BP2 are generated by alternative translational initiation. PLoS One 7(3):e33140 |
| abstractText | IGF2BP2 is a member of a family of mRNA binding proteins that, collectively, have been shown to bind to several different mRNAs in mammalian cells, including one of the mRNAs encoding insulin-like growth factor-2. Polymorphisms in the Igf2bp2 gene are associated with risk of developing type 2 diabetes, but detailed functional characterisation of IGF2BP2 protein is lacking. By immunoblotting with C-terminally reactive antibodies we identified a novel IGF2BP2 isoform with a molecular weight of 58 kDa in both human and rodents, that is expressed at somewhat lower levels than the full-length 65 kDa protein. We demonstrated by mutagenesis that this isoform is generated by alternative translation initiation at the internal Met69. It lacks a conserved N-terminal RNA Recognition Motif (RRM) and would be predicted to differ functionally from the canonical full length isoform. We further investigated IGF2BP2 mRNA transcripts by amplification of cDNA using 5'-RACE. We identified multiple transcription start sites of the human, mouse and rat Igf2bp2 genes in a highly conserved region only 50-90 nts upstream of the major translation start site, ruling out the existence of N-terminally extended isoforms. We conclude that structural heterogeneity of IGF2BP2 protein should be taken into account when considering cellular function. |
