Mesoderm Induction Early Response Protein 1 (MIER1)

Mi-er1 is a fibroblast growth factor-inducible early response gene activated during mesoderm induction in Xenopus embryos. The human orthologue of mi-er1 was shown to be upregulated in breast carcinoma cell lines and breast tumours when compared to normal breast cells. hmi-er1 is a single copy gene located at 1p31.2 and spanning 63 kb. It contains 17 exons and includes one skipped exon, a facultative intron and three polyadenylation signals to produce 12 transcripts encoding six distinct proteins. hmi-er1 transcripts were expressed at very low levels in most human adult tissues and the mRNA isoform pattern varied with the tissue. Alternate use of a facultative intron regulates the subcellular localization of hMI-ER1 proteins and this may have important implications for hMI-ER1 function.