Analysis of the human type I insulin-like growth factor receptor promoter region

We isolated genomic fragments containing the 5′ region of the human type I insulin-like growth factor receptor gene. A unique transcription start site was identified, defining a 1038 bp 5′-untranslated region. No TATA or CCAAT elements were identified in the proximal 480 nucleotides of 5′-flanking region. The region surrounding the transcription start site was similar to a recently described "initiator" sequence. The 5′-flanking and 5′-untranslated regions were highly GC-rich, with numerous potential Sp1 binding sites. A potential AP-2 binding site was identified in the 5′-flanking region and a potential thyroid response element was identified in the 5′-untranslated region. The 5′ region of the human gene was very similar to that of the rat gene, with conservation of many of the potential regulatory elements.