TRANSCRIPTIONAL REGULATION OF THE MAJOR PROMOTERS OF THE HUMAN IGF-II GENE

The human insulin-like growth factor-II (IGF-II) gene constitutes a complex transcriptional unit that is controlled by four different promoters preceding multiple 5'-untranslated exons. Expression of the IGF-II gene is development and tissue specific and yields a family of mRNAs that all encode preproIGF-II. We have analyzed the sequences and factors involved in the transcriptional activation of promoters P1 and P3. Detailed analysis revealed several characteristic elements and protein binding sequences. P1, which is expressed only in adult liver tissue, contains a region that can be specifically activated by the CCAAT/enhancer binding protein (C/EBP). P3 consists of a proximal promoter region that supports general transcription, whereas cell-specific elements are located upstream (C) 1993 Wiley-Liss, Inc.