Organization and Expression of the Genes Encoding the Human Somatomedins
The somatomedins or insulin-like growth factors (IGF) are small polypeptides which play an important role in fetal and postnatal growth and development (1,2). Two major human IGFs have been fully characterized: IGF-I is a basic peptide of 70 amino acids, which is required for postnatal growth, while IGF-II is a neutral peptide containing 67 residues probably involved in fetal development (3,4). Recently, the nucleotide sequences of cDNAs encoding IGF-I and IGF-II were reported (5–9). From the cDNA sequences it can be derived that both IGFs are synthesized as larger precursor molecules which undergo extensive processing. Employing the IGF-specific cDNAs as probes, the chromosomal assignment and structure of the IGF genes has been established. In this communication, our current insight in the organization and expression of the IGF genes will be presented.
KeywordsAdult Liver Insulin Gene Adult Human Liver Noncoding Exon Primer Extension Experiment
Unable to display preview. Download preview PDF.
- 3.Rinderknecht E, Humbel RE. The amino acid sequence of human insulin-like growth factor I and its structural homology with pro- insulin. J Biol Chem 1978; 253: 2769.Google Scholar
- 20.Frunzio R, Chairotti L, Brown AL, Graham DE, Rechler MM, Bruni CB. Structure and expression of the rat insulin-like growth factor II (rIGF-II) gene. J Biol Chem 1986; 262: 17138.Google Scholar