Mosaic evolution of the insulin-like growth factors. Organization, sequence, and expression of the rat insulin-like growth factor I gene.

A. Shimatsu, P. Rotwein

Research output: Contribution to journalArticlepeer-review

245 Scopus citations

Abstract

Insulin-like growth factor I (IGF-I) plays a major role in mammalian growth and regenerative processes as a mediator of many of the biological effects of growth hormone. We have demonstrated recently that the human IGF-I gene is transcribed and processed into distinct messenger RNA molecules, each of which directs the synthesis of unique IGF-I-containing peptides. As a means to determine whether a similar model of IGF-I gene organization and expression is the paradigm in mammals and as an initial step in devising experimental approaches to the study of regulation of IGF-I biogenesis, we have isolated and characterized the rat IGF-I gene. The rat gene, like its human counterpart, is very large, extending over at least 73 kilobases, and is composed of five exons subdivided by four introns. As in the human example, the rat IGF-I gene hybridizes to several messenger RNAs: 0.8-1.2, 1.6-2.1, and 7.8 kilobases. There is extensive nucleotide and amino acid sequence conservation between the two genes. The predicted mature rat IGF-I protein is identical to the human peptide in 67 of 70 residues. A comparably high degree of amino acid sequence identity is also found for both the amino- and carboxyl-terminal extension peptides, suggesting that, like mature IGF-I, the extension molecules may have physiological function.

Original languageEnglish (US)
Pages (from-to)7894-7900
Number of pages7
JournalJournal of Biological Chemistry
Volume262
Issue number16
StatePublished - Jun 5 1987

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Mosaic evolution of the insulin-like growth factors. Organization, sequence, and expression of the rat insulin-like growth factor I gene.'. Together they form a unique fingerprint.

Cite this