Cloning and developmental regulation of a novel member of the insulin-like gene family in Caenorhabditis elegans

Francine M. Gregoire, Nathalie Chomiki, Donna Kachinskas, Craig H Warden

Research output: Contribution to journalArticle

50 Scopus citations

Abstract

Aging, metabolism and fat accumulation in Caenorhabditis elegans (C. elegans) are influenced by mutations in DAF-2, a putative insulin-like receptor. Ten putative insulin-like genes have been recently identified from the C. elegans genome database. However, it is unclear if these genes are orthologues of human insulin since they lack the C-peptide dibasic amino acid proteolysis sites. We have identified and measured mRNA expression during development of two novel members of the C. elegans insulin-like gene family. We also report the sequence characterization and gene structure for one of these, the insulin-like protein-1 (ILP1). We focused on ILP1 characterization because it has structural features consistent with its being a candidate insulin ligand for the DAF-2 insulin-like receptor. For example, ILP1 has a putative C-peptide flanked by dibasic amino acids, exhibits conserved cysteine residues that could provide disulfide bonds between the A and B chains, and has two introns. Northern blot analysis revealed that ILP1 mRNA is expressed at very high levels in embryos and is downregulated very early during postnatal development, suggesting that it may influence embryonic development, but not Dauer formation. We also identified a novel insulin-like growth factor-1-like protein (T28B8/IGF-I) that exhibits a very different developmental expression profile than ILP1. Our results are consistent with the hypothesis that members of the unusually large and complex C. elegans insulin-like protein family exhibit complex and perhaps redundant roles.

Original languageEnglish (US)
Pages (from-to)385-390
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume249
Issue number2
DOIs
StatePublished - Aug 19 1998

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this