Insulin-like growth factor I receptor primary structure: comparison with insulin receptor suggests structural determinants that define functional specificity

EMBO J. 1986 Oct;5(10):2503-12.


To identify structural characteristics of the closely related cell surface receptors for insulin and IGF-I that define their distinct physiological roles, we determined the complete primary structure of the human IGF-I receptor from cloned cDNA. The deduced sequence predicts a 1367 amino acid receptor precursor, including a 30-residue signal peptide, which is removed during translocation of the nascent polypeptide chain. The 1337 residue, unmodified proreceptor polypeptide has a predicted Mr of 151,869, which compares with the 180,000 Mr IGF-I receptor precursor. In analogy with the 152,784 Mr insulin receptor precursor, cleavage of the Arg-Lys-Arg-Arg sequence at position 707 of the IGF-I receptor precursor will generate alpha (80,423 Mr) and beta (70,866 Mr) subunits, which compare with approximately 135,000 Mr (alpha) and 90,000 Mr (beta) fully glycosylated subunits.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA / analysis
  • Female
  • Humans
  • Placenta / metabolism
  • Poly A / genetics
  • Pregnancy
  • RNA, Messenger / genetics
  • Receptor, Insulin / genetics*
  • Receptor, Insulin / isolation & purification
  • Receptor, Insulin / metabolism
  • Receptors, Somatomedin
  • Sequence Homology, Nucleic Acid


  • RNA, Messenger
  • Receptors, Somatomedin
  • Poly A
  • DNA
  • Receptor, Insulin

Associated data

  • GENBANK/M24599