The molecular and cellular biology of insulin-like growth factor II

Prog Growth Factor Res. 1992;4(3):257-90. doi: 10.1016/0955-2235(92)90023-b.


Insulin-like growth factor II (IGF-II) is a 67 amino acid polypeptide that belongs to the family of insulin-like peptides. The IGF-II gene is coupled to the insulin gene and paternally imprinted. Multiple IGF-II mRNAs with identical coding regions and 3' untranslated regions (UTRs) but different 5' UTRs are generated from 3 promoters. The transcripts are translationally discriminated and inactivated by a specific endonucleolytic cleavage in their 3' UTR. These features may be important in the control of IGF-II production. IGF-II functions in an auto- and paracrine manner and binds to two types of receptors. The IGF-I receptor that is a tyrosine kinase and closely related with the insulin receptor and the IGF-II/mannose 6-phosphate (IGF-II/Man 6-P) receptor that is identical with the cation-independent mannose 6-phosphate receptor. The mitogenic and metabolic actions of IGF-II are propagated by the IGF-I receptor. In contrast, the IGF-II/Man 6-P receptor, that target lysosomal enzymes from the Golgi apparatus or the plasma membrane to the lysosomes, mediates the rapid internalization and degradation of IGF-II. IGF-II is expressed at high levels during foetal life and it is a major growth factor for the foetus in rodents. The developmental profiles and tissue distribution of the IGF-I and the maternally imprinted IGF-II/Man 6-P receptors both parallel that of IGF-II. In this scenario IGF-II promotes the growth of the embryo through the IGF-I receptor, whereas the IGF-II/Man 6-P receptor balance the activity by controlling the extracellular level of IGF-II.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Physiological Phenomena*
  • Embryonic and Fetal Development / physiology
  • Gene Expression
  • Humans
  • Insulin-Like Growth Factor II / chemistry
  • Insulin-Like Growth Factor II / genetics
  • Insulin-Like Growth Factor II / physiology*
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Receptor, IGF Type 2 / metabolism


  • Receptor, IGF Type 2
  • Insulin-Like Growth Factor II