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TY - JOUR AU - Dull, Thomas J. AU - Gray, Alane AU - Hayflick, Joel S. AU - Ullrich, Axel PY - 1984 DA - 1984/08/01 TI - Insulin-like growth factor II precursor gene organization in relation to insulin gene family JO - Nature SP - 777 EP - 781 VL - 310 IS - 5980 AB - The insulin gene family1,2, comprised of insulin, relaxin, insulin-like growth factors I and II (IGF-I and IGF-II) and possibly the β-subunit of 7S nerve growth factor3, represents a group of structurally related polypeptides whose biological functions have diverged. The IGFs, or somatomedins, constitute a class of polypeptides that have a key role in pre-adolescent mammalian growth (see ref. 4 for review). IGF-I expression is regulated by growth hormone5,6 and mediates postnatal growth, while IGF-II appears to be induced by placental lactogen during prenatal development6. The primary structures of both human IGFs have been determined and are closely related7,8. A polypeptide highly homologous to human IGF-II is secreted by the rat liver cell line, BRL-3A9,10. As this polypeptide, termed multiplication stimulating activity (MSA), differs from human IGF-II by only five amino acid residues, MSA probably represents the rat IGF-II protein11. Using molecular cloning techniques, we have isolated cDNA and chromosomal genes coding for the MSA and human IGF-II precursors, respectively. Our data, presented here, indicate that both MSA12 and human IGF-II are synthesized initially as larger precursor molecules. The deduced preprohormones both have molecular weights (MWs) of 20,100 and contain C-terminal propeptides of 89 amino acid residues, which we have named E-peptides. The organization of the IGF-II precursor gene is discussed in relation to that of other insulin gene family members. SN - 1476-4687 UR - https://doi.org/10.1038/310777a0 DO - 10.1038/310777a0 ID - Dull1984 ER -