Description
The IGF-II gene encodes a single transcript which results in an 156 amino acid protein, including an 89 amino acid E-domain. ProIGF-II contains sites of O-linked glycosylation. ProIGF-II is converted to mature IGF-II by sequential cleavage after amino acids 104, 87 and 67. Differential glycosylation and cleavage within the E-domain can therefore result in multiple proIGF-II isoforms.The proIGF-II proteins make up 10-20% of circulating IGF-II. ProIGF-II proteins are secreted by some tumor cell lines and levels are elevated in non-islet cell tumor hypoglycemia