Insulin-Like Growth Factor-Binding Protein 3 Protein (IGFBP3) Human Active Protein

This gene is a member of the insulin-like growth factor binding protein (IGFBP) family and encodes a protein with an IGFBP domain and a thyroglobulin type-I domain. The protein forms a ternary complex with insulin-like growth factor acid-labile subunit (IGFALS) and either insulin-like growth factor (IGF) I or II. In this form, it circulates in the plasma, prolonging the half-life of IGFs and altering their interaction with cell surface receptors. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008]

IGFBP3: IGF-binding proteins prolong the half-life of the IGFs and have been shown to either inhibit or stimulate the growth promoting effects of the IGFs on cell culture. They alter the interaction of IGFs with their cell surface receptors. Also exhibits IGF-independent antiproliferative and apoptotic effects mediated by its receptor TMEM219/IGFBP-3R.

Protein type: Cell development/differentiation; Secreted; Secreted, signal peptide

Chromosomal Location of Human Ortholog: 7p12.3

Cellular Component: endoplasmic reticulum lumen; extracellular region; extracellular space; insulin-like growth factor binding protein complex; nucleus

Molecular Function: fibronectin binding; insulin-like growth factor I binding; insulin-like growth factor II binding; protein binding; protein tyrosine phosphatase activator activity

Biological Process: cellular protein metabolic process; negative regulation of cell proliferation; negative regulation of protein amino acid phosphorylation; negative regulation of smooth muscle cell migration; negative regulation of smooth muscle cell proliferation; positive regulation of apoptosis; positive regulation of myoblast differentiation; post-translational protein modification; protein amino acid phosphorylation; regulation of apoptosis; regulation of insulin-like growth factor receptor signaling pathway