IGFBP1
Function
Multifunctional protein that plays a critical role in regulating the availability of IGFs such as IGF1 and IGF2 to their receptors and thereby regulates IGF-mediated cellular processes including cell migration, proliferation, differentiation or apoptosis in a cell-type specific manner (PubMed:11397844, PubMed:15972819). Plays also a positive role in cell migration by interacting with integrin ITGA5:ITGB1 through its RGD motif (PubMed:7504269). Mechanistically, binding to integrins leads to activation of focal adhesion kinase/PTK2 and stimulation of the mitogen-activated protein kinase (MAPK) pathway (PubMed:11397844). Regulates cardiomyocyte apoptosis by suppressing HIF-1alpha/HIF1A ubiquitination and subsequent degradation (By similarity).
Post-translational modifications
Phosphorylated; probably by casein kinase II. Phosphorylation alters the affinity of the protein for IGFs. In amniotic fluid, the unmodified protein is the most abundant form, while mono-, bi-, tri- and tetraphosphorylated forms are present in decreasing amounts. The phosphorylation state may influence the propensity to proteolysis.
Cellular localization
- Secreted
Alternative names
IBP1, IGFBP1, Insulin-like growth factor-binding protein 1, IBP-1, IGF-binding protein 1, IGFBP-1, Placental protein 12, PP12