Insulin-like growth factor binding protein (IGFBP)

Insulin-like growth factor binding proteins (IGFBPs) are a family of secreted proteins (IGFBP-1 to IGFBP-6) that bind insulin-like growth factors I and II (IGF-I and IGF-II) with high affinity. They serve primarily as modulators of IGF signaling by transporting, stabilizing, and regulating the bioavailability of IGFs in circulation and tissues. IGFBPs extend the half-life of IGFs, control their distribution, and either inhibit or, under some conditions, enhance IGF interaction with cognate receptors, thereby influencing cellular processes such as growth, proliferation, migration, differentiation, and apoptosis. In addition to IGF-dependent effects, some IGFBPs have IGF-independent biological activities, including influencing gene expression and interacting with other cellular proteins. Differential regulation and expression of IGFBPs participate in normal physiology and in disease states like cancer, metabolic disorders, and autoimmune diseases. While not classical drug targets themselves, IGFBPs are key biomarkers and potential modulators within the IGF signaling network.

Other names

IGFBPIGF binding proteinInsulin-like growth factor-binding protein familyIGFBP-1IGFBP-2IGFBP-3IGFBP-4IGFBP-5IGFBP-6

Sequestration of IGFs, thus reducing their receptor binding and signaling. Modulation of IGF transport and clearance from circulation. IGF-independent modulation of cell signaling and gene expression.