Description
Among IGFs, insulinlike growth factor 2 (IGF2) is a key regulator of cell growth, survival, migration and differentiation. The type 2 IGF receptor (IGF2R) modulates circulating and tissue levels of IGF2 by targeting it to lysosomes for degradation. The extracytoplasmic region of IGF2R has three binding sites: one for IGF2 in domain 11 and two for Man-6-P in domains 3, 5 and 9. Binding between IGF2 and IGF2R induces the lysosomal degradation of IGF2. IGF2R serves to clear IGF2 from the circulation or degrade excess circulating IGF2. Soluble IGF2R can affect the size of some organs exclusively by reducing the biological activity of IGF2