Insulin-like growth factor-binding protein 4 (IGFBP4)

Insulin-like growth factor-binding protein 4 (IGFBP4) is a secreted glycoprotein member of the IGFBP family that binds both insulin-like growth factor I and II with high affinity, thereby modulating their half-life and bioactivity in circulation and local tissues[3][7][2]. IGFBP4 is expressed in a diverse range of tissues and fluids and exists in glycosylated and non-glycosylated forms[2][3][7]. Its major function is to restrict or inhibit IGF-mediated cell proliferation, growth, and survival by sequestering IGFs away from the IGF-1 receptor; it can also have IGF-independent effects, including roles in apoptosis and anti-angiogenesis[2][3][6]. IGFBP-4 is proteolytically cleaved by the metalloprotease pregnancy-associated plasma protein-A (PAPP-A), a process that enables local IGF bioavailability and is implicated in physiological processes like wound healing, bone metabolism, reproduction, and pathological processes such as atherosclerosis and cancer progression[4][5][2]. IGFBP-4 levels or activity can function as a potential disease biomarker and a therapeutic target in oncology, cardiology, and endocrinology[6].

Other names

IGFBP-4IBP4IBP-4IGF-binding protein 4BP-4HT29-IGFBP

Indirect modulation of IGF-I and IGF-II signal transduction by binding IGFs, thereby inhibiting their interaction with the IGF-1 receptor or enhancing local IGF proteolysis[2][4][5][7].