Role of the Gas6/TAM System as a Disease Marker and Potential Drug Target

摘要

Growth arrest-specific 6 (Gas6) is a gene cloned in 1993 [1] encoding for a vitamin K-dependent protein expressed in different tissues [1–3]. Its biological activities are mediated by the interaction with three tyrosine kinase receptors: Tyro3, Axl, and MerTK, which are commonly and collectively abbreviated as TAM [4]. These receptors share a common feature: their extracellular domain is proteolytically cleaved and released in a soluble form (sTyro3, sAxl, and sMer; sTAM collectively) and acts as a decoy receptor; consistently, the shedding of the ectodomain entails the reduction of transmembrane receptors available for the ligands [5, 6].