TYRO3

TYRO3 (also known as Sky, Brt, or Dtk) is one of the three TAM receptor tyrosine kinases alongside Axl and Mer. Its extracellular region contains two immunoglobulin-like domains followed by two fibronectin type III domains, and its ligands are the vitamin K-dependent proteins Gas6 and PROS1 presented on apoptotic cell surfaces. TYRO3 signaling supports apoptotic cell clearance, myelination in the nervous system, natural killer cell homeostasis, and dendritic cell tolerance through induction of SOCS proteins. Among TAM members, TYRO3 is distinguished by its prominent expression in neurons, glia, and lymphoid cells, and by reported roles as an entry cofactor for enveloped viruses and a modifier of autoimmune and neurodegenerative disease models.