TYRO3

TYRO3

TYRO3 is a member of the TAM receptor tyrosine kinase family, which also includes AXL and MERTK. These receptors are characterized by their role in the regulation of immune responses, cell survival, and phagocytosis. TYRO3, in particular, is encoded by the TYRO3 gene located on chromosome 15 in humans.

Structure

TYRO3 is a transmembrane protein that consists of an extracellular domain, a single transmembrane helix, and an intracellular tyrosine kinase domain. The extracellular domain contains two immunoglobulin-like domains and two fibronectin type III domains, which are involved in ligand binding.

Function

TYRO3 plays a crucial role in various physiological processes, including:

• Immune Regulation: TYRO3, along with other TAM receptors, helps in the regulation of the immune system by inhibiting inflammatory responses and promoting the clearance of apoptotic cells.
• Cell Survival and Proliferation: It is involved in promoting cell survival and proliferation through the activation of downstream signaling pathways such as the PI3K/AKT pathway.
• Nervous System Development: TYRO3 is expressed in the central nervous system and is involved in the development and maintenance of neural tissues.

Ligands

The primary ligands for TYRO3 are Gas6 (growth arrest-specific 6) and Protein S. These ligands bind to the extracellular domain of TYRO3, leading to receptor dimerization and activation of its kinase activity.

Clinical Significance

Dysregulation of TYRO3 has been implicated in various diseases, including:

• Cancer: Overexpression of TYRO3 has been observed in several types of cancer, where it may contribute to tumor growth and metastasis.
• Autoimmune Diseases: Altered TYRO3 signaling can lead to improper immune responses, contributing to autoimmune conditions.
• Neurodegenerative Diseases: Given its role in the nervous system, TYRO3 dysfunction may be involved in neurodegenerative diseases such as Alzheimer's disease.

Research and Therapeutic Potential

Research is ongoing to explore TYRO3 as a potential therapeutic target. Inhibitors of TYRO3 are being investigated for their ability to modulate immune responses and as potential treatments for cancer.

Also see

• AXL
• MERTK
• Receptor Tyrosine Kinase
• Gas6
• Protein S