Growth arrest – specific 6, also known as GAS6, is a human gene coding for the GAS6 protein. It is similar to the Protein S with the same domain organization and 43% amino acid identity. It was originally found as a gene upregulated by growth arrested fibroblasts.
Gas6 is a gamma-carboxyglutamic acid (Gla) domain-containing protein thought to be involved in the stimulation of cell proliferation.[5]
Gas6 has been shown to interact with AXL receptor tyrosine kinase, MerTK and TYRO3.[6][7]
The presence of Gla needs a vitamin K-dependent enzymatic reaction that carboxylates the gamma carbon of certain glutamic residues of the protein during its production in the endoplasmic reticulum. The action of vitamin K is essential on GAS6 function.[8]