Signalling and functional diversity within the Axl subfamily of receptor tyrosine kinases.
The related Axl, Sky and Mer receptor tyrosine kinases (RTKs) are increasingly being implicated in a host of discrete cellular responses including cell survival, proliferation, migration and phagocytosis. Furthermore, their ligands Gas6 and protein S are characteristically dependent on vitamin K for expression of their functions. The Gas6/Axl system is implicated in several types of human cancer as well as inflammatory, autoimmune, vascular and kidney diseases. Each member of the Axl RTK subfamily possesses distinct expression profiles as well as discrete functions. In this article, we review the knowledge so far on the intracellular signalling interactions and pathways concerning each of the Axl RTKs. In this way, we hope to gain a greater understanding of the mechanisms that set each of them apart, and that relay their associated functions.
Hafizi
Sassan
S
Department of Clinical Chemistry, Lund University, Wallenberg Laboratory, University Hospital Malmö, SE-205 02 Malmö, Sweden. sassan.hafizi@med.lu.se
Dahlbäck
Björn
B
D000818:Animals; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D051379:Mice; D015513:Oncogene Proteins / Q000145:classification / Q000378:metabolism / Q000502:physiology*; D017293:Protein S / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000502:physiology; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000145:classification / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D000076202:c-Mer Tyrosine Kinase; D000094963:Axl Receptor Tyrosine Kinase; D000099255:Growth Arrest-Specific Protein 6
D036341:Intercellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D017293:Protein S; D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases; D000076202:c-Mer Tyrosine Kinase; D000094963:Axl Receptor Tyrosine Kinase; D000099255:Growth Arrest-Specific Protein 6; C097072:MERTK protein, human