Tyrosine-protein kinase that acts as cell-surface receptor for the cytokine kitlg/scf and plays a role in the regulation of cell survival and proliferation, hematopoiesis, stem cell maintenance, gametogenesis, and in mast cell development, migration and function. Required for the migration of cells in the melanocyte lineage and the survival of embryonic melanocytes. Required for the differentiation of some, but not all, melanocytes. Not essential for hematopoiesis or primordial germ cell development. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Expressed in cells of the neural crest-melanocyte lineage. In the embryo, also expressed in mesodermal cells that give rise to hematopoietic precursors, notochord, neural crest-derived cells of the branchial arches, pineal gland, retina and mechanoreceptive sensory cells of lateral line neuromasts. Not detected in primordial germ cells or larval gut. Ubiquitinated. Rapidly ubiquitinated after autophosphorylation induced by kitlg/scf binding, leading to internalization and degradation. Autophosphorylated on tyrosine residues. Phosphorylated tyrosine residues are important for interaction with specific binding partners (By similarity). Defects in the number and distribution of melanocytes. Belongs to the protein kinase superfamily. Tyr protein kinase family. CSF-1/PDGF receptor subfamily.