SCF-KIT signaling induces endothelin-3 synthesis and secretion: Thereby activates and regulates endothelin-B-receptor for generating temporally- and spatially-precise nitric oxide to modulate SCF- and or KIT-expressing cell functions
Fig 2
Autophosphorylation, internalization, and nuclear localization of activated KIT with tyrosine phosphorylation at 568/570 (pY568/pY570KIT).
(A), IHC of frozen sections of an aggressive GIST (a-c) and a normal human adult testis as external control (d-f) using pan-KIT antibody (a and d), pY568/pY570KIT antibody (b and e, red arrow indicates nuclear localization), and pY703KIT antibody (c and f) respectively. (B), In situ IHC to assess kinetics of SCF-induced nuclear translocation of pY568/pY570KIT using WM793 melanoma cells cultured in 4-well chamber tissue culture treated glass slides. Control (g) without SCF stimulation, after addition of SCF to culture media, the nuclear localization of pY568/pY570KIT increases progressively (h-j) in more than 90% of WM793 cells, reaches a plateau about 40–60 minutes (i and j), begins to decrease at 90 minutes (k), and is completely absent in nucleus with relocation back to the cytoplasm at 4 hours, some residual cytoplasmic staining remains visible (l).