title: Tumor necrosis factor-alpha-converting enzyme controls surface expression of c-Kit and survival of embryonic stem cell-derived mast cells.
abstract: Transmembrane metalloproteinases of the disintegrin and metalloproteinase (ADAM) family control cell signaling interactions via hydrolysis of protein extracellular domains. Prior work has shown that the receptor tyrosine kinase, c-Kit (CD117), is essential for mast cell survival and that serum levels of c-Kit increase in proliferative mast cell disorders, suggesting the existence of c-Kit shedding pathways in mast cells. In the present work, we report that tumor necrosis factor alpha-converting enzyme (TACE; ADAM-17) mediates shedding of c-Kit. Stimulation of transfected cells with phorbol 12-myristate 13-acetate (PMA) induced metalloproteinase-mediated release of c-Kit ectodomain, which increased further upon TACE overexpression. By contrast, TACE-deficient fibroblasts did not demonstrate inducible release, thus identifying TACE as the metalloproteinase primarily responsible for PMA-induced c-Kit shedding. Surface expression of c-Kit by the human mast cell-1 line decreased upon phorbol-induced shedding, which involved metalloproteinase activity susceptible to inhibition by tissue inhibitor of metalloproteinase (TIMP)-3. To further explore the role of TACE in shedding of c-Kit from mast cells, we compared the behavior of mast cells derived from murine embryonic stem cells. In these studies, PMA decreased surface c-Kit levels on mast cells expressing wild-type (+/+) TACE but not on those expressing an inactive mutant (DeltaZn/DeltaZn), confirming the role of TACE in PMA-induced c-Kit shedding. Compared with TACE(+/+) cells, TACE(DeltaZn/DeltaZn) mast cells also demonstrated decreased constitutive shedding and increased basal surface expression of c-Kit, with diminished apoptosis in response to c-Kit ligand deprivation. These data suggest that TACE controls mast cell survival by regulating shedding and surface expression of c-Kit.
authors: Cardiovascular Research Institute, University of California, San Francisco, California 94143, USA.
authors: Anthony C
authors: AC
authors: Cruz
authors: Brendon T
authors: BT
authors: Frank
authors: Samuel T
authors: ST
authors: Edwards
authors: Paul F
authors: PF
authors: Dazin
authors: Jacques J
authors: JJ
authors: Peschon
authors: Kenneth C
authors: KC
authors: Fang
mesh_terms: D051722:ADAM Proteins; D000072198:ADAM17 Protein; D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D002469:Cell Separation; D002470:Cell Survival; D003593:Cytoplasm / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000166:cytology*; D005347:Fibroblasts / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D015151:Immunoblotting; D008024:Ligands; D008407:Mast Cells / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D016297:Mutagenesis, Site-Directed; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis / Q000378:metabolism*; D019089:Stem Cell Factor / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism*; D014162:Transfection
chemical_list: D003902:Detergents; D008024:Ligands; D019089:Stem Cell Factor; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D019009:Proto-Oncogene Proteins c-kit; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; C000606463:Adam17 protein, mouse