I787 provides signals for c-Kit receptor internalization and functionality that control mast cell survival and development.
Mast cell (MC) differentiation, survival, and activation are controlled by the membrane tyrosine kinase c-Kit upon interaction with stem cell factor (SCF). Here we describe a single point mutation induced by N-ethyl-N-nitrosurea (ENU) mutagenesis in C57BL/6J mice-an A to T transversion at position 2388 (exon 17) of the c-Kit gene, resulting in the isoleucine 787 substitution by phenylalanine (787F), and analyze the consequences of this mutation for ligand binding, signaling, and MC development. The Kit(787F/787F) mice carrying the single amino acid exchange of c-Kit lacks both mucosal and connective tissue-type MCs. In bone marrow-derived mast cells (BMMCs), the 787F mutation does not affect SCF binding and c-Kit receptor shedding, but strongly impairs SCF-induced cytokine production, degranulation enhancement, and apoptosis rescue. Interestingly, c-Kit downstream signaling in 787F BMMCs is normally initiated (Erk1/2 and p38 activation as well as c-Kit autophosphorylation) but fails to be sustained thereafter. In addition, 787F c-Kit does not efficiently mediate Cbl activation, leading to the absence of subsequent receptor ubiquitination and impaired c-Kit internalization. Thus, I787 provides nonredundant signals for c-Kit internalization and functionality.
Orinska
Zane
Z
Department of Immunology and Cell Biology, Research Center Borstel, Borstel, Germany. zorinska@fz-borstel.de
Föger
Niko
N
Huber
Michael
M
Marschall
Julia
J
Mirghomizadeh
Farhad
F
Du
Xin
X
Scheller
Marina
M
Rosenstiel
Philip
P
Goldmann
Torsten
T
Bollinger
Annalena
A
Beutler
Bruce A
BA
Bulfone-Paus
Silvia
S
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000494:pharmacology; D007532:Isoleucine / Q000737:chemistry; D008407:Mast Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D050721:Proto-Oncogene Proteins c-cbl / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D019089:Stem Cell Factor / Q000378:metabolism
D017931:DNA Primers; D007377:Interleukin-3; D050505:Mutant Proteins; D019089:Stem Cell Factor; D007532:Isoleucine; D050721:Proto-Oncogene Proteins c-cbl; D019009:Proto-Oncogene Proteins c-kit; C493849:Cbl protein, mouse