The D816V mutation of c-Kit circumvents a requirement for Src family kinases in c-Kit signal transduction.
Författare
Summary, in English
The receptor tyrosine kinase c-Kit plays a critical role in hematopoiesis and gain-of-function mutations of the receptor are frequently seen in several malignancies, including acute myeloid leukemia (AML), gastrointestinal stromal tumors and testicular carcinoma. The most common mutation of c-Kit in these disorders is a substitution of the aspartic acid residue in position 816 to a valine (D816V), leading to constitutive activation of the receptor. In this study we aimed to investigate the role of Src family kinases in c-Kit/D816V signaling. Src family kinases are necessary for the phosphorylation of wild-type c-Kit as well as of activation of downstream signaling pathways including receptor ubiquitination and the Ras/Mek/Erk pathway. Our data demonstrate that, unlike wild-type c-Kit, the phosphorylation of c-Kit/D816V is not dependent on Src family kinases. In addition we found that neither receptor ubiquitination nor Erk activation by c-Kit/D816V required activation of Src family kinases. In vitro kinase assay using synthetic peptides revealed that c-Kit/D816V had an altered substrate specificity resembling Src and Abl tyrosine kinases. We further present evidence that, in contrast to wild-type c-Kit, Src family kinases are dispensable for c-Kit/D816V cell survival, proliferation and colony formation. Taken together, we demonstrate that the signal transduction pathways mediated by c-Kit/D816V are markedly different from those activated by wild-type c-Kit and that altered substrate specificity of c-Kit circumvents a need for Src family kinases in signaling of growth and survival, thereby contributing to the transforming potential of c-Kit/D816V.
Avdelning/ar
Publiceringsår
2009
Språk
Engelska
Sidor
11039-11047
Publikation/Tidskrift/Serie
Journal of Biological Chemistry
Volym
284
Issue
17
Fulltext
Dokumenttyp
Artikel i tidskrift
Förlag
American Society for Biochemistry and Molecular Biology
Ämne
- Medicinal Chemistry
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1083-351X