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The c-Kit/D816V mutation eliminates the differences in signal transduction and biological responses between two isoforms of c-Kit.

Pedersen, Malin LU ; Rönnstrand, Lars LU and Sun, Jianmin LU (2009) In Cellular Signalling 21. p.413-418
Abstract
Activating mutations of codon 816 of the Kit gene have been implicated in malignant cell growth of acute myeloid leukemia (AML), systemic mastocytosis and germ cell tumors. Substitution of aspartic acid with valine (D816V) renders the receptor independent of ligand for activation and signaling. Wild-type c-Kit is a tyrosine kinase receptor that requires its ligand, stem cell factor (SCF), for activation. Several isoforms of c-Kit exist as a result of alternative mRNA splicing, of which two are characterized by the presence or absence of four amino acids (GNNK- and GNNK+, respectively) in the extracellular domain. The two isoforms show differences in signal transduction and biological activities and the shorter isoform seems to be highly... (More)
Activating mutations of codon 816 of the Kit gene have been implicated in malignant cell growth of acute myeloid leukemia (AML), systemic mastocytosis and germ cell tumors. Substitution of aspartic acid with valine (D816V) renders the receptor independent of ligand for activation and signaling. Wild-type c-Kit is a tyrosine kinase receptor that requires its ligand, stem cell factor (SCF), for activation. Several isoforms of c-Kit exist as a result of alternative mRNA splicing, of which two are characterized by the presence or absence of four amino acids (GNNK- and GNNK+, respectively) in the extracellular domain. The two isoforms show differences in signal transduction and biological activities and the shorter isoform seems to be highly expressed than the longer isoform in human malignancies. In this study we analysed the signal transduction downstream of the oncogenic c-Kit mutant D816V in an isoform specific context, using the hematopoietic cell line Ba/F3 stably transfected with the different versions of isoform and mutant receptor. Our data show that in contrast to the differences shown in the activation of wild-type c-Kit isoforms, both isoforms of c-Kit/D816V are constitutively phosphorylated to the same extent. By the use of Western blot analysis we investigated the activation of different signaling proteins and found that both D816V/GNNK- and D816V/GNNK+ constitutively phosphorylated Gab2, Shc, SHP-2 and Cbl to almost the same extent as c-Kit/GNNK-. In addition, both isoforms of c-Kit/D816V induced SCF-independent cell survival and proliferation equally well. This is in contrast to wild-type c-Kit, where c-Kit/GNNK- induced better cell survival and stronger proliferation than c-Kit/GNNK+, and both required stimulation with SCF. Taken together, these findings reveal that the differences in downstream signal transduction and biological responses between the two GNNK isoforms are eliminated by the D816V mutant. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Cellular Signalling
volume
21
pages
413 - 418
publisher
Elsevier
external identifiers
  • wos:000263584500006
  • pmid:19049823
  • scopus:58249134128
ISSN
1873-3913
DOI
10.1016/j.cellsig.2008.11.008
language
English
LU publication?
yes
id
5cc200d0-dbb8-4164-bdb8-c1f539038512 (old id 1276567)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/19049823?dopt=Abstract
date added to LUP
2009-01-09 08:21:03
date last changed
2017-01-01 07:32:02
@article{5cc200d0-dbb8-4164-bdb8-c1f539038512,
  abstract     = {Activating mutations of codon 816 of the Kit gene have been implicated in malignant cell growth of acute myeloid leukemia (AML), systemic mastocytosis and germ cell tumors. Substitution of aspartic acid with valine (D816V) renders the receptor independent of ligand for activation and signaling. Wild-type c-Kit is a tyrosine kinase receptor that requires its ligand, stem cell factor (SCF), for activation. Several isoforms of c-Kit exist as a result of alternative mRNA splicing, of which two are characterized by the presence or absence of four amino acids (GNNK- and GNNK+, respectively) in the extracellular domain. The two isoforms show differences in signal transduction and biological activities and the shorter isoform seems to be highly expressed than the longer isoform in human malignancies. In this study we analysed the signal transduction downstream of the oncogenic c-Kit mutant D816V in an isoform specific context, using the hematopoietic cell line Ba/F3 stably transfected with the different versions of isoform and mutant receptor. Our data show that in contrast to the differences shown in the activation of wild-type c-Kit isoforms, both isoforms of c-Kit/D816V are constitutively phosphorylated to the same extent. By the use of Western blot analysis we investigated the activation of different signaling proteins and found that both D816V/GNNK- and D816V/GNNK+ constitutively phosphorylated Gab2, Shc, SHP-2 and Cbl to almost the same extent as c-Kit/GNNK-. In addition, both isoforms of c-Kit/D816V induced SCF-independent cell survival and proliferation equally well. This is in contrast to wild-type c-Kit, where c-Kit/GNNK- induced better cell survival and stronger proliferation than c-Kit/GNNK+, and both required stimulation with SCF. Taken together, these findings reveal that the differences in downstream signal transduction and biological responses between the two GNNK isoforms are eliminated by the D816V mutant.},
  author       = {Pedersen, Malin and Rönnstrand, Lars and Sun, Jianmin},
  issn         = {1873-3913},
  language     = {eng},
  pages        = {413--418},
  publisher    = {Elsevier},
  series       = {Cellular Signalling},
  title        = {The c-Kit/D816V mutation eliminates the differences in signal transduction and biological responses between two isoforms of c-Kit.},
  url          = {http://dx.doi.org/10.1016/j.cellsig.2008.11.008},
  volume       = {21},
  year         = {2009},
}