☆ 4.7 Article

Transformation by oncogenic mutants and ligand-dependent activation of FLT3 wild-type requires the tyrosine residues 589 and 591

CLINICAL CANCER RESEARCH (2008)

Journal

CLINICAL CANCER RESEARCH

Volume 14, Issue 14, Pages 4437-4445

Publisher

AMER ASSOC CANCER RESEARCH

DOI: 10.1158/1078-0432.CCR-07-1873

Keywords

Ask authors/readers for more resources

Protocol

Community support

Reagent

Community support

Abstract

Purpose: Mutations in the receptor tyrosine kinase FLT3 are found in up to 30% of acute myelogenous leukemia patients and are associated with an inferior prognosis. In this study, we characterized critical tyrosine residues responsible for the transforming potential of active FLT3-receptor mutants and ligand-dependent activation of FLT3-WT. Experimental Design: We performed a detailed structure-function analysis of putative autophosphorylation tyrosine residues in the FLT3-D835Y tyrosine kinase domain (TKD) mutant. All tyrosine residues in the juxtamembrane domain (Y566, Y572, Y589, Y591, Y597, and Y599), interkinase domain (Y726 and Y768), and COOH-terminal domain (Y955 and Y969) of the FLT3-D835Y construct were successively mutated to phenylalanine and the transforming activity of these mutants was analyzed in interleukin-3-dependent Ba/F3 cells. Tyrosine residues critical for the transforming potential of FLT3-D835Y were also analyzed in FLT3 internal tandem duplication mutants (FLT3-ITD)and the FLT3 wild-type (FLT3-WT) receptor. Result: The substitution of the tyrosine residues by phenylalanine in the juxtamembrane, interkinase, and COOH-terminal domains resulted in a complete loss of the transforming potential of FLT3-D835Y-expressing cells which can be attributed to a significant reduction of signal tranducer and activator of transcription 5 (STAT5) phosphorylation at the molecular level. Reintroduction of single tyrosine residues revealed the critical role of Y589 and Y591 in reconstituting interleukin-3-independent growth of FLT3-TKD-expressing cells. Combined mutation of Y589 and Y591 to phenylalanine also abrogated ligand-dependent proliferation of FLT3-WT and the transforming potential of FLT3-ITD-with a subsequent abrogation of STAT5 phosphorylation. Conclusion: We identified two tyrosine residues,Y589 and Y591, in the juxtamembrane domain that are critical for the ligand-dependent activation of FLT3-WT and the transforming potential of oncogenic FLT3 mutants.

Authors

I am an author on this paper

Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7

Not enough ratings

Secondary Ratings

Novelty

Significance

Scientific rigor

Rate this paper

Cryo-EM analyses of KIT and oncogenic mutants reveal structural oncogenic plasticity and a target for therapeutic intervention

Stefan G. Krimmer, Nicole Bertoletti, Yoshihisa Suzuki, Luka Katic, Jyotidarsini Mohanty, Sheng Shu, Sangwon Lee, Irit Lax, Wei Mi, Joseph Schlessinger

Summary: The development of various cells, including hematopoietic stem cells and germ cells, relies on the receptor tyrosine kinase KIT and its ligand stem cell factor (SCF). Somatic mutations in KIT lead to several types of human cancers. Cryo electron microscopy analysis reveals that oncogenic KIT mutants exhibit distinct structural arrangements compared to wild-type KIT. The D5 region of KIT is identified as a potential target for therapeutic intervention.

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA (2023)