A coiled-coil tetramerization domain of BCR-ABL is essential for the interactions of SH2-containing signal transduction molecules.
BCR-ABL is a chimeric oncoprotein that exhibits deregulated tyrosine kinase activity and is implicated in the pathogenesis of Philadelphia chromosome (Ph1)-positive leukemia. We have previously shown SH2-containing phosphotyrosine phosphatase SHP-2 forms stable complexes with BCR-ABL and Grb2 in BCR-ABL-transformed cells (Tauchi, T., Feng, G. S., Shen, R., Song, H. Y., Donner, D., Pawson, T., and Broxmeyer, H. E. (1994) J. Biol. Chem. 269, 15381-15387). To elucidate the structural requirement of BCR-ABL for the interactions with SH2-containing signaling molecules, we examined a series of BCR-ABL mutants which include the Grb2 binding site-deleted BCR-ABL (1-63 BCR/ABL), the tetramerization domain-deleted BCR-ABL (64-509 BCR/ABL), and the SH2 domain-deleted BCR-ABL (BCR/ABL deltaSH2). These BCR-ABL mutants were previously shown to reduce the transforming activity in fibroblasts. We found that the tetramerization domain-deleted BCR-ABL did not induce the tyrosine phosphorylation of SHP-2 and the interactions of BCR-ABL, SHP-2, and Grb2. In vitro kinase assays have also shown that the tetramerization domain-deleted BCR-ABL mutant did not phosphorylate GST-SHP-2 in vitro. SHP-2 was co-immunoprecipitated with phosphatidylinositol 3-kinase in BCR/ABL p210-transformed cells; however, this interaction was not observed in the tetramerization domain-deleted BCR-ABL mutant. Therefore the tetramerization domain of BCR-ABL is essential for interactions of these downstream molecules.
Tauchi
T
T
First Department of Internal Medicine, Tokyo Medical College, Japan.
Miyazawa
K
K
Feng
G S
GS
Broxmeyer
H E
HE
Toyama
K
K
D002460:Cell Line; D006801:Humans; D015513:Oncogene Proteins / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D011487:Protein Conformation; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D016315:Proto-Oncogene Proteins c-abl / Q000737:chemistry* / Q000378:metabolism; D051562:Proto-Oncogene Proteins c-bcr; D015398:Signal Transduction; D014162:Transfection; D018909:src Homology Domains
D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; D016315:Proto-Oncogene Proteins c-abl; C496613:BCR protein, human; D051562:Proto-Oncogene Proteins c-bcr