Use of a temperature-sensitive mutant to define the biological effects of the p210BCR-ABL tyrosine kinase on proliferation of a factor-dependent murine myeloid cell line.

摘要: The Philadelphia chromosome, detected in virtually all cases of chronic myelogenous leukemia, is formed by a reciprocal translocation between chromosomes 9 and 22 that fuses BCR encoded sequences upstream exon 2 c-ABL. This oncogene produces fusion protein, p210BCR-ABL, which the ABL tyrosine kinase activity elevated. elevated essential for transformation, but mechanisms involved are unknown. To investigate p210BCR-ABL function we constructed model system was inducible. Two amino acid substitutions, Arg to His at 457 Tyr 469 c-abl, modeled on mutations known render v-src temperature-sensitive activity, were introduced into p210BCR-ABL. mutant characterized an IL-3 growth factor dependent murine myeloid cell line, 32Dc13. Cell lines expressing remained non-permissive temperature, permissive temperature displayed marked reduction death absence exaggerated proliferative response low levels IL-3. Both phosphorylated proteins increased temperature. Further, phosphorylation potential substrates kinase, p120 rasGAP its associated p190 p62, only occurs cells mutant.