The proto-oncogene product p120CBL and the adaptor proteins CRKL and c-CRK link c-ABL, p190BCR/ABL and p210BCR/ABL to the phosphatidylinositol-3' kinase pathway

Oncogene. 1996 Feb 15;12(4):839-46.


Chronic myelogenous leukemia (CML) and some acute lymphoblastic leukemias (ALL) are caused by the t(9;22) chromosome translocation, which produces the constitutively activated BCR/ABL tyrosine kinase. When introduced into factor dependent hematopoietic cell lines, BCR/ABL induces the tyrosine phosphorylation of many cellular proteins. One prominent BCR/ABL substrate is p120CBL, the cellular homolog of the v-Cbl oncoprotein. In an effort to understand the possible contribution of p120CBL to transformation by BCR/ABL, we looked for cellular proteins which associate with p120CBL in hematopoietic cell lines transformed by BCR/ABL. In addition to p210BCR/ABL and c-ABL, p120CBL coprecipitated with an 85 kDa phosphoprotein, which was identified as the p85 subunit of PI3K. Anti-p120CBL immunoprecipitates from BCR/ABL-transformed, but not from untransformed, cell lines contained PI3K lipid kinase activity. Interestingly, the adaptor proteins CRKL and c-CRK were also found in these complexes. In vitro binding studies indicated that the SH2 domains of CRKL and c-CRK bound directly to p120CBL, while the SH3 domains of c-CRK and CRKL bound to BCR/ABL and c-ABL. The N-terminal and the C-terminal SH2 and the SH3 domain of p85PI3K bound directly in vitro to p120CBL. The ABL-SH2, but not ABL-SH3, could also bind to p120CBL. These data suggest that BCR/ABL may induce the formation of multimeric complexes of signaling proteins which include p120CBL, PI3K, c-CRK or CRKL, c-ABL and BCR/ABL itself.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Antibodies, Monoclonal
  • Blotting, Western
  • Cell Line
  • Cell Line, Transformed
  • Chromosomes, Human, Pair 21
  • Chromosomes, Human, Pair 9
  • Fusion Proteins, bcr-abl / metabolism*
  • Humans
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics
  • Lymphocytes
  • Nuclear Proteins / metabolism*
  • Phosphatidylinositol 3-Kinases
  • Phosphoproteins / metabolism
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics
  • Protein Binding
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-abl / metabolism*
  • Proto-Oncogene Proteins c-cbl
  • Proto-Oncogene Proteins c-crk
  • Translocation, Genetic
  • Ubiquitin-Protein Ligases*


  • Adaptor Proteins, Signal Transducing
  • Antibodies, Monoclonal
  • CRKL protein
  • Nuclear Proteins
  • Phosphoproteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-crk
  • Proto-Oncogene Proteins c-cbl
  • Ubiquitin-Protein Ligases
  • Phosphatidylinositol 3-Kinases
  • Phosphotransferases (Alcohol Group Acceptor)
  • Protein-Tyrosine Kinases
  • Fusion Proteins, bcr-abl
  • Proto-Oncogene Proteins c-abl
  • CBL protein, human