Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphorylation by the constitutively activated BCR-ABL tyrosine kinase is associated with the pathogenesis of the human chronic myelogenous leukemia (CML). It is difficult to characterize kinase response to stimuli or drug treatment because regulatory phosphorylation events are largely transient changes affecting low abundance proteins. Stable isotope labeling with amino acids in cell culture (SILAC) has emerged as a pivotal technology for quantitative proteomics. By metabolically labeling proteins with light or heavy tyrosine, we are able to quantify the change in phosphorylation of BCR-ABL kinase and its substrates in response to drug treatment in human CML cells. In this study, we observed that BCR-ABL kinase is phosphorylated at tyrosines 393 and 644, and that SH2-domain containing inositol phosphatase (SHIP)-2 and downstream of kinase (Dok)-2 are phosphorylated at tyrosine 1135 and 299, respectively. Based on the relative intensity of isotopic peptide pairs, we demonstrate that the level of phosphorylation of BCR-ABL kinase as well as SHIP-2 and Dok-2 is reduced approximately 90% upon treatment with Imatinib, a specific inhibitor of BCR-ABL kinase. Furthermore, proteins, such as SHIP-1, SH2-containing protein (SHC) and Casitas B-lineage lymphoma proto-oncogene (CBL), are also regulated by Imatinib. These results demonstrate the simplicity and utility of SILAC as a method to quantify dynamic changes in phosphorylation at specific sites in response to stimuli or drug treatment in cell culture.
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PMID:Quantification of change in phosphorylation of BCR-ABL kinase and its substrates in response to Imatinib treatment in human chronic myelogenous leukemia cells. 1685 28

Many patients with chronic myeloid leukemia in deep remission experience return of clinical disease after withdrawal of tyrosine kinase inhibitors (TKIs). This suggests signaling of inactive BCR-ABL, which allows the survival of cancer cells, and relapse. We show that TKI treatment inhibits catalytic activity of BCR-ABL, but does not dissolve BCR-ABL core signaling complex, consisting of CRKL, SHC1, GRB2, SOS1, cCBL, p85a-PI3K, STS1 and SHIP2. Peptide microarray and co-immunoprecipitation results demonstrate that CRKL binds to proline-rich regions located in C-terminal, intrinsically disordered region of BCR-ABL, that SHC1 requires pleckstrin homology, src homology and tyrosine kinase domains of BCR-ABL for binding, and that BCR-ABL sequence motif located in disordered region around phosphorylated tyrosine 177 mediates binding of three core complex members, i.e., GRB2, SOS1, and cCBL. Further, SHIP2 binds to the src homology and tyrosine kinase domains of BCR-ABL and its inositol phosphatase activity contributes to BCR-ABL-mediated phosphorylation of SHC1. Together, this study characterizes protein-protein interactions within the BCR-ABL core complex and determines the contribution of particular BCR-ABL domains to downstream signaling. Understanding the structure and dynamics of BCR-ABL interactome is critical for the development of drugs targeting integrity of the BCR-ABL core complex.
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PMID:Elucidation of protein interactions necessary for the maintenance of the BCR-ABL signaling complex. 3182 37