Charting the molecular network of the drug target Bcr-Abl.
The tyrosine kinase Bcr-Abl causes chronic myeloid leukemia and is the cognate target of tyrosine kinase inhibitors like imatinib. We have charted the protein-protein interaction network of Bcr-Abl by a 2-pronged approach. Using a monoclonal antibody we have first purified endogenous Bcr-Abl protein complexes from the CML K562 cell line and characterized the set of most tightly-associated interactors by MS. Nine interactors were subsequently subjected to tandem affinity purifications/MS analysis to obtain a molecular interaction network of some hundred cellular proteins. The resulting network revealed a high degree of interconnection of 7 "core" components around Bcr-Abl (Grb2, Shc1, Crk-I, c-Cbl, p85, Sts-1, and SHIP-2), and their links to different signaling pathways. Quantitative proteomics analysis showed that tyrosine kinase inhibitors lead to a disruption of this network. Certain components still appear to interact with Bcr-Abl in a phosphotyrosine-independent manner. We propose that Bcr-Abl and other drug targets, rather than being considered as single polypeptides, can be considered as complex protein assemblies that remodel upon drug action.
Brehme
Marc
M
Research Center for Molecular Medicine, Austrian Academy of Sciences, Lazarettgasse 19, 1090 Vienna, Austria.
Hantschel
Oliver
O
Colinge
Jacques
J
Kaupe
Ines
I
Planyavsky
Melanie
M
Köcher
Thomas
T
Mechtler
Karl
K
Bennett
Keiryn L
KL
Superti-Furga
Giulio
G
D002460:Cell Line; D016044:Fusion Proteins, bcr-abl / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D006801:Humans; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D025941:Protein Interaction Mapping; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D040901:Proteomics
D009097:Multienzyme Complexes; D047428:Protein Kinase Inhibitors; D016044:Fusion Proteins, bcr-abl