Role and Mechanism of the Interaction of BCR-ABL with E3 Ligase c-CBL in Targeting Therapy of Chronic Myelogenous Leukemia / 中国实验血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the interaction domains between BCR-ABL and E3 liagase c-CBL, so as to reveal the structure-basis for the arsenic to treat chronic myelogenous leukemia(CML).</p><p><b>METHODS</b>The interactional interface of BCR-ABL and c-CBL was simulated and analyzed according to the available structure model. Based on the structural information, the WT and mutant Migr1-BCR-ABL-GFP (&Delta;SH2,&Delta;TyrKC,&Delta;SH2/TyrKC (S/H) and pFlag-c-CBL (&Delta;RF) were constructed and co-transfected into the 293T and HeLa cells. The co-immunoprecipitation (Co-IP) was performed by using M2 beads (anti-Flag), anti-GFP antibody and protein A beads, and the interaction was identified by using GFP and M2 antibody, respectively. Moreover, the colocalization of BCR-ABL and c-CBL was further evaluated by using immunofluorescent(IF) assay in transfected HeLa cells.</p><p><b>RESULTS</b>Co-IP demonstrated that the TyrKC domain of BCR-ABL was primarily involved in the interaction with c-CBL, while both the SH2 domain of BCR-ABL and the RF domain of c-CBL also participated in the interaction to a certain degree, which were consistent with the structure-based simulation. IF elucidated that the colocalization of BCR-ABL and c-CBL was almost entirely vanished when the deleted TyrKC domain of BCR-ABL was co-transfected with c-CBL, which were elegantly coincident with the results from Co-IP.</p><p><b>CONCLUSION</b>The TyrKC domain of BCR-ABL is sufficient and necessary to mediate the interaction between BCR-ABL and c-CBL, the SH2 domain of BCR-ABL and the RF domain of c-CBL are also involved in the association between the two proteins. It suggests that the association of BCR-ABL and c-CBL can modulate the stability and degradation of BCR-ABL, thus illustrating the molecular mechanisms of the targeting therapy for CML by arsenic.</p>