FIGURE 7.

Model illustrating the proposed mechanism of Bcr-Abl destabilization in response to inhibition of PTP1B. Expression of Bcr-Abl protein can be altered by inhibition of PTP1B. In the presence of PTP1B (top panel), Bcr-Abl associates with PTP1B, which provides stability to Bcr-Abl. The treatment with PTP1B inhibitor (bottom panel) elicits tyrosine phosphorylation (P) of critical residues of Bcr-Abl, and this acts as a trigger for Bcr-Abl to be ubiquitinated and degraded in the lysosome. Ub, ubiquitin.