Figure 6. Identification of PP6 as the Aurora A T-loop phosphatase. (A) HeLa cells were transfected with siRNA pools for 72 human phosphatase subunits for 54 h, treated for 18 h with nocodazole, and then lysed in the absence of phosphatase inhibitors for 2 h on ice. Control samples were lysed in the pres- ence or absence of phosphatase inhibitors (PP-Inh). Samples were Western blotted for total Aurora A and Aurora A pT288. The graph shows the ratio of 1322 JCB • VOLUME 191 • NUMBER 7 • 2010