FIGURE 4.

NPM-ALK phosphorylates NIPA at Ser-354 via p42/44 MAPK. A and B, FLAG-tagged NIPA and NPM-ALK or MG (MSCV-IRES-GFP) empty vector was cotransfected in HEK293T cells. 48 h after transfection, the medium was supplemented with different concentrations of MEK inhibitor PD98059 (A), MEK inhibitor U0126 (B), or Me₂SO for 12 h. Whole cell lysate extracts were prepared, and immunoblot (IB) analyses were subsequently performed using the indicated antibodies. C, KARPAS 299 cells were treated with 5 μm U0126 and harvested after 6 h. Whole cell lysate extracts were prepared, and immunoblot analyses were subsequently performed using the indicated antibodies. untr., untransfected.