FIG. 2.

Stably expressed EBNA-LP is phosphorylated in BJAB cells. (A) Schematic representation of various deletion mutants of EBNA-LP. The levels of phosphorylation of the mutants are also shown. (B) Autoradiographic images of ³²P-radiolabeled EBNA-LP and its mutants stably expressed in BJAB cells. BJAB cells were stably transfected with the empty vector (lanes 1 and 6), pEBVHis-EBNA-LPR4(F) (lanes 2 and 7), pEBVHis-EBNA-LPR4d3(F) (lanes 3 and 8), pEBVHis-EBNA-LPR4d2(F) (lanes 4 and 9), or pEBVHis-EBNA-LPR4d1(F) (lanes 5 and 10) and selected in the presence of hygromycin B. Each stable transformant was labeled with [³²P]orthophosphate for 4 h and then harvested, solubilized, immunoprecipitated with anti-FLAG monoclonal antibody (M2) (lanes 1 to 5) or anti-His monoclonal antibody (D-8) (lanes 6 to 10), electrophoretically separated in a denaturing gel, and subjected to autoradiography.