The EphA4 JM domain is required for preventing LCL proliferation. (A) Flag-tagged EphA4 WT, KD (kinase dead with V653M), and 2M (JM region mutant with 2 tyrosine auto-phosphorylation sites Y569F and Y602F) expression plasmids for lentivirus packaging were illustrated. (B-C) LCLs from 2 donors were infected with EphA4 WT, mutants, or vector control-expressing lentiviruses for 2 days and then reseeded at 1 × 104 cells per well in 96-well plates for 5 days. Cell proliferation assays were measured by AlamarBlue reduction. Relative folds of proliferation were standardized with vector controls (*P < .05; **P < .01, Student t test). Total proteins were obtained from primary B cells and LCLs expressing WT and mutant forms of EphA4 at day 5 postreseeding. EphA4, LMP1, and β-actin expression levels were detected by western blotting (right panel). β-actin served as an internal control. ns, no significance.
