Effect of Lyp and 3 variants on T cell signaling.
(A) Jurkat T cells were transfected with the His/Myc tagged full-length Lyp plasmids or mutated variants, and stimulated with medium or anti-CD3 (OKT3) antibody for 5 min. The level of full-length Lyp protein was detected by anti-Myc antibody. The phosphorylation of Lck394 and phosphorylation of ERK1/2 were monitored by immunoblotting with specific antibodies. Actin was detected as loading control. (B–C) Statistical analysis of Lck394 phosphorylation and ERK1/2 phosphorylation in Jurkat T cells overexpressed with Lyp wild type and variants. ** represents P<0.01 compared to the signals in control T cells stimulated with anti-CD3. ## represents P<0.01 compared to the stimulated signals in T cells overexpressed with wild-type Lyp.