Fig. 4
Active Lck kinase activity in Jurkat mitochondria. (a) Equal amount of proteins isolated from Jurkat and Jcam mitochondria were immunoprecipitated by anti-Lck (lanes 1 and 2) or control IgG (lane 3). Immunoprecipitates were blotted sequentially with antibodies specific for Tyr394-phosphorylated Lck (pLck) and total Lck (lanes 1-3). A small fraction of mitochondrial lysates were blotted for GAPDH, lamin B1 and VDAC1 to confirm fraction purity (lanes 4 and 5). Jcam whole cell lysate was included as a positive control for markers (lane 6). (b) Total proteins from mitochondrial fractions of Jurkat and Jcam cells were subjected to anti-phosphotyrosine immunoblotting (upper panel). Molecular weight markers are denoted on the right. VDAC1 immunoblot was used as a loading control (lower panel)