Fig. 1. A, schematic description of the p94fer and p51ferT proteins. Boxed c in p94fer, CC-forming region; SL, kinase domain small lobe; LL, kinase domain large lobe. Stippled box in p51ferT, the unique NH2-terminal sequences of the enzyme. B, subcellular distribution of the FER proteins in mouse primary fibroblasts. Subconfluent actively growing mouse primary fibroblasts were transiently transfected with HA-p94fer (a and b) or HA-p51ferT (c) expression vectors. Exogenously expressed proteins were detected with mouse monoclonal -HA antibody which were then reacted with FITC - conjugated donkey antimouse antibodies. d, antibody incubated with nontransfected cells. Photographs represent stacked confocal laser sections taken 1 µm apart. Scale bar, 20 µm.