Fig. 1. The signal-mediated import and passive diffusion of small substrates into the nucleus of control fibroblasts, and experimental cells treated with cycloheximide for 3 hours. (A) Fluorescent micrographs showing the intracellular distribution of FITC-BSA-NLS and FITC-BSA in control and experimental cells that were analyzed 1 and 60 minutes after cytoplasmic injection. (B) The nuclear uptake kinetics (N/C ratios) of 20 control and 23 experimental cells injected with FITC-BSA-NLS, 22 control and 28 experimental cells injected with FITC-BSA, 16 control and 22 experimental cells injected with FITC-ovalbumin, and 27 control cells injected with FITC-dextran. The data are presented as the means±s.e.m.
