Figure 2.

Localization of Npl3p in transport mutants. (A) Each temperature-sensitive mutant was incubated at 23°C, at 37°C, or at 37°C with 20 μg/ml thiolutin for 1 hr, fixed and immunostained to localize Npl3p. To evaluate the contribution of newly synthesized Npl3p to the cytoplasmic signal detected at 37°C, we have also conducted these incubations ±100 μg/ml cycloheximide. In no case does cycloheximide reduce the cytoplasmic signal. (B) Graphical summary of data from experiments comparable to those illustrated in A. Each set of three columns indicates the percentage of cells that show a cytosolic Npl3p signal and no obvious nuclear signal. (C) Summary of groupings of mutants with regard to the distribution of Npl3p. (D) Influence of cse1 on the distribution of Srp1p and Npl3p. cse1 was incubated 3 hr at 37°C with inclusion of thiolutin for the final hour. Npl3p and Srp1p are concentrated in the same nuclei.