Fig. 3. The C-domain of Sac3p contains a nuclear pore-targeting sequence. (A) Schematic of the Sac3p protein indicating the N-, M- and C-domain and their amino acid boundaries. (B) The C-domain of Sac3p mediates nuclear pore targeting. Fluorescence microscopy of full-length Sac3p and its different domains, all tagged with GFP and expressed in sac3Δ cells. (C) Individual Sac3p domains cannot rescue the growth defect of sac3Δ cells. Strain sac3Δ was transformed with the indicated plasmid constructs and cells were spotted in 10^–1 dilutions on selective plates and incubated for 3 days at 30°C. (D) Individual Sac3p domains cannot rescue the mRNA export defect of sac3Δ cells. Localization of poly(A)⁺ RNA was analyzed by oligo(dT) in situ hybridization. DNA was stained with DAPI.