Figure 2.—

High-copy suppressor analysis. High-copy plasmids encoding the nuclear transport factors, importin-β (pAC592), Cse1 (pAC1303), and Nup2 (pAC1385), were transformed into srp1-55, srp1-E402Q, and srp1-31 cells, which also contained a wild-type SRP1 URA3 plasmid (pAC876). As a control, each mutant was also transformed with vector alone (pRS424) or with wild-type SRP1 plasmid (pAC1354). Genetic suppression was assessed by serially diluting and spotting on control plates (where the wild-type SRP1 plasmid is retained) or on 5-FOA plates (where the wild-type SRP1 plasmid is lost). Plates were incubated at the indicated temperatures for 3–6 days. Suppression was scored as enhanced growth at the nonpermissive temperature as compared to the vector control.