FIG. 8.

Tus1p participates in Avo2p- and Slm1p-mediated, but not Avo1p-mediated, suppression of avo3^ts phenotypes. Three known Rho1p GEF genes, ROM1, ROM2, and TUS1, were individually deleted in avo3^ts mutants. The resulting strains were transformed by allele-specific multicopy suppressors. Transformants were subjected to spot assays for growth to test the effects of GEF deletion on suppression. (A) Rho1p-GEF deletions have no effect on AVO1-mediated suppression of the avo3-1^ts phenotype. Plasmid pRS424 (Vector), pTSS1 (AVO3), or pHS2 (AVO1) was transformed into YMY99 (avo3-1^ts), YMY212 (avo3-1^ts rom1Δ), YMY213 (avo3-1^ts rom2Δ), or YMY214 (avo3-1^ts tus1Δ). The resulting transformants were tested for growth at different temperatures. (B) Deletion of TUS1, but not ROM1 or ROM2, reduces AVO2- and SLM1-mediated suppression of the avo3-2^ts phenotype. Plasmid pRS424 (Vector), pTSS1 (AVO3), pHS5 (AVO2), or pHS6 (SLM1) was transformed into YMY100 (avo3-2^ts), YMY312 (avo3-2^ts rom1Δ), YMY313 (avo3-2^ts rom2Δ), or YMY314 (avo3-2^ts tus1Δ). Transformants were tested for growth at different temperatures.