FIG. 2.

Both TPR domains of Sti1 are important for prion curing by overexpressed Hsp104. (A) Domain structure of Sti1 and mutants used in this study. Numbers above the diagram indicate the amino acid residue position; asterisks indicate the locations of point mutations indicated on the left. Deleted regions are indicated with horizontal lines. DP, aspartate-proline region. (B) Rates of prion curing were determined in cultures overexpressing Hsp104 for four or five generations. Strains to the right of the wild type (wt; carries empty vector) are sti1Δ with an empty vector or a vector encoding the indicated Sti1 protein. Values are averages of the results for three independent experiments ± standard deviation. (C) Western analysis of abundance of proteins indicated on the left in cells from experiments shown in panel B that were grown for four generations. All strains were exposed to copper and carry either an empty vector (−) or pMR26 for expression of Hsp104 (+), as indicated above each lane. Lower panel (load) is a portion of the blotted membrane stained by amido black as a loading and transfer control.