Fig. 3.

Sis1 binding to a conserved chaperone-binding motif in the non-prion-forming domain of Rnq1. (a) A schematic showing the domain structure of Rnq1. The underlined region in the nonprion domain of Rnq1 represents a chaperone-binding motif identified via screening a cellulose peptide array (see Fig. S2). (b) Sis1-dependent binding of Hsp70 Ssa1 to the peptide in the Rnq1 peptide array that is bound most strongly by Sis1. (c) Mutation L94A in the chaperone-binding motif reduces the ability of Sis1 to form coimmunoprecipitable complexes with Rnq1-GFP in [RNQ⁺] cells. Rnq1-GFP was expressed by using the CUP1 promoter. Levels of the indicated proteins in c were visualized by Western blot (WB) analysis.