Figure 5.

An acidic domain region of Mks1p contains the portable degron sequence. (A) Diagrammatic representation of constructs expressing various fragments of Mks1p. Numbers indicate the Mks1p residues expressed. Two dashed lines indicate a stretch of acidic amino acid-rich residues of Mks1p. (B) Residues 291-346 of Mks1p are required to confer Mks1p instability. The stability of various Mks1p constructs in rtg2Δ GRR1-1 cells was determined using the cycloheximide chase assay. (C) A diagrammatic representation of sequence conservation of Mks1p from eight fungal species. Five conserved sequence blocks, I-V, are indicated, with Block II shown in detail. AD indicates a conserved acidic amino acid-rich subdomain. Sce, S. cerevisiae; Spa, S. paradoxus; Smi, S. mikatae; Sba, S. bayanus; Cgl, Candida glabrata; Kla, Kluyveromyces lactis; Kwa, Kluyveromyces waltii; Ago; Ashbya gossypii. (D) Mks1p residues 287-346 confer Grr1p-dependent instability to GST. GST or GST-Mks1p (287-346) fusion protein expressed in cells as indicated were examined for stability.