GTP-locked versions of Cdc42p are present at low levels. Role of the WW domains of Rsp5p and the HSP40 Ydj1p in the degradation of Cdc42p. (A) Levels of GFP-Cdc42p (Cdc42, PC6454) and GFP-Cdc42p^G12V (G12V, PC7668) were examined in wild-type cells (PC538) grown in SD-URA for 6 h. Cdc42/Pgk1 ratio refers to relative levels of GFP-Cdc42p to Pgk1p. Anti-GFP and anti-Pgk1p antibodies were used. (B) GFP-Cdc42p (PC6454) levels were examined in wild-type cells (WT, PC5801), and in the rsp5-ww2 (PC5802) and the rsp5-ww3 (PC5803) mutants in the S288c background. See A for details. (C) Levels of GFP-Cdc42p (Cdc42, PC6454) and GFP-Cdc42p^Q61L (Q61L, PC7458) in wild-type cells (WT, PC5801) and in the rsp5-ww3 (PC5803) mutant. See A for details. (D) GFP-Cdc42p (PC6454) levels in wild-type cells (WT, PC986) and in the ydj1Δ mutant (PC7657) in the S288c background. See A for details. Source data are available for this figure: SourceData FS1.