Dfm1 specifically influences solubility of misfolded membrane proteins.

(A) Western blot of aggregated versus non-aggregated membrane proteins at the ER. Lysates from WT, hrd1Δ, or hrd1Δ+HRD1 cells containing HMG2-GFP were blotted using anti-GFP to detect Hmg2. T is total protein, P is pellet (ER aggregated) fraction, and S is soluble (ER non-aggregated) fraction. (B) Western blot of aggregated versus non-aggregated membrane proteins at the ER as in (A) except with dfm1Δ cells containing SEC61-GFP with add-back of EV, WT DFM1-HA, or DFM1-5Ashp-HA. Anti-GFP was used to detect SEC61-GFP. (C) Western blot of aggregated versus non-aggregated membrane proteins at the ER as in (A) except with dfm1Δ cells containing PDR5*-HA with add-back of WT DFM1-HA or EV. Anti-HA was used to detect PDR5*-HA. (D) Western blot of aggregated versus non-aggregated membrane proteins at the ER as in (A) except with dfm1Δ cells containing STE6*-GFP with add-back of WT DFM1-HA or EV. Anti-GFP was used to detect STE6*-GFP. (E) Western blot of aggregated versus non-aggregated membrane proteins at the ER as in (A) except with dfm1Δ cells containing CPY*-GFP with add-back of EV or WT DFM1-HA. Anti-GFP was used to detect CPY*-GFP. (F) Western blot of aggregated versus non-aggregated membrane proteins at the ER as in (A) except with dfm1Δ cells containing HMG2-GFP with add-back of EV, DERLIN-1-Myc, and DERLIN-2-Myc. Anti-Myc was used to detect DERLIN-1-Myc and DERLIN-2-Myc. Data information: All detergent solubility assays were performed with 3 biological replicates (N = 3). ER, endoplasmic reticulum; EV, empty vector.