AP-TMT-MudPIT: TMT-AP-MS experiments using Flag DNAJB8 H31Q were performed as described previously . Briefly, six 10 cm plates of HEK293T cells were transfected by the calcium phosphate method with 5 μg of plasmid DNA encoding Flag DNAJB8 H31Q in the pFLAG backbone. Plates were treated with 1 mM of the indicated chloroacetanilide at 40-46 hours post transfection for 30 min in serum free media. Cells were harvested by scraping in DPBS. Cells were then lysed in 9 parts RIPA Buffer (150 mM NaCl, 50 mM Tris pH 7.5, 1% Triton X-100, 0.5% sodium deoxycholate, 0.1% SDS) and 1 part 10x PIC on ice for 30 min. Samples were centrifuged 21,000 x g for 15 min at 4 °C to separate lysate from cell debris. The Bradford assay was used to quantify protein in each lysate. Lysates were incubated with 15 μL Sepharose-4B beads for 30 min at 4 °C, then centrifuged at 1,500 x g for 1 min to pellet beads. Lysate was then separated and then incubated with 15 μL of M2 anti-Flag Magnetic Beads and rotated overnight at 4 °C. The anti-Flag beads were washed the next day four times with RIPA buffer. Each wash included rotation for 10 minutes at ambient temperature. Proteins bound to the anti-Flag beads were eluted by boiling for 5 min at 100 °C in 30 μL of Laemmli concentrate (120 mM Tris pH 6.8, 60% glycerol, 12% SDS, brilliant phenol blue to color). 5 μL of the elutes were saved for silver stain analysis and the remainder was prepped for mass spectrometry and TMT-labeled from a 6-plex TMT set.