Stx2b

We have previously described the GFP-SNX1 and GFP-Rab5 plasmids used in this study [16 (link)]. Monoclonal anti-GM130 (#610822) was from BD Biosciences (San Jose, CA, USA). Tamoxifen (TAM) was purchased from Sigma-Aldrich (St. Louis, MO, USA). Derivative compounds were synthesized at the Center for Innovative Drug Discovery (University of Texas at San Antonio, San Antonio, TX, USA; see Supplementary Materials). All compounds were dissolved in DMSO and used at 10 µM final concentration unless specified otherwise.
STx2 holotoxin and STx2B were obtained from BEI Resources (Manassas, VA, USA). For transport assays, STx2B was labeled using Alexa Fluor™ 555 Microscale Protein Labeling Kit using manufacturer’s instructions (ThermoFischer, Waltham, MA, USA).

TAM, TOR, RAL, BAZ, 4HOT, END, OSP, BFA1, and CLQ were purchased from Sigma-Aldrich. TAM was used at 10 μM unless specified otherwise. TOR, RAL, BAZ, 4HOT, END, and OSP were all used at 10 μM. BFA1 was used at 100 nM, and CLQ was used at 50 μM. DMSO was added at 0.1% when used as a vehicle control. Leupeptin and pepstatin were used at final concentrations of 100 and 50 μg/ml, respectively, as described by us previously (8 (link), 9 (link)). Compounds were present in the media during transport assays performed using STx1B or STx2B and during exposure to STx1 or STx2 holotoxins, which were obtained from BEI Resources. Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reagent, as described by us recently (9 (link)).