Fig. 4: TMPRSS2-TcsH interaction is CROPs-dependent.
From: Paeniclostridium sordellii hemorrhagic toxin targets TMPRSS2 to induce colonic epithelial lesions
a The MCF-7 WT, GMDS‒/‒, TMPRSS2‒/‒, and GMDS‒/‒/TMPRSS2‒/‒ (DKO) cells showed similar sensitivities to TcsH1–1832, measured by the cell-rounding assay. b The pull-down assay showed that TcsH, but not TcsH1–1832, binds to Fc-TMPRSS2106-492/R255Q. TcsH1832–2816 is weakly pulled down by Fc-TMPRSS2106-492/R255Q. c BLI assays showed that TcsH1832–2618 (1 μM), but not TcdA1832–2252 (1 μM) or TcdA2245–2710 (1 μM), binds to Fc-TMPRSS2106-492/R255Q. d Ectopic expression of TMPRSS2 and TMPRSS2R255Q, but not others, enhanced the sensitivity of HeLa cells to TcsH. The HeLa cells were treated with 2 nM TcsH for 3 h. The percentages of round-shaped cells were quantified and plotted on the bar chart. Error bars represent mean ± s.d., n = 6. two-sided Student’s t-test. e Overexpression of a mouse Tmprss2 further sensitizes the MCF-7 GMDS‒/‒ and FUT4‒/‒ cells to TcsH (10 pM, 10 h). The scale bar represents 50 μm. f The percentages of round-shaped cells in e were quantified and plotted on the bar chart. g The MCF-7 DKO cells are more resistant than either the GMDS‒/‒ or TMPRSS2‒/‒ cells, assayed by cell-rounding count. h Confocal fluorescence images (overexposed) show that knocking-out TMPRSS2 in the GMDS‒/‒ cells would diminish the residue TcsH binding. The scale bar represents 20 μm. i Fc-TMPRSS2106-492/R255Q further protected the TMPRSS2‒/‒ cells from TcsH (100 pM), as showed by the cell-rounding assay over time. The percentage of round-shaped cells was quantified and plotted on the chart. Error bars represent mean ± s.d., n = 6.
