Dynamin2 regulates the UPEC invasion of BECs. (A) Forced overexpression of wild-type (WT) dynamin2 significantly increases the type 1 fimbriated E. coli ORN103(pSH2) invasion of BECs after 1 h of incubation, whereas the forced overexpression of GTPase-deficient dominant-negative dynamin2 K44A significantly blocks the bacterial entry. Data are expressed relative to control empty vector (EV)–expressing cells. n = 5; *, P < 0.05 versus empty vector values. (B and C) Bacterial adherence (B) or bacterial invasion (C) after exposure of BECs stably expressing GFPshRNA or Dyn2shRNA to CFT073, UTI89, or UTI89ΔFimH. For CFT073, data are shown relative to GFPshRNA-expressing cells. For UTI89 and UTI89ΔFimH, data are shown relative to GFPshRNA-expressing cells that were incubated with UTI89. n = 3; *, P < 0.05 versus values from corresponding GFPshRNA-transfected samples. (D) Rescue of shRNA-mediated stable knockdown of endogenous dynamin2 expression with shRNA-resistant wild-type and K44A dynamin2. BECs stably expressing GFPshRNA or Dyn2shRNA were transfected with cDNAs encoding control empty vector or shRNA-resistant wild-type (Dyn2r) or K44A (Dyn2-K44Ar) dynamin2. Cell lysates were analyzed for expression of dynamin2 (top) and GAPDH (bottom) proteins. (E) Re-expression of wild-type, but not K44A, dynamin2 restores bacterial invasion. n = 3; *, P < 0.05 versus values obtained from GFPshRNA-expressing cells. Data in A–C and E represent means ± SEM.