Fig. 6.

Podosome formation in A7r5 cells requires CLASPs. (A–F) Cortactin immunostaining of vehicle-treated (A–C) and PDBu-treated (D–F) cells. Arrows, podosomes. Cells were transfected with non-targeted control siRNA (A,D), CLASP-specific siRNA combination 1 (CLsi1; B,E) or CLASP-specific siRNA combination 2 (CLsi2; C,F). Podosomes are formed in controls (D, arrows), but not in CLASP-depleted cells (E,F). Images were acquired by using wide-field fluorescence microscopy. (G–J) In cells treated with CLASP-specific siRNA combination 2, podosome formation in PDBu (I) is rescued by expression of siRNA2-insensitive RFP–CLASP2 (H,J). Cortactin immunostaining is shown in G,I. Arrows show podosomes. (K) Podosome numbers were quantified, based on data similar to that shown in A–J. Data show the mean+s.e.m. (N = 45±15); *P<1×10⁻⁵ (Student's unpaired two-tailed t-test).