Fig. 4. Expression of WASP-related proteins in HeLa cells and recruitment of N-WASP at phagocytic cups. (A) HeLa, WAVE2-knockdown (KD) and Abi1-knockdown cell lysates were subjected to western blotting with anti-WAVE1, anti-WAVE2 and anti-actin. WAVE1 is overexpressed in WAVE2-knockdown cells. WAVE1 and WAVE2 protein amounts are strongly reduced in Abi1-knockdown cells. (B) N-WASP is localized at phagocytic cups in HeLa cells. Cells were stained with anti-N-WASP antibodies, DAPI to detect bacteria, and phalloidin-488 (red, blue and green, respectively, in the merged images in the right-hand panels). a, a bacterium not associated with N-WASP; b, a bacterium associated with N-WASP and F-actin-rich phagocytic cups; c, a bacterium associated with N-WASP and no actin filaments. (C) NWASP-GFP is recruited at bacterial entry site (arrows). Bacteria are labelled with DAPI. Bar, 2 µm.