Figure 5.

NHS is essential for co-ordinated actin regulatory protein dynamics. (A) Knockdown of NHS results in lamellipod formation and consistent localization of Abi1, HSPC300 and Arp2/3 at the cell membrane in the absence of EGF. Endogenous Abi1, HSPC300 and Arp2/3 were localized in unstimulated and EGF-stimulated (3 min) MTLn3 cells after treatment with control or NHS siRNAs. Abi1, HSPC300, and the p34 subunit of Arp2/3 are in red, F-actin in green. Scale bar 10 µm. (B) Ectopic expression of NHS-1A inhibited the ability of cells to respond to EGF stimulation. Cell lamella area measurements for stimulated or unstimulated MTLn3 cells transfected with either control (NHS-C) or NHS-1A ±standard deviation. Cells transfected with NHS-1A containing the WHD fail to extend lamellipods compared with the NHS-C construct lacking the WHD (*P < 0.001). (C) NHS depletion in Caco-2 cells caused mislocalization of Arp2/3 (red) and Abi1 (red). Scale bar 10 µm.