N-WASP involvement in dorsal ruffle formation in mouse embryonic fibroblasts.

The Wiskott-Aldrich syndrome protein (WASP) family activates the Arp2/3 complex leading to the formation of new actin filaments. Here, we study the involvement of Scar1, Scar2, N-WASP, and Arp2/3 complex in dorsal ruffle formation in mouse embryonic fibroblasts (MEFs). Using platelet-derived growth factor to stimulate circular dorsal ruffle assembly in primary E13 and immortalized E9 Scar1(+/+) and Scar1 null MEFs, we establish that Scar1 loss does not impair the formation of dorsal ruffles.

Epstein-Barr virus latent membrane protein 1 (LMP1) activates the phosphatidylinositol 3-kinase/Akt pathway to promote cell survival and induce actin filament remodeling.

The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) is an integral membrane protein that functions as a constitutively activated member of the tumor necrosis factor receptor family. Whereas LMP1 has been shown to activate the NF-kappaB and mitogen-activated protein kinase pathways, these effects alone are unable to account for the profound oncogenic properties of LMP1. Here we show that LMP1 can activate phosphatidylinositol 3-kinase (PI3K), a lipid kinase responsible for activating a diverse range of cellular processes in response to extracellular stimuli.