Fig. 4
From: Phosphoinositides: multipurpose cellular lipids with emerging roles in cell death
Regulation of actin remodelling by phosphoinositides PI(3,4,5)P2, synthesised from PI(4,5)P2 upon receptor-mediated stimulation of PI3K via Ras GTPase, recruits GEFs to plasma membrane. GEFs then facilitate GTP loading on Rho family GTPases Cdc42 and Rac, leading to activation of actin nucleators WASPs and, subsequently, Arp2/3 complex. PI(4,5)P2 directly binds to and activates protein mediating membrane-cytoskeleton interaction (e.g. ERM proteins) or inhibits actin depolymerising factor ADF/cofilin, capping proteins (e.g. CapZ) and severing proteins (e.g. gelsolin). PI3K phosphoinositide 3-kinases, Ras Rat sarcoma GTPase, Cdc42 cell division control protein 42 homologue, Rac Ras-related C3 botulinum toxin substrate, GEF guanine nucleotide exchange factor, WASP Wiskott-Aldrich syndrome protein, Arp2/3 actin-related proteins 2/3 complex, ERM erzin, radixin and moesin, ADF actin depolymerising factor
