Fig. 9
From: Spatial oxidation of L-plastin downmodulates actin-based functions of tumor cells
Proposed models: a the redox regulation of the actin-bundling function of LPL and b–d the regulation of peripheral actin dynamics by spatial oxidation of LPL. a LPL bundles F-actin by sequential binding of ABD1 and ABD2 to adjacent actin filaments. The regulatory helix (RH) domain folds onto ABD2. H2O2 treatment leads to disulfide bridge formation between Cys101 (located at the RH) and Cys42 (located at the EF-hand module), thereby leading to dissociation of ABD2 or less efficient binding of ABD2 to F-actin. Red colored flags show the location of Cys42 and Cys101 on LPL. b Cell spreading through peripheral actin dynamics is halted by H2O2 treatment. After weak adherence, cells spread by forming actin-based cellular extrusions. Administration of exogenous ROS blocks cellular extrusion formation and cell spreading. c, d Enlarged cartoon of the boxed region in b. c Under control conditions, actin bundling by reduced LPL is involved in the formation of cellular extensions. d Under pro-oxidative conditions, the formation of actin bundles by LPL is prevented, impeding the formation of cellular extrusions. The color scale from light to dark green indicates the concentration gradient of TRX1. In the absence of antioxidant systems at such rapidly forming structures, the likelihood of protein oxidation is elevated
