β-propeller domain and transmembrane proteins regulate Rac1 using different mechanisms.

<p><b>(A)</b> Example of the abundance of endogenous Coro1A (left, top panel) and CD98 (right, top panel) proteins upon transfection of COS1 cells with the indicated siRNAs (top). As control, we used in both cases the abundance of tubulin α (bottom panels). The antibodies used in the WBs are indicated on the right of each panel. <b>(B</b> and <b>D)</b> COS1 cells transfected with the indicated combinations of siRNAs (B and D, bottom), AU5-Rac1 (B and D, top) and fusion EGFPs (B and D; indicated on the left) were fixed, stained with antibodies to AU5 plus Alexa Fluor 635-phalloidin, and subjected to confocal microscopy. Signals from EGFPs, AU5-Rac1 and F-actin are shown in green, red, and blue color in the panels, respectively. Scale bar, 20 μm. <b>(C</b> and <b>E)</b> Quantification of the Rac1 translocation index obtained in experiments shown in B and D, respectively. ***, <i>P</i> ≤ 0.001 compared to cells expressing AU5-Rac1 alone (mock).