Fig. S4.

The cellular and cytoplasmic contents of Arp3 in V-1 overexpressing cells. (A) Western blot of whole cell extracts of control (lane 1) and mRFP-V-1 overexpressing cells (lane 2) probed for actin and Arp3, showing that the cellular content of Arp3 is unchanged in V-1 overexpressing cells. (B) The ratio of Arp3 fluorescence in pseudopodia to that in the cytoplasm for control cells (CTL) and cells expressing L, M, and H levels of mRFP-V-1, showing that the loss of cortical Arp3 signal seen in V-1 overexpressing cells reported in Fig. 4 can be accounted for by an increase in Arp3 signal in the central cytoplasm. Mean and SD values are: CTL, 3.29 ± 0.84; L, 2.81 ± 0.57; M, 1.83 ± 0.28; H, 1.32 ± 0.31.