Figure 8
From: Phosphorylation of CRN2 by CK2 regulates F-actin and Arp2/3 interaction and inhibits cell migration
Expression of phosphomimetic S463D mutant CRN2 changes the F-actin network in the front of lamellipodia.
Wild-type (not shown) as well as S463A (A) and S463D (B) mutant GFP-CRN2 was expressed in U373 glioblastoma cells where the endogenous CRN2 was knocked down (95% efficiency, shown in8). The CRN2 over-expression constructs are resistant to the CRN2 specific shRNA used for the knock-down (see Materials and Methods). A,B, left three panels, double stainings of CRN2 (GFP-fluorescence) and actin (TRITC-phalloidin fluorescence). A,B, right three panels, double stainings of CRN2 (GFP-fluorescence) and Arp2/3 (indirect immunofluorescence). Lamellipodia of cells expressing S463D mutant CRN2 demonstrate actin filaments within their fronts which were re-organized into irregular spiky structures in conjunction with irregularly distributed Arp2/3 complex (arrows) and a thinner region of CRN2 and Arp2/3 complex co-localization (distance labels). In contrast S463A induced regular patterns of F-actin and Arp2/3 in the front of lamellipodia (arrowheads). The patterns observed for wild-type CRN2 expressing cells varied between the ones detected for S463A and S463D CRN2 expressing cells and are not shown; see also Fig. S3.
