Fig. 2.
CaMKIIβ bound to F-actin in the F-actin rich structures. (A) Confocal images of a GFP-CaMKIIβ transfected neuron before bleaching (−0.06 s), at bleach time 0 s, and 5 s after bleaching are shown as examples. GFP-CaMKIIβ enriched areas can be seen as white pixels. A region of interest (ROI) (circle 1) to be bleached was chosen from GFP-CaMKIIβ fluorescently intense areas. (Scale bar, 1 μm.) (B) Fluorescence recovery of GFP, GFP-CaMKIIβ, and paraformaldehyde cross-linked GFP-CaMKIIβ. Fluorescence intensity in the ROI was normalized to an unbleached ROI. (C) Fluorescence recovery of GFP-CaMKIIβ, GFP-CaMKIIα, and GFP-CaMKIIβ-Δ355–392. (D) Time in which fluorescence recovery of GFP-CaMKIIβ, GFP-CaMKIIα, and GFP-CaMKIIβ-Δ355–392 reached half-maximal recovery and full recovery. *, P < 0.05 compared with CaMKIIβ. (E) CaMKIIα expression increased CaMKIIβ recovery rate. Fluorescence recovery of GFP-CaMKIIβ when cotransfected with either control vector, CaMKIIα at 1:1 molar ratio, or at 1:2 molar ratio is shown. (F) Time in which fluorescence recovery of GFP-CaMKIIβ cotransfected with either control vector, CaMKIIα at 1:1 molar ratio, or at 1:2 molar ratio reached half maximal recovery. *, P < 0.05. (G) The percentage of cells transfected as indicated that contained F-actin-rich microspikes. GFP-CaMKIIβ was cotransfected with CaMKIIα at 1:1 molar ratio. Data for each condition is from a minimum of 350 cells from two independent experiments. *, P < 0.05.