ROCK-dependence of RNA but not actin turnover in MSV-MDCK-INV cell
pseudopodia. A, MSV-MDCK-INV cells stably expressing pEGFP-actin
(β-actin-GFP) and untransfected MSV-MDCK-INV cells labeled with
the cell-permeant dye Syto14 (Syto14 RNA) were either left untreated
(control) or treated with Y27632 for 60 min (+Y27632). Cells were imaged prior
to photobleaching (prebleach), immediately after photobleaching of
the pseudopodial region with the 488-nm laser (bleach), and 90 s
after photobleaching (postbleach). A representative graph of three
experiments shows the fluorescence intensity in the bleached region over time
(t = 0 corresponds to the time immediately after photobleaching) for
β-actin-GFP (B) or Syto14 labeled RNA (C). Untreated
cells (control) are shown in blue, and Y27632-treated cells are in
red. The values have been normalized to the prebleach intensity. The
mobile fraction, representing the percent of fluorescence recovered in the
bleached region, and half-time of recovery of control and Y27632 treated cells
are shown in graph form for β-actin-GFP (B) and Syto14 RNA
(C) (means ± S.E.; n = 3; *, p
< 0.01). Scale bar, 20 μm.