Figure 7.

Expression of RGS4 (wild type) but not RGS4(131–205) impairs transport of AQP1 to the plasma membrane in LLC-PK1 cells. Cells stably transfected with AQP1 were transiently transfected with plasmids encoding GFP (A), GFP–RGS4 (wild type) (B), or GFP–RGS4(131–205) (mut) (C). Left column represents GFP-, GFP–RGS4 (wild type)-, and GFP–RGS4(131–205)-expressing cells; middle column shows AQP1 distribution; and right column is the merge of the two images in each row. Arrows indicate AQP1 distribution in the perinuclear region, and arrowheads indicate AQP1 localization in the plasma membrane of LLC-PK1 cells. The asterisk indicates a GFP–RGS4 (wild type) transfected cell with mistargeted and dispersed AQP1. Plasma membrane staining is not detectable in this cell, in contrast to surrounding cells. Bars, 5 μm.