Figure 7.

ATI1 Interacts with NPQ4 and APE1 in Planta and Is Required for the Degradation of PrxA.

(A) Confocal imaging of a BiFC assay (see Methods) involving coexpression of ATI1-YC with either APE1-YN (top panel) or NPQ4-YN (bottom panel). The yellow signal indicates an interaction between the two proteins. In both images, plastids are detected by their chlorophyll autofluorescence (magenta signal) and colocalization of the yellow and magenta signals results in white color.

(B) Immunoblot analysis on triplicate samples of rosette leaves taken from 4-week-old wild-type, ati1 knockout, and ATI-KD double knockdown plants. Immunolabeling was conducted with either an anti-PrxA antibody (labeling of the 22-kD PrxA protein, top panel) or the anti-RBCL antibody (∼55-kD large subunit of Rubisco, middle panel, as a negative control). A fraction of the total protein staining (membrane stained with amido black) is shown in the bottom panel.