Subcellular and suborganellar localization of FtsHi4.

<p>A, <i>In vivo</i> targeting of green fluorescent protein (GFP) mediated by the FtsHi4 signal peptide in protoplasts. <i>Arabidopsis</i> protoplasts transformed by fusion between the FtsHi4 signal peptide and GFP. GFP fluorescence, chlorophyll autofluorescence, and merged images are shown. Free GFP was used as the control. B, Suborganellar localization of FtsHi4 protein. Thylakoid membranes were prepared from wild-type plants, fractionated by SDS-PAGE, transferred to polyvinylidene difluoride membranes, and visualized using antibodies raised against the FtsHi4 segment, PsbO (a 33-kDa luminal protein of PSII), or CP47 (a core protein of PSII). Membranes that were not subjected to salt treatment (CK) were used as controls.