Arabidopsis FTSH11 mutant

The membrane-integrated metallo-protease FtsH11 of Arabidopsis thaliana is proposed to be dual targeted to mitochondria and chloroplasts. A bleached phenotype was observed in ftsh11 grown at long days or continuous light, pointing to disturbances in the chloroplast. Under these growth conditions the morphology of the chloroplast became drastically altered, accompanied by a drop of NPQ, and the amount of PSI decreased relative to PSII. The abundance of plastidic proteins, especially of photosynthetic proteins, was altered in ftsh11 even during growth in normal conditions and short days. FtsH11 is crucial for chloroplast structure and function during growth in prolonged photoperiod . In chloroplasts FtsH11 was found to be located exclusively in the chloroplast envelope. Thanks to proteomic analyses, the Tic22-like protein and YGGT, both chloroplast proteins of unknown function, are proposed to be the substrates of FtsH11 .