Chloroplast inner envelope protein FtsH11 is involved in the adjustment of assembly of chloroplast ATP synthase under heat stress. (4th January 2023)

• Record Type: Journal Article
• Authors: Yue, Xiaohong; Ke, Xiangsheng; Shi, Yafei; Li, Yangsheng; Zhang, Chenhao; Wang, Yetao; Hou, Xin
• Is Part Of: Plant, cell and environment. Volume 46:Number 3(2023)
• Page Start: 850
• Page End: 864
• Publication Date: 2023-01-04
• Subjects: FtsH -- photosynthesis -- proton gradient -- thermostress; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.14525
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: The maintenance of a proton gradient across the thylakoid membrane is an integral aspect of photosynthesis that is mainly established by the splitting of water molecules in photosystem II and plastoquinol oxidation at the cytochrome complex, and it is necessary for the generation of ATP in the last step of photophosphorylation. Although environmental stresses, such as high temperatures, are known to disrupt this fundamental process, only a few studies have explored the molecular mechanisms underlying proton gradient regulation during stress. The present study identified a heat‐sensitive mutant that displays aberrant photosynthesis at high temperatures. This mutation was mapped to AtFtsH11, which encodes an ATP‐dependent AAA‐family metalloprotease. We showed that AtFtsH11 localizes to the chloroplast inner envelope membrane and is capable of degrading the ATP synthase assembly factor BFA3 under heat stress. We posit that this function limits the amount of ATP synthase integrated into the thylakoid membrane to regulate proton efflux from the lumen to the stroma. Our data also suggest that AtFtsH11 is critical in stabilizing photosystem II and cytochrome complexes at high temperatures, and additional studies can further elucidate the specific molecular functions of this critical regulator of photosynthetic thermotolerance. Summary statement: FtsH11 is essential for the thermotolerance of photosynthesis by stabilizing photosystem II and cytochrome b6/f complexes as well as ATP synthase. FtsH11 interacts with and degrades ATP synthase assembly factor BFA3 to adjust ATP synthase activity and maintain the lumen proton gradient under thermostress.