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Photosynthesis drives pre-protein processing and progression of chloroplast biogenesis during early plant development

ABSTRACT: Photosynthetic capacity is the result of chloroplast biogenesis, but whether photosynthesis itself is required for chloroplast biogenesis has not been investigated. In this study we use 680nm red light to overexcite Photosystem II to disrupt photosynthesis in two conditional mutants (var2 and abc1k1) and demonstrate that this arrests chloroplast biogenesis. During their biogenesis, chloroplasts import the majority of proteins associated with photosynthesis and some are transported further across the thylakoid membrane by the evolutionarily conserved SEC (Secretory) and TAT (Twin Arginine Translocation) pathways, energized by ATP and the proton gradient, respectively. Most luminal thylakoid proteins are synthesized in the cytoplasm with bi-partite, cleavable targeting sequences (first for the chloroplast envelope, second for the thylakoid membrane). Two-step cleavage of these peptides is essential for chloroplast biogenesis. Linked to the photosynthetic defect in var2 and abc1k1 under red light, six incompletely cleaved essential proteins at the thylakoid lumen side of Photosystems I and II accumulated to high levels in the mutants. In summary, the results show that the processing of a specific module of photosynthesis-associated proteins and concomitantly progression of chloroplast biogenesis depend on photosynthesis at the earliest stages of seedling development.

INSTRUMENT(S): timsTOF Pro

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Seedling

SUBMITTER: Manfredo Quadroni

LAB HEAD: Felix Kessler

PROVIDER: PXD050814 | Pride | 2024-12-13

REPOSITORIES: Pride

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			Action	DRS
	4343_11-30-2022_Collombat_15241_DIA_140min_6ul_RB1.d.zip	Other
	4344_11-30-2022_Collombat_15244_DIA_140min_6ul_RB2.d.zip	Other
	4345_11-30-2022_Collombat_14917_d5x_DIA_140min_6ul_RB3.d.zip	Other
	4348_12-1-2022_Collombat_15242_DIA_140min_6ul_RB4.d.zip	Other
	4349_12-1-2022_Collombat_15245_DIA_140min_6ul_RB5.d.zip	Other

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Photosynthesis drives pre-protein processing and progression of chloroplast biogenesis during early plant development

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