Proteomes reveal the lipid metabolic network in the complex plastid of Phaeodactylum tricornutum

• DOI: 10.1111/tpj.16477
• Publication Date: 2023-09-21T17:55:32Z
• Authors: Teng Huang; Yufang Pan; Eric Maréchal; Hanhua Hu
• Keywords: Phaeodactylum tricornutum; Proteome

SUMMARY Phaeodactylum tricornutum plastid is surrounded by four membranes, and its protein composition function remain mysterious. In this study, the P. plastid‐enriched fraction was obtained 2850 proteins were identified, including 92 plastid‐encoded proteins, through label‐free quantitative proteomic technology. Among them, 839 nuclear‐encoded further determined to be plastidial based on BLAST alignments within Plant Proteome DataBase subcellular localization prediction, in spite of strong contamination mitochondria‐encoded putative plasma membrane proteins. According our data, we reconstructed metabolic pathways highlighted hybrid nature diatom plastid. Triacylglycerol (TAG) hydrolysis glycolysis, as well photosynthesis, glycan metabolism, tocopherol triterpene biosynthesis, occur addition, synthesis long‐chain acyl‐CoAs, elongation, desaturation fatty acids (FAs), lipids TAG are confined four‐layered‐membrane GFP‐fusion data. The whole process generation docosahexaenoic acid (22:6) from palmitic (16:0), via elongation FAs, occurs chloroplast endoplasmic reticulum membrane, outermost Desaturation that generates 16:4 16:0 stroma outer envelope membrane. Quantitative analysis glycerolipids between cells isolated plastids shows similar composition, FA profile not different. This study combines functions usually separated photosynthetic eukaryotes, differs green alga plant chloroplasts undertaking lipid biosynthesis.