Dynamic light‐ and acetate‐dependent regulation of the proteome and lysine acetylome of Chlamydomonas. (18th November 2021)

• Record Type: Journal Article
• Authors: Füßl, Magdalena; König, Ann‐Christine; Eirich, Jürgen; Hartl, Markus; Kleinknecht, Laura; Bohne, Alexandra‐Viola; Harzen, Anne; Kramer, Katharina; Leister, Dario; Nickelsen, Jörg; Finkemeier, Iris
• Is Part Of: Plant journal. Volume 109:Number 1(2022)
• Page Start: 261
• Page End: 277
• Publication Date: 2021-11-18
• Subjects: Chlamydomonas -- lysine acetylation -- acetate -- proteome -- citrate synthase -- glyoxylate cycle -- RuBisCO; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.15555
• Languages: English
• ISSNs: 0960-7412

Abstract

SUMMARY: The green alga Chlamydomonas reinhardtii is one of the most studied microorganisms in photosynthesis research and for biofuel production. A detailed understanding of the dynamic regulation of its carbon metabolism is therefore crucial for metabolic engineering. Post‐translational modifications can act as molecular switches for the control of protein function. Acetylation of the ɛ‐amino group of lysine residues is a dynamic modification on proteins across organisms from all kingdoms. Here, we performed mass spectrometry‐based profiling of proteome and lysine acetylome dynamics in Chlamydomonas under varying growth conditions. Chlamydomonas liquid cultures were transferred from mixotrophic (light and acetate as carbon source) to heterotrophic (dark and acetate) or photoautotrophic (light only) growth conditions for 30 h before harvest. In total, 5863 protein groups and 1376 lysine acetylation sites were identified with a false discovery rate of <1%. As a major result of this study, our data show that dynamic changes in the abundance of lysine acetylation on various enzymes involved in photosynthesis, fatty acid metabolism, and the glyoxylate cycle are dependent on acetate and light. Exemplary determination of acetylation site stoichiometries revealed particularly high occupancy levels on K175 of the large subunit of RuBisCO and K99 and K340 of peroxisomal citrate synthase under heterotrophic conditions. The lysine acetylation stoichiometries correlated with increased activities of cellular citrate synthase and the known inactivation of the Calvin–Benson cycle under heterotrophic conditions. In conclusion, the newly identified dynamic lysine acetylation sites may be of great value for genetic engineering of metabolic pathways in Chlamydomonas . Significance Statement: Chlamydomonas reinhardtii can grow heterotrophically with just acetate as carbon source, mixotrophically with acetate and light, and fully photoautotrophically with just light and carbon dioxide to fuel metabolism, which indicates that Chlamydomonas is able to swiftly switch activities of metabolic pathways. Quantitative proteomics profiling of Chlamydomonas cells transferred to different growth conditions revealed acetate‐ and light‐dependent dynamic changes in lysine acetylation on various enzymes involved in photosynthesis and the glyoxylate cycle.