Premium
Long‐chain acyl‐CoA synthetases activate fatty acids for lipid synthesis, remodeling and energy production in Chlamydomonas
Author(s) -
Bai Fan,
Yu Lihua,
Shi Jianan,
LiBeisson Yonghua,
Liu Jin
Publication year - 2022
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.17813
Subject(s) - chlamydomonas , chlamydomonas reinhardtii , biology , biochemistry , fatty acid , lipid droplet , catabolism , lipid metabolism , organelle , microbiology and biotechnology , enzyme , mutant , gene
Summary Long‐chain acyl‐CoA synthetases (LACSs) play many roles in mammals, yeasts and plants, but knowledge on their functions in microalgae remains fragmented. Here via genetic, biochemical and physiological analyses, we unraveled the function and roles of LACSs in the model microalga Chlamydomonas reinhardtii . In vitro assays on purified recombinant proteins revealed that CrLACS1, CrLACS2 and CrLACS3 all exhibited bona fide LACS activities toward a broad range of free fatty acids. The Chlamydomonas mutants compromised in CrLACS1, CrLACS2 or CrLACS3 did not show any obvious phenotypes in lipid content or growth under nitrogen (N)‐replete condition. But under N‐deprivation, CrLACS1 or CrLACS 2 suppression resulted in c . 50% less oil, yet with a higher amount of chloroplast lipids. By contrast, CrLACS3 suppression impaired oil remobilization and cell growth severely during N‐recovery, supporting its role in fatty acid β‐oxidation to provide energy and carbon sources for regrowth. Transcriptomics analysis suggested that the observed lipid phenotypes are likely not due to transcriptional reprogramming but rather a shift in metabolic adjustment. Taken together, this study provided solid experimental evidence for essential roles of the three Chlamydomonas LACS enzymes in lipid synthesis, remodeling and catabolism, and highlighted the importance of lipid homeostasis in cell growth under nutrient fluctuations.