Biology subjects

Sorigue, D.

Publications and source records attributed to Sorigue, D..

4 recordsLinked to original sources

bioRxiv2025

ALGAL HOMOLOGS OF THE PLANT CER1 AND CER3 PROTEINS ARE FUNCTIONAL HYDROCARBON-FORMING ENZYMES

In plants, very-long-chain (VLC) alkanes (C25-C35) are secreted onto the epidermal surface of aerial organs, often forming the primary component of the waterproof cuticular wax layer. This secretion plays a vital role in preventing desiccation in terrestrial environments. The key to VLC alkane biosynthesis in plants lies in the complex formed by two homologous membrane-bound proteins, ECERIFERUM 3 (CER3) and ECERIFERUM 1 (CER1). This complex transforms an acyl-CoA substrate into an aldehyde intermediate, which is then converted into an alkane. The ability to synthesize and secrete alkanes is believed to have been a pivotal event in the evolution of land plants from their green algal ancestors. Interestingly, a single homolog of CER1 and CER3, known as CER1/3, has been identified in certain algae. However, the functionality of this protein remains to be investigated. In this study, we present the functional characterization in yeast of CER1/3 proteins from various algal species belonging to the green lineage. We demonstrate that CER1/3 proteins alone can efficiently mediate hydrocarbon biosynthesis. Furthermore, we demonstrate that point mutations in conserved motifs in the N- or C-terminal domains of CER1/3 lead to impaired hydrocarbon biosynthesis. Additionally, we show that coexpressing plant CER3 with algal CER1/3 results in longer alkanes being formed in yeast. Together, these findings support the hypothesis that the alkane-forming CER1/CER3 complex found in land plants evolved from a green algal CER1/3 bifunctional enzyme through a process of gene duplication followed by protein specialization.

plant biology↗

bioRxiv2024

Microbial photoproduction of heptane

Fatty Acid Photodecarboxylase (FAP) has emerged as a promising catalyst for the biological production of long-chain hydrocarbons. We have recently shown that purified FAP or FAP-expressing bacteria can efficiently convert octanoic acid into heptane, thus extending the potential applications of FAP to medium-chain hydrocarbons (i.e., solvent- or kerosene-type). The scarcity of natural sources of octanoic acid presents a challenge however. Here, we explore the heptane production capacity of a FAP-expressing E. coli strain engineered to biosynthesize octanoic acid via a specific thioesterase. Various FAPs and C8-specific thioesterases were tested. A blue-light-inducible promoter was used to avoid chemical inducers. We found that the expression of FAP fused with TrxA resulted in a 10-fold increase in heptane production. Coexpression of Cuphea hookeriana thioesterase and Chlorella variabilis FAP achieved the highest heptane titer (12.5 mg.L-1). Scale-up experiments in 100 mL photobioreactors allowed a constant production of heptane over two days (22 mg.L-1.day-1). Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/603920v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@1dbfebforg.highwire.dtl.DTLVardef@31dbaforg.highwire.dtl.DTLVardef@14dfcd5org.highwire.dtl.DTLVardef@11234d4_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIAn E. coli strain producing heptane under blue light is described. C_LIO_LIExpression of FAP fused with TrxA increases heptane by 10-fold. C_LIO_LIA blue light-inducible promoter ensures high coexpression of FAP and thioesterase. C_LIO_LICuphea hookeriana thioesterase and Chlorella variabilis FAP give highest production C_LIO_LIHighest reported heptane productivity (22 mg.L-1.day-1) in 100 mL photobioreactors. C_LI

bioengineering↗

bioRxiv2023

The α/β hydrolase domain-containing protein 1 (ABHD1) acts as a lysolipid lipase and is involved in lipid droplet formation

Lipid droplets (LDs) are the major sites of lipid and energy homeostasis. However, few LD biogenesis proteins have been identified. Here, using Chlamydomonas as a model, we show that ABHD1, a member of the /{beta} hydrolase domain-containing protein family, is a novel type of LD-associated protein which stimulates LD formation through two distinct actions on the LD surface, one enzymatic and the other structural. ABHD1 was localized to LD surface in Chlamydomonas cells. The knockout mutants contained similar amounts of triacylglycerols (TAG) but their LDs showed an increased content in lyso- derivatives of the betaine lipid diacylglyceryl-N,N,N-trimethylhomoserine (DGTS). Over-expression of ABHD1 in Chlamydomonas induced LD formation and boosted TAG content, suggesting a key role in LD biogenesis. The purified recombinant ABHD1 protein hydrolyzed lyso-DGTS, producing a free fatty acid and a glyceryltrimethylhomoserine moiety. In vitro experiments using droplet- embedded vesicles showed that ABHD1 promoted LD emergence. Taken together, these results identify ABHD1 as a new player in LD formation by its lipase activity on lyso-DGTS and by its distinct biophysical property. This study further suggests that lipases targeted to LDs and able to act on their polar lipid coat may be interesting tools to promote LD assembly in eukaryotic cells. Significant statementLipid droplets are subcellular organelles specialized for triacylglycerol storage. Their dynamic turnover is key to managing energy homeostasis in response to cell cycle states and environmental cues. To gain insights into LD biogenesis, we characterized a putative /{beta}- hydrolase (ABHD1) in the model algae Chlamydomonas reinhardtii and show it is located at the LD surface. We found that ABHD1 overexpression promotes LD formation and acts as a lipase mainly on lyso derivatives of the betaine lipid diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), the major lipid constituent of the LD hemi-membrane. We also show that ABHD1 has a remarkable biophysical property favoring LD budding. This work thus identifies a novel type of lipase acting on betaine lipid and provides a first example of a protein with a dual function nvolved in LD formation.

biochemistry↗

bioRxiv2020

Fatty acid photodecarboxylase is an ancient photoenzyme responsible for hydrocarbon formation in the thylakoid membranes of algae

ABSTRACTFatty acid photodecarboxylase (FAP) is one of the three enzymes that require light for their catalytic cycle (photoenzymes). FAP has been first identified in the green microalga Chlorella variabilis NC64A and belongs an algae-specific subgroup of the glucose-methanol-choline oxidoreductase family. While the FAP from Chlorella and its Chlamydomonas reinhardtii homolog CrFAP have demonstrated in vitro activity, their activity and physiological function have not been studied in vivo. Besides, the conservation of FAP activity beyond green microalgae remains hypothetical. Here, using a Chlamydomonas FAP knockout line (fap), we show that CrFAP is responsible for the formation of 7-heptadecene, the only hydrocarbon present in this alga. We further show that CrFAP is associated to the thylakoids and that 90% of 7-heptadecene is recovered in this cell fraction. In the fap mutant, photosynthesis activity was not affected under standard growth conditions but was reduced after cold acclimation. A phylogenetic analysis including sequences from Tara Ocean identified almost 200 putative FAPs and indicated that FAP was acquired early after primary endosymbiosis. Within Bikonta, FAP was kept in photosynthetic secondary endosymbiosis lineages but absent in those that lost the plastid. Characterization of recombinant FAPs from various algal genera (Nannochloropsis, Ectocarpus, Galdieria, Chondrus) provided experimental evidence that FAP activity is conserved in red and brown algae and is not limited to unicellular species. These results thus indicate that FAP has been conserved during evolution of most algal lineages when photosynthesis was kept and suggest that its function is linked to photosynthetic membranes.One sentence summary FAP is present in thylakoids and conserved beyond green algae.Competing Interest StatementThe authors have declared no competing interest.View Full Text

plant biology↗