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Open AccessArticle
A Conserved N-Terminal Di-Arginine Motif Stabilizes Plant DGAT1 and Modulates Lipid Droplet Organization
by
Somrutai Winichayakul
Somrutai Winichayakul *
,
Hong Xue
Hong Xue and
Nick Roberts
Nick Roberts
Resilient Agriculture, AgResearch Grasslands, Palmerston North 4442, New Zealand
*
Author to whom correspondence should be addressed.
Int. J. Mol. Sci. 2025, 26(15), 7406; https://doi.org/10.3390/ijms26157406 (registering DOI)
Submission received: 6 June 2025
/
Revised: 28 July 2025
/
Accepted: 29 July 2025
/
Published: 31 July 2025
Abstract
Diacylglycerol-O-acyltransferase 1 (DGAT1, EC 2.3.1.20) is a pivotal enzyme in plant triacylglycerol (TAG) biosynthesis. Previous work identified conserved di-arginine (R) motifs (R-R, R-X-R, and R-X-X-R) in its N-terminal cytoplasmic acyl-CoA binding domain. To elucidate their functional significance, we engineered R-rich sequences in the N-termini of Tropaeolum majus and Zea mays DGAT1s. Comparative analysis with their respective non-mutant constructs showed that deleting or substituting R with glycine in the N-terminal region of DGAT1 markedly reduced lipid accumulation in both Camelina sativa seeds and Saccharomyces cerevisiae cells. Immunofluorescence imaging revealed co-localization of non-mutant and R-substituted DGAT1 with lipid droplets (LDs). However, disruption of an N-terminal di-R motif destabilizes DGAT1, alters LD organization, and impairs recombinant oleosin retention on LDs. Further evidence suggests that the di-R motif mediates DGAT1 retrieval from LDs to the endoplasmic reticulum (ER), implicating its role in dynamic LD–ER protein trafficking. These findings establish the conserved di-R motifs as important regulators of DGAT1 function and LD dynamics, offering insights for the engineering of oil content in diverse biological systems.
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MDPI and ACS Style
Winichayakul, S.; Xue, H.; Roberts, N.
A Conserved N-Terminal Di-Arginine Motif Stabilizes Plant DGAT1 and Modulates Lipid Droplet Organization. Int. J. Mol. Sci. 2025, 26, 7406.
https://doi.org/10.3390/ijms26157406
AMA Style
Winichayakul S, Xue H, Roberts N.
A Conserved N-Terminal Di-Arginine Motif Stabilizes Plant DGAT1 and Modulates Lipid Droplet Organization. International Journal of Molecular Sciences. 2025; 26(15):7406.
https://doi.org/10.3390/ijms26157406
Chicago/Turabian Style
Winichayakul, Somrutai, Hong Xue, and Nick Roberts.
2025. "A Conserved N-Terminal Di-Arginine Motif Stabilizes Plant DGAT1 and Modulates Lipid Droplet Organization" International Journal of Molecular Sciences 26, no. 15: 7406.
https://doi.org/10.3390/ijms26157406
APA Style
Winichayakul, S., Xue, H., & Roberts, N.
(2025). A Conserved N-Terminal Di-Arginine Motif Stabilizes Plant DGAT1 and Modulates Lipid Droplet Organization. International Journal of Molecular Sciences, 26(15), 7406.
https://doi.org/10.3390/ijms26157406
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