A conserved E3 ubiquitin ligase rewires carotenoid, sterol, and lipid metabolism in <i>Xanthophyllomyces dendrorhous</i>

R Ruilin Huang (Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences) J Jiurong Wang (Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences) R Ruirui Ding (Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences) Y Yu Liu J Juanjuan Su (Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences) Z Zhihang Chen (Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences) Y Yong Fan (Center for AI and Data Science for Integrated Diagnostics, Perelman School of Medicine, University of Pennsylvania) F Fuli Li (Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences) L Linqi Wang (State Key Laboratory of Microbial Diversity and Innovative Utilization, Institute of Microbiology, Chinese Academy of Sciences) X Xiao Liu S Shi’an Wang (Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences)

Abstract

Sterols, lipids, and carotenoids are major metabolites that share common biosynthetic precursors and underpin key physiological processes in eukaryotes. Yet, how cells coordinate metabolic flux through these competing pathways to maintain homeostasis remains unclear. Here, we identify a conserved RING-type E3 ubiquitin ligase, PTR1, as a central regulatory hub that orchestrates the interplay among these pathways in the yeast Xanthophyllomyces dendrorhous . Disruption of PTR1 triggers a concerted metabolic rewiring that enhances astaxanthin and sterol biosynthesis while shifting fatty acid composition toward polyunsaturation. Integrated multiomics and protein interaction analyses suggest that PTR1 targets White Collar 1 (WC1) for ubiquitination, establishing a reciprocal regulatory loop that maintains carotenoid homeostasis. Beyond WC1, PTR1 interfaces with a broader metabolic network to fine-tune central metabolism through discrete regulatory nodes. Notably, PTR1 homologs are found across evolutionarily distant eukaryotic lineages, including fungi, algae, plants, and animals, highlighting deep evolutionary conservation of the underlying protein architecture. These findings uncover a mechanism by which protein ubiquitination contributes to the coordination of distinct yet interconnected biosynthetic pathways in X. dendrorhous and point to the potential broader relevance of ubiquitin-mediated metabolic coordination beyond this species.

Article Details

Volume / Issue Vol. 123, Issue 17
Published April 28, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (11)

R

Ruilin Huang

Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

J

Jiurong Wang

Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

R

Ruirui Ding

Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

Y

Yu Liu

J

Juanjuan Su

Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

Z

Zhihang Chen

Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

Y

Yong Fan

Center for AI and Data Science for Integrated Diagnostics, Perelman School of Medicine, University of Pennsylvania

F

Fuli Li

Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

L

Linqi Wang

State Key Laboratory of Microbial Diversity and Innovative Utilization, Institute of Microbiology, Chinese Academy of Sciences

X

Xiao Liu

S

Shi’an Wang

Shandong Provincial Key Laboratory of Synthetic Biology, Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences