Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism
Chromochloris zofingiensis represents an industrially relevant and unique green alga, given its capability of synthesizing triacylglycerol (TAG) and astaxanthin simultaneously for storage in lipid droplets (LDs). To further decipher lipid metabolism, the nitrogen deprivation (ND)-induced LDs from C....
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| Format: | Article |
| Language: | English |
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Elsevier
2019-06-01
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| Series: | Genomics, Proteomics & Bioinformatics |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1672022918302730 |
| _version_ | 1797330727610613760 |
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| author | Xiaofei Wang Hehong Wei Xuemei Mao Jin Liu |
| author_facet | Xiaofei Wang Hehong Wei Xuemei Mao Jin Liu |
| author_sort | Xiaofei Wang |
| collection | DOAJ |
| description | Chromochloris zofingiensis represents an industrially relevant and unique green alga, given its capability of synthesizing triacylglycerol (TAG) and astaxanthin simultaneously for storage in lipid droplets (LDs). To further decipher lipid metabolism, the nitrogen deprivation (ND)-induced LDs from C. zofingiensis were isolated, purified, and subjected to proteomic analysis. Intriguingly, many C. zofingiensis LD proteins had no orthologs present in LD proteome of the model alga Chlamydomonas reinhardtii. Seven novel LD proteins (i.e., two functionally unknown proteins, two caleosins, two lipases, and one l-gulonolactone oxidase) and the major LD protein (MLDP), which were all transcriptionally up-regulated by ND, were selected for further investigation. Heterologous expression in yeast demonstrated that all tested LD proteins were localized to LDs and all except the two functionally unknown proteins enabled yeast to produce more TAG. MLDP could restore the phenotype of mldp mutant strain and enhance TAG synthesis in wild-type strain of C. reinhardtii. Although MLDP and caleosins had a comparable abundance in LDs, they responded distinctly to ND at the transcriptional level. The two lipases, instead of functioning as TAG lipases, likely recycled polar lipids to support TAG synthesis. For the first time, we reported that l-gulonolactone oxidase was abundant in LDs and facilitated TAG accumulation. Moreover, we also proposed a novel working model for C. zofingiensis LDs. Taken together, our work unravels the unique characteristics of C. zofingiensis LDs and provides insights into algal LD biogenesis and TAG synthesis, which would facilitate genetic engineering of this alga for TAG improvement. Keywords: Lipid droplet, Caleosin, Proteomics, Triacylglycerol, Lipase |
| first_indexed | 2024-03-08T07:24:44Z |
| format | Article |
| id | doaj.art-e778056473d8446d831c767339cf59bb |
| institution | Directory Open Access Journal |
| issn | 1672-0229 |
| language | English |
| last_indexed | 2024-03-08T07:24:44Z |
| publishDate | 2019-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Genomics, Proteomics & Bioinformatics |
| spelling | doaj.art-e778056473d8446d831c767339cf59bb2024-02-02T22:29:14ZengElsevierGenomics, Proteomics & Bioinformatics1672-02292019-06-01173260272Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid MetabolismXiaofei Wang0Hehong Wei1Xuemei Mao2Jin Liu3Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, ChinaLaboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, ChinaLaboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, ChinaCorresponding author.; Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, ChinaChromochloris zofingiensis represents an industrially relevant and unique green alga, given its capability of synthesizing triacylglycerol (TAG) and astaxanthin simultaneously for storage in lipid droplets (LDs). To further decipher lipid metabolism, the nitrogen deprivation (ND)-induced LDs from C. zofingiensis were isolated, purified, and subjected to proteomic analysis. Intriguingly, many C. zofingiensis LD proteins had no orthologs present in LD proteome of the model alga Chlamydomonas reinhardtii. Seven novel LD proteins (i.e., two functionally unknown proteins, two caleosins, two lipases, and one l-gulonolactone oxidase) and the major LD protein (MLDP), which were all transcriptionally up-regulated by ND, were selected for further investigation. Heterologous expression in yeast demonstrated that all tested LD proteins were localized to LDs and all except the two functionally unknown proteins enabled yeast to produce more TAG. MLDP could restore the phenotype of mldp mutant strain and enhance TAG synthesis in wild-type strain of C. reinhardtii. Although MLDP and caleosins had a comparable abundance in LDs, they responded distinctly to ND at the transcriptional level. The two lipases, instead of functioning as TAG lipases, likely recycled polar lipids to support TAG synthesis. For the first time, we reported that l-gulonolactone oxidase was abundant in LDs and facilitated TAG accumulation. Moreover, we also proposed a novel working model for C. zofingiensis LDs. Taken together, our work unravels the unique characteristics of C. zofingiensis LDs and provides insights into algal LD biogenesis and TAG synthesis, which would facilitate genetic engineering of this alga for TAG improvement. Keywords: Lipid droplet, Caleosin, Proteomics, Triacylglycerol, Lipasehttp://www.sciencedirect.com/science/article/pii/S1672022918302730 |
| spellingShingle | Xiaofei Wang Hehong Wei Xuemei Mao Jin Liu Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism Genomics, Proteomics & Bioinformatics |
| title | Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism |
| title_full | Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism |
| title_fullStr | Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism |
| title_full_unstemmed | Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism |
| title_short | Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism |
| title_sort | proteomics analysis of lipid droplets from the oleaginous alga chromochloris zofingiensis reveals novel proteins for lipid metabolism |
| url | http://www.sciencedirect.com/science/article/pii/S1672022918302730 |
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