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Næsted, Henrik; Frandsen, Gitte I.; Jauh, Guang‐Yuh; Hernández-Pinzón, Inmaculada; Nielsen, Holger Frits Bech; Murphy, Denis J.; Rogers, John C.; Mundy, John

doi:10.1023/a:1026564411918

Cited by 163 publications

(43 citation statements)

References 49 publications

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“…Caleosins are LD-associated Ca 2ϩ binding proteins that have been found in many plants, several oleaginous fungi, and algae (3,41). The biological functions of caleosins have been shown to stabilize the oil body (alias of lipid droplet) of cycad megagametophytes (42) and to interact with vacuoles and promote degradation of storage lipids in Arabidopsis seeds (43).…”

Section: Resultsmentioning

confidence: 99%

Dynamics of the Lipid Droplet Proteome of the Oleaginous Yeast Rhodosporidium toruloides

et al. 2015

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c Lipid droplets (LDs) are ubiquitous organelles that serve as a neutral lipid reservoir and a hub for lipid metabolism. Manipulating LD formation, evolution, and mobilization in oleaginous species may lead to the production of fatty acid-derived biofuels and chemicals. However, key factors regulating LD dynamics remain poorly characterized. Here we purified the LDs and identified LD-associated proteins from cells of the lipid-producing yeast Rhodosporidium toruloides cultured under nutrient-rich, nitrogen-limited, and phosphorus-limited conditions. The LD proteome consisted of 226 proteins, many of which are involved in lipid metabolism and LD formation and evolution. Further analysis of our previous comparative transcriptome and proteome data sets indicated that the transcription level of 85 genes and protein abundance of 77 proteins changed under nutrient-limited conditions. Such changes were highly relevant to lipid accumulation and partially confirmed by reverse transcription-quantitative PCR. We demonstrated that the major LD structure protein Ldp1 is an LD marker protein being upregulated in lipid-rich cells. When overexpressed in Saccharomyces cerevisiae, Ldp1 localized on the LD surface and facilitated giant LD formation, suggesting that Ldp1 plays an important role in controlling LD dynamics. Our results significantly advance the understanding of the molecular basis of lipid overproduction and storage in oleaginous yeasts and will be valuable for the development of superior lipid producers. Lipid droplets (LDs), intracellular organelles with deposits of neutral lipids and involved in many cellular activities, are widely present in both eukaryotic and prokaryotic cells (1-4). These organelles consist of a neutral lipid core surrounded by a phospholipid monolayer and associated proteins (3, 5). It has been known that LDs serve as the energy reservoir of cells, which may increase the adaptation by mobilization and degradation of lipids during nutrient deprivation, and also connect with other cellular processes, including lipid transport, membrane biogenesis, lipotoxicity relief, protein storage and degradation, pathogenicity, and autophagy (6-9). Because the biology of LDs is closely linked to some diseases, such as obesity, type 2 diabetes, and atherosclerosis, great progress has been made in elucidating the cellular trafficking, dynamics, and biogenesis of LDs in mammalian cells (2, 7, 10). However, there have been few studies on LDs in other species, especially naturally lipid-producing microorganisms (11-13). Analysis of these microorganisms is motivated by the fact that microbial lipid production holds a great promise to convert waste materials, including lignocellulosic biomass, into fatty acid-derived fuel molecules and chemicals in a scenario of biorefinery and sustainable development (14, 15).The major components of LDs are neutral lipids, including triacylglycerols (TAGs), sterol esters, and ether lipids (16). Neutral lipids constitute more than 90% of LDs by weight, but the ratio of TAGs to ste...

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Section: Resultsmentioning

confidence: 99%

Dynamics of the Lipid Droplet Proteome of the Oleaginous Yeast Rhodosporidium toruloides

et al. 2015

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“…The calcium-binding capacity of caleosins has been demonstrated by Takahashi et al [50] for AtCLO3 (encoded by AT2G33380 ) isolated from A. thaliana and by Chen et al [4] for caleosin from Sesamum indicum . Calcium ions are capable of promoting aggregation of purified OBs and are predicted to play an important role in OB aggregation and regulation during biogenesis processes [8]. This observation suggests that during the evolution of caleosin, sites in the Ca 2+ -binding motif appear to have coevolved.…”

Section: Discussionmentioning

confidence: 99%

“…Caleosin genes are widely distributed in true fungi, unicellular microalgae, and higher plants [8]. The first caleosin sequence was cloned and characterized in rice seeds germinating in response to abscisic acid treatment by Fradsen et al in 1996 [9].…”

Section: Introductionmentioning

confidence: 99%

Delineation of plant caleosin residues critical for functional divergence, positive selection and coevolution

et al. 2014

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BackgroundThe caleosin genes encode proteins with a single conserved EF hand calcium-binding domain and comprise small gene families found in a wide range of plant species. These proteins may be involved in many cellular and biological processes coupled closely to the synthesis, degradation, or stability of oil bodies. Although previous studies of this protein family have been reported for Arabidopsis and other species, understanding of the evolution of the caleosin gene family in plants remains inadequate.ResultsIn this study, comparative genomic analysis was performed to investigate the phylogenetic relationships, evolutionary history, functional divergence, positive selection, and coevolution of caleosins. First, 84 caleosin genes were identified from five main lineages that included 15 species. Phylogenetic analysis placed these caleosins into five distinct subfamilies (sub I–V), including two subfamilies that have not been previously identified. Among these subfamilies, sub II coincided with the distinct P-caleosin isoform recently identified in the pollen oil bodies of lily; caleosin genes from the same lineage tended to be clustered together in the phylogenetic tree. A special motif was determined to be related with the classification of caleosins, which may have resulted from a deletion in sub I and sub III occurring after the evolutionary divergence of monocot and dicot species. Additionally, several segmentally and tandem-duplicated gene pairs were identified from seven species, and further analysis revealed that caleosins of different species did not share a common expansion model. The ages of each pair of duplications were calculated, and most were consistent with the time of genome-wide duplication events in each species. Functional divergence analysis showed that changes in functional constraints have occurred between subfamilies I/IV, II/IV, and II/V, and some critical amino acid sites were identified during the functional divergence. Additional analyses revealed that caleosins were under positive selection during evolution, and seven candidate amino acid sites (70R, 74G, 88 L, 89G, 100 K, 106A, 107S) for positive selection were identified. Interestingly, the critical amino acid residues of functional divergence and positive selection were mainly located in C-terminal domain. Finally, three groups of coevolved amino acid sites were identified. Among these coevolved sites, seven from group 2 were located in the Ca2+-binding region of crucial importance.ConclusionIn this study, the evolutionary and expansion patterns of the caleosin gene family were predicted, and a series of amino acid sites relevant to their functional divergence, adaptive evolution, and coevolution were identified. These findings provide data to facilitate further functional analysis of caleosin gene families in the plant lineage.

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“…Caleosins (Pfam reference PF05042) are a group of structurally related genes that appear to be ubiquitous in Streptophytes, including land plants, and in the Chlorophyte green algae; while similar genes are also found in most, but not all, fungal clades (Naested et al, 2000; Partridge and Murphy, 2009; Hanano et al, 2015a). The proteins encoded by caleosin genes share a single highly conserved calcium-binding, EF-hand motif plus an invariant heme-binding histidine residue in the region proximal to the N terminus.…”

Section: Introductionmentioning

confidence: 99%

Specific Caleosin/Peroxygenase and Lipoxygenase Activities Are Tissue-Differentially Expressed in Date Palm (Phoenix dactylifera L.) Seedlings and Are Further Induced Following Exposure to the Toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin

et al. 2017

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Two caleosin/peroxygenase isoforms from date palm, Phoenix dactylifera L., PdCLO2 and PdCLO4, were characterized with respect to their tissue expression, subcellular localization, and oxylipin pathway substrate specificities in developing seedlings. Both PdCLO2 and PdCLO4 had peroxygenase activities that peaked at the mid-stage (radicle length of 2.5 cm) of seedling growth and were associated with the lipid droplet (LD) and microsomal fractions. Recombinant PdCLO2 and PdCLO4 proteins heterologously expressed in yeast cells were localized in both LD and microsomal fractions. Each of the purified recombinant proteins exhibited peroxygenase activity but they were catalytically distinct with respect to their specificity and product formation from fatty acid epoxide and hydroxide substrates. We recently showed that date palm CLO genes were upregulated following exposure to the potent toxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (Hanano et al., 2016), and we show here that transcripts of 9- and 13-lipoxygenase (LOX) genes were also induced by TCDD exposure. At the enzyme level, 9-LOX and 13-LOX activities were present in a range of seedling tissues and responded differently to TCDD exposure, as did the 9- and 13-fatty acid hydroperoxide reductase activities. This demonstrates that at least two branches of the oxylipin pathway are involved in responses to the environmental organic toxin, TCDD in date palm.

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Cited by 163 publications

References 49 publications

Dynamics of the Lipid Droplet Proteome of the Oleaginous Yeast Rhodosporidium toruloides

Dynamics of the Lipid Droplet Proteome of the Oleaginous Yeast Rhodosporidium toruloides

Delineation of plant caleosin residues critical for functional divergence, positive selection and coevolution

Specific Caleosin/Peroxygenase and Lipoxygenase Activities Are Tissue-Differentially Expressed in Date Palm (Phoenix dactylifera L.) Seedlings and Are Further Induced Following Exposure to the Toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin

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