Publikationsdatum:
2021-02-11
Beschreibung:
‘Oleaginous’ yeasts have the ability to store greater than of 20% of their mass as neutral lipids, in the form of triaclglycerides. The ATP:Citrate lyase is thought to play a key role in triaclglyceride synthesis, but the relationship between expression levels of this and other related enzymes are not well understood in the role of total lipid accumulation conferring the oleaginous phenotype. We conducted comparative proteomic analyses with the oleaginous yeast, Yarrowia lipolytica, grown in either nitrogen-sufficient rich media, or nitrogen-limited minimal media for comparison. Total proteins extracted from cells collected during logarithmic and late stationary growth phases were analyzed by one-dimensional liquid chromatography, followed by mass spectroscopy. The ATP:Citrate lyase enzyme was expressed at similar concentrations in both conditions, in both logarithmic and stationary phase, but many upstream and downstream enzymes showed drastically different expression levels. In non-lipogenic conditions, several pyruvate enzymes were expressed at higher concentration. These enzymes, especially the pyruvate decarboxylase and pyruvate dehydrogenase may be regulating carbon flux away from central metabolism and reducing the amount of citrate being produced in the mitochondria. While crucial for the oleaginous phenotype, the constitutively expressed ATP:Citrate lyase appears to cleave citrate in response to carbon flux upstream from other enzymes creating the oleaginous phenotype.
Print ISSN:
1567-1356
Digitale ISSN:
1567-1364
Thema:
Biologie
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