Isolation of lipid particles from baker's yeast

Clausen, Marianne K.; Christiansen, Karl O.; Jensen, P.K.; Behnke, O.

doi:10.1016/0014-5793(74)80994-4

Cited by 94 publications

(52 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They are characterized by a high triacylglycerol content (data not shown) and a high ergosteryl ester-to-ergo'sterol ratio of 13.3: 1, which is in sharp contrast to membranous subcellular fractions. These results are in ood agreement with data reported earlier by Clausen et al (9). It is conceivable that lipid particles are the major location of ergosteryl esters within the yeast cell and that the presence of ergosteryl esters in membrane preparations of vacuoles and nuclei is the result of cross-contamination with lipid particles.…”

Section: Resultssupporting

confidence: 93%

Phospholipid synthesis and lipid composition of subcellular membranes in the unicellular eukaryote Saccharomyces cerevisiae

et al. 1991

View full text Add to dashboard Cite

improved procedures and analyzed for their lipid composition and their capacity to synthesize phospholipids and to catalyze sterol A24-methylation. The microsomal fraction is heterogeneous in terms of density and classical microsomal marker proteins and also with respect to the distribution of phospholipid-synthesizing enzymes. The specific activity of phosphatidylserine synthase was highest in a microsomal subfraction which was distinct from heavier microsomes harboring phosphatidylinositol synthase and the phospholipid N-methyltransferases. The exclusive location of phosphatidylserine decarboxylase in mitochondria was confirmed. CDP-diacylglycerol synthase activity was found both in mitochondria and in microsomal membranes. Highest specific activities of glycerol-3-phosphate acyltransferase and sterol A24-methyltransferase were observed in the lipid particle fraction. Nuclear and plasma membranes, vacuoles, and peroxisomes contain only marginal activities of the lipid-synthesizing enzymes analyzed. The plasma membrane and secretory vesicles are enriched in ergosterol and in phosphatidylserine. Lipid particles are characterized by their high content of ergosteryl esters. The rigidity of the plasma membrane and of secretory vesicles, determined by measuring fluorescence anisotropy by using trimethylammonium diphenylhexatriene as a probe, can be attributed to the high content of ergosterol.Most of the enzymes involved in cellular phospholipid biosynthesis are membrane associated. In mammalian cells, the majority of phospholipids is synthesized in the endoplasmic reticulum (14). Phospholipids specifically required for mitochondrial function (cardiolipin and its precursor phosphatidylglycerol) as well as phosphatidylethanolamine (via decarboxylation of phosphatidylserine) are synthesized in mitochondrial membranes (11).In previous studies, several enzymes of phospholipid biosynthesis of the yeast Saccharomyces cerevisiae (10,26), namely glycerol-3-phosphate acyltransferase, CDP-diacylglycerol synthase, phosphatidylserine synthase, and phosphatidylinositol synthase, were detected both in the microsomal fraction and in the outer mitochondrial membrane. These observations were based mainly on the separation of subcellular membranes by differential centrifugation and on commonly used marker enzymes for the respective fractions. Motivated by our interest in the mechanisms of lipid flow and membrane assembly in yeasts and by conflicting data concerning the subcellular targeting of phosphatidylserine synthase (38), we reinvestigated the subcellular distribution of lipid-synthesizing enzymes by employing recently developed or improved fractionation procedures for mitochondrial and microsomal membranes, the nuclear membrane (24), the plasma membrane (37) Yeast subcellular membranes were also characterized with respect to their protein-to-lipid ratio, their content of ergosterol and ergosteryl esters, and their pattern of individual glycerophospholipids. Measurements of fluorescence anisotropy revealed significant difference...

show abstract

Section: Resultssupporting

confidence: 93%

Phospholipid synthesis and lipid composition of subcellular membranes in the unicellular eukaryote Saccharomyces cerevisiae

et al. 1991

View full text Add to dashboard Cite

show abstract

“…3I-II,C,D), two distinct structures were observed, although no more than four structures could be seen in sections so far examined. These distinct structures are similar not only to the one demonstrated in Toxoplasma (Charron and Sibley, 2002) but also to the cytoplasmic lipid droplets and/or lipid bodies purified from mammalian, yeast and fungal cells (Clausen et al, 1974;Dylewski et al, 1984;Kamisaka et al, 1999;Fujimoto et al, 2001). However, no such structures could be found in the parasitophorous vacuole (PV) from schizont and segmented schizont sections.…”

Section: Composition and Distribution Of Neutral Lipid Species In Infsupporting

confidence: 73%

Developmental-stage-specific triacylglycerol biosynthesis, degradation and trafficking as lipid bodies inPlasmodium falciparum-infected erythrocytes

Palacpac

Hiramine

Mi-ichi

et al. 2004

Journal of Cell Science

View full text Add to dashboard Cite

Triacylglycerol (TAG) serves as a major energy storage molecule in eukaryotes. In Plasmodium, however, this established function of TAG appears unlikely, despite detecting previously considerable amount of TAG associated with intraerythrocytic parasites, because plasmodial cells have very little capacity to oxidize fatty acids. Thus, it is plausible that TAG and its biosynthesis in Plasmodium have other functions. As a first step in understanding the biological significance of TAG and its biosynthesis to the intraerythrocytic proliferation of Plasmodium falciparum, we performed detailed characterization of TAG metabolism and trafficking in parasitized erythrocyte. Metabolic labeling using radiolabeled-oleic and palmitic acids in association with serum albumin, which have been shown to be among the serum essential factors for intraerythrocytic proliferation of P. falciparum, revealed that accumulation of TAG was strikingly pronounced from trophozoite to schizont, whereas TAG degradation became active from schizont to segmented schizont; the consequent products, free fatty acids, were released into the medium during schizont rupture and/or merozoite release. These results were further supported by visualization of lipid bodies through immunofluorescence and electron microscopy. At the schizont stages, there is some evidence that the lipid bodies are partly localized in the parasitophorous vacuole. Interestingly, the discrete formation and/or trafficking of lipid bodies are inhibited by brefeldin A and trifluoperazine. Inhibition by trifluoperazine hints at least that a de novo TAG biosynthetic pathway via phosphatidic acid contributes to lipid body formation. Indeed, biochemical analysis reveals a higher activity of acyl-CoA:diacylglycerol acyltransferase, the principal enzyme in the sn-glycerol-3-phosphate pathway for TAG synthesis, at trophozoite and schizont stages. Together, these results establish that TAG metabolism and trafficking in P. falciparum-infected erythrocyte occurs in a stage-specific manner during the intraerythrocytic cycle and we propose that these unique and dynamic cellular events participate during schizont rupture and/or merozoite release.

show abstract

“…accumulate lipid bodies that become enriched in esterified cholesterol (Fruchart, 1992). Similarly, yeast (Clausen et al, 1974;Taylor and Parks, 1978) and tobacco (Maillot-Vernier et al, 1991;Schaller et al, 1992;Gondet, 1993) mutants that overproduce sterols spontaneously produce an abundance of lipid globules, which sequester the excess sterols. In seeds, excess triacylglycerols accumulate within oleosomes (Appelqvist, 1975), which consist of a triacylglycerol core surrounded by a layer of polar lipids that contain an oleosome-specific protein termed oleosin (Vance and Huang, 1987;Li et al, 1992;Tzen and Huang, 1992).…”

Section: Introductionmentioning

confidence: 99%

Fibril assembly and carotenoid overaccumulation in chromoplasts: a model for supramolecular lipoprotein structures.

et al. 1994

View full text Add to dashboard Cite

Chromoplast development in ripening bell pepper fruits is characterized by a massive synthesis of carotenoid pigments, resulting in their distinctlve red color. We have shown that 95% of these pigments accumulate in chromoplasts in speclfic lipoprotein fibrils. In addltion to carotenoids, purified fibrils contain galactolipids, phospholipids, and a single, 32-kD protein, designated fibrillin, which has antigenically related counterparts in other species. Fibrlls were reconstltuted in vitro when purified fibrillin was combined with carotenoids and polar llpids in the same stoichlometrlc ratlo found in fibrils in vivo. Antibodies dlrected against fibrillin were used to isolate a fibrillin cDNA clone and, in immunological studies, to follow its accumulation during the chloroplast-tothromoplast transltlon under different condltions. A model for fibril amhitecture is proposed wherein carotenoids accumulate in the center of the fibrils and are surrounded by a layer of polar lipids, which in turn are surrounded by an outer layer of fibrillin. Topological analysis of purlfied fibrils verified this structure. Collectively, these results suggest that the process of fibrll self-assembly in chromoplasts 1s an example of a general phenomenon shared among cells that target excess membrane llpids into deposit structures to avoid their destabilizing or toxic effects. In addition, we have shown that abscisic acid stimulates this phenomenon in chromoplasts, whereas gibberellic acid and auxin delay it.

show abstract

Isolation of lipid particles from baker's yeast

Cited by 94 publications

References 14 publications

Phospholipid synthesis and lipid composition of subcellular membranes in the unicellular eukaryote Saccharomyces cerevisiae

Phospholipid synthesis and lipid composition of subcellular membranes in the unicellular eukaryote Saccharomyces cerevisiae

Developmental-stage-specific triacylglycerol biosynthesis, degradation and trafficking as lipid bodies inPlasmodium falciparum-infected erythrocytes

Fibril assembly and carotenoid overaccumulation in chromoplasts: a model for supramolecular lipoprotein structures.

Contact Info

Product

Resources

About