Composition of the protoplast membrane from <i>Saccharomyces cerevisiae</i>

Longley, R. P.; Rose, Anthony H.; Knights, B.A.

doi:10.1042/bj1080401

Cited by 139 publications

(42 citation statements)

References 46 publications

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“…Mass spectral fragmentation patterns of 1A and 1T are typical of C 27 tetraene sterol derivatives (25)(26)(27)(28)(29)(30)(31), based on comparison with literature spectra for C 27 sterol acetates and TMS ethers. The molecular ions (m/z 422 for 1A and m/z 452 for 1T) suggest that this molecule has four unsaturations.…”

Section: Resultsmentioning

confidence: 99%

Sterols in a unicellular relative of the metazoans

Kodner

Summons

Pearson

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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Molecular clocks suggest that animals originated well before they first appear as macroscopic fossils, but geologic tests of these hypotheses have been elusive. A rare steroid hydrocarbon, 24-isopropylcholestane, has been hypothesized to be a biomarker for sponges or their immediate ancestors because of its relatively high abundance in pre-Ediacaran to Early Cambrian sedimentary rocks and oils. Biolipid precursors of this sterane have been reported to be prominent in several demosponges. Whether 24-isopropylcholestane can be interpreted as a sponge (and, hence, animal) biomarker, and so provide clues about early metazoan history, depends on an understanding of the distribution of sterol biosynthesis among animals and their protistan relatives. Accordingly, we characterized the sterol profile of the choanoflagellate Monosiga brevicollis, a representative of the unicellular sister group of animals. M. brevicollis does not produce a candidate sterol precursor for 24-isopropylcholestane under our experimental growth conditions. It does, however, produce a number of other sterols, and comparative genomics confirms its biosynthetic potential to produce the full suite of compounds recovered. Consistent with the phylogenetic position of choanoflagellates, the sterol profile and biosynthetic pathway of M. brevicollis display characteristics of both fungal and poriferan sterol biosynthesis. This is an example in which genomic and biochemical information have been used together to investigate the taxonomic specificity of a fossil biomarker.choanoflagellates ͉ molecular fossils ͉ origin of metazoans ͉ Monosiga brevicollis S terols constitute a diverse class of triterpenoid lipids having wide ranging importance in biology. All eukaryotes require sterols; they serve important functions because membrane lipids play roles as developmental regulators and precursors to steroid hormones in multicellular organisms. Recently, sterols have emerged as an important investigative tool for paleontologists (1-4) because steranes, the hydrocarbon skeletons of sterols, resist microbial attack and remain stable over long periods of time. Thus, they are well represented as molecular fossils in sedimentary rocks. The discovery of diverse steranes in the geologic record has fueled a search for unique precursor sterols in many branches of the eukaryotic tree, because for a molecular fossil to be useful as a biomarker, it must have significant taxonomic and/or physiological specificity.One candidate for a paleobiologically useful biomarker is 24-isopropylcholestane, the geologically stable derivative of the C 30 sterol 24-isopropylcholesterol. Although much of eukaryotic sterol diversity is manifested in double bonds and functional groups that do not preserve in fossil hydrocarbon skeletons, the isopropyl moiety in the side chain of 24-isopropylcholesterol and related sterols results in a structure that is both unique and preservable. Particularly abundant as a molecular fossil in rocks deposited during the Ediacaran and Cambrian periods (3, 5) i...

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Section: Resultsmentioning

confidence: 99%

Sterols in a unicellular relative of the metazoans

Kodner

Summons

Pearson

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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“…This could explain the sensitivity of fungi for these antibiotics. The protoplast membrane lipids from Saccharomyces cerevisiae contain 20--30 mol% ergosterol [15]. At an ergosterol content of 30 mol%, egg lecithin liposomes show a maximal effect of pimaricin, etruscomycin and amphotericin B (Figs.…”

Section: Discussionmentioning

confidence: 99%

The action of pimaricin, etruscomycin and amphotericin B on liposomes with varying sterol content

Teerlink

Kruijff

Demel

1980

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Summary1. The effect of pimaricin, etruscomycin and amphotericin B on the K ÷ release from liposomes is strongly dependent on their sterol concentration.Pimaricin and etruscomycin induce K ÷ release from egg lecithin liposomes with cholesterol contents of more than 25 and 10 mol%, respectively, at polyene concentrations of 100 and 10 ~g/ml, respectively. Amphotericin B shows a maximal effect at a cholesterol content of 20 mol% at a concentration of 0.4 pg/ml.2. For liposomes containing ergosterol the sensitivity is shifted to a lower sterol content. All three l~olyenes show activity at 10 mol% ergosterol. The sensitivity for amphothericin B is increased approx. 15 times by the incorporation of ergosterol compared to cholesterol. The increase in sensitivity is much less for pimaricin and etruscomycin. The K ÷ release is maximal at an ergosterol concentration of 30 mol%.3. Pimaricin, etruscomycin and amphotericin B can induce K ÷ release from erythrocytes without the release of haemoglobin at concentrations of 20, 2 and 1/~g/ml, respectively. For these polyenes a selective permeability change is also demonstrated for liposomes since K ÷ is released but no ['4C]dextran. Filipin shows a nonselective release of solutes from erythrocytes and liposomes.4. At cholesterol concentrations higher than 20 mol% and ergosterol concentrations higher than 10 mol%, etruscomycin, pimaricin and amphotericin B show little dependence of the bflayer thickness and are able to release K ÷ from didocosenoyl phosphatidylcholine liposomes after addition of the polyene to one side of the membrane.A possible mechanism is discussed. 485

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“…This suggested to us that ergosterol, a major component of the plasma membrane accounting for about 15% of the membrane lipids (Longley et al, 1968), is the possible target of the toxin. A null mutant of syrI did not contain ergosterol in the membrane, but was viable and resistant to syringomycin.…”

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confidence: 99%

Protection by sterols against the cytotoxicity of syringomycin in the yeast Saccharomyces cereuisiae

Julmanop

Takano

Takemoto

et al. 1993

Journal of General Microbiology

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A brief exposure (ca 20 min) of the yeast Saccharomyces cerevisiae to the phytotoxin syringomycin was sufficient to kill the cell. The protective effect of sterols against this cytotoxicity of syringomycin was investigated. Syringomycin was much more toxic to growing cells than to stationary-phase cells. The cytotoxicity of syringomycin was reduced in an environment containing sterols. Cytotoxicity of syringomycin at 3 pg ml-' (ca 2-5 p~) was completely abolished by the simultaneous presence of 10 pwcholesterol in the medium. Cholesterol acetate had no protective effect. Ergosterol, sitosterol and stigmasterol also protected against syringomycin, but they were less effective than cholesterol. The protective effect of sterols against the action of syringomycin is consistent with our hypothesis that membrane ergosterol is a critical component for syringomycin-binding as suggested by recent genetic studies.

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Composition of the protoplast membrane from Saccharomyces cerevisiae

Cited by 139 publications

References 46 publications

Sterols in a unicellular relative of the metazoans

Sterols in a unicellular relative of the metazoans

The action of pimaricin, etruscomycin and amphotericin B on liposomes with varying sterol content

Protection by sterols against the cytotoxicity of syringomycin in the yeast Saccharomyces cereuisiae

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