Flux of sterol intermediates in a yeast strain deleted of the lanosterol C-14 demethylase Erg11p
| Autor: | Helmut Bergler, Rene G. Ott, Karin Athenstaedt, Erich Leitner, Claudia Hrastnik, Günther Daum |
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| Rok vydání: | 2005 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Saccharomyces cerevisiae Mutant Biology Endoplasmic Reticulum chemistry.chemical_compound Sterol 14-Demethylase Cytochrome P-450 Enzyme System polycyclic compounds Molecular Biology Ergosterol Lanosterol Cell Membrane Wild type Biological Transport Cell Biology biology.organism_classification Sterol Sterols chemistry Biochemistry biology.protein lipids (amino acids peptides and proteins) Oxidoreductases Gene Deletion Lanosterol synthase |
| Zdroj: | TU Graz |
| ISSN: | 0006-3002 |
| Popis: | Lanosterol C-14 demethylase Erg11p of the yeast Saccharomyces cerevisiae catalyzes the enzymatic step following formation of lanosterol by the lanosterol synthase Erg7p in lipid particles (LP). Localization experiments employing microscopic inspection and cell fractionation revealed that Erg11p in contrast to Erg7p is associated with the endoplasmic reticulum (ER). An erg11Delta mutation in erg3Delta background, which is required to circumvent lethality of the erg11 defect, did not only change the sterol pattern but also the sterol distribution within the cell. Whereas in wild type the plasma membrane was highly enriched in ergosterol and LP harbored large amounts of sterol precursors in the form of steryl esters, sterol intermediates were more or less evenly distributed among organelles of erg11Delta erg3Delta. This distribution is not result of the erg3Delta background, because in the erg3Delta strain the major intermediate formed, ergosta-7,22-dienol, is also highly enriched in the plasma membrane similar to ergosterol in wild type. These results indicate that (i) exit of lanosterol from LP occurs independently of functional Erg11p, (ii) random supply of sterol intermediates to all organelles of erg11Delta erg3Delta appears to compensate for the lack of ergosterol in this mutant, and (iii) preferential sorting of ergosterol in wild type, but also of ergosta-7,22-dienol in erg3Delta, supplies sterol to the plasma membrane. |
| Databáze: | OpenAIRE |
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