Depletion of acyl-coenzyme A-binding protein affects sphingolipid synthesis and causes vesicle accumulation and membrane defects in Saccharomyces cerevisiae.
Mol Biol Cell
; 12(4): 1147-60, 2001 Apr.
Article
em En
| MEDLINE
| ID: mdl-11294913
ABSTRACT
Deletion of the yeast gene ACB1 encoding Acb1p, the yeast homologue of the acyl-CoA-binding protein (ACBP), resulted in a slower growing phenotype that adapted into a faster growing phenotype with a frequency >110(5). A conditional knockout strain (Y700pGAL1-ACB1) with the ACB1 gene under control of the GAL1 promoter exhibited an altered acyl-CoA profile with a threefold increase in the relative content of C180-CoA, without affecting total acyl-CoA level as previously reported for an adapted acb1Delta strain. Depletion of Acb1p did not affect the general phospholipid pattern, the rate of phospholipid synthesis, or the turnover of individual phospholipid classes, indicating that Acb1p is not required for general glycerolipid synthesis. In contrast, cells depleted for Acb1p showed a dramatically reduced content of C260 in total fatty acids and the sphingolipid synthesis was reduced by 50-70%. The reduced incorporation of [(3)H]myo-inositol into sphingolipids was due to a reduced incorporation into inositol-phosphoceramide and mannose-inositol-phosphoceramide only, a pattern that is characteristic for cells with aberrant endoplasmic reticulum to Golgi transport. The plasma membrane of the Acb1p-depleted strain contained increased levels of inositol-phosphoceramide and mannose-inositol-phosphoceramide and lysophospholipids. Acb1p-depleted cells accumulated 50- to 60-nm vesicles and autophagocytotic like bodies and showed strongly perturbed plasma membrane structures. The present results strongly suggest that Acb1p plays an important role in fatty acid elongation and membrane assembly and organization.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Esfingolipídeos
/
Proteínas Fúngicas
/
Proteínas de Transporte
Tipo de estudo:
Etiology_studies
Idioma:
En
Revista:
Mol Biol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2001
Tipo de documento:
Article