• Register
X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

X

Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.

No
Yes

Lag1p and Lac1p are essential for the Acyl-CoA-dependent ceramide synthase reaction in Saccharomyces cerevisae.

Lag1p and Lac1p are two homologous transmembrane proteins of the endoplasmic reticulum in Saccharomyces cerevisiae. Homologous genes have been found in a wide variety of eukaryotes. In yeast, both genes, LAC1 and LAG1, are required for efficient endoplasmic reticulum-to-Golgi transport of glycosylphosphatidylinositol-anchored proteins. In this study, we show that lag1 Delta lac1 Delta cells have reduced sphingolipid levels due to a block of the fumonisin B1-sensitive and acyl-CoA-dependent ceramide synthase reaction. The sphingolipid synthesis defect in lag1 Delta lac1 Delta cells can be partially corrected by overexpression of YPC1 or YDC1, encoding ceramidases that have been reported to have acyl-CoA-independent ceramide synthesis activity. Quadruple mutant cells (lag1 Delta lac1 Delta ypc1 Delta ydc1 Delta) do not make any sphingolipids, but are still viable probably because they produce novel lipids. Moreover, lag1 Delta lac1 Delta cells are resistant to aureobasidin A, an inhibitor of the inositolphosphorylceramide synthase, suggesting that aureobasidin A may be toxic because it leads to increased ceramide levels. Based on these data, LAG1 and LAC1 are the first genes to be identified that are required for the fumonisin B1-sensitive and acyl-CoA-dependent ceramide synthase reaction.

Pubmed ID: 11694577

Authors

  • Schorling S
  • VallĂ©e B
  • Barz WP
  • Riezman H
  • Oesterhelt D

Journal

Molecular biology of the cell

Publication Data

November 5, 2001

Associated Grants

None

Mesh Terms

  • Acyl Coenzyme A
  • Amidohydrolases
  • Carboxylic Acids
  • Ceramidases
  • Ceramides
  • Enzyme Inhibitors
  • Fumonisins
  • Fungal Proteins
  • Membrane Proteins
  • Mutagenesis
  • Oxidoreductases
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Sphingolipids