High impact information on LAC1

• In this study, we expressed tagged versions of Lac1p and Lag1p and purified them to near homogeneity [1].
• C26-CoA-dependent ceramide synthesis of Saccharomyces cerevisiae is operated by Lag1p and Lac1p [2].
• A close homolog of this gene, which we call LAC1, has been found in the yeast genome [3].
• Lag1p and Lac1p are two highly homologous membrane proteins of the endoplasmic reticulum. lag1delta lac1delta double mutants in Saccharomyces cerevisiae lack an acyl-CoA-dependent ceramide synthase and are either very sick or nonviable, depending on the genetic background [4].
• 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 [5].

Biological context of LAC1

• YKL156 is a homolog to UOG-1, an open reading frame associated with the cDNA clone of the mammalian growth/differentiation factor 1 [6].
• The N- and C-termini of the proteins are in the cytoplasm and eight putative membrane-spanning domains were identified in Lag1p and Lac1p by insertion of glycosylation and factor Xa cleavage sites at various positions [7].
• Reporter gene, Northern blot, and Western blot assays indicated that the expression level of Lac1p is approximately three times that of Lag1p [8].

Anatomical context of LAC1

• Lag1p and Lac1p are two homologous transmembrane proteins of the endoplasmic reticulum in Saccharomyces cerevisiae [5].

Associations of LAC1 with chemical compounds

• 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 [5].
• Differential regulation of ceramide synthase components LAC1 and LAG1 in Saccharomyces cerevisiae [8].
• 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 [5].
• The lac1 gene encoding an extracellular laccase was isolated from the thermophilic fungus Melanocarpus albomyces [9].

Regulatory relationships of LAC1

• Detailed analyses of the LAC1 promoter demonstrated that transcription of this gene is inhibited by the presence of the transcription factor Cbf1p and the anaerobic repressor Rox1p [8].

Other interactions of LAC1

• In yeast, both genes, LAC1 and LAG1, are required for efficient endoplasmic reticulum-to-Golgi transport of glycosylphosphatidylinositol-anchored proteins [5].
• Neither deletion of LAC1 nor overexpression of YPC1 had a detectable effect on wild-type life span [10].
• The data presented here demonstrate that the pleiotropic drug resistance (Pdr) regulatory pathway regulates the transcription of multiple genes encoding steps in sphingolipid biosynthesis, including LAC1 [8].

References