Back to Search
Start Over
The Saccharomyces cerevisiae Actin Patch Protein App1p Is a Phosphatidate Phosphatase Enzyme
- Source :
- Journal of Biological Chemistry. 287:40186-40196
- Publication Year :
- 2012
- Publisher :
- Elsevier BV, 2012.
-
Abstract
- Phosphatidate phosphatase (PAP) plays diverse roles in lipid metabolism and cell signaling.A novel yeast PAP is identified as the actin patch protein encoded by APP1.APP1 and other known genes (PAH1, DPP1, LPP1) are responsible for all detectable PAP activity in yeast.Identification of App1p as a PAP enzyme will facilitate the understanding of its cellular function. Phosphatidate phosphatase (PAP) catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol. In the yeast Saccharomyces cerevisiae, PAP is encoded by PAH1, DPP1, and LPP1. The presence of PAP activity in the pah1Δ dpp1Δ lpp1Δ triple mutant indicated another gene(s) encoding the enzyme. We purified PAP from the pah1Δ dpp1Δ lpp1Δ triple mutant by salt extraction of mitochondria followed by chromatography with DE52, Affi-Gel Blue, phenyl-Sepharose, MonoQ, and Superdex 200. Liquid chromatography/tandem mass spectrometry analysis of a PAP-enriched sample revealed multiple putative phosphatases. By analysis of PAP activity in mutants lacking each of the proteins, we found that APP1, a gene whose molecular function has been unknown, confers ~30% PAP activity of wild type cells. The overexpression of APP1 in the pah1Δ dpp1Δ lpp1Δ mutant exhibited a 10-fold increase in PAP activity. The PAP activity shown by App1p heterologously expressed in Escherichia coli confirmed that APP1 is the structural gene for the enzyme. Introduction of the app1Δ mutation into the pah1Δ dpp1Δ lpp1Δ triple mutant resulted in a complete loss of PAP activity, indicating that distinct PAP enzymes in S. cerevisiae are encoded by APP1, PAH1, DPP1, and LPP1. Lipid analysis of cells lacking the PAP genes, singly or in combination, showed that Pah1p is the only PAP involved in the synthesis of triacylglycerol as well as in the regulation of phospholipid synthesis. App1p, which shows interactions with endocytic proteins, may play a role in vesicular trafficking through its PAP activity.
- Subjects :
- Amino Acid Motifs
Saccharomyces cerevisiae
Phosphatase
Mutant
Biology
Aminopeptidases
Biochemistry
Phosphatidate
Molecular Biology
Diacylglycerol kinase
Arabidopsis Proteins
Structural gene
Wild type
Membrane Proteins
Cell Biology
respiratory system
Phosphatidate phosphatase
Lipid Metabolism
biology.organism_classification
Lipids
Molecular biology
female genital diseases and pregnancy complications
lipids (amino acids, peptides, and proteins)
human activities
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 287
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi.dedup.....f17c2e4864924299308748f4737d9d1c
- Full Text :
- https://doi.org/10.1074/jbc.m112.421776