The yeast proteolipid Pmp3p affects plasma membrane sphingolipid abundance
(2014)
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- Authors
- Supervisors
- Morsomme, Pierre
- Abstract
- Sphingolipids are essential components of plasma membrane in higher eucaryotes. In the yeast S. cerevisiae, their metabolism is tightly regulated and dependent on temperature, carbon source and growth phase. Most proteins involved in their metabolism have been studied. Their transport is thought to be non-specific, through the secretory and endocytic pathways. The UPF0057 protein family of unknown function is widespread amongst yeasts, bacteria, nematodes and plants. This family is composed of four proteins in the budding yeast: Sna1p/Pmp3p localized at the plasma membrane and Sna2p, Sna3p and Sna4p in the vacuole membrane and lumen. Their targeting sequences have been thoroughly studied in our laboratory, but their primary function has still to be discovered. In this study, we searched for the function of these proteins in the yeast Saccharomyces cerevisiae. Thanks to phenotypic growth tests and thorough literature analysis we discovered genetic interactions between PMP3 and genes involved in sphingolipid metabolism. Then a lipidomic mass spectrometry analysis of plasma membrane purified from wild-type and pmp3∆ strains showed an accumulation of mannose-inositol-phosphoceramide in pmp3∆ plasma membrane. Finally proteins – lipids interactions measurement underscored the higher affinity of Pmp3p for sphingolipids compared to other lipids. Our data suggest that Pmp3p affects plasma membrane sphingolipid abundance. We propose that the Sna family carries or helps the transport of mannose-inositol-phosphoceramide from the plasma membrane to the vacuole. A lack of this transport has effects on the plasma membrane proteome and lipidome and on mitochondria function.
- Affiliations
Citations
De Block, J. (2014). The yeast proteolipid Pmp3p affects plasma membrane sphingolipid abundance. https://hdl.handle.net/2078.5/193355