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Genetic interactions between a phospholipase A2 and the Rim101 pathway components in S. cerevisiae reveal a role for this pathway in response to changes in membrane composition and shape.

Mattiazzi M, Jambhekar A, Kaferle P, Derisi JL, Krizaj I, Petrovic U - Mol. Genet. Genomics (2010)

Bottom Line: We have conducted a genome-wide analysis of cellular effects of a PLA(2) in the yeast Saccharomyces cerevisiae as a model system.Our results suggest that the composition and/or the shape of the endosomal membrane affect the Rim101 pathway.This study provides a list of the players involved in the global response to changes in membrane composition and shape in a model eukaryotic cell, and further studies are needed to understand the precise molecular mechanisms connecting them.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Biomedical Sciences, Jozef Stefan Institute, 1000 Ljubljana, Slovenia.

ABSTRACT
Modulating composition and shape of biological membranes is an emerging mode of regulation of cellular processes. We investigated the global effects that such perturbations have on a model eukaryotic cell. Phospholipases A(2) (PLA(2)s), enzymes that cleave one fatty acid molecule from membrane phospholipids, exert their biological activities through affecting both membrane composition and shape. We have conducted a genome-wide analysis of cellular effects of a PLA(2) in the yeast Saccharomyces cerevisiae as a model system. We demonstrate functional genetic and biochemical interactions between PLA(2) activity and the Rim101 signaling pathway in S. cerevisiae. Our results suggest that the composition and/or the shape of the endosomal membrane affect the Rim101 pathway. We describe a genetically and functionally related network, consisting of components of the Rim101 pathway and the prefoldin, retromer and SWR1 complexes, and predict its functional relation to PLA(2) activity in a model eukaryotic cell. This study provides a list of the players involved in the global response to changes in membrane composition and shape in a model eukaryotic cell, and further studies are needed to understand the precise molecular mechanisms connecting them.

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Related in: MedlinePlus

PLA2 expression inhibits endocytosis in yeast. The rate of endocytosis in the PLA2-expressing strain (WT + PLA2) is reduced to 45% (±10%) as compared to the control non-PLA2-expressing wild-type strain (WT). As a positive control, we measured the rate of endocytosis in the end3Δ strain. Lucifer Yellow dye uptake measurement was done as described in the “Materials and methods”. Represented are the relative endocytosis rates for the WT + PLA2 and end3Δ strains that were calculated by normalizing to the WT measurement. The rate of endocytosis was measured for the same three strains also at alkaline pH (3 right columns) and normalized to the WT measurement at acidic pH (left column). The ratios of relative endocytosis rates are independent of pH
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Fig2: PLA2 expression inhibits endocytosis in yeast. The rate of endocytosis in the PLA2-expressing strain (WT + PLA2) is reduced to 45% (±10%) as compared to the control non-PLA2-expressing wild-type strain (WT). As a positive control, we measured the rate of endocytosis in the end3Δ strain. Lucifer Yellow dye uptake measurement was done as described in the “Materials and methods”. Represented are the relative endocytosis rates for the WT + PLA2 and end3Δ strains that were calculated by normalizing to the WT measurement. The rate of endocytosis was measured for the same three strains also at alkaline pH (3 right columns) and normalized to the WT measurement at acidic pH (left column). The ratios of relative endocytosis rates are independent of pH

Mentions: It has recently been proposed that endocytosis of plasma membrane pH sensors is an upstream event leading to Rim101p activation (Boysen and Mitchell 2006). We therefore measured LY uptake to determine the effect of PLA2 expression on the rate of endocytosis in yeast cells. As a control, we measured the rate of endocytosis in the end3Δ strain (Fig. 2). The rate of endocytosis in the wild-type strain expressing PLA2 was reduced to ~45% of the control (wild-type, non-PLA2-expressing) strain. The effect of PLA2 on the rate of endocytosis was also observed under alkaline conditions, since also at pH 7.4 relative differences in the rate of LY uptake remained unchanged, while the absolute values were lower (Fig. 2).Fig. 2


Genetic interactions between a phospholipase A2 and the Rim101 pathway components in S. cerevisiae reveal a role for this pathway in response to changes in membrane composition and shape.

Mattiazzi M, Jambhekar A, Kaferle P, Derisi JL, Krizaj I, Petrovic U - Mol. Genet. Genomics (2010)

PLA2 expression inhibits endocytosis in yeast. The rate of endocytosis in the PLA2-expressing strain (WT + PLA2) is reduced to 45% (±10%) as compared to the control non-PLA2-expressing wild-type strain (WT). As a positive control, we measured the rate of endocytosis in the end3Δ strain. Lucifer Yellow dye uptake measurement was done as described in the “Materials and methods”. Represented are the relative endocytosis rates for the WT + PLA2 and end3Δ strains that were calculated by normalizing to the WT measurement. The rate of endocytosis was measured for the same three strains also at alkaline pH (3 right columns) and normalized to the WT measurement at acidic pH (left column). The ratios of relative endocytosis rates are independent of pH
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2872012&req=5

Fig2: PLA2 expression inhibits endocytosis in yeast. The rate of endocytosis in the PLA2-expressing strain (WT + PLA2) is reduced to 45% (±10%) as compared to the control non-PLA2-expressing wild-type strain (WT). As a positive control, we measured the rate of endocytosis in the end3Δ strain. Lucifer Yellow dye uptake measurement was done as described in the “Materials and methods”. Represented are the relative endocytosis rates for the WT + PLA2 and end3Δ strains that were calculated by normalizing to the WT measurement. The rate of endocytosis was measured for the same three strains also at alkaline pH (3 right columns) and normalized to the WT measurement at acidic pH (left column). The ratios of relative endocytosis rates are independent of pH
Mentions: It has recently been proposed that endocytosis of plasma membrane pH sensors is an upstream event leading to Rim101p activation (Boysen and Mitchell 2006). We therefore measured LY uptake to determine the effect of PLA2 expression on the rate of endocytosis in yeast cells. As a control, we measured the rate of endocytosis in the end3Δ strain (Fig. 2). The rate of endocytosis in the wild-type strain expressing PLA2 was reduced to ~45% of the control (wild-type, non-PLA2-expressing) strain. The effect of PLA2 on the rate of endocytosis was also observed under alkaline conditions, since also at pH 7.4 relative differences in the rate of LY uptake remained unchanged, while the absolute values were lower (Fig. 2).Fig. 2

Bottom Line: We have conducted a genome-wide analysis of cellular effects of a PLA(2) in the yeast Saccharomyces cerevisiae as a model system.Our results suggest that the composition and/or the shape of the endosomal membrane affect the Rim101 pathway.This study provides a list of the players involved in the global response to changes in membrane composition and shape in a model eukaryotic cell, and further studies are needed to understand the precise molecular mechanisms connecting them.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Biomedical Sciences, Jozef Stefan Institute, 1000 Ljubljana, Slovenia.

ABSTRACT
Modulating composition and shape of biological membranes is an emerging mode of regulation of cellular processes. We investigated the global effects that such perturbations have on a model eukaryotic cell. Phospholipases A(2) (PLA(2)s), enzymes that cleave one fatty acid molecule from membrane phospholipids, exert their biological activities through affecting both membrane composition and shape. We have conducted a genome-wide analysis of cellular effects of a PLA(2) in the yeast Saccharomyces cerevisiae as a model system. We demonstrate functional genetic and biochemical interactions between PLA(2) activity and the Rim101 signaling pathway in S. cerevisiae. Our results suggest that the composition and/or the shape of the endosomal membrane affect the Rim101 pathway. We describe a genetically and functionally related network, consisting of components of the Rim101 pathway and the prefoldin, retromer and SWR1 complexes, and predict its functional relation to PLA(2) activity in a model eukaryotic cell. This study provides a list of the players involved in the global response to changes in membrane composition and shape in a model eukaryotic cell, and further studies are needed to understand the precise molecular mechanisms connecting them.

Show MeSH
Related in: MedlinePlus