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Plasma membrane microdomains regulate turnover of transport proteins in yeast.

Grossmann G, Malinsky J, Stahlschmidt W, Loibl M, Weig-Meckl I, Frommer WB, Opekarová M, Tanner W - J. Cell Biol. (2008)

Bottom Line: Deletion of Pil1, a component of eisosomes, or of Nce102, an integral membrane protein of MCC, results in the dissipation of all MCC markers.These deletion mutants also show accelerated endocytosis of MCC-resident permeases Can1 and Fur4.Addition of arginine to wild-type cells leads to a similar redistribution and increased turnover of Can1.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cell Biology and Plant Physiology, University of Regensburg, 93053 Regensburg, Germany.

ABSTRACT
In this study, we investigate whether the stable segregation of proteins and lipids within the yeast plasma membrane serves a particular biological function. We show that 21 proteins cluster within or associate with the ergosterol-rich membrane compartment of Can1 (MCC). However, proteins of the endocytic machinery are excluded from MCC. In a screen, we identified 28 genes affecting MCC appearance and found that genes involved in lipid biosynthesis and vesicle transport are significantly overrepresented. Deletion of Pil1, a component of eisosomes, or of Nce102, an integral membrane protein of MCC, results in the dissipation of all MCC markers. These deletion mutants also show accelerated endocytosis of MCC-resident permeases Can1 and Fur4. Our data suggest that release from MCC makes these proteins accessible to the endocytic machinery. Addition of arginine to wild-type cells leads to a similar redistribution and increased turnover of Can1. Thus, MCC represents a protective area within the plasma membrane to control turnover of transport proteins.

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Related in: MedlinePlus

10 new proteins sharing the MCC localization. Cortical distributions of 10 proteins (left; green in merge) were colocalized with the MCC pattern marked with Sur7-mRFP (middle; red in merge). Tangential confocal sections are presented showing the cell surface and fluorescence intensity profiles (diagrams) measured along the arrows. Mean filter was applied on the plotted curves to reduce the noise present in the raw data. Red and green curves were normalized to the same maximum value. Bar, 5 μm.
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fig1: 10 new proteins sharing the MCC localization. Cortical distributions of 10 proteins (left; green in merge) were colocalized with the MCC pattern marked with Sur7-mRFP (middle; red in merge). Tangential confocal sections are presented showing the cell surface and fluorescence intensity profiles (diagrams) measured along the arrows. Mean filter was applied on the plotted curves to reduce the noise present in the raw data. Red and green curves were normalized to the same maximum value. Bar, 5 μm.

Mentions: Visual inspection of the yeast database of proteins fused to GFP (Huh et al., 2003), covering two thirds of all annotated ORFs, revealed potential patch formation of several proteins. These proteins were tested for colocalization with Sur7–monomeric red fluorescent protein (mRFP), an endogenous marker of MCC (Malínská et al., 2004). In addition to the known set of 11 proteins, 10 new proteins that colocalized with the MCC pattern were identified (Fig. 1 and Table I). The set includes nine integral plasma membrane proteins with either 12 or four predicted transmembrane domains, three of which are transporters for small molecules. The 12 other proteins are soluble, and their patchy appearance at the cell cortex indicates their accumulation at the cytoplasmic side of the plasma membrane. These proteins include the eisosomal components Pil1 and Lsp1, two protein kinases that regulate endocytosis (Pkh1 and Pkh2), Slm1, a protein involved in actin cytoskeleton formation, several flavodoxin-like proteins (Pst2, Rfs1, and Ycp4), and four proteins with an unknown function. A BLAST (basic local alignment search tool) analysis did not identify conserved domains in the 21 proteins that would indicate the existence of a specific targeting sequence motif. Because of the incomplete localization database, even further MCC-associated proteins can be expected.


Plasma membrane microdomains regulate turnover of transport proteins in yeast.

Grossmann G, Malinsky J, Stahlschmidt W, Loibl M, Weig-Meckl I, Frommer WB, Opekarová M, Tanner W - J. Cell Biol. (2008)

10 new proteins sharing the MCC localization. Cortical distributions of 10 proteins (left; green in merge) were colocalized with the MCC pattern marked with Sur7-mRFP (middle; red in merge). Tangential confocal sections are presented showing the cell surface and fluorescence intensity profiles (diagrams) measured along the arrows. Mean filter was applied on the plotted curves to reduce the noise present in the raw data. Red and green curves were normalized to the same maximum value. Bar, 5 μm.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2600745&req=5

fig1: 10 new proteins sharing the MCC localization. Cortical distributions of 10 proteins (left; green in merge) were colocalized with the MCC pattern marked with Sur7-mRFP (middle; red in merge). Tangential confocal sections are presented showing the cell surface and fluorescence intensity profiles (diagrams) measured along the arrows. Mean filter was applied on the plotted curves to reduce the noise present in the raw data. Red and green curves were normalized to the same maximum value. Bar, 5 μm.
Mentions: Visual inspection of the yeast database of proteins fused to GFP (Huh et al., 2003), covering two thirds of all annotated ORFs, revealed potential patch formation of several proteins. These proteins were tested for colocalization with Sur7–monomeric red fluorescent protein (mRFP), an endogenous marker of MCC (Malínská et al., 2004). In addition to the known set of 11 proteins, 10 new proteins that colocalized with the MCC pattern were identified (Fig. 1 and Table I). The set includes nine integral plasma membrane proteins with either 12 or four predicted transmembrane domains, three of which are transporters for small molecules. The 12 other proteins are soluble, and their patchy appearance at the cell cortex indicates their accumulation at the cytoplasmic side of the plasma membrane. These proteins include the eisosomal components Pil1 and Lsp1, two protein kinases that regulate endocytosis (Pkh1 and Pkh2), Slm1, a protein involved in actin cytoskeleton formation, several flavodoxin-like proteins (Pst2, Rfs1, and Ycp4), and four proteins with an unknown function. A BLAST (basic local alignment search tool) analysis did not identify conserved domains in the 21 proteins that would indicate the existence of a specific targeting sequence motif. Because of the incomplete localization database, even further MCC-associated proteins can be expected.

Bottom Line: Deletion of Pil1, a component of eisosomes, or of Nce102, an integral membrane protein of MCC, results in the dissipation of all MCC markers.These deletion mutants also show accelerated endocytosis of MCC-resident permeases Can1 and Fur4.Addition of arginine to wild-type cells leads to a similar redistribution and increased turnover of Can1.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cell Biology and Plant Physiology, University of Regensburg, 93053 Regensburg, Germany.

ABSTRACT
In this study, we investigate whether the stable segregation of proteins and lipids within the yeast plasma membrane serves a particular biological function. We show that 21 proteins cluster within or associate with the ergosterol-rich membrane compartment of Can1 (MCC). However, proteins of the endocytic machinery are excluded from MCC. In a screen, we identified 28 genes affecting MCC appearance and found that genes involved in lipid biosynthesis and vesicle transport are significantly overrepresented. Deletion of Pil1, a component of eisosomes, or of Nce102, an integral membrane protein of MCC, results in the dissipation of all MCC markers. These deletion mutants also show accelerated endocytosis of MCC-resident permeases Can1 and Fur4. Our data suggest that release from MCC makes these proteins accessible to the endocytic machinery. Addition of arginine to wild-type cells leads to a similar redistribution and increased turnover of Can1. Thus, MCC represents a protective area within the plasma membrane to control turnover of transport proteins.

Show MeSH
Related in: MedlinePlus