Saccharomyces cerevisiae; endoplasmic reticulum; sterol-binding proteins; CAP/SCP proteins; lipid droplets; cholesterol; topology of lipid synthesis; lipid homeostasis
Darwiche R, Schneiter R (2017), A Ligand-Binding Assay to Measure the Affinity and Specificity of Sterol-Binding Proteins In Vitro., in Barredo Jose-Luis and Herraiz Ignacio (ed.), Springer, New York, 361-368.
Debelyy MO, Waridel P, Quadroni M, Schneiter R, Conzelmann A (2017), Chemical crosslinking and mass spectrometry to elucidate the topology of integral membrane proteins., in PLoS One
, 12(10), 0186840-0186840.
Luo Z, Kelleher AJ, Darwiche R, Hudspeth EM, Shittu OK, Krishnavajhala A, Schneiter R, Lopez JE, Asojo OA (2017), Crystal Structure of Borrelia turicatae protein, BTA121, a differentially regulated gene in the tick-mammalian transmission cycle of relapsing fever spirochetes., in Sci Rep
, 7(1), 15310-15310.
Baroni RM, Luo Z, Darwiche R, Hudspeth EM, Schneiter R, Pereira GAG, Mondego JMC, Asojo OA (2017), Crystal Structure of MpPR-1i, a SCP/TAPS protein from Moniliophthora perniciosa, the fungus that causes Witches' Broom Disease of Cacao., in Sci Rep
, 7(1), 7818-7818.
Darwiche R, El Atab O, Baroni RM, Teixeira PJPL, Mondego JMC, Pereira GAG, Schneiter R (2017), Plant pathogenesis-related proteins of the cacao fungal pathogen Moniliophthora perniciosa differ in their lipid-binding specificities., in Plant J
Knupp J, Martinez-Montañés F, Van Den Bergh F, Cottier S, Schneiter R, Beard D, Chang A (2017), Sphingolipid accumulation causes mitochondrial dysregulation and cell death., in Cell Death Differ
, 24(12), 2044-2053.
Darwiche R, Mène-Saffrané L, Gfeller D, Asojo OA, Schneiter R (2017), The pathogen-related yeast protein Pry1, a member of the CAP protein superfamily, is a fatty acid-binding protein., in J Biol Chem
, 292(20), 8304-8314.
Gamir J, Darwiche R, Van't Hof P, Choudhary V, Stumpe M, Schneiter R, Mauch F (2017), The sterol-binding activity of PATHOGENESIS-RELATED PROTEIN 1 reveals the mode of action of an antimicrobial protein., in Plant J
, 89(3), 502-509.
Martínez-Montañés F, Lone MA, Hsu FF, Schneiter R (2016), Accumulation of long-chain bases in yeast promotes their conversion to a long-chain base vinyl ether., in J Lipid Res
, 57(11), 2040-2050.
Vazquez HM, Vionnet C, Roubaty C, Mallela SK, Schneiter R, Conzelmann A (2016), Chemogenetic E-MAP in Saccharomyces cerevisiae for Identification of Membrane Transporters Operating Lipid Flip Flop., in PLoS Genet
, 12(7), e1006160-e1006160.
Darwiche R, Schneiter R (2016), Cholesterol-binding by the yeast CAP faimily member, Pry1, requires the presence of an aliphatic side chain on cholesterol., in J Steroids Hormon Sci
, 7(172), 2-2.
Martínez-Montañés F, Schneiter R (2016), Following the flux of long-chain bases through the sphingolipid pathway in vivo using mass spectrometry., in J Lipid Res
, 57(5), 906-15.
Mishra S, Khaddaj R, Cottier S, Stradalova V, Jacob C, Schneiter R (2016), Mature lipid droplets are accessible to ER luminal proteins., in J Cell Sci
, 129(20), 3803-3815.
Darwiche R, Kelleher A, Hudspeth EM, Schneiter R, Asojo OA (2016), Structural and functional characterization of the CAP domain of pathogen-related yeast 1 (Pry1) protein., in Sci Rep
, 6, 28838-28838.
Martínez-Montañés F, Schneiter R (2016), Tools for the analysis of metabolic flux through the sphingolipid pathway., in Biochimie
, 130, 76-80.
Jadhav S, Russo S, Cottier S, Schneiter R, Cowart A, Greenberg ML (2016), Valproate Induces the Unfolded Protein Response by Increasing Ceramide Levels., in J Biol Chem
, 291(42), 22253-22261.
Mishra S, Schneiter R (2015), Expression of perilipin 5 promotes lipid droplet formation in yeast., in Commun Integr Biol
, 8(6), e1071728-e1071728.
Fugi MA, Kaiser M, Tanner M, Schneiter R, Maser P, Guan XL (2015), Match-making for posaconazole through systems thinking., in Trends Parasitol
, 31(2), 46-51.
Lone MA, Atkinson AE, Hodge CA, Cottier S, Martínez-Montañés F, Maithel S, Mène-Saffrané L, Cole CN, Schneiter R (2015), Yeast integral membrane proteins Apq12, Brl1, and Brr6 form a complex important for regulation of membrane homeostasis and nuclear pore complex biogenesis., in Eukaryot Cell
, 14(12), 1217-1227.
Kelleher A, Darwiche R, Rezende WC, Farias LP, Leite LC, Schneiter R, Asojo OA (2014), Schistosoma mansoni venom allergen-like protein 4 (SmVAL4) is a novel lipid-binding SCP/TAPS protein that lacks the prototypical CAP motifs., in Acta Crystallogr D Biol Crystallogr
, 70(8), 2186-96.
Choudhary V, Darwiche R, Gfeller D, Zoete V, Michielin O, Schneiter R (2014), The caveolin-binding motif of the pathogen-related yeast protein Pry1, a member of the CAP protein superfamily, is required for in vivo export of cholesteryl acetate., in J Lipid Res
, 55(5), 883-94.
Dubots E, Cottier S, Peli-Gulli MP, Jaquenoud M, Bontron S, Schneiter R, De Virgilio C (2014), TORC1 Regulates Pah1 Phosphatidate Phosphatase Activity via the Nem1/Spo7 Protein Phosphatase Complex., in PLoS One
, 9(8), 104194-104194.
Darwiche R, El Atab O, Cottier S, Schneiter R, The function of yeast CAP family proteins in lipid export, mating and pathogen defense., in FEBS Lett
Lipid homeostasis is essential to ensure proper membrane function and cell viability. In this proposal, we address two basic aspects of this homeostatic regulation. In the first part, the topology of lipid storage and the biogenesis of lipid droplets are being addressed. In the second part, we propose to perform a detailed structural and functional analysis of a novel class of secreted sterol-binding proteins, the Pry (pathogen related in yeast) family. Both projects build on our established expertise and they constitute a rational continuation of our previously published work in this field. Lipid droplets constitute a globular intracellular compartment that is dedicated to the storage of fat/neutral lipids. The droplet is composed of a core of neutral lipids, particularly triacylglycerols and steryl esters and covered by a monolayer membrane onto which a small number of proteins associate. Many of these proteins function in lipid metabolism, for example as acyltransferases or lipases. We have previously shown that some of these lipid droplet associated proteins are integral membrane proteins and that they can move between the membrane of the endoplasmic reticulum (ER) and the surface of lipid droplets. These as well as other observations indicate that lipid droplets are closely associated with the ER membrane. The nature of this association, however, has not yet been resolved and is currently debated. Here, we will test if lipid droplets are accessible from within the ER lumen by targeting soluble lipid droplet-associated proteins into the luminal space of the ER. Preliminary results indicate that this indeed is the case, thus challenging some of the current models of lipid droplet biogenesis. To complement these studies, we will artificially generate ER-luminal lipid droplets by targeting heterologous lipid droplet-scaffolding proteins inside the ER luminal space. We have previously shown that cytosolic expression of such proteins in yeast results in the induction of lipid droplets and preliminary results indicate that lipid droplet induction is also observed if these proteins are targeted into the ER lumen. Thus having an experimental system to form cytosolic as well as ER luminal lipid droplets will allows us to compare their properties with naturally formed lipid droplets and thus allow us to define their origin and the nature of their association with the ER. Pry proteins belong to a large protein superfamily known as CAP/SCP (sperm coating proteins). These proteins are implicated in a multitude of physiologically important processes in all kingdoms of life, including but not limited to immune defense in animals and plants, pathogen virulence, sperm maturation and fertilization, venom toxicity and prostate and brain cancer. CAP proteins are mostly secreted glycoproteins and are stable in the extracellular environments over a wide range of conditions. Their mode of action, however, has remained elusive. We could recently show that the yeast Pry proteins bind sterols and related small hydrophobic compounds in vivo and in vitro. This sterol-binding activity is confined to the CAP domain of Pry1, and conserved in a human CAP family member, CRISP2, suggesting that CAP family members exert their various functions through binding sterols or related small hydrophobic compounds. Aim of this part of the project is to characterize the ligand binding activity of Pry1 at the structural level and to define its ligand-specificity. The results of this work will provide the foundation to understand the mode of action of this important class of proteins; not only in fungi but also in plants and vertebrates.