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Adam Kawałek, Chandhuru Jagadeesan, Ida J van der Klei
The non-bilayer forming lipids cardiolipin (CL) and phosphatidylethanolamine (PE) modulate membrane curvature, facilitate membrane fusion and affect the stability and function of membrane proteins. Yeast peroxisomal membranes contain significant amounts of CL and PE. We analysed the effect of CL deficiency and PE depletion on peroxisome biogenesis and proliferation in Saccharomyces cerevisiae. Our data indicate that deletion of CRD1, which encodes cardiolipin synthase, does not affect peroxisome biogenesis or abundance, both at peroxisome repressing (glucose) or inducing (oleate) growth conditions...
October 13, 2016: Biochemical and Biophysical Research Communications
Shaoxiao Wang, Siyuan Zhang, Chuan Xu, Addie Barron, Floyd Galiano, Dhaval Patel, Yong Joo Lee, Guy A Caldwell, Kim A Caldwell, Stephan N Witt
We have been investigating the role that phosphatidylethanolamine (PE) and phosphatidylcholine (PC) content plays in modulating the solubility of the Parkinson's disease protein alpha-synuclein (α-syn) using Saccharomyces cerevisiae and Caenorhabditis elegans. One enzyme that synthesizes PE is the conserved enzyme phosphatidylserine decarboxylase (Psd1/yeast; PSD-1/worms), which is lodged in the inner mitochondrial membrane. We previously found that decreasing the level of PE due to knockdown of Psd1/psd-1 affects the homeostasis of α-syn in vivo...
2016: PloS One
Francesca Di Bartolomeo, Ariane Wagner, Günther Daum
Phosphatidylethanolamine is one of the most abundant phospholipids whose major amounts are formed by phosphatidylserine decarboxylases (PSD). Here we provide a comprehensive description of different types of PSDs in the different kingdoms of life. In eukaryotes, type I PSDs are mitochondrial enzymes, whereas other PSDs are localized to other cellular compartments. We describe the role of mitochondrial Psd1 proteins, their function, enzymology, biogenesis, assembly into mitochondria and their contribution to phospholipid homeostasis in much detail...
September 17, 2016: Biochimica et Biophysica Acta
Antoni W James, Ramachandran Gowsalya, Vasanthi Nachiappan
The endoplasmic reticulum (ER) has numerous biological functions including protein synthesis, protein folding, and lipid synthesis. The CAX4 gene encodes dolichyl pyrophosphate (Dol-PP) phosphatase, which is involved in protein N-glycosylation. In cax4Δ cells, the N-glycosylation of the vacuolar carboxypeptidase (CPY) was severely affected, and expression of the ER chaperone Kar2p was elevated, which resulted in UPR activation as an adaptive response. The cax4Δ cell growth was reduced, and this could be attributed to the formation of clumped aggregates, high vesiculation of the intracellular membrane, and plasma membrane alterations were depicted using DiOC6 fluorescence...
August 12, 2016: Biochimica et Biophysica Acta
C M Fernandes, P A de Castro, A Singh, F L Fonseca, M D Pereira, Tvm Vila, G C Atella, S Rozental, M Savoldi, M Del Poeta, G H Goldman, E Kurtenbach
C8-desaturated and C9-methylated glucosylceramide (GlcCer) is a fungal-specific sphingolipid that plays an important role in the growth and virulence of many species. In this work, we investigated the contribution of Aspergillus nidulans sphingolipid Δ8-desaturase (SdeA), sphingolipid C9-methyltransferases (SmtA/SmtB) and glucosylceramide synthase (GcsA) to fungal phenotypes, sensitivity to Psd1 defensin and Galleria mellonella virulence. We showed that ΔsdeA accumulated C8-saturated and unmethylated GlcCer, while gcsA deletion impaired GlcCer synthesis...
August 1, 2016: Molecular Microbiology
Mari J Aaltonen, Jonathan R Friedman, Christof Osman, Bénédicte Salin, Jean-Paul di Rago, Jodi Nunnari, Thomas Langer, Takashi Tatsuta
Mitochondria exert critical functions in cellular lipid metabolism and promote the synthesis of major constituents of cellular membranes, such as phosphatidylethanolamine (PE) and phosphatidylcholine. Here, we demonstrate that the phosphatidylserine decarboxylase Psd1, located in the inner mitochondrial membrane, promotes mitochondrial PE synthesis via two pathways. First, Ups2-Mdm35 complexes (SLMO2-TRIAP1 in humans) serve as phosphatidylserine (PS)-specific lipid transfer proteins in the mitochondrial intermembrane space, allowing formation of PE by Psd1 in the inner membrane...
June 6, 2016: Journal of Cell Biology
Fang Ji, Min Xu, Chao Wang, Xiaoyuan Li, Wei Gao, Yunfei Zhang, Baorui Wang, Guangping Tang, Xiaobin Yue
The cubic Fe3O4 nanoparticles with sharp horns that display the size distribution between 100 and 200 nm are utilized to substitute the magnetic sensitive medium (carbonyl iron powders, CIPs) and abrasives (CeO2/diamond) simultaneously which are widely employed in conventional magnetorheological finishing fluid. The removal rate of this novel fluid is extremely low compared with the value of conventional one even though the spot of the former is much bigger. This surprising phenomenon is generated due to the small size and low saturation magnetization (M s) of Fe3O4 and corresponding weak shear stress under external magnetic field according to material removal rate model of magnetorheological finishing (MRF)...
December 2016: Nanoscale Research Letters
Stephan N Witt
We recently reported that knocking down the enzyme phosphatidylserine decarboxylase, which synthesizes the phospholipid phosphatidylethanolamine (PE) in mitochondria, perturbs the homeostasis of the human Parkinson disease (PD) protein α-synuclein (expressed in yeast or worms). In yeast, low PE in the psd1Δ deletion mutant induces α-synuclein to enter cytoplasmic foci, the level of this protein increases 3-fold compared to wild-type cells, and the mutant cells are severely sick. The metabolite ethanolamine protects both yeast and worms from the deleterious synergistic effects of low mitochondrial PE and α-synuclein...
December 2014: Communicative & Integrative Biology
Non Miyata, Takuya Miyoshi, Takanori Yamaguchi, Toshimitsu Nakazono, Motohiro Tani, Osamu Kuge
Phosphatidylethanolamine (PE) in the yeast Saccharomyces cerevisiae is synthesized through decarboxylation of phosphatidylserine (PS), catalysed by PS decarboxylase 1 (Psd1p) and 2 (Psd2p) and the cytidine 5'-diphosphate (CDP)-ethanolamine (CDP-Etn) pathway. PSD1 null (psd1Δ) and PSD2 null (psd2Δ) mutants are viable in a synthetic minimal medium, but a psd1Δ psd2Δ double mutant exhibits Etn auxotrophy, which is incorporated into PE through the CDP-Etn pathway. We have previously shown that psd1Δ is synthetic lethal with deletion of VID22 (vid22Δ) [Kuroda et al...
December 15, 2015: Biochemical Journal
Martina Gsell, Ariane Fankl, Lisa Klug, Gerald Mascher, Claudia Schmidt, Claudia Hrastnik, Günther Zellnig, Günther Daum
In a previous study we demonstrated up-regulation of the yeast GPH1 gene under conditions of phosphatidylethanolamine (PE) depletion caused by deletion of the mitochondrial (M) phosphatidylserine decarboxylase 1 (PSD1) (Gsell et al., 2013, PLoS One. 8(10):e77380. doi: 10.1371/journal.pone.0077380). Gph1p has originally been identified as a glycogen phosphorylase catalyzing degradation of glycogen to glucose in the stationary growth phase of the yeast. Here we show that deletion of this gene also causes decreased levels of phosphatidylcholine (PC), triacylglycerols and steryl esters...
2015: PloS One
Julie M Wolf, Javier Espadas, Jose Luque-Garcia, Todd Reynolds, Arturo Casadevall
Microbial secretion is integral for regulating cell homeostasis as well as releasing virulence factors during infection. The genes encoding phosphatidylserine synthase (CHO1) and phosphatidylserine decarboxylase (PSD1 and PSD2) are Candida albicans genes involved in phospholipid biosynthesis, and mutations in these genes affect mitochondrial function, cell wall thickness, and virulence in mice. We tested the roles of these genes in several agar-based secretion assays and observed that the cho1Δ/Δ and psd1Δ/Δ psd2Δ/Δ strains manifested less protease and phospholipase activity...
August 2015: Eukaryotic Cell
Juan Du, Hien T T Ngo, KyungHwa Won, Ki-Young Kim, Feng-Xie Jin, Tae-Hoo Yi
Strain THG-EP9T, a Gram-stain-negative, aerobic, motile, rod-shaped bacterium was isolated from field-grown eggplant (Solanum melongena) rhizosphere soil collected in Pyeongtaek, Gyeonggi-do, Republic of Korea. Based on 16S rRNA gene sequence comparisons, strain THG-EP9T had closest similarity with Chryseobacterium ginsenosidimutans THG 15T (97.3 % 16S rRNA gene sequence similarity), Chryseobacterium soldanellicola PSD1-4T (97.2%), Chryseobacterium zeae JM-1085T (97.2%) and Chryseobacterium indoltheticum LMG 4025T (96...
August 2015: International Journal of Systematic and Evolutionary Microbiology
P Rockenfeller, M Koska, F Pietrocola, N Minois, O Knittelfelder, V Sica, J Franz, D Carmona-Gutierrez, G Kroemer, F Madeo
Autophagy is a cellular recycling program that retards ageing by efficiently eliminating damaged and potentially harmful organelles and intracellular protein aggregates. Here, we show that the abundance of phosphatidylethanolamine (PE) positively regulates autophagy. Reduction of intracellular PE levels by knocking out either of the two yeast phosphatidylserine decarboxylases (PSD) accelerated chronological ageing-associated production of reactive oxygen species and death. Conversely, the artificial increase of intracellular PE levels, by provision of its precursor ethanolamine or by overexpression of the PE-generating enzyme Psd1, significantly increased autophagic flux, both in yeast and in mammalian cell culture...
March 2015: Cell Death and Differentiation
Luciano Neves de Medeiros, Tatiana Domitrovic, Paula Cavalcante de Andrade, Jane Faria, Eliana Barreto Bergter, Gilberto Weissmüller, Eleonora Kurtenbach
Psd1 is a plant defensin that has antifungal activity against several pathogenic and nonpathogenic fungi. Previous analysis of Psd1 chemical shift perturbations by nuclear magnetic resonance (NMR) spectroscopy demonstrated that this defensin interacts with phospholipids and the sphingolipid glucosylceramide isolated from Fusarium solani (GlcCer(Fusarium solani)). In this study, these interactions were evaluated by real-time surface plasmon resonance (SPR) analysis. The data obtained demonstrated that Psd1 could bind more strongly to small unilamellar vesicles (SUV)-containing GlcCer(Fusarium solani) than to SUV that was composed of phosphatidylcholine (PC) alone or was enriched with GlcCer that had been isolated from soybeans...
November 2014: Biopolymers
Shaoxiao Wang, Siyuan Zhang, Liang-Chun Liou, Qun Ren, Zhaojie Zhang, Guy A Caldwell, Kim A Caldwell, Stephan N Witt
Phosphatidylserine decarboxylase, which is embedded in the inner mitochondrial membrane, synthesizes phosphatidylethanolamine (PE) and, in some cells, synthesizes the majority of this important phospholipid. Normal levels of PE can decline with age in the brain. Here we used yeast and worms to test the hypothesis that low levels of PE alter the homeostasis of the Parkinson disease-associated protein α-synuclein (α-syn). In yeast, low levels of PE in the phosphatidylserine decarboxylase deletion mutant (psd1Δ) cause decreased respiration, endoplasmic reticulum (ER) stress, a defect in the trafficking of the uracil permease, α-syn accumulation and foci, and a slow growth phenotype...
September 23, 2014: Proceedings of the National Academy of Sciences of the United States of America
Kim Vriens, Bruno P A Cammue, Karin Thevissen
Plant defensins are small, cysteine-rich peptides that possess biological activity towards a broad range of organisms. Their activity is primarily directed against fungi, but bactericidal and insecticidal actions have also been reported. The mode of action of various antifungal plant defensins has been studied extensively during the last decades and several of their fungal targets have been identified to date. This review summarizes the mechanism of action of well-characterized antifungal plant defensins, including RsAFP2, MsDef1, MtDef4, NaD1 and Psd1, and points out the variety by which antifungal plant defensins affect microbial cell viability...
2014: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Shingo Kobayashi, Aya Mizuike, Hiroyuki Horiuchi, Ryouichi Fukuda, Akinori Ohta
In eukaryotic cells, phospholipids are synthesized exclusively in the defined organelles specific for each phospholipid species. To explain the reason for this compartmental specificity in the case of phosphatidylcholine (PC) synthesis, we constructed and characterized a Saccharomyces cerevisiae strain that lacked endogenous phosphatidylethanolamine (PE) methyltransferases but had a recombinant PE methyltransferase from Acetobacter aceti, which was fused with a mitochondrial targeting signal from yeast Pet100p and a 3×HA epitope tag...
September 2014: Biochimica et Biophysica Acta
Thomas P Loch, Mohamed Faisal
Two strains (T68T and T62) of a Gram-reaction-negative, yellow-pigmented bacterium containing flexirubin-type pigments were recovered from the kidney of a cultured lake trout (Salvelinus namaycush) and necrotic fins of a brown trout (Salmo trutta) during disease surveillance in 2009. Both isolates possessed catalase and cytochrome oxidase activities and degraded multiple substrates (e.g. gelatin, casein, elastin and Tweens 20 and 80). The mean DNA G+C content of strain T68T was 34.1 mol%. 16S rRNA gene sequencing demonstrated that strains T68T and T62 had nearly identical sequences (≥99 % similarity) and placed the bacterium within the genus Chryseobacterium, where Chryseobacterium ginsenosidimutans THG 15T (97...
May 2014: International Journal of Systematic and Evolutionary Microbiology
Riqing Li, Jixing Xia, Yiwei Xu, Xiucai Zhao, Yao-Guang Liu, Yuanling Chen
Plant height is an important agronomic trait for crop architecture and yield. Most known factors determining plant height function in gibberellin or brassinosteroid biosynthesis or signal transduction. Here, we report a japonica rice (Oryza sativa ssp. japonica) dominant dwarf mutant, Photoperiod-sensitive dwarf 1 (Psd1). The Psd1 mutant showed impaired cell division and elongation, and a severe dwarf phenotype under long-day conditions, but nearly normal growth in short-day. The plant height of Psd1 mutant could not be rescued by gibberellin or brassinosteroid treatment...
January 2014: TAG. Theoretical and Applied Genetics. Theoretische und Angewandte Genetik
Martina Gsell, Gerald Mascher, Irmgard Schuiki, Birgit Ploier, Claudia Hrastnik, Günther Daum
In the yeast, Saccharomyces cerevisiae, the synthesis of the essential phospholipid phosphatidylethanolamine (PE) is accomplished by a network of reactions which comprises four different pathways. The enzyme contributing most to PE formation is the mitochondrial phosphatidylserine decarboxylase 1 (Psd1p) which catalyzes conversion of phosphatidylserine (PS) to PE. To study the genome wide effect of an unbalanced cellular and mitochondrial PE level and in particular the contribution of Psd1p to this depletion we performed a DNA microarray analysis with a ∆psd1 deletion mutant...
2013: PloS One
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