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Savvidou MG, Boli E, Logothetis D, Lymperopoulou T, Ferraro A, Louli V, Mamma D, Kekos D, Magoulas K, Kolisis FN. A Study on the Effect of Macro- and Micro- Nutrients on Nannochloropsis oceanica Growth, Fatty Acid Composition and Magnetic Harvesting Efficiency. PLANTS (BASEL, SWITZERLAND) 2020; 9:E660. [PMID: 32456121 PMCID: PMC7284572 DOI: 10.3390/plants9050660] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/19/2020] [Accepted: 05/21/2020] [Indexed: 12/13/2022]
Abstract
The effect of iron, manganese, phosphorus and nitrogen on growth and lipid synthesis of the microalgae Nannochloropsis oceanica CCMP1779, as well as their impact on the magnetic harvesting efficiency, are examined under their depriving cell culture conditions. Herein, it is demonstrated that nitrogen and manganese depletion primarily reduced cell growth while phosphorus and iron restriction led to higher dry biomass. Subsequently, the role of those nutrients on fatty acids profile was examined. Phosphorus and nitrogen restriction resulted in lower and higher lipid content, respectively. High amounts of polyunsaturated fatty acids like eicosapentaenoic acid are produced under iron and manganese depletion. Phosphorus deprivation favors monounsaturated fatty acids such as C18:1 and C16:1, while nitrogen restriction favors saturated fatty acid production like C14:0, C16:0 and C18:0. Since the presence/absence of macro- and micro-elements may affect the overall electrostatic charges on the outmost microalgae surface, it was also analyzed how these elements affect the magnetic harvesting efficiency. Results showed that phosphorus deprivation led to the best magnetic harvesting efficiency of N. oceanica cells (93%) as compared to other nutrient starvation as well as standard medium.
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Affiliation(s)
- Maria G. Savvidou
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Elenitsa Boli
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Dimitrios Logothetis
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Theopisti Lymperopoulou
- Environment and Quality of Life Center, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece;
| | - Angelo Ferraro
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Vasiliki Louli
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Diomi Mamma
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Dimitris Kekos
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Kostis Magoulas
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Fragiskos N. Kolisis
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
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Manganese-induced cellular disturbance in the baker's yeast, Saccharomyces cerevisiae with putative implications in neuronal dysfunction. Sci Rep 2019; 9:6563. [PMID: 31024033 PMCID: PMC6484083 DOI: 10.1038/s41598-019-42907-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 04/09/2019] [Indexed: 12/24/2022] Open
Abstract
Manganese (Mn) is an essential element, but in humans, chronic and/or acute exposure to this metal can lead to neurotoxicity and neurodegenerative disorders including Parkinsonism and Parkinson’s Disease by unclear mechanisms. To better understand the effects that exposure to Mn2+ exert on eukaryotic cell biology, we exposed a non-essential deletion library of the yeast Saccharomyces cerevisiae to a sub-inhibitory concentration of Mn2+ followed by targeted functional analyses of the positive hits. This screen produced a set of 43 sensitive deletion mutants that were enriched for genes associated with protein biosynthesis. Our follow-up investigations demonstrated that Mn reduced total rRNA levels in a dose-dependent manner and decreased expression of a β-galactosidase reporter gene. This was subsequently supported by analysis of ribosome profiles that suggested Mn-induced toxicity was associated with a reduction in formation of active ribosomes on the mRNAs. Altogether, these findings contribute to the current understanding of the mechanism of Mn-triggered cytotoxicity. Lastly, using the Comparative Toxicogenomic Database, we revealed that Mn shared certain similarities in toxicological mechanisms with neurodegenerative disorders including amyotrophic lateral sclerosis, Alzheimer’s, Parkinson’s and Huntington’s diseases.
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Manganese Suppresses the Haploinsufficiency of Heterozygous trpy1Δ/TRPY1 Saccharomyces cerevisiae Cells and Stimulates the TRPY1-Dependent Release of Vacuolar Ca 2+ under H₂O₂ Stress. Cells 2019; 8:cells8020079. [PMID: 30678234 PMCID: PMC6406398 DOI: 10.3390/cells8020079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/09/2019] [Accepted: 01/18/2019] [Indexed: 11/17/2022] Open
Abstract
Transient potential receptor (TRP) channels are conserved cation channels found in most eukaryotes, known to sense a variety of chemical, thermal or mechanical stimuli. The Saccharomyces cerevisiae TRPY1 is a TRP channel with vacuolar localization involved in the cellular response to hyperosmotic shock and oxidative stress. In this study, we found that S. cerevisiae diploid cells with heterozygous deletion in TRPY1 gene are haploinsufficient when grown in synthetic media deficient in essential metal ions and that this growth defect is alleviated by non-toxic Mn2+ surplus. Using cells expressing the Ca2+-sensitive photoprotein aequorin we found that Mn2+ augmented the Ca2+ flux into the cytosol under oxidative stress, but not under hyperosmotic shock, a trait that was absent in the diploid cells with homozygous deletion of TRPY1 gene. TRPY1 activation under oxidative stress was diminished in cells devoid of Smf1 (the Mn2+-high-affinity plasma membrane transporter) but it was clearly augmented in cells lacking Pmr1 (the endoplasmic reticulum (ER)/Golgi located ATPase responsible for Mn2+ detoxification via excretory pathway). Taken together, these observations lead to the conclusion that increased levels of intracytosolic Mn2+ activate TRPY1 in the response to oxidative stress.
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Sahu PK, Tomar RS. The natural anticancer agent cantharidin alters GPI-anchored protein sorting by targeting Cdc1-mediated remodeling in endoplasmic reticulum. J Biol Chem 2019; 294:3837-3852. [PMID: 30659098 DOI: 10.1074/jbc.ra118.003890] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 01/10/2019] [Indexed: 11/06/2022] Open
Abstract
Cantharidin (CTD) is a potent anticancer small molecule produced by several species of blister beetle. It has been a traditional medicine for the management of warts and tumors for many decades. CTD suppresses tumor growth by inducing apoptosis, cell cycle arrest, and DNA damage and inhibits protein phosphatase 2 phosphatase activator (PP2A) and protein phosphatase 1 (PP1). CTD also alters lipid homeostasis, cell wall integrity, endocytosis, adhesion, and invasion in yeast cells. In this study, we identified additional molecular targets of CTD using a Saccharomyces cerevisiae strain that expresses a cantharidin resistance gene (CRG1), encoding a SAM-dependent methyltransferase that methylates and inactivates CTD. We found that CTD specifically affects phosphatidylethanolamine (PE)-associated functions that can be rescued by supplementing the growth media with ethanolamine (ETA). CTD also perturbed endoplasmic reticulum (ER) homeostasis and cell wall integrity by altering the sorting of glycosylphosphatidylinositol (GPI)-anchored proteins. A CTD-dependent genetic interaction profile of CRG1 revealed that the activity of the lipid phosphatase cell division control protein 1 (Cdc1) in GPI-anchor remodeling is the key target of CTD, independently of PP2A and PP1 activities. Moreover, experiments with human cells further suggested that CTD functions through a conserved mechanism in higher eukaryotes. Altogether, we conclude that CTD induces cytotoxicity by targeting Cdc1 activity in GPI-anchor remodeling in the ER.
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Affiliation(s)
- Pushpendra Kumar Sahu
- From the Laboratory of Chromatin Biology, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, 462066 Madhya Pradesh, India
| | - Raghuvir Singh Tomar
- From the Laboratory of Chromatin Biology, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, 462066 Madhya Pradesh, India
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Kamei M, Tsukagoshi Y, Banno S, Ichiishi A, Fukumori F, Fujimura M. Phenotypic abnormalities of fr , sp , and och-1 single mutants are suppressed by loss of putative GPI-phospholipase A2 in Neurospora crassa. MYCOSCIENCE 2017. [DOI: 10.1016/j.myc.2016.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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A repetitive DNA-directed program of chromosome packaging during mitosis. J Genet Genomics 2016; 43:471-6. [PMID: 27567067 DOI: 10.1016/j.jgg.2016.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/26/2016] [Accepted: 04/04/2016] [Indexed: 11/20/2022]
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Busti S, Mapelli V, Tripodi F, Sanvito R, Magni F, Coccetti P, Rocchetti M, Nielsen J, Alberghina L, Vanoni M. Respiratory metabolism and calorie restriction relieve persistent endoplasmic reticulum stress induced by calcium shortage in yeast. Sci Rep 2016; 6:27942. [PMID: 27305947 PMCID: PMC4910072 DOI: 10.1038/srep27942] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 05/27/2016] [Indexed: 11/26/2022] Open
Abstract
Calcium homeostasis is crucial to eukaryotic cell survival. By acting as an enzyme cofactor and a second messenger in several signal transduction pathways, the calcium ion controls many essential biological processes. Inside the endoplasmic reticulum (ER) calcium concentration is carefully regulated to safeguard the correct folding and processing of secretory proteins. By using the model organism Saccharomyces cerevisiae we show that calcium shortage leads to a slowdown of cell growth and metabolism. Accumulation of unfolded proteins within the calcium-depleted lumen of the endoplasmic reticulum (ER stress) triggers the unfolded protein response (UPR) and generates a state of oxidative stress that decreases cell viability. These effects are severe during growth on rapidly fermentable carbon sources and can be mitigated by decreasing the protein synthesis rate or by inducing cellular respiration. Calcium homeostasis, protein biosynthesis and the unfolded protein response are tightly intertwined and the consequences of facing calcium starvation are determined by whether cellular energy production is balanced with demands for anabolic functions. Our findings confirm that the connections linking disturbance of ER calcium equilibrium to ER stress and UPR signaling are evolutionary conserved and highlight the crucial role of metabolism in modulating the effects induced by calcium shortage.
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Affiliation(s)
- Stefano Busti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
- SYSBIO, Centre of Systems Biology, Milan, Italy
| | - Valeria Mapelli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
- Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, Gothenburg, Sweden
| | - Farida Tripodi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
- SYSBIO, Centre of Systems Biology, Milan, Italy
| | - Rossella Sanvito
- Department of Health Sciences, University of Milano-Bicocca, Milan, Italy
| | - Fulvio Magni
- Department of Health Sciences, University of Milano-Bicocca, Milan, Italy
| | - Paola Coccetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
- SYSBIO, Centre of Systems Biology, Milan, Italy
| | - Marcella Rocchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark
| | - Lilia Alberghina
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
- SYSBIO, Centre of Systems Biology, Milan, Italy
| | - Marco Vanoni
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
- SYSBIO, Centre of Systems Biology, Milan, Italy
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Cd(2+) sensitivity and permeability of a low voltage-activated Ca(2+) channel with CatSper-like selectivity filter. Cell Calcium 2016; 60:41-50. [PMID: 27134080 DOI: 10.1016/j.ceca.2016.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/21/2016] [Accepted: 03/30/2016] [Indexed: 11/22/2022]
Abstract
CatSper is a sperm-specific Ca(2+) channel that plays an essential role in the male fertility. However, its biophysical properties have been poorly characterized mainly due to its deficient heterologous expression. As other voltage-gated Ca(2+) channels (CaVs), CatSper possesses a conserved Ca(2+)-selective filter motif ([T/S]x[D/E]xW) in the pore region. Interestingly, CatSper conserves four aspartic acids (DDDD) as the negatively charged residues in this motif while high voltage-activated CaVs have four glutamic acids (EEEE) and low voltage-activated CaVs possess two glutamic acids and two aspartic acids (EEDD). Previous studies based on site-directed mutagenesis of L- and T-type channels showed that the number of D seems to have a negative correlation with their cadmium (Cd(2+)) sensitivity. These results suggest that CatSper (DDDD) would have low sensitivity to Cd(2+). To explore Cd(2+)-sensitivity and -permeability of CatSper, we performed two types of experiments: 1) Electrophysiological analysis of heterologously expressed human CaV3.1 channel and three pore mutants (DEDD, EDDD and DDDD), 2) Cd(2+) imaging of human spermatozoa with FluoZin-1. Electrophysiological studies showed a significant increase in Cd(2+) and manganese (Mn(2+)) currents through the CaV3.1 mutants as well as a reduction in the inhibitory effect of Cd(2+) on the Ca(2+) current. In fluorescence imaging with human sperm, we observed an increase in Cd(2+) influx potentiated by progesterone, a potent activator of CatSper. These results support our hypothesis, namely that Cd(2+)-sensitivity and -permeability are related to the absolute number of D in the Ca(2+)-selective filter independently to the type of the Cav channels.
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Fokina AV, Chechenova MB, Karginov AV, Ter-Avanesyan MD, Agaphonov MO. Genetic Evidence for the Role of the Vacuole in Supplying Secretory Organelles with Ca2+ in Hansenula polymorpha. PLoS One 2015; 10:e0145915. [PMID: 26717478 PMCID: PMC4696657 DOI: 10.1371/journal.pone.0145915] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 12/10/2015] [Indexed: 11/18/2022] Open
Abstract
Processes taking place in the secretory organelles require Ca2+ and Mn2+, which in yeast are supplied by the Pmr1 ion pump. Here we observed that in the yeast Hansenula polymorpha Ca2+ deficiency in the secretory pathway caused by Pmr1 inactivation is exacerbated by (i) the ret1-27 mutation affecting COPI-mediated vesicular transport, (ii) inactivation of the vacuolar Ca2+ ATPase Pmc1 and (iii) inactivation of Vps35, which is a component of the retromer complex responsible for protein transport between the vacuole and secretory organelles. The ret1-27 mutation also exerted phenotypes indicating alterations in transport between the vacuole and secretory organelles. These data indicate that ret1-27, pmc1 and vps35 affect a previously unknown Pmr1-independent route of the Ca2+ delivery to the secretory pathway. We also observed that the vacuolar protein carboxypeptidase Y receives additional modifications of its glycoside chains if it escapes the Vps10-dependent sorting to the vacuole.
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Affiliation(s)
- Anastasia V. Fokina
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Maria B. Chechenova
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Azamat V. Karginov
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Michael D. Ter-Avanesyan
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Michael O. Agaphonov
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
- * E-mail:
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Rigamonti M, Groppi S, Belotti F, Ambrosini R, Filippi G, Martegani E, Tisi R. Hypotonic stress-induced calcium signaling in Saccharomyces cerevisiae involves TRP-like transporters on the endoplasmic reticulum membrane. Cell Calcium 2015; 57:57-68. [DOI: 10.1016/j.ceca.2014.12.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/05/2014] [Accepted: 12/06/2014] [Indexed: 11/28/2022]
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Vazquez HM, Vionnet C, Roubaty C, Conzelmann A. Cdc1 removes the ethanolamine phosphate of the first mannose of GPI anchors and thereby facilitates the integration of GPI proteins into the yeast cell wall. Mol Biol Cell 2014; 25:3375-88. [PMID: 25165136 PMCID: PMC4214784 DOI: 10.1091/mbc.e14-06-1033] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The essential CDC1 gene of yeast encodes a Mn2+-dependent lipid phosphatase of the endoplasmic reticulum. Hypomorphic alleles affect Ca2+ signaling, actin polarization, Golgi inheritance, and cell cycle progression. Cdc1 removes an ethanolamine phosphate from the glycosylphosphatidylinositol (GPI) anchor and thereby facilitates integration of GPI proteins into the yeast cell wall. Temperature-sensitive cdc1ts mutants are reported to stop the cell cycle upon a shift to 30°C in early G2, that is, as small budded cells having completed DNA replication but unable to duplicate the spindle pole body. A recent report showed that PGAP5, a human homologue of CDC1, acts as a phosphodiesterase removing an ethanolamine phosphate (EtN-P) from mannose 2 of the glycosylphosphatidylinositol (GPI) anchor, thus permitting efficient endoplasmic reticulum (ER)-to-Golgi transport of GPI proteins. We find that the essential CDC1 gene can be deleted in mcd4∆ cells, which do not attach EtN-P to mannose 1 of the GPI anchor, suggesting that Cdc1 removes the EtN-P added by Mcd4. Cdc1-314ts mutants do not accumulate GPI proteins in the ER but have a partial secretion block later in the secretory pathway. Growth tests and the genetic interaction profile of cdc1-314ts pinpoint a distinct cell wall defect. Osmotic support restores GPI protein secretion and actin polarization but not growth. Cell walls of cdc1-314ts mutants contain large amounts of GPI proteins that are easily released by β-glucanases and not attached to cell wall β1,6-glucans and that retain their original GPI anchor lipid. This suggests that the presumed transglycosidases Dfg5 and Dcw1 of cdc1-314ts transfer GPI proteins to cell wall β1,6-glucans inefficiently.
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Affiliation(s)
- Hector M Vazquez
- Department of Biology, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Christine Vionnet
- Department of Biology, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Carole Roubaty
- Department of Biology, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Andreas Conzelmann
- Department of Biology, University of Fribourg, CH-1700 Fribourg, Switzerland
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Lulu L, Ling Z, Dongmei W, Xiaolian G, Hisanori T, Hidehiko K, Jiong H. Identification of a xylitol dehydrogenase gene from Kluyveromyces marxianus NBRC1777. Mol Biotechnol 2013; 53:159-69. [PMID: 22351371 DOI: 10.1007/s12033-012-9508-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Xylitol dehydrogenase (XDH) (EC 1.1.1.9) is one of the key enzymes in the xylose fermentation pathway in yeast and fungi. A xylitol dehydrogenase gene (XYL2) encoding a XDH was cloned from Kluyveromyces marxianus NBRC 1777, and the in vivo function was validated by disruption and complementation analysis. The highest activity of KmXDH could be observed at pH 9.5 during 55°C. The values of k(cat)/K(m) indicate that KmXDH prefers NAD(+) to NADP(+) (k(cat)/K(m NAD)(+) 3681/min mM and k(cat)/K(m NADP)(+) 1361/min mM). The different coenzyme preference between KmXR and KmXDH caused an accumulation of NADH in the xylose utilization pathway. The redox imbalance may be one of the reasons to cause the poor xylose fermentation under oxygen-limited conditions in K. marxianus NBRC1777.
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Affiliation(s)
- Li Lulu
- School of Life Science, University of Science and Technology of China, Hefei, 230027 Anhui, People's Republic of China
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Abstract
All living organisms require nutrient minerals for growth and have developed mechanisms to acquire, utilize, and store nutrient minerals effectively. In the aqueous cellular environment, these elements exist as charged ions that, together with protons and hydroxide ions, facilitate biochemical reactions and establish the electrochemical gradients across membranes that drive cellular processes such as transport and ATP synthesis. Metal ions serve as essential enzyme cofactors and perform both structural and signaling roles within cells. However, because these ions can also be toxic, cells have developed sophisticated homeostatic mechanisms to regulate their levels and avoid toxicity. Studies in Saccharomyces cerevisiae have characterized many of the gene products and processes responsible for acquiring, utilizing, storing, and regulating levels of these ions. Findings in this model organism have often allowed the corresponding machinery in humans to be identified and have provided insights into diseases that result from defects in ion homeostasis. This review summarizes our current understanding of how cation balance is achieved and modulated in baker's yeast. Control of intracellular pH is discussed, as well as uptake, storage, and efflux mechanisms for the alkali metal cations, Na(+) and K(+), the divalent cations, Ca(2+) and Mg(2+), and the trace metal ions, Fe(2+), Zn(2+), Cu(2+), and Mn(2+). Signal transduction pathways that are regulated by pH and Ca(2+) are reviewed, as well as the mechanisms that allow cells to maintain appropriate intracellular cation concentrations when challenged by extreme conditions, i.e., either limited availability or toxic levels in the environment.
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Nakayama Y, Yoshimura K, Iida H. Organellar mechanosensitive channels in fission yeast regulate the hypo-osmotic shock response. Nat Commun 2013; 3:1020. [PMID: 22910366 DOI: 10.1038/ncomms2014] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 07/18/2012] [Indexed: 01/13/2023] Open
Abstract
A key molecule of sensing machineries essential for survival upon hypo-osmotic shock is the mechanosensitive channel. The bacterial mechanosensitive channel MscS functions directly for this purpose by releasing cytoplasmic solutes out of the cell, whereas plant MscS homologues are found to function in chloroplast organization. Here we show that the fission yeast MscS homologues, designated Msy1 and Msy2, participate in the hypo-osmotic shock response by a mechanism different from that operated by the bacterial MscS. Upon hypo-osmotic shock, msy2(-) and msy1(-) msy2(-) cells display greater cell swelling than wild-type cells and undergo cell death. Cell swelling precedes an intracellular Ca(2+) increase, which was greater in msy1(-) and msy1(-) msy2(-) cells than in wild-type cells. Fluorescent microscopy showed that Msy1 and Msy2 localize mainly to the endoplasmic reticulum. These observations suggest that organellar Msy1 and Msy2 regulate intracellular Ca(2+) and cell volume for survival upon hypo-osmotic shock.
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Affiliation(s)
- Yoshitaka Nakayama
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui Kita-machi, Koganei-shi, Tokyo 184-8501, Japan.
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García-Rodríguez N, Díaz de la Loza MDC, Andreson B, Monje-Casas F, Rothstein R, Wellinger RE. Impaired manganese metabolism causes mitotic misregulation. J Biol Chem 2012; 287:18717-29. [PMID: 22493290 DOI: 10.1074/jbc.m112.358309] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Manganese is an essential trace element, whose intracellular levels need to be carefully regulated. Mn(2+) acts as a cofactor for many enzymes and excess of Mn(2+) is toxic. Alterations in Mn(2+) homeostasis affect metabolic functions and mutations in the human Mn(2+)/Ca(2+) transporter ATP2C1 have been linked to Hailey-Hailey disease. By deletion of the yeast orthologue PMR1 we have studied the impact of Mn(2+) on cell cycle progression and show that an excess of cytosolic Mn(2+) alters S-phase transit, induces transcriptional up-regulation of cell cycle regulators, bypasses the need for S-phase cell cycle checkpoints and predisposes to genomic instability. On the other hand, we find that depletion of the Golgi Mn(2+) pool requires a functional morphology checkpoint to avoid the formation of polyploid cells.
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Affiliation(s)
- Néstor García-Rodríguez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC, Sevilla, Spain
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Brand A, Lee K, Veses V, Gow NAR. Calcium homeostasis is required for contact-dependent helical and sinusoidal tip growth in Candida albicans hyphae. Mol Microbiol 2009; 71:1155-64. [PMID: 19154328 PMCID: PMC2680325 DOI: 10.1111/j.1365-2958.2008.06592.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hyphae of the dimorphic fungus, Candida albicans, exhibit directional tip responses when grown in contact with surfaces. On hard surfaces or in liquid media, the trajectory of hyphal growth is typically linear, with tip re-orientation events limited to encounters with topographical features (thigmotropism). In contrast, when grown on semisolid surfaces, the tips of C. albicans hyphae grow in an oscillatory manner to form regular two-dimensional sinusoidal curves and three-dimensional helices. We show that, like thigmotropism, initiation of directional tip oscillation in C. albicans hyphae is severely attenuated when Ca2+ homeostasis is perturbed. Chelation of extracellular Ca2+ or deletion of the Ca2+ transporters that modulate cytosolic [Ca2+] (Mid1, Cch1 or Pmr1) did not affect hyphal length but curve formation was severely reduced in mid1Delta and cch1Delta and abolished in pmr1Delta. Sinusoidal hypha morphology was altered in the mid1Delta, chs3Delta and heterozygous pmr1Delta/PMR1 strains. Treatments that affect cell wall integrity, changes in surface mannosylation or the provision of additional carbon sources had significant but less pronounced effects on oscillatory growth. The induction of two- and three-dimensional sinusoidal growth in wild-type C. albicans hyphae is therefore the consequence of mechanisms that involve Ca2+ influx and signalling rather than gross changes in the cell wall architecture.
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Affiliation(s)
- Alexandra Brand
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
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Cdc1p is an endoplasmic reticulum-localized putative lipid phosphatase that affects Golgi inheritance and actin polarization by activating Ca2+ signaling. Mol Cell Biol 2008; 28:3336-43. [PMID: 18332110 DOI: 10.1128/mcb.00567-07] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the budding yeast Saccharomyces cerevisiae, mutations in the essential gene CDC1 cause defects in Golgi inheritance and actin polarization. However, the biochemical function of Cdc1p is unknown. Previous work showed that cdc1 mutants accumulate intracellular Ca(2+) and display enhanced sensitivity to the extracellular Mn(2+) concentration, suggesting that Cdc1p might regulate divalent cation homeostasis. By contrast, our data indicate that Cdc1p is a Mn(2+)-dependent protein that can affect Ca(2+) levels. We identified a cdc1 allele that activates Ca(2+) signaling but does not show enhanced sensitivity to the Mn(2+) concentration. Furthermore, our studies show that Cdc1p is an endoplasmic reticulum-localized transmembrane protein with a putative phosphoesterase domain facing the lumen. cdc1 mutant cells accumulate an unidentified phospholipid, suggesting that Cdc1p may be a lipid phosphatase. Previous work showed that deletion of the plasma membrane Ca(2+) channel Cch1p partially suppressed the cdc1 growth phenotype, and we find that deletion of Cch1p also suppresses the Golgi inheritance and actin polarization phenotypes. The combined data fit a model in which the cdc1 mutant phenotypes result from accumulation of a phosphorylated lipid that activates Ca(2+) signaling.
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18
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Devasahayam G, Burke DJ, Sturgill TW. Golgi manganese transport is required for rapamycin signaling in Saccharomyces cerevisiae. Genetics 2007; 177:231-8. [PMID: 17603109 PMCID: PMC2013697 DOI: 10.1534/genetics.107.073577] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The Pmr1 Golgi Ca2+/Mn2+ ATPase negatively regulates target of rapamycin complex (TORC1) signaling, the rapamycin-sensitive TOR complex in Saccharomyces cerevisiae. Since pmr1 causes resistance to rapamycin and tor1 causes hypersensitivity, we looked for genetic interactions of pmr1 with tor1. Deletion of TOR1 restored two wild-type phenotypes. Loss of TOR1 restored the ability of the pmr1 strain to grow on media containing 2 mm MnCl2 and conferred wild type as well as the wild-type sensitivity to rapamycin. Mn2+ additions to media partially suppressed rapamycin resistance of wild type and pmr1 tor1, suggesting that Tor1 and Tor2 are regulated by manganese. We parsed the roles of Ca2+ and Mn2+ transport and the compartments in rapamycin response using separation-of-function mutants available for Pmr1. A strain containing the D53A mutant (Mn2+ transporting) of Pmr1 is rapamycin sensitive, but the Q783A mutant (Ca2+ transporting) strain is rapamycin resistant. Mn2+ transport into the Golgi lumen appears to be required for rapamycin sensitivity. Overexpression of Ca2+ pump SERCA1, Ca2+/H+ antiporter Vcx1, or a Mn2+ transporting mutant of Vcx1 (Vcx1-M1) failed to restore rapamycin sensitivity, and loss of Pmr1 but not other transporters of Ca2+ or Mn2+ results in rapamycin resistance. Overexpression of Ccc1, a Fe2+ and Mn2+ transporter that has been localized to Golgi and the vacuole, does restore rapamycin sensitivity to pmr1Delta. We conclude that Mn2+ in the Golgi inhibits TORC1 signaling.
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Affiliation(s)
- Gina Devasahayam
- Department of Pharmacology, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA
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19
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Flanagan JJ, Barlowe C. Cysteine-disulfide cross-linking to monitor SNARE complex assembly during endoplasmic reticulum-Golgi transport. J Biol Chem 2005; 281:2281-8. [PMID: 16303754 DOI: 10.1074/jbc.m511695200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Assembly of cognate SNARE proteins into SNARE complexes is required for many intracellular membrane fusion reactions. However, the mechanisms that govern SNARE complex assembly and disassembly during fusion are not well understood. We have devised a new in vitro cross-linking assay to monitor SNARE complex assembly during fusion of endoplasmic reticulum (ER)-derived vesicles with Golgi-acceptor membranes. In Saccharomyces cerevisiae, anterograde ER-Golgi transport requires four SNARE proteins: Sec22p, Bos1p, Bet1p, and Sed5p. After tethering of ER-derived vesicles to Golgi-acceptor membranes, SNARE proteins are thought to assemble into a four-helix coiled-coil bundle analogous to the structurally characterized neuronal and endosomal SNARE complexes. Molecular modeling was used to generate a structure of the four-helix ER-Golgi SNARE complex. Based on this structure, cysteine residues were introduced into adjacent SNARE proteins such that disulfide bonds would form if assembled into a SNARE complex. Our initial studies focused on disulfide bond formation between the SNARE motifs of Bet1p and Sec22p. Expression of SNARE cysteine derivatives in the same strain produced a cross-linked heterodimer of Bet1p and Sec22p under oxidizing conditions. Moreover, this Bet1p-Sec22p heterodimer formed during in vitro transport reactions when ER-derived vesicles containing the Bet1p derivative fused with Golgi membranes containing the Sec22p derivative. Using this disulfide cross-linking assay, we show that inhibition of transport with anti-Sly1p antibodies blocked formation of the Bet1p-Sec22p heterodimer. In contrast, chelation of divalent cations did not inhibit formation of the Bet1p-Sec22p heterodimer during in vitro transport but potently inhibited Golgi-specific carbohydrate modification of glyco-pro-alpha factor. This data suggests that Ca(2+) is not directly required for membrane fusion between ER-derived vesicles and Golgi-acceptor membranes.
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Affiliation(s)
- John J Flanagan
- Department of Biochemistry, Dartmouth Medical School, Hanover, NH 03755, USA
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20
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Abstract
The cell wall of growing plant tissues has frequently been interpreted in terms of inextensible cellulose microfibrils 'tethered' by hemicellulose polymers attached to the microfibril surface by hydrogen bonds, with growth occurring when tethers are broken or 'peeled' off the microfibril surface by expansins. This has sometimes been described as the 'sticky network' model. In this paper, a number of theoretical difficulties with this model, and discrepancies between predicted behaviour and observations by a number of researchers, are noted. (i) Predictions of cell wall moduli, based upon the sticky network model, suggest that the cell wall should be much weaker than is observed. (ii) The maximum hydrogen bond energy between tethers and microfibrils is less than the work done in expansion and therefore breakage of such hydrogen bonds is unlikely to limit growth. (iii) Composites of bacterial cellulose with xyloglucan are weaker than pellicles of pure cellulose so that it seems unlikely that hemicelluloses bind the microfibrils together. (iv) Calcium chelators promote creep of plant material in a similar way to expansins. (v) Reduced relative 'permittivities' inhibit the contraction of cell wall material when an applied stress is decreased. Revisions of the sticky network model that might address these issues are considered, as are alternatives including a model of cell wall biophysics in which cell wall polymers act as 'scaffolds' to regulate the space available for microfibril movement. Experiments that support the latter hypothesis, by demonstrating that reducing cell wall free volume decreases extensibility, are briefly described.
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Affiliation(s)
- David Stuart Thompson
- School of Biosciences, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK.
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Eguez L, Chung YS, Kuchibhatla A, Paidhungat M, Garrett S. Yeast Mn2+ transporter, Smf1p, is regulated by ubiquitin-dependent vacuolar protein sorting. Genetics 2005; 167:107-17. [PMID: 15166140 PMCID: PMC1470849 DOI: 10.1534/genetics.167.1.107] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Conditional cdc1(Ts) mutants of S. cerevisiae arrest with a phenotype similar to that exhibited by Mn(2+)-depleted cells. Sequence similarity between Cdc1p and a class of Mn(2+)-dependent phosphoesterases, as well as the observation that conditional cdc1(Ts) growth can be ameliorated by Mn(2+) supplement, suggests that Cdc1p activity is sensitive to intracellular Mn(2+) levels. This article identifies several previously uncharacterized cdc1(Ts) suppressors as class E vps (vacuolar protein sorting) mutants and shows that these, as well as other vps mutants, accumulate high levels of intracellular Mn(2+). Yeast VPS genes play a role in delivery of membrane transporters to the vacuole for degradation, and we show that the vps mutants accumulate elevated levels of the high-affinity Mn(2+) transporter Smf1p. cdc1(Ts) conditional growth is also alleviated by mutations, including doa4 and ubc4, that compromise protein ubiquitination, and these ubiquitination defects are associated with Smf1p accumulation. Epistasis studies show that these suppressors require functional Smf1p to alleviate the cdc1(Ts) growth defect, whereas Smf1p is dispensable for cdc1(Ts) suppression by a mutation (cos16/per1) that does not influence intracellular Mn(2+) levels. Because Smf1p is ubiquitinated in vivo, we propose that Smf1p is targeted to the vacuole for degradation by ubiquitination-dependent protein sorting.
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Affiliation(s)
- Lorena Eguez
- Department of Microbiology and Molecular Genetics and Graduate School of Biomedical Sciences, University of Medicine and Dentistry-New Jersey Medical School, Newark, New Jersey 07103-2714, USA
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22
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Van Baelen K, Dode L, Vanoevelen J, Callewaert G, De Smedt H, Missiaen L, Parys JB, Raeymaekers L, Wuytack F. The Ca2+/Mn2+ pumps in the Golgi apparatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1742:103-12. [PMID: 15590060 DOI: 10.1016/j.bbamcr.2004.08.018] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Accepted: 08/31/2004] [Indexed: 11/28/2022]
Abstract
Recent evidence highlights the functional importance of the Golgi apparatus as an agonist-sensitive intracellular Ca(2+) store. Besides Ca(2+)-release channels and Ca(2+)-binding proteins, the Golgi complex contains Ca(2+)-uptake mechanisms consisting of the well-known sarco/endoplasmic reticulum Ca(2+)-transport ATPases (SERCA) and the much less characterized secretory-pathway Ca(2+)-transport ATPases (SPCA). SPCA supplies the Golgi compartments and, possibly, the more distal compartments of the secretory pathway with both Ca(2+) and Mn(2+) and, therefore, plays an important role in the cytosolic and intra-Golgi Ca(2+) and Mn(2+) homeostasis. Mutations in the human gene encoding the SPCA1 pump (ATP2C1) resulting in Hailey-Hailey disease, an autosomal dominant skin disorder, are discussed.
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Affiliation(s)
- Kurt Van Baelen
- Laboratorium voor Fysiologie, K.U. Leuven Campus Gasthuisberg O/N, Herestraat 49, B-3000, Leuven, Belgium
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23
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Maeda T, Sugiura R, Kita A, Saito M, Deng L, He Y, Yabin L, Fujita Y, Takegawa K, Shuntoh H, Kuno T. Pmr1, a P-type ATPase, and Pdt1, an Nramp homologue, cooperatively regulate cell morphogenesis in fission yeast: the importance of Mn2+ homeostasis. Genes Cells 2004; 9:71-82. [PMID: 14723709 DOI: 10.1111/j.1356-9597.2004.00699.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Schizosaccharomyces pombe pmr1+ gene is homologous to Saccharomyces cerevisiae PMR1 gene, which encodes the P-type Ca2+/Mn2+-ATPase. Addition of Mn2+, as well as Ca2+, to the medium induced pmr1+ gene expression in a calcineurin-dependent manner. The pmr1 knockout (Deltapmr1) cells exhibited hypersensitivity to EGTA. A screen for high gene dosage-suppressors of the EGTA-hypersensitive phenotype of Deltapmr1 led to the identification of pdt1+ gene, which encodes an Nramp-related metal transporter. The Deltapmr1 cells showed round cell morphology. Although Deltapdt1 cells appeared normal in the regular medium, it showed round cell morphology similar to that of the Deltapmr1 cells when Mn2+ was removed from the medium. The removal of Mn2+ also exacerbated the round morphology of the Deltapmr1 cells. The Deltapmr1Deltapdt1 double mutants grew very slowly and showed extremely aberrant cell morphology with round, enlarged and depolarized shape. The addition of Mn2+, but not Ca2+, to the medium completely suppressed the morphological defects, while both Mn2+ and Ca2+ markedly improved the slow growth of the double mutants. These results suggest that Pmr1 and Pdt1 cooperatively regulate cell morphogenesis through the control of Mn2+ homeostasis, and that calcineurin functions as a Mn2+ sensor as well as a Mn2+ homeostasis regulator.
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Affiliation(s)
- Takuya Maeda
- Division of Molecular Pharmacology and Pharmacogenomics, Department of Genome Sciences, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
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24
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Aiello DP, Fu L, Miseta A, Sipos K, Bedwell DM. The Ca2+ Homeostasis Defects in a pgm2Δ Strain of Saccharomyces cerevisiae Are Caused by Excessive Vacuolar Ca2+ Uptake Mediated by the Ca2+-ATPase Pmc1p. J Biol Chem 2004; 279:38495-502. [PMID: 15252028 DOI: 10.1074/jbc.m400833200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Loss of the major isoform of phosphoglucomutase (PGM) causes an accumulation of glucose 1-phosphate when yeast cells are grown with galactose as the carbon and energy source. Remarkably, the pgm2Delta strain also exhibits a severe imbalance in intracellular Ca(2+) homeostasis when grown under these conditions. In the present study, we examined how the pgm2Delta mutation alters yeast Ca(2+) homeostasis in greater detail. We found that a shift from glucose to galactose as the carbon source resulted in a 2-fold increase in the rate of cellular Ca(2+) uptake in wild-type cells, whereas Ca(2+) uptake increased 8-fold in the pgm2Delta mutant. Disruption of the PMC1 gene, which encodes the vacuolar Ca(2+)-ATPase Pmc1p, suppressed the Ca(2+)-related phenotypes observed in the pgm2Delta strain. This suggests that excessive vacuolar Ca(2+) uptake is tightly coupled to these defects in Ca(2+) homeostasis. An in vitro assay designed to measure Ca(2+) sequestration into intracellular compartments confirmed that the pgm2Delta mutant contained a higher level of Pmc1p-dependent Ca(2+) transport activity than the wild-type strain. We found that this increased rate of vacuolar Ca(2+) uptake also coincided with a large induction of the unfolded protein response in the pgm2Delta mutant, suggesting that Ca(2+) uptake into the endoplasmic reticulum compartment was reduced. These results indicate that the excessive Ca(2+) uptake and accumulation previously shown to be associated with the pgm2Delta mutation are due to a severe imbalance in the distribution of cellular Ca(2+) into different intracellular compartments.
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Affiliation(s)
- David P Aiello
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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25
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Abstract
Ca2+-activated K+ channels were studied in C6-glioma cells in an attempt to correlate changes in expression with cell proliferation and differentiation. In this study, we treated C6-glioma cells with thapsigargin for 48 h. Cell proliferation was markedly inhibited, and cell morphology changed from round to a spindle differentiated shape. Furthermore, intracellular calcium concentration was initially increased during acute treatment with thapsigargin. The internal [Ca2+]i pool was eventually depleted after a 48-h thapsigargin treatment. We have characterized Ca2+-activated K+ currents in less differentiated C6 cells. After differentiation of C6 cells induced by thapsigargin, Ca2+-activated K+ currents were selectively suppressed. These data lend further support to the notion that the expression of Ca2+-activated K+ channels is intimately associated with the proliferation of C6-glioma cells, and the suppression of Ca2+-activated K+ channels coincides with the inhibition of proliferation and subsequent induction of cell differentiation.
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Affiliation(s)
- Tsun-Cheng Kuo
- Department of Cosmetic Science, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan.
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26
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Mandal D, Rulli SJ, Rao R. Packing interactions between transmembrane helices alter ion selectivity of the yeast Golgi Ca2+/Mn2+-ATPase PMR1. J Biol Chem 2003; 278:35292-8. [PMID: 12824173 DOI: 10.1074/jbc.m306166200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PMR1 is the yeast secretory pathway pump responsible for high affinity transport of Mn2+ and Ca2+ into the Golgi, where these ions are sequestered and effectively removed from the cytoplasm. Phenotypic growth assays allow for convenient screening of side chains important for Ca2+ and Mn2+ transport. Earlier we demonstrated that mutant Q783A at the cytoplasmic interface of M6 could transport Ca2+, but not Mn2+. Scanning mutagenesis of side chains proximal to residue Gln-783 in membrane helices M2, M4, M5, and M6 revealed additional residues near the cytoplasmic interface, notably Leu-341 (M5), Phe-738 (M5), and Leu-785 (M6) that are sensitive to substitution. Importantly, we obtained evidence for a packing interaction between Val-335 in M4 and Gln-783 in M6 that is critical for Mn2+ transport. Thus, mutant V335G mimics the Mn2+ transport defect of Q783A and mutant V335I can effectively suppress the Mn2+-defective phenotype of Q783A. These changes in ion selectivity were confirmed by cation-dependent ATP hydrolysis using purified enzyme. Other substitutions at these sites are tolerated individually, but not in combination. Exchange of side chains at 335 and 783 also results in ion selectivity defects, suggesting that the packing interaction may be conformation-sensitive. Homology models of M4, M5, and M6 of PMR1 have been generated, based on the structures of the sarcoplasmic reticulum Ca2+-ATPase. The models are supported by data from mutagenesis and reveal that Gln-783 and Val-335 show conformation-sensitive packing at the cytoplasmic interface. We suggest that this region may constitute a gate for access of Mn2+ ions.
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Affiliation(s)
- Debjani Mandal
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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27
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Delhaize E, Kataoka T, Hebb DM, White RG, Ryan PR. Genes encoding proteins of the cation diffusion facilitator family that confer manganese tolerance. THE PLANT CELL 2003; 15:1131-42. [PMID: 12724539 PMCID: PMC153721 DOI: 10.1105/tpc.009134] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2002] [Accepted: 03/02/2003] [Indexed: 05/18/2023]
Abstract
The yeast Saccharomyces cerevisiae expressing a cDNA library prepared from Stylosanthes hamata was screened for enhanced Mn(2+) tolerance. From this screen, we identified four related cDNAs that encode membrane-bound proteins of the cation diffusion facilitator (CDF) family. One of these cDNAs (ShMTP1) was investigated in detail and found to confer Mn(2+) tolerance to yeast by internal sequestration rather than by efflux of Mn(2+). Expression of ShMTP1 in a range of yeast mutants suggested that it functions as a proton:Mn(2+) antiporter on the membrane of an internal organelle. Similarly, when expressed in Arabidopsis, ShMTP1 conferred Mn(2+) tolerance through internal sequestration. The ShMTP1 protein fused to green fluorescent protein was localized to the tonoplast of Arabidopsis cells but appeared to localize to the endoplasmic reticulum of yeast. We suggest that the ShMTP1 proteins are members of the CDF family involved in conferring Mn(2+) tolerance and that at least one of these proteins (ShMTP1) confers tolerance by sequestering Mn(2+) into internal organelles.
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Affiliation(s)
- Emmanuel Delhaize
- Commonwealth Scientific and Industrial Research Organization Plant Industry, Canberra ACT 2601, Australia.
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28
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Wu Z, Liang F, Hong B, Young JC, Sussman MR, Harper JF, Sze H. An endoplasmic reticulum-bound Ca(2+)/Mn(2+) pump, ECA1, supports plant growth and confers tolerance to Mn(2+) stress. PLANT PHYSIOLOGY 2002; 130:128-37. [PMID: 12226493 PMCID: PMC166546 DOI: 10.1104/pp.004440] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Plants can grow in soils containing highly variable amounts of mineral nutrients, like Ca(2+) and Mn(2+), though the mechanisms of adaptation are poorly understood. Here, we report the first genetic study to determine in vivo functions of a Ca(2+) pump in plants. Homozygous mutants of Arabidopsis harboring a T-DNA disruption in ECA1 showed a 4-fold reduction in endoplasmic reticulum-type calcium pump activity. Surprisingly, the phenotype of mutant plants was indistinguishable from wild type when grown on standard nutrient medium containing 1.5 mM Ca(2+) and 50 microM Mn(2+). However, mutants grew poorly on medium with low Ca(2+) (0.2 mM) or high Mn(2+) (0.5 mM). On high Mn(2+), the mutants failed to elongate their root hairs, suggesting impairment in tip growth processes. Expression of the wild-type gene (CAMV35S::ECA1) reversed these conditional phenotypes. The activity of ECA1 was examined by expression in a yeast (Saccharomyces cerevisiae) mutant, K616, which harbors a deletion of its endogenous calcium pumps. In vitro assays demonstrated that Ca(2+), Mn(2+), and Zn(2+) stimulated formation of a phosphoenzyme intermediate, consistent with the translocation of these ions by the pump. ECA1 provided increased tolerance of yeast mutant to toxic levels of Mn(2+) (1 mM) and Zn(2+)(3 mM), consistent with removal of these ions from the cytoplasm. These results show that despite the potential redundancy of multiple Ca(2+) pumps and Ca(2+)/H(+) antiporters in Arabidopsis, pumping of Ca(2+) and Mn(2+) by ECA1 into the endoplasmic reticulum is required to support plant growth under conditions of Ca(2+) deficiency or Mn(2+) toxicity.
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Affiliation(s)
- Zhongyi Wu
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, USA
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29
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Bonilla M, Nastase KK, Cunningham KW. Essential role of calcineurin in response to endoplasmic reticulum stress. EMBO J 2002; 21:2343-53. [PMID: 12006487 PMCID: PMC126012 DOI: 10.1093/emboj/21.10.2343] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Depletion of calcium ions (Ca2+) from the endoplasmic reticulum (ER) of yeast cells resulted in the activation of the unfolded protein response (UPR) signaling pathway involving Ire1p and Hac1p. The depleted ER also stimulated Ca2+ influx at the plasma membrane through the Cch1p-Mid1p Ca2+ channel and another system. Surprisingly, both Ca2+ influx systems were stimulated upon accumulation of misfolded proteins in the ER even in the presence of Ca2+. The ability of misfolded ER proteins to stimulate Ca2+ influx at the plasma membrane did not require Ire1p or Hac1p, and Ca2+ influx and signaling factors were not required for initial UPR signaling. However, activation of the Ca2+ channel, calmodulin, calcineurin and other factors was necessary for long-term survival of cells undergoing ER stress. A similar calcium cell survival (CCS) pathway operates in the pathogenic fungi and promotes resistance to azole antifungal drugs. These findings reveal an unanticipated new regulatory mechanism that couples ER stress to Ca2+ influx and signaling pathways, which help to prevent cell death and promote resistance to an important class of fungistatic drugs.
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Affiliation(s)
| | | | - Kyle W. Cunningham
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
Corresponding author e-mail:
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30
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Ton VK, Mandal D, Vahadji C, Rao R. Functional expression in yeast of the human secretory pathway Ca(2+), Mn(2+)-ATPase defective in Hailey-Hailey disease. J Biol Chem 2002; 277:6422-7. [PMID: 11741891 DOI: 10.1074/jbc.m110612200] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The discovery and biochemical characterization of the secretory pathway Ca(2+)-ATPase, PMR1, in Saccharomyces cerevisiae, has paved the way for identification of PMR1 homologues in many species including rat, Caenorhabditis elegans, and Homo sapiens. In yeast, PMR1 has been shown to function as a high affinity Ca(2+)/Mn(2+) pump and has been localized to the Golgi compartment where it is important for protein sorting, processing, and glycosylation. However, little is known about PMR1 homologues in higher organisms. Loss of one functional allele of the human gene, hSPCA1, has been linked to Hailey-Hailey disease, characterized by skin ulceration and improper keratinocyte adhesion. We demonstrate that expression of hSPCA1 in yeast fully complements pmr1 phenotypes of hypersensitivity to Ca(2+) chelators and Mn(2+) toxicity. Similar to PMR1, epitope-tagged hSPCA1 also resides in the Golgi when expressed in yeast or in chinese hamster ovary cells. (45)Ca(2+) transport by hSPCA1 into isolated yeast Golgi vesicles shows an apparent Ca(2+) affinity of 0.26 microm, is inhibitable by Mn(2+), but is thapsigargin-insensitive. In contrast, heterologous expression of vertebrate sarcoplasmic reticulum and plasma membrane Ca(2+)-ATPases in yeast complement the Ca(2+)- but not Mn(2+)-related phenotypes of the pmr1-null strain, suggesting that high affinity Mn(2+) transport is a unique feature of the secretory pathway Ca(2+)-ATPases.
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Affiliation(s)
- Van-Khue Ton
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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31
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Jakubovics NS, Jenkinson HF. Out of the iron age: new insights into the critical role of manganese homeostasis in bacteria. MICROBIOLOGY (READING, ENGLAND) 2001; 147:1709-1718. [PMID: 11429449 DOI: 10.1099/00221287-147-7-1709] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Nicholas S Jakubovics
- Oral Microbiology Unit, Department of Oral and Dental Science, University of Bristol, Dental School and Hospital, Lower Maudlin Street, Bristol BS1 2LY, UK1
| | - Howard F Jenkinson
- Oral Microbiology Unit, Department of Oral and Dental Science, University of Bristol, Dental School and Hospital, Lower Maudlin Street, Bristol BS1 2LY, UK1
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Rossanese OW, Reinke CA, Bevis BJ, Hammond AT, Sears IB, O'Connor J, Glick BS. A role for actin, Cdc1p, and Myo2p in the inheritance of late Golgi elements in Saccharomyces cerevisiae. J Cell Biol 2001; 153:47-62. [PMID: 11285273 PMCID: PMC2185536 DOI: 10.1083/jcb.153.1.47] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In Saccharomyces cerevisiae, Golgi elements are present in the bud very early in the cell cycle. We have analyzed this Golgi inheritance process using fluorescence microscopy and genetics. In rapidly growing cells, late Golgi elements show an actin-dependent concentration at sites of polarized growth. Late Golgi elements are apparently transported into the bud along actin cables and are also retained in the bud by a mechanism that may involve actin. A visual screen for mutants defective in the inheritance of late Golgi elements yielded multiple alleles of CDC1. Mutations in CDC1 severely depolarize the actin cytoskeleton, and these mutations prevent late Golgi elements from being retained in the bud. The efficient localization of late Golgi elements to the bud requires the type V myosin Myo2p, further suggesting that actin plays a role in Golgi inheritance. Surprisingly, early and late Golgi elements are inherited by different pathways, with early Golgi elements localizing to the bud in a Cdc1p- and Myo2p-independent manner. We propose that early Golgi elements arise from ER membranes that are present in the bud. These two pathways of Golgi inheritance in S. cerevisiae resemble Golgi inheritance pathways in vertebrate cells.
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Affiliation(s)
- Olivia W. Rossanese
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637
| | - Catherine A. Reinke
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637
| | - Brooke J. Bevis
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637
| | - Adam T. Hammond
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637
| | - Irina B. Sears
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637
| | - James O'Connor
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637
| | - Benjamin S. Glick
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637
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Aramburu J, Rao A, Klee CB. Calcineurin: from structure to function. CURRENT TOPICS IN CELLULAR REGULATION 2000; 36:237-95. [PMID: 10842755 DOI: 10.1016/s0070-2137(01)80011-x] [Citation(s) in RCA: 248] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- J Aramburu
- Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
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Mandal D, Woolf TB, Rao R. Manganese selectivity of pmr1, the yeast secretory pathway ion pump, is defined by residue gln783 in transmembrane segment 6. Residue Asp778 is essential for cation transport. J Biol Chem 2000; 275:23933-8. [PMID: 10801856 DOI: 10.1074/jbc.m002619200] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have solubilized and purified the histidine-tagged yeast secretory pathway/Golgi ion pump Pmr1 to near homogeneity in one step, using nickel affinity chromatography. The purified pump demonstrates both Ca(2+)- and Mn(2+)-dependent ATP hydrolysis and phosphoenzyme intermediate formation in forward (ATP) and reverse (P(i)) directions. This preparation has allowed us to examine, in detail, the properties of mutations D778A and Q783A in transmembrane segment M6 of Pmr1. In phenotypic screens of Ca(2+) chelator and Mn(2+) toxicity reported separately (Wei, Y., Chen, J., Rosas, G., Tompkins, D.A., Holt, P.A., and Rao, R. (2000) J. Biol. Chem. 275, XXXX-XXXX), D778A was a loss-of-function mutant apparently defective for transport of both Ca(2+) and Mn(2+), whereas mutant Q783A displayed a differential sensitivity consistent with the selective loss of Mn(2+) transport. We show that mutant D778A is devoid of cation-dependent ATP hydrolytic activity and phosphoenzyme formation from ATP. However, reverse phosphorylation from P(i) is preserved but is insensitive to inhibition by Ca(2+) or Mn(2+) ions, which is evidence for a specific inability to bind cations in this mutant. We also show that Ca(2+) can activate ATP hydrolysis in the purified Q783A mutant, with a half-maximal concentration of 0.06 micrometer, essentially identical to that of wild type (0.07 micrometer). Mn(2+) activation of ATP hydrolysis was half-maximal at 0.02 micrometer in wild type, establishing a normal selectivity profile of Mn(2+) > Ca(2+). Strikingly, Mn(2+)-ATPase in the Q783A mutant was nearly abolished, even at concentrations of up to 10 micrometer. These results were confirmed in assays of phosphoenzyme intermediates. Molecular modeling of the packing between helices M4 and M6 suggests that residue Gln(783) in M6 may form a critical hydrophobic interaction with Val(335) in M4, such that the Ala substitution modifies the packing or tilt of the helices and thus the ion pore. The data emphasize the critical role of transmembrane segment M6 in defining the cation binding pocket of P-type ATPases.
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Affiliation(s)
- D Mandal
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Asleson CM, Asleson JC, Malandra E, Johnston S, Berman J. Filamentous growth of Saccharomyces cerevisiae is regulated by manganese. Fungal Genet Biol 2000; 30:155-62. [PMID: 11017771 DOI: 10.1006/fgbi.2000.1214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Candida albicans INT1 gene is a virulence factor that contributes to both adhesion and filamentous growth of the fungus. Expression of INT1 in the budding yeast Saccharomyces cerevisiae directs both adhesion and filamentous growth. Because Int1p contains two predicted divalent cation-binding motifs, we asked whether divalent cations are important for the role of Int1p in filament formation. In this study, we found that INT1-induced filamentous growth (I-IFG) is sensitive to the divalent cation chelator EDTA and that this EDTA sensitivity can be ameliorated by the addition of Mn(2+), but not Mg(2+) or Ca(2+) ions. The addition of MnCl(2) restored both the proportion of cells forming filaments and the length of filaments formed. Expression of INT1 in S. cerevisiae mutants that reduce the intracellular concentration of Mn(2+) did not affect I-IFG. Interestingly, the Mn(2+) dependence of I-IFG is not dependent upon the presence of the putative divalent cation-binding domains found in INT1. Rather, we found that polarized growth induced by mutations in CDC12 and CLA4 or by expression of excess SWE1 was also sensitive to EDTA treatment and was restored by the addition of MnCl(2) but not by the addition of CaCl(2). Thus, our results suggest that in S. cerevisiae polarized growth is dependent upon the presence of Mn(2+) ions.
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Affiliation(s)
- C M Asleson
- Department of Genetics, Cell Biology and Development, University of Minnesota, 250 Biological Sciences Center, St. Paul, Minnesota 55108, USA
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36
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Sone T, Griffiths AJ. The frost gene of Neurospora crassa is a homolog of yeast cdc1 and affects hyphal branching via manganese homeostasis. Fungal Genet Biol 1999; 28:227-37. [PMID: 10669587 DOI: 10.1006/fgbi.1999.1169] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Neurospora crassa mutant frost has a hyperbranching phenotype that can be corrected by adding Ca(2+), suggesting that characterization of this gene might clarify the mechanism of Ca(2+)-dependent tip growth. The wild-type allele was cloned by sib selection using protoplasts from arthroconidia. RFLP analysis revealed that the cloned DNA fragment mapped to the fr locus. The nucleotide sequence of genomic and cDNA was determined. The deduced amino acid sequence showed homology to the Saccharomyces cerevisiae CDC1 protein, implicated in manganese homeostasis. The fr mutant was sensitive to Mn(2+), and a revertant allele whose product differs by one amino acid was tolerant to Mn(2+). Mn(2+) depletion induced the wild-type strain to hyperbranch, resulting in a morphology similar to that of fr. The fr mutant was also sensitive to calcineurin inhibitors. These results suggest that fr is involved in Mn(2+) homeostasis and point to a role for Mn(2+) in Neurospora branching.
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Affiliation(s)
- T Sone
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada
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37
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Wei Y, Marchi V, Wang R, Rao R. An N-terminal EF hand-like motif modulates ion transport by Pmr1, the yeast Golgi Ca(2+)/Mn(2+)-ATPase. Biochemistry 1999; 38:14534-41. [PMID: 10545175 DOI: 10.1021/bi9911233] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pmr1, a novel member of the family of P-type ATPases, localizes to the Golgi compartment in yeast where it provides Ca(2+) and Mn(2+) for a variety of normal secretory processes. We have previously characterized Ca(2+) transport in isolated Golgi vesicles, and described an expression system for the analysis of Pmr1 mutants in a yeast strain devoid of background Ca(2+) pump activity [Sorin, A., Rosas, G., and Rao, R. (1997) J. Biol. Chem. 272, 9895-9901]. Here we show, using recombinant bacterial fusions, that an N-terminal EF hand-like motif in Pmr1 binds Ca(2+). Increasing disruptions of this motif led to progressive loss of pump function; thus, the single point mutations D51A and D53A retained pump activity but with drastic reductions in the affinity for Ca(2+) transport, while the double mutant was largely unable to exit the endoplasmic reticulum. In-frame deletions of the Ca(2+)-binding motif resulted in complete loss of function. Interestingly, the single point mutations conferred differential affinities for transport of Ca(2+) and Mn(2+) ions. Further, the proteolytic stability of the catalytic ATP-binding domain is altered by the N-terminal mutations, suggesting an interaction between these two regions of polypeptide. These studies implicate the N-terminal domain of Pmr1 in the modulation of ion transport, and may help elucidate the role of N-terminal metal-binding sites of Cu(2+)-ATPases, defective in Wilson and Menkes disease.
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Affiliation(s)
- Y Wei
- Department of Physiology, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, USA
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38
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Abstract
By now, the EUROFAN programme for the functional analysis of genes from the yeast genome has attained its cruising speed. Indeed, several hundreds of yeast mutants with no phenotype as tested by growth on standard media and no significant sequence similarity to proteins of known function are available through the efforts of various laboratories. Based on the methodology initiated during the pilot project on yeast chromosome III (Yeast 13, 1547-1562, 1997) we adapted it to High Throughput Screening (HTS), using robotics. The first 100 different gene deletions from EUROSCARF, constructed in an FY1679 strain background, were run against a collection of about 300 inhibitors. Many of these inhibitors have not been reported until now to interfere in vivo with growth of Saccharomyces cerevisiae. In the present paper we provide a list of novel growth conditions and a compilation of 49 yeast deletants (from chromosomes II, IV, VII, X, XIV, XV) corresponding to 58% of the analysed genes, with at least one clear and stringent phenotype. The majority of these deletants are sensitive to one or two compounds (monotropic phenotype) while a distinct subclass of deletants displays a hyper-pleiotropic phenotype with sensitivities to a dozen or more compounds. Therefore, chemotyping of unknown genes with a large spectrum of drugs opens new vistas for a more in-depth functional analysis and a more precise definition of molecular targets.
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Affiliation(s)
- K J Rieger
- Centre de Génétique Moléculaire du Centre National de la Recherche Scientifique, Laboratoire Propre Associé à L'Université Pierre et Marie Curie, F-91198 Gif-sur-Yvette, France
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Gustin MC, Albertyn J, Alexander M, Davenport K. MAP kinase pathways in the yeast Saccharomyces cerevisiae. Microbiol Mol Biol Rev 1998; 62:1264-300. [PMID: 9841672 PMCID: PMC98946 DOI: 10.1128/mmbr.62.4.1264-1300.1998] [Citation(s) in RCA: 703] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A cascade of three protein kinases known as a mitogen-activated protein kinase (MAPK) cascade is commonly found as part of the signaling pathways in eukaryotic cells. Almost two decades of genetic and biochemical experimentation plus the recently completed DNA sequence of the Saccharomyces cerevisiae genome have revealed just five functionally distinct MAPK cascades in this yeast. Sexual conjugation, cell growth, and adaptation to stress, for example, all require MAPK-mediated cellular responses. A primary function of these cascades appears to be the regulation of gene expression in response to extracellular signals or as part of specific developmental processes. In addition, the MAPK cascades often appear to regulate the cell cycle and vice versa. Despite the success of the gene hunter era in revealing these pathways, there are still many significant gaps in our knowledge of the molecular mechanisms for activation of these cascades and how the cascades regulate cell function. For example, comparison of different yeast signaling pathways reveals a surprising variety of different types of upstream signaling proteins that function to activate a MAPK cascade, yet how the upstream proteins actually activate the cascade remains unclear. We also know that the yeast MAPK pathways regulate each other and interact with other signaling pathways to produce a coordinated pattern of gene expression, but the molecular mechanisms of this cross talk are poorly understood. This review is therefore an attempt to present the current knowledge of MAPK pathways in yeast and some directions for future research in this area.
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Affiliation(s)
- M C Gustin
- Department of Biochemistry and Cell Biology Rice University, Houston, Texas 77251-1892, USA.
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40
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Abstract
Transition metals such as iron, copper, manganese, and zinc are essential nutrients. The yeast Saccharomyces cerevisiae is an ideal organism for deciphering the mechanism and regulation of metal ion transport. Recent studies of yeast have shown that accumulation of any single metal ion is mediated by two or more substrate-specific transport systems. High-affinity systems are active in metal-limited cells, whereas low-affinity systems play the predominant roles when the substrate is more abundant. Metal ion uptake systems of cells are tightly controlled, and both transcriptional and posttranscriptional regulatory mechanisms have been identified. Most importantly, studies of S. cerevisiae have identified a large number of genes that function in metal ion transport and have illuminated the existence of importance of gene families that play related roles in these processes in mammals.
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Affiliation(s)
- D J Eide
- Nutritional Sciences Program, University of Missouri-Columbia 65203, USA.
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41
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Dürr G, Strayle J, Plemper R, Elbs S, Klee SK, Catty P, Wolf DH, Rudolph HK. The medial-Golgi ion pump Pmr1 supplies the yeast secretory pathway with Ca2+ and Mn2+ required for glycosylation, sorting, and endoplasmic reticulum-associated protein degradation. Mol Biol Cell 1998; 9:1149-62. [PMID: 9571246 PMCID: PMC25337 DOI: 10.1091/mbc.9.5.1149] [Citation(s) in RCA: 309] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The yeast Ca2+ adenosine triphosphatase Pmr1, located in medial-Golgi, has been implicated in intracellular transport of Ca2+ and Mn2+ ions. We show here that addition of Mn2+ greatly alleviates defects of pmr1 mutants in N-linked and O-linked protein glycosylation. In contrast, accurate sorting of carboxypeptidase Y (CpY) to the vacuole requires a sufficient supply of intralumenal Ca2+. Most remarkably, pmr1 mutants are also unable to degrade CpY*, a misfolded soluble endoplasmic reticulum protein, and display phenotypes similar to mutants defective in the stress response to malfolded endoplasmic reticulum proteins. Growth inhibition of pmr1 mutants on Ca2+-deficient media is overcome by expression of other Ca2+ pumps, including a SERCA-type Ca2+ adenosine triphosphatase from rabbit, or by Vps10, a sorting receptor guiding non-native luminal proteins to the vacuole. Our analysis corroborates the dual function of Pmr1 in Ca2+ and Mn2+ transport and establishes a novel role of this secretory pathway pump in endoplasmic reticulum-associated processes.
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Affiliation(s)
- G Dürr
- Institut für Biochemie der Universität Stuttgart, D-70569 Stuttgart, Germany
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42
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Paidhungat M, Garrett S. Cdc1 and the vacuole coordinately regulate Mn2+ homeostasis in the yeast Saccharomyces cerevisiae. Genetics 1998; 148:1787-98. [PMID: 9560393 PMCID: PMC1460059 DOI: 10.1093/genetics/148.4.1787] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The yeast CDC1 gene encodes an essential protein that has been implicated in the regulation of cytosolic [Mn2+]. To identify factors that impinge upon Cdc1 or the Cdc1-dependent process, we isolated second-site suppressors of the conditional cdc1-1(Ts) growth defect. Recessive suppressors define 15 COS (CdcOne Suppressor) genes. Seven of the fifteen COS genes are required for biogenesis of the vacuole, an organelle known to sequester intracellular Mn2+. An eighth gene, COS16, encodes a vacuolar membrane protein that seems to be involved in Mn2+ homeostasis. These results suggest mutations that block vacuolar Mn2+ sequestration compensate for defects in Cdc1 function. Interestingly, Cdc1 is dispensable in a cos16delta deletion strain, and a cdc1delta cos16delta double mutant exhibits robust growth on medium supplemented with Mn2+. Thus, the single, essential function of Cdc1 is to regulate intracellular, probably cytosolic, Mn2+.
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Affiliation(s)
- M Paidhungat
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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43
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Paidhungat M, Garrett S. Cdc1 is required for growth and Mn2+ regulation in Saccharomyces cerevisiae. Genetics 1998; 148:1777-86. [PMID: 9560392 PMCID: PMC1460114 DOI: 10.1093/genetics/148.4.1777] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cdc1 function was initially implicated in bud formation and nuclear division because cdc1(Ts) cells arrested with a small bud, duplicated DNA, and undivided nucleus. Our studies show that Cdc1 is necessary for cell growth at several stages of the cell cycle, as well as in pheromone-treated cells. Thus, Cdc1 depletion might affect bud formation and nuclear division, as well as other cellular processes, by blocking a process involved in general cell growth. Cells depleted of intracellular Mn2+ also exhibit a cdc1-like phenotype and recent results suggested Cdc1 might be a Mn2+-dependent protein. We show that all of the conditional Cdc1(Ts) alleles tested cause cells to become sensitive to Mn2+ depletion. In addition, Cdc1 overproduction alleviates the chelator sensitivity of several Mn2+ homeostasis mutants. These findings are compatible with a model in which Cdc1 regulates intracellular, and in particular cytosolic, Mn2+ levels which, in turn, are necessary for cell growth.
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Affiliation(s)
- M Paidhungat
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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44
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MacDiarmid CW, Gardner RC. Overexpression of the Saccharomyces cerevisiae magnesium transport system confers resistance to aluminum ion. J Biol Chem 1998; 273:1727-32. [PMID: 9430719 DOI: 10.1074/jbc.273.3.1727] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Ionic aluminum (Al3+) is toxic to plants, microbes, fish, and animals, but the mechanism of its toxicity is unknown. We describe the isolation of two yeast genes (ALR1 and ALR2) which confer increased tolerance to Al3+ and Ga3+ ions when overexpressed while increasing strain sensitivity to Zn2+, Mn2+, Ni2+, Cu2+, Ca2+, and La3+ ions. The Alr proteins are homologous to the Salmonella typhimurium CorA protein, a bacterial Mg2+ and Co2+ transport system located in the periplasmic membrane. Yeast strains lacking ALR gene activity required additional Mg2+ for growth, and expression of either ALR1 or ALR2 corrected the Mg(2+)-requiring phenotype. The results suggest that the ALR genes encode the yeast uptake system for Mg2+ and other divalent cations. This hypothesis was supported by evidence that 57Co2+ accumulation was elevated in ALR-overexpressing strains and reduced in strains lacking ALR expression. ALR overexpression also overcame the inhibition of Co2+ uptake by Al3+ ions. The results indicate that aluminum toxicity to yeast occurs as a consequence of reduced Mg2+ influx via the Alr proteins. The molecular identification of the yeast Mg2+ transport system should lead to a better understanding of the regulation of Mg2+ homeostasis in eukaryote cells.
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Affiliation(s)
- C W MacDiarmid
- School of Biological Sciences, University of Auckland, New Zealand
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45
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Dove JE, Brockenbrough JS, Aris JP. Isolation of nuclei and nucleoli from the yeast Saccharomyces cerevisiae. Methods Cell Biol 1998; 53:33-46. [PMID: 9348503 PMCID: PMC3668690 DOI: 10.1016/s0091-679x(08)60873-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J E Dove
- Department of Anatomy and Cell Biology, University of Florida, Gainesville 32610, USA
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46
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Matheos DP, Kingsbury TJ, Ahsan US, Cunningham KW. Tcn1p/Crz1p, a calcineurin-dependent transcription factor that differentially regulates gene expression in Saccharomyces cerevisiae. Genes Dev 1997; 11:3445-58. [PMID: 9407036 PMCID: PMC316804 DOI: 10.1101/gad.11.24.3445] [Citation(s) in RCA: 277] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ca2+ signals regulate gene expression in animal and yeast cells through mechanisms involving calcineurin, a protein phosphatase activated by binding Ca2+ and calmodulin. Tcn1p, also named Crz1p, was identified as a transcription factor in yeast required for the calcineurin-dependent induction of PMC1, PMR1, PMR2A, and FKS2 which confer tolerance to high Ca2+, Mn2+, Na+, and cell wall damage, respectively. Tcn1p was not required for other calcineurin-dependent processes, such as inhibition of a vacuolar H+/Ca2+ exchanger and inhibition of a pheromone-stimulated Ca2+ uptake system, suggesting that Tcn1p functions downstream of calcineurin on a branch of the calcium signaling pathway leading to gene expression. Tcn1p contains three zinc finger motifs at its carboxyl terminus resembling the DNA-binding domains of Zif268, Swi5p, and other transcription factors. When fused to the transcription activation domain of Gal4p, the carboxy terminal domain of Tcn1p directed strong calcineurin-independent expression of PMC1-lacZ and other target genes. The amino-terminal domain of Tcn1p was found to function as a calcineurin-dependent transcription activation domain when fused to the DNA-binding domain of Gal4p. This amino-terminal domain also formed Ca2+-dependent and FK506-sensitive interactions with calcineurin in the yeast two-hybrid assay. These findings suggest that Tcn1p functions as a calcineurin-dependent transcription factor. Interestingly, induction of Tcn1p-dependent genes was found to be differentially controlled in response to physiological Ca2+ signals generated by treatment with mating pheromone and high salt. We propose that different promoters are sensitive to variations in the strength of Ca2+ signals generated by these stimuli and to effects of other signaling pathways.
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Affiliation(s)
- D P Matheos
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218 USA
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47
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Paidhungat M, Garrett S. A homolog of mammalian, voltage-gated calcium channels mediates yeast pheromone-stimulated Ca2+ uptake and exacerbates the cdc1(Ts) growth defect. Mol Cell Biol 1997; 17:6339-47. [PMID: 9343395 PMCID: PMC232485 DOI: 10.1128/mcb.17.11.6339] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Previous studies attributed the yeast (Saccharomyces cerevisiae) cdc1(Ts) growth defect to loss of an Mn2+-dependent function. In this report we show that cdc1(Ts) temperature-sensitive growth is also associated with an increase in cytosolic Ca2+. We identified two recessive suppressors of the cdc1(Ts) temperature-sensitive growth which block Ca2+ uptake and accumulation, suggesting that cytosolic Ca2+ exacerbates or is responsible for the cdc1(Ts) growth defect. One of the cdc1(Ts) suppressors is identical to a gene, MID1, recently implicated in mating pheromone-stimulated Ca2+ uptake. The gene (CCH1) corresponding to the second suppressor encodes a protein that bears significant sequence similarity to the pore-forming subunit (alpha1) of plasma membrane, voltage-gated Ca2+ channels from higher eukaryotes. Strains lacking Mid1 or Cch1 protein exhibit a defect in pheromone-induced Ca2+ uptake and consequently lose viability upon mating arrest. The mid1delta and cch1delta mutants also display reduced tolerance to monovalent cations such as Li+, suggesting a role for Ca2+ uptake in the calcineurin-dependent ion stress response. Finally, mid1delta cch1delta double mutants are, by both physiological and genetic criteria, identical to single mutants. These and other results suggest Mid1 and Cch1 are components of a yeast Ca2+ channel that may mediate Ca2+ uptake in response to mating pheromone, salt stress, and Mn2+ depletion.
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Affiliation(s)
- M Paidhungat
- Department of Molecular Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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48
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Liang F, Cunningham KW, Harper JF, Sze H. ECA1 complements yeast mutants defective in Ca2+ pumps and encodes an endoplasmic reticulum-type Ca2+-ATPase in Arabidopsis thaliana. Proc Natl Acad Sci U S A 1997; 94:8579-84. [PMID: 9238019 PMCID: PMC23025 DOI: 10.1073/pnas.94.16.8579] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/1997] [Accepted: 05/27/1997] [Indexed: 02/04/2023] Open
Abstract
To understand the structure, role, and regulation of individual Ca2+ pumps in plants, we have used yeast as a heterologous expression system to test the function of a gene from Arabidopsis thaliana (ECA1). ECA1 encoded a 116-kDa polypeptide that has all the conserved domains common to P-type Ca2+ pumps (EC 3.6.1.38). The amino acid sequence shared more identity with sarcoplasmic/endoplasmic reticulum (53%) than with plasma membrane (32%) Ca2+ pumps. Yeast mutants defective in a Golgi Ca2+ pump (pmr1) or both Golgi and vacuolar Ca2+ pumps (pmr1 pmc1 cnb1) were sensitive to growth on medium containing 10 mM EGTA or 3 mM Mn2+. Expression of ECA1 restored growth of either mutant on EGTA. Membranes were isolated from the pmr1 pmc1 cnb1 mutant transformed with ECA1 to determine if the ECA1 polypeptide (ECA1p) could be phosphorylated as intermediates of the reaction cycle of Ca2+-pumping ATPases. In the presence of [gamma-32P]ATP, ECA1p formed a Ca2+-dependent [32P]phosphoprotein of 106 kDa that was sensitive to hydroxylamine. Cyclopiazonic acid, a blocker of animal sarcoplasmic/endoplasmic reticulum Ca2+ pumps, inhibited the formation of the phosphoprotein, whereas thapsigargin did not. Immunoblotting with an antibody against the carboxyl tail showed that ECA1p was associated mainly with the endoplasmic reticulum membranes isolated from Arabidopsis plants. The results support the model that ECA1 encodes an endoplasmic reticulum-type Ca2+ pump in Arabidopsis. The ability of ECA1p to restore growth of mutant pmr1 on medium containing Mn2+, and the formation of a Mn2+-dependent phosphoprotein suggested that ECA1p may also regulate Mn2+ homeostasis by pumping Mn2+ into endomembrane compartments of plants.
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Affiliation(s)
- F Liang
- Department of Plant Biology, University of Maryland, College Park, MD 20742, USA
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Catty P, de Kerchove d'Exaerde A, Goffeau A. The complete inventory of the yeast Saccharomyces cerevisiae P-type transport ATPases. FEBS Lett 1997; 409:325-32. [PMID: 9224683 DOI: 10.1016/s0014-5793(97)00446-8] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A total of sixteen open reading frames encoding for P-type ATPases have been identified in the complete genome sequence of Saccharomyces cerevisiae. Phylogenetic analysis distinguishes 6 distinct families. Topology predictions, identification of aminoacid sequence motifs and phenotype analysis of the available mutants suggest that these families correspond to ATPases transporting either H+ (2 members), Ca2+ (2 members), Na+ (3 members), heavy metals (2 members), possibly aminophospholipids (5 members including 4 new ones) or unknown substrates (2 new members). It is proposed that the latter family which has homologs in Tetrahymena thermophila, Plasmodium falciparum and Caenorhabditis elegans constitutes a new group called P4-ATPases with characteristic topology and aminoacid signatures.
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Affiliation(s)
- P Catty
- Unité de Biochimie Physiologique, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
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