57 research outputs found

    Consequences of chronic diseases and other limitations associated with old age - A scoping review

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    Funding Information: This work supported in part by the LTC INTER COST, Evaluation of the Potential for Reducing Health and Social Expenses for Elderly People Using the Smart Environment, through the Ministry of Education, Youth and Sports, Czech Republic, under Project LTC18035; and in part by the project of Excellence, University of Hradec Kralove, FIM, Czech Republic (ID: 2205–2019). First author – Petra Maresova is principle investigator of LTC18035 INTER COST project, from which Petra Maresova, Ondrej Krejcar and Kamil Kuca are funded for all expenses including personal costs. Ehsan Javanmardi is funded from project of Excellence ID: 2205–2019 for personal costs. Sabina Barakovic, Jasmina Barakovic Husic and Signe Tomsone are members of COST ACTION 16226 of which also Petra Maresova and Ondrej Krejcar are paticipants, while this article also ACKnowledge this project CA16226. Funding Information: The authors would like to hereby acknowledge COST Action CA16226 for their networking support. The Indoor Living Space Improvement: Smart Habitat for the Elderly played a role of networking platform for knowledge sharing and interchanging ideas for joint research and publication, what was the base for creating this study. Based on CA16226 project LTC18035 INTER COST was proposed for national funding support of COST ACTION Framework. COST is a funding agency that helps innovation and research networks. Our Action was instrumental in connecting research programmes throughout the EU region. Their contribution has made it possible for scientists to connect with each other and share their ideas and findings. This allows for more research and better innovation. More information can be found at www.cost.eu. The authors would also like to acknowledge the Excellence 2019 internal research project, Faculty of Informatics and Management, University of Hradec Kralove, Czech Republic. Publisher Copyright: © 2019 The Author(s).Background: The phenomenon of the increasing number of ageing people in the world is arguably the most significant economic, health and social challenge that we face today. Additionally, one of the major epidemiologic trends of current times is the increase in chronic and degenerative diseases. This paper tries to deliver a more up to date overview of chronic diseases and other limitations associated with old age and provide a more detailed outlook on the research that has gone into this field. Methods: First, challenges for seniors, including chronic diseases and other limitations associated with old age, are specified. Second, a review of seniors' needs and concerns is performed. Finally, solutions that can improve seniors' quality of life are discussed. Publications obtained from the following databases are used in this scoping review: Web of Science, PubMed, and Science Direct. Four independent reviewers screened the identified records and selected relevant publications published from 2010 to 2017. A total of 1916 publications were selected. In all, 52 papers were selected based on abstract content. For further processing, 21 full papers were screened." Results: The results indicate disabilities as a major problem associated with seniors' activities of daily living dependence. We founded seven categories of different conditions - psychological problems, difficulties in mobility, poor cognitive function, falls and incidents, wounds and injuries, undernutrition, and communication problems. In order to minimize ageing consequences, some areas require more attention, such as education and training; technological tools; government support and welfare systems; early diagnosis of undernutrition, cognitive impairment, and other diseases; communication solutions; mobility solutions; and social contributions. Conclusions: This scoping review supports the view on chronic diseases in old age as a complex issue. To prevent the consequences of chronic diseases and other limitations associated with old age related problems demands multicomponent interventions. Early recognition of problems leading to disability and activities of daily living (ADL) dependence should be one of essential components of such interventions.publishersversionPeer reviewe

    Potassium and Sodium Transport in Yeast

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    [EN] As the proper maintenance of intracellular potassium and sodium concentrations is vital for cell growth, all living organisms have developed a cohort of strategies to maintain proper monovalent cation homeostasis. In the model yeast Saccharomyces cerevisiae, potassium is accumulated to relatively high concentrations and is required for many aspects of cellular function, whereas high intracellular sodium/potassium ratios are detrimental to cell growth and survival. The fact that S. cerevisiae cells can grow in the presence of a broad range of concentrations of external potassium (10 M–2.5 M) and sodium (up to 1.5 M) indicates the existence of robust mechanisms that have evolved to maintain intracellular concentrations of these cations within appropriate limits. In this review, current knowledge regarding potassium and sodium transporters and their regulation will be summarized. The cellular responses to high sodium and potassium and potassium starvation will also be discussed, as well as applications of this knowledge to diverse fields, including antifungal treatments, bioethanol production and human disease.L.Y. is funded by grant BFU2011-30197-C03-03 from the Spanish Ministry of Science and Innovation (Madrid, Spain) and EUI2009-04147 [Systems Biology of Microorganisms (SysMo2) European Research Area-Network (ERA-NET)].Yenush, L. (2016). Potassium and Sodium Transport in Yeast. Advances in Experimental Medicine and Biology. 892:187-228. https://doi.org/10.1007/978-3-319-25304-6_8S187228892Ahmed A, Sesti F, Ilan N, Shih TM, Sturley SL et al (1999) A molecular target for viral killer toxin: TOK1 potassium channels. Cell 99:283–291Albert A, Yenush L, Gil-Mascarell MR, Rodriguez PL, Patel S et al (2000) X-ray structure of yeast Hal2p, a major target of lithium and sodium toxicity, and identification of framework interactions determining cation sensitivity. J Mol Biol 295:927–938Albertyn J, Hohmann S, Thevelein JM, Prior BA (1994) GPD1, which encodes glycerol-3-phosphate dehydrogenase, is essential for growth under osmotic stress in Saccharomyces cerevisiae, and its expression is regulated by the high-osmolarity glycerol response pathway. Mol Cell Biol 14:4135–4144Alepuz PM, Cunningham KW, Estruch F (1997) Glucose repression affects ion homeostasis in yeast through the regulation of the stress-activated ENA1 gene. Mol Microbiol 26:91–98Ali R, Brett CL, Mukherjee S, Rao R (2004) Inhibition of sodium/proton exchange by a Rab-GTPase-activating protein regulates endosomal traffic in yeast. J Biol Chem 279:4498–4506Alijo R, Ramos J (1993) Several routes of activation of the potassium uptake system of yeast. Biochim Biophys Acta 1179:224–228Anderson JA, Huprikar SS, Kochian LV, Lucas WJ, Gaber RF (1992) Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 89:3736–3740Anderson JA, Nakamura RL, Gaber RF (1994) Heterologous expression of K+ channels in Saccharomyces cerevisiae: strategies for molecular analysis of structure and function. Symp Soc Exp Biol 48:85–97André B, Scherens B (1995) The yeast YBR235w gene encodes a homolog of the mammalian electroneutral Na(+)-(K+)-C1- cotransporter family. Biochem Biophys Res Commun 217:150–153Andrés MT, Viejo-Díaz M, Fierro JF (2008) Human lactoferrin induces apoptosis-like cell death in Candida albicans: critical role of K+-channel-mediated K+ efflux. Antimicrob Agents Chemother 52:4081–4088Anemaet IG, van Heusden GP (2014) Transcriptional response of Saccharomyces cerevisiae to potassium starvation. BMC Genomics 15:1040Arino J, Ramos J, Sychrova H (2010) Alkali metal cation transport and homeostasis in yeasts. Microbiol Mol Biol Rev 74:95–120Babazadeh R, Furukawa T, Hohmann S, Furukawa K (2014) Rewiring yeast osmostress signalling through the MAPK network reveals essential and non-essential roles of Hog1 in osmoadaptation. Sci Rep 4:4697Baev D, Rivetta A, Li XS, Vylkova S, Bashi E et al (2003) Killing of Candida albicans by human salivary histatin 5 is modulated, but not determined, by the potassium channel TOK1. Infect Immun 71:3251–3260Baev D, Rivetta A, Vylkova S, Sun JN, Zeng GF et al (2004) The TRK1 potassium transporter is the critical effector for killing of Candida albicans by the cationic protein, Histatin 5. J Biol Chem 279:55060–55072Bagriantsev SN, Ang KH, Gallardo-Godoy A, Clark KA, Arkin MR et al (2013) A high-throughput functional screen identifies small molecule regulators of temperature- and mechano-sensitive K2P channels. ACS Chem Biol 8:1841–1851Bañuelos MA, Sychrová H, Bleykasten-Grosshans C, Souciet JL, Potier S (1998) The Nha1 antiporter of Saccharomyces cerevisiae mediates sodium and potassium efflux. Microbiology 144(Pt 10):2749–2758Bañuelos MA, Ruiz MC, Jiménez A, Souciet JL, Potier S et al (2002) Role of the Nha1 antiporter in regulating K(+) influx in Saccharomyces cerevisiae. Yeast 19:9–15Barnett JA (2008) A history of research on yeasts 13. Active transport and the uptake of various metabolites. Yeast 25:689–731Barreto L, Canadell D, Petrezselyova S, Navarrete C, Maresova L et al (2011) A genomewide screen for tolerance to cationic drugs reveals genes important for potassium homeostasis in Saccharomyces cerevisiae. Eukaryot Cell 10:1241–1250Barreto L, Canadell D, Valverde-Saubí D, Casamayor A, Ariño J (2012) The short-term response of yeast to potassium starvation. Environ Microbiol 14:3026–3042Benito B, Moreno E, Lagunas R (1991) Half-life of the plasma membrane ATPase and its activating system in resting yeast cells. Biochim Biophys Acta 1063:265–268Benito B, Quintero FJ, Rodríguez-Navarro A (1997) Overexpression of the sodium ATPase of Saccharomyces cerevisiae: conditions for phosphorylation from ATP and Pi. Biochim Biophys Acta 1328:214–226Benito B, Garciadeblás B, Rodríguez-Navarro A (2002) Potassium- or sodium-efflux ATPase, a key enzyme in the evolution of fungi. Microbiology 148:933–941Benito B, Garciadeblás B, Schreier P, Rodríguez-Navarro A (2004) Novel p-type ATPases mediate high-affinity potassium or sodium uptake in fungi. Eukaryot Cell 3:359–368Bernardi P (1999) Mitochondrial transport of cations: channels, exchangers, and permeability transition. Physiol Rev 79:1127–1155Bertl A, Slayman CL, Gradmann D (1993) Gating and conductance in an outward-rectifying K+ channel from the plasma membrane of Saccharomyces cerevisiae. J Membr Biol 132:183–199Bertl A, Bihler H, Reid JD, Kettner C, Slayman CL (1998) Physiological characterization of the yeast plasma membrane outward rectifying K+ channel, DUK1 (TOK1), in situ. J Membr Biol 162:67–80Bertl A, Ramos J, Ludwig J, Lichtenberg-Fraté H, Reid J et al (2003) Characterization of potassium transport in wild-type and isogenic yeast strains carrying all combinations of trk1, trk2 and tok1 null mutations. Mol Microbiol 47:767–780Bihler H, Slayman CL, Bertl A (1998) NSC1: a novel high-current inward rectifier for cations in the plasma membrane of Saccharomyces cerevisiae. FEBS Lett 432:59–64Bihler H, Slayman CL, Bertl A (2002) Low-affinity potassium uptake by Saccharomyces cerevisiae is mediated by NSC1, a calcium-blocked non-specific cation channel. Biochim Biophys Acta 1558:109–118Blomberg A (1995) Global changes in protein synthesis during adaptation of the yeast Saccharomyces cerevisiae to 0.7 M NaCl. J Bacteriol 177:3563–3572Blomberg A (2000) Metabolic surprises in Saccharomyces cerevisiae during adaptation to saline conditions: questions, some answers and a model. FEMS Microbiol Lett 182:1–8Borst-Pauwels GW (1981) Ion transport in yeast. Biochim Biophys Acta 650:88–127Botstein D, Fink GR (2011) Yeast: an experimental organism for 21st Century biology. Genetics 189:695–704Bouillet LE, Cardoso AS, Perovano E, Pereira RR, Ribeiro EM et al (2012) The involvement of calcium carriers and of the vacuole in the glucose-induced calcium signaling and activation of the plasma membrane H(+)-ATPase in Saccharomyces cerevisiae cells. Cell Calcium 51:72–81Bowers K, Levi BP, Patel FI, Stevens TH (2000) The sodium/proton exchanger Nhx1p is required for endosomal protein trafficking in the yeast Saccharomyces cerevisiae. Mol Biol Cell 11:4277–4294Breinig F, Tipper DJ, Schmitt MJ (2002) Kre1p, the plasma membrane receptor for the yeast K1 viral toxin. Cell 108:395–405Brett CL, Tukaye DN, Mukherjee S, Rao R (2005) The yeast endosomal Na+K+/H+ exchanger Nhx1 regulates cellular pH to control vesicle trafficking. Mol Biol Cell 16:1396–1405Cagnac O, Leterrier M, Yeager M, Blumwald E (2007) Identification and characterization of Vnx1p, a novel type of vacuolar monovalent cation/H+ antiporter of Saccharomyces cerevisiae. J Biol Chem 282:24284–24293Cagnac O, Aranda-Sicilia MN, Leterrier M, Rodriguez-Rosales MP, Venema K (2010) Vacuolar cation/H+ antiporters of Saccharomyces cerevisiae. J Biol Chem 285:33914–33922Calahorra M, Lozano C, Sánchez NS, Peña A (2011) Ketoconazole and miconazole alter potassium homeostasis in Saccharomyces cerevisiae. Biochim Biophys Acta 1808:433–445Canadell D, González A, Casado C, Ariño J (2015) Functional interactions between potassium and phosphate homeostasis in Saccharomyces cerevisiae. Mol Microbiol 95:555–572Casado C, Yenush L, Melero C, del Carmen Ruiz M, Serrano R et al (2010) Regulation of Trk-dependent potassium transport by the calcineurin pathway involves the Hal5 kinase. FEBS Lett 584:2415–2420Causton HC, Ren B, Koh SS, Harbison CT, Kanin E et al (2001) Remodeling of yeast genome expression in response to environmental changes. Mol Biol Cell 12:323–337Clotet J, Posas F (2007) Control of cell cycle in response to osmostress: lessons from yeast. Methods Enzymol 428:63–76Cornet M, Gaillardin C (2014) pH signaling in human fungal pathogens: a new target for antifungal strategies. Eukaryot Cell 13:342–352Courchesne WE (2002) Characterization of a novel, broad-based fungicidal activity for the antiarrhythmic drug amiodarone. J Pharmacol Exp Ther 300:195–199Courchesne WE, Ozturk S (2003) Amiodarone induces a caffeine-inhibited, MID1-dependent rise in free cytoplasmic calcium in Saccharomyces cerevisiae. Mol Microbiol 47:223–234Crespo JL, Daicho K, Ushimaru T, Hall MN (2001) The GATA transcription factors GLN3 and GAT1 link TOR to salt stress in Saccharomyces cerevisiae. J Biol Chem 276:34441–34444Cunningham KW, Fink GR (1996) Calcineurin inhibits VCX1-dependent H+/Ca2+ exchange and induces Ca2+ ATPases in Saccharomyces cerevisiae. Mol Cell Biol 16:2226–2237Curto M, Valledor L, Navarrete C, Gutiérrez D, Sychrova H et al (2010) 2-DE based proteomic analysis of Saccharomyces cerevisiae wild and K+ transport-affected mutant (trk1,2) strains at the growth exponential and stationary phases. J Proteomics 73:2316–2335D’Avanzo N, Cheng WW, Xia X, Dong L, Savitsky P et al (2010) Expression and purification of recombinant human inward rectifier K+ (KCNJ) channels in Saccharomyces cerevisiae. Protein Expr Purif 71:115–121Daran-Lapujade P, Daran JM, Luttik MA, Almering MJ, Pronk JT et al (2009) An atypical PMR2 locus is responsible for hypersensitivity to sodium and lithium cations in the laboratory strain Saccharomyces cerevisiae CEN.PK113-7D. FEMS Yeast Res 9:789–792Davis DA (2009) How human pathogenic fungi sense and adapt to pH: the link to virulence. Curr Opin Microbiol 12:365–370de Nadal E, Posas F (2011) Elongating under stress. Genet Res Int 2011:326286de Nadal E, Clotet J, Posas F, Serrano R, Gomez N et al (1998) The yeast halotolerance determinant Hal3p is an inhibitory subunit of the Ppz1p Ser/Thr protein phosphatase. Proc Natl Acad Sci U S A 95:7357–7362de Nadal E, Calero F, Ramos J, Ariño J (1999) Biochemical and genetic analyses of the role of yeast casein kinase 2 in salt tolerance. J Bacteriol 181:6456–6462de Nadal E, Alepuz PM, Posas F (2002) Dealing with osmostress through MAP kinase activation. EMBO Rep 3:735–740De Nadal E, Zapater M, Alepuz PM, Sumoy L, Mas G et al (2004) The MAPK Hog1 recruits Rpd3 histone deacetylase to activate osmoresponsive genes. Nature 427:370–374Dimmer KS, Fritz S, Fuchs F, Messerschmitt M, Weinbach N et al (2002) Genetic basis of mitochondrial function and morphology in Saccharomyces cerevisiae. Mol Biol Cell 13:847–853Durell SR, Guy HR (1999) Structural models of the KtrB, TrkH, and Trk1,2 symporters based on the structure of the KcsA K(+) channel. Biophys J 77:789–807Eide DJ, Clark S, Nair TM, Gehl M, Gribskov M et al (2005) Characterization of the yeast ionome: a genome-wide analysis of nutrient mineral and trace element homeostasis in Saccharomyces cerevisiae. Genome Biol 6:R77Elicharova H, Sychrova H (2014) Fluconazole affects the alkali-metal-cation homeostasis and susceptibility to cationic toxic compounds of Candida glabrata. Microbiology 160:1705–1713Endele S, Fuhry M, Pak SJ, Zabel BU, Winterpacht A (1999) LETM1, a novel gene encoding a putative EF-hand Ca(2+)-binding protein, flanks the Wolf-Hirschhorn syndrome (WHS) critical region and is deleted in most WHS patients. Genomics 60:218–225Eraso P, Mazón MJ, Portillo F (2006) Yeast protein kinase Ptk2 localizes at the plasma membrane and phosphorylates in vitro the C-terminal peptide of the H+-ATPase. Biochim Biophys Acta 1758:164–170Erez O, Kahana C (2002) Deletions of SKY1 or PTK2 in the Saccharomyces cerevisiae trk1Deltatrk2Delta mutant cells exert dual effect on ion homeostasis. Biochem Biophys Res Commun 295:1142–1149Estrada E, Agostinis P, Vandenheede JR, Goris J, Merlevede W et al (1996) Phosphorylation of yeast plasma membrane H+-ATPase by casein kinase I. J Biol Chem 271:32064–32072Fairman C, Zhou X, Kung C (1999) Potassium uptake through the TOK1 K+ channel in the budding yeast. J Membr Biol 168:149–157Farnaud S, Evans RW (2003) Lactoferrin – a multifunctional protein with antimicrobial properties. Mol Immunol 40:395–405Fell GL, Munson AM, Croston MA, Rosenwald AG (2011) Identification of yeast genes involved in k homeostasis: loss of membrane traffic genes affects k uptake. G3 (Bethesda) 1:43–56Fernandes AR, Sá-Correia I (2003) Transcription patterns of PMA1 and PMA2 genes and activity of plasma membrane H+-ATPase in Saccharomyces cerevisiae during diauxic growth and stationary phase. Yeast 20:207–219Ferrando A, Kron SJ, Rios G, Fink GR, Serrano R (1995) Regulation of cation transport in Saccharomyces cerevisiae by the salt tolerance gene HAL3. Mol Cell Biol 15:5470–5481Ferrigno P, Posas F, Koepp D, Saito H, Silver PA (1998) Regulated nucleo/cytoplasmic exchange of HOG1 MAPK requires the importin beta homologs NMD5 and XPO1. EMBO J 17:5606–5614Flegelova H, Haguenauer-Tsapis R, Sychrova H (2006) Heterologous expression of mammalian Na/H antiporters in Saccharomyces cerevisiae. Biochim Biophys Acta 1760:504–516Flis K, Hinzpeter A, Edelman A, Kurlandzka A (2005) The functioning of mammalian ClC-2 chloride channel in Saccharomyces cerevisiae cells requires an increased level of Kha1p. Biochem J 390:655–664Forment J, Mulet JM, Vicente O, Serrano R (2002) The yeast SR protein kinase Sky1p modulates salt tolerance, membrane potential and the Trk1,2 potassium transporter. Biochim Biophys Acta 1565:36–40Froschauer E, Nowikovsky K, Schweyen RJ (2005) Electroneutral K+/H+ exchange in mitochondrial membrane vesicles involves Yol027/Letm1 proteins. Biochim Biophys Acta 1711:41–48Fukuda A, Nakamura A, Tagiri A, Tanaka H, Miyao A et al (2004) Function, intracellular localization and the importance in salt tolerance of a vacuolar Na(+)/H(+) antiporter from rice. Plant Cell Physiol 45:146–159Gaber RF (1992) Molecular genetics of yeast ion transport. Int Rev Cytol 137:299–353Gaber RF, Styles CA, Fink GR (1988) TRK1 encodes a plasma membrane protein required for high-affinity potassium transport in Saccharomyces cerevisiae. Mol Cell Biol 8:2848–2859Gaxiola RA, Rao R, Sherman A, Grisafi P, Alper SL et al (1999) The Arabidopsis thaliana proton transporters, AtNhx1 and Avp1, can function in cation detoxification in yeast. Proc Natl Acad Sci U S A 96:1480–1485Gelis S, Curto M, Valledor L, González A, Ariño J et al (2012) Adaptation to potassium starvation of wild-type and K(+)-transport mutant (trk1,2) of Saccharomyces cerevisiae: 2-dimensional gel electrophoresis-based proteomic approach. Microbiologyopen 1:182–193Gómez MJ, Luyten K, Ramos J (1996) The capacity to transport potassium influences sodium tolerance in Saccharomyces cerevisiae. FEMS Microbiol Lett 135:157–160González A, Casado C, Petrezsélyová S, Ruiz A, Ariño J (2013) Molecular analysis of a conditional hal3 vhs3 yeast mutant links potassium homeostasis with flocculation and invasiveness. Fungal Genet Biol 53:1–9Goossens A, de La Fuente N, Forment J, Serrano R, Portillo F (2000) Regulation of yeast H(+)-ATPase by protein kinases belonging to a family dedicated to activation of plasma membrane transporters. Mol Cell Biol 20:7654–7661Gupta SS, Canessa CM (2000) Heterologous expression of a mammalian epithelial sodium channel in yeast. FEBS Lett 481:77–80Gustin MC, Martinac B, Saimi Y, Culbertson MR, Kung C (1986) Ion channels in yeast. Science 233:1195–1197Haass FA, Jonikas M, Walter P, Weissman JS, Jan YN et al (2007) Identification of yeast proteins necessary for cell-surface function of a potassium channel. Proc Natl Acad Sci U S A 104:18079–18084Haro R, Rodríguez-Navarro A (2002) Molecular analysis of the mechanism of potassium uptake through the TRK1 transporter of Saccharomyces cerevisiae. Biochim Biophys Acta 1564:114–122Haro R, Rodríguez-Navarro A (2003) Functional analysis of the M2(D) helix of the TRK1 potassium transporter of Saccharomyces cerevisiae. Biochim Biophys Acta 1613:1–6Haro R, Garciadeblas B, Rodríguez-Navarro A (1991) A novel P-type ATPase from yeast involved in sodium transport. FEBS Lett 291:189–191Hasenbrink G, Schwarzer S, Kolacna L, Ludwig J, Sychrova H et al (2005) Analysis of the mKir2.1 channel activity in potassium influx defective Saccharomyces cerevisiae strains determined as changes in growth characteristics. FEBS Lett 579:1723–1731Herrera R, Álvarez MC, Gelis S, Ramos J (2013) Subcellular potassium and sodium distribution in Saccharomyces cerevisiae wild-type and vacuolar mutants. Biochem J 454:525–532Herrera R, Alvarez MC, Gelis S, Kodedová M, Sychrová H et al (2014) Role of Saccharomyces cerevisiae Trk1 in stabilization of intracellular potassium content upon changes in external potassium levels. Biochim Biophys Acta 1838:127–133Hess DC, Lu W, Rabinowitz JD, Botstein D (2006) Ammonium toxicity and potassium limitation in yeast. PLoS Biol 4:e351Hoeberichts FA, Perez-Valle J, Montesinos C, Mulet JM, Planes MD et al (2010) The role of K+ and H+ transport systems during glucose- and H2O2-induced cell death in Saccharomyces cerevisiae. Yeast 27:713–725Hohmann S (2002) Osmotic stress signaling and osmoadaptation in yeasts. Microbiol Mol Biol Rev 66:300–372Hohmann S, Krantz M, Nordlander B (2007) Yeast osmoregulation. Methods Enzymol 428:29–45Idnurm A, Walton FJ, Floyd A, Reedy JL, Heitman J (2009) Identification of ENA1 as a virulence gene of the human pathogenic fungus Cryptococcus neoformans through signature-tagged insertional mutagenesis. Eukaryot Cell 8:315–326Jung KW, Strain AK, Nielsen K, Jung KH, Bahn YS (2012) Two cation transporters Ena1 and Nha1 cooperatively modulate ion homeostasis, antifungal drug resistance, and virulence of Cryptococcus neoformans via the HOG pathway. Fungal Genet Biol 49:332–345Kafadar KA, Cyert MS (2004) Integration of stress responses: modulation of calcineurin signaling in Saccharomyces cerevisiae by protein kinase A. Eukaryot Cell 3:1147–1153Kahm M, Navarrete C, Llopis-Torregrosa V, Herrera R, Barreto L et al (2012) Potassium starvation in yeast: mechanisms of homeostasis revealed by mathematical modeling. PLoS Comput Biol 8:e1002548Kallay LM, Brett CL, Tukaye DN, Wemmer MA, Chyou A et al (2011) Endosomal Na+(K+)/H+ exchanger Nhx1/Vps44 functions independently and downstream of multivesicular body formation. J Biol Chem 286:44067–44077Kane PM (2007) The long physiological reach of the yeast vacuolar H+-ATPase. J Bioenerg Biomembr 39:415–421Kane PM (2012) Targeting reversible disassembly as a mechanism of controlling V-ATPase activity. Curr Protein Pept Sci 13:117–123Ke R, Ingram PJ, Haynes K (2013) An integrative model of ion regulation in yeast. PLoS Comput Biol 9:e1002879Ketchum KA, Joiner WJ, Sellers AJ, Kaczmarek LK, Goldstein SA (1995) A new family of outwardly rectifying potassium channel proteins with two pore domains in tandem. Nature 376:690–695Kinclová O, Ramos J, Potier S, Sychrová H (2001) Functional study of the Saccharomyces cerevisiae Nha1p C-terminus. Mol Microbiol 40:656–668Kinclova-Zimmermannova O, Sychrova H (2006) Functional study of the Nha1p C-terminus: involvement in cell response to changes in external osmolarity. Curr Genet 49:229–236Kinclová-Zimmermannová O, Flegelová H, Sychrová H (2004) Rice Na+/H+-antiporter Nhx1 partially complements the alkali-metal-cation sensitivity of yeast strains lacking three sodium transporters. Folia Microbiol (Praha) 49:519–525Kinclova-Zimmermannova O, Gaskova D, Sychrova H (2006) The Na+, K+/H+ -antiporter Nha1 influences the plasma membrane potential of Saccharomyces cerevisiae. FEMS Yeast Res 6:792–800Klee CB, Draetta GF, Hubbard MJ (1988) Calcineurin. Adv Enzymol Relat Areas Mol Biol 61:149–200Klipp E, Nordlander B, Krüger R, Gennemark P, Hohmann S (2005) Integrative model of the response of yeast to osmotic shock. Nat Biotechnol 23:975–982Ko CH, Gaber RF (1991) TRK1 and TRK2 encode structurally related K+ transporters in Saccharomyces cerevisiae. Mol Cell Biol 11:4266–4273Ko CH, Buckley AM, Gaber RF (1990) TRK2 is required for low affinity K+ transport in Saccharomyces cerevisiae. Genetics 125:305–312Ko CH, Liang H, Gaber RF (1993) Roles of multiple glucose transporters in Saccharomyces cerevisiae. Mol Cell Biol 13:638–648Kojima A, To

    Single-cell analysis: visualizing pharmaceutical and metabolite uptake in cells with label-free 3D mass spectrometry imaging

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    Detecting metabolites and parent compound within a cell type is now a priority for pharmaceutical development. In this context, three-dimensional secondary ion mass spectrometry (SIMS) imaging was used to investigate the cellular uptake of the antiarrhythmic agent amiodarone, a phospholipidosis-inducing pharmaceutical compound. The high lateral resolution and 3D imaging capabilities of SIMS combined with the multiplex capabilities of ToF mass spectrometric detection allows for the visualization of pharmaceutical compound and metabolites in single cells. The intact, unlabeled drug compound was successfully detected at therapeutic dosages in macrophages (cell line: NR8383). Chemical information from endogenous biomolecules was used to correlate drug distributions with morphological features. From this spatial analysis, amiodarone was detected throughout the cell with the majority of the compound found in the membrane and subsurface regions and absent in the nuclear regions. Similar results were obtained when the macrophages were doped with amiodarone metabolite, desethylamiodarone. The FWHM lateral resolution measured across an intracellular interface in a high lateral resolution ion images was approximately 550 nm. Overall, this approach provides the basis for studying cellular uptake of pharmaceutical compounds and their metabolites on the single cell level

    Requirement for Ergosterol in V-ATPase Function Underlies Antifungal Activity of Azole Drugs

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    Ergosterol is an important constituent of fungal membranes. Azoles inhibit ergosterol biosynthesis, although the cellular basis for their antifungal activity is not understood. We used multiple approaches to demonstrate a critical requirement for ergosterol in vacuolar H+-ATPase function, which is known to be essential for fungal virulence. Ergosterol biosynthesis mutants of S. cerevisiae failed to acidify the vacuole and exhibited multiple vma− phenotypes. Extraction of ergosterol from vacuolar membranes also inactivated V-ATPase without disrupting membrane association of its subdomains. In both S. cerevisiae and the fungal pathogen C. albicans, fluconazole impaired vacuolar acidification, whereas concomitant ergosterol feeding restored V-ATPase function and cell growth. Furthermore, fluconazole exacerbated cytosolic Ca2+ and H+ surges triggered by the antimicrobial agent amiodarone, and impaired Ca2+ sequestration in purified vacuolar vesicles. These findings provide a mechanistic basis for the synergy between azoles and amiodarone observed in vitro. Moreover, we show the clinical potential of this synergy in treatment of systemic fungal infections using a murine model of Candidiasis. In summary, we demonstrate a new regulatory component in fungal V-ATPase function, a novel role for ergosterol in vacuolar ion homeostasis, a plausible cellular mechanism for azole toxicity in fungi, and preliminary in vivo evidence for synergism between two antifungal agents. New insights into the cellular basis of azole toxicity in fungi may broaden therapeutic regimens for patient populations afflicted with systemic fungal infections

    Involvement of the exomer complex in the polarized transport of Ena1 required for Saccharomyces cerevisiae survival against toxic cations

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    [EN] Exomer is an adaptor complex required for the direct transport of a selected number of cargoes from the trans-Golgi network (TGN) to the plasma membrane in Saccharomyces cerevisiae However, exomer mutants are highly sensitive to increased concentrations of alkali metal cations, a situation that remains unexplained by the lack of transport of any known cargoes. Here we identify several HAL genes that act as multicopy suppressors of this sensitivity and are connected to the reduced function of the sodium ATPase Ena1. Furthermore, we find that Ena1 is dependent on exomer function. Even though Ena1 can reach the plasma membrane independently of exomer, polarized delivery of Ena1 to the bud requires functional exomer. Moreover, exomer is required for full induction of Ena1 expression after cationic stress by facilitating the plasma membrane recruitment of the molecular machinery involved in Rim101 processing and activation of the RIM101 pathway in response to stress. Both the defective localization and the reduced levels of Ena1 contribute to the sensitivity of exomer mutants to alkali metal cations. Our work thus expands the spectrum of exomer-dependent proteins and provides a link to a more general role of exomer in TGN organization.We acknowledge Emma Keck for English language revision. We also thank members of the Translucent group, J. Arino, J. Ramos, and L. Yenush, for many useful discussions throughout this work and especially L. Yenush for her generous gift of strains and reagents. The help of O. Vincent was essential for developing the work involving RIM101. We also thank R. Valle for her technical assistance at the CR Laboratory. M. Trautwein is acknowledged for data acquisition and discussions during the early stages of the project. C.A. is supported by a USAL predoctoral fellowship. Work at the Spang laboratory was supported by the University of Basel and the Swiss National Science Foundation (31003A-141207 and 310030B-163480). C.R. was supported by grant SA073U14 from the Regional Government of Castilla y Leon and by grant BFU2013-48582-C2-1-P from the CICYT/FEDER Spanish program. J.M.M. acknowledges the financial support from Universitat Politecnica de Valencia project PAID-06-10-1496.Anton, C.; Zanolari, B.; Arcones, I.; Wang, C.; Mulet, JM.; Spang, A.; Roncero, C. (2017). Involvement of the exomer complex in the polarized transport of Ena1 required for Saccharomyces cerevisiae survival against toxic cations. Molecular Biology of the Cell. 28(25):3672-3685. https://doi.org/10.1091/mbc.E17-09-0549S367236852825Ariño, J., Ramos, J., & Sychrová, H. (2010). Alkali Metal Cation Transport and Homeostasis in Yeasts. Microbiology and Molecular Biology Reviews, 74(1), 95-120. doi:10.1128/mmbr.00042-09Bard, F., & Malhotra, V. (2006). The Formation of TGN-to-Plasma-Membrane Transport Carriers. Annual Review of Cell and Developmental Biology, 22(1), 439-455. doi:10.1146/annurev.cellbio.21.012704.133126Barfield, R. M., Fromme, J. C., & Schekman, R. (2009). The Exomer Coat Complex Transports Fus1p to the Plasma Membrane via a Novel Plasma Membrane Sorting Signal in Yeast. Molecular Biology of the Cell, 20(23), 4985-4996. doi:10.1091/mbc.e09-04-0324Bonifacino, J. S. (2014). Adaptor proteins involved in polarized sorting. Journal of Cell Biology, 204(1), 7-17. doi:10.1083/jcb.201310021Bonifacino, J. S., & Glick, B. S. (2004). The Mechanisms of Vesicle Budding and Fusion. Cell, 116(2), 153-166. doi:10.1016/s0092-8674(03)01079-1Bonifacino, J. S., & Lippincott-Schwartz, J. (2003). Coat proteins: shaping membrane transport. Nature Reviews Molecular Cell Biology, 4(5), 409-414. doi:10.1038/nrm1099Carlson, M., & Botstein, D. (1982). Two differentially regulated mRNAs with different 5′ ends encode secreted and intracellular forms of yeast invertase. Cell, 28(1), 145-154. doi:10.1016/0092-8674(82)90384-1Costanzo, M., Baryshnikova, A., Bellay, J., Kim, Y., Spear, E. D., Sevier, C. S., … Mostafavi, S. (2010). The Genetic Landscape of a Cell. Science, 327(5964), 425-431. doi:10.1126/science.1180823De Matteis, M. A., & Luini, A. (2008). Exiting the Golgi complex. Nature Reviews Molecular Cell Biology, 9(4), 273-284. doi:10.1038/nrm2378De Nadal, E., Clotet, J., Posas, F., Serrano, R., Gomez, N., & Arino, J. (1998). The yeast halotolerance determinant Hal3p is an inhibitory subunit of the Ppz1p Ser/Thr protein phosphatase. Proceedings of the National Academy of Sciences, 95(13), 7357-7362. doi:10.1073/pnas.95.13.7357Drubin, D. G., & Nelson, W. J. (1996). Origins of Cell Polarity. Cell, 84(3), 335-344. doi:10.1016/s0092-8674(00)81278-7Fell, G. L., Munson, A. M., Croston, M. A., & Rosenwald, A. G. (2011). Identification of Yeast Genes Involved in K+Homeostasis: Loss of Membrane Traffic Genes Affects K+Uptake. G3: Genes|Genomes|Genetics, 1(1), 43-56. doi:10.1534/g3.111.000166Ferrando, A., Kron, S. J., Rios, G., Fink, G. R., & Serrano, R. (1995). Regulation of cation transport in Saccharomyces cerevisiae by the salt tolerance gene HAL3. Molecular and Cellular Biology, 15(10), 5470-5481. doi:10.1128/mcb.15.10.5470Forsmark, A., Rossi, G., Wadskog, I., Brennwald, P., Warringer, J., & Adler, L. (2011). Quantitative Proteomics of Yeast Post-Golgi Vesicles Reveals a Discriminating Role for Sro7p in Protein Secretion. Traffic, 12(6), 740-753. doi:10.1111/j.1600-0854.2011.01186.xGaber, R. F., Styles, C. A., & Fink, G. R. (1988). TRK1 encodes a plasma membrane protein required for high-affinity potassium transport in Saccharomyces cerevisiae. Molecular and Cellular Biology, 8(7), 2848-2859. doi:10.1128/mcb.8.7.2848Galindo, A., Calcagno-Pizarelli, A. M., Arst, H. N., & Penalva, M. A. (2012). An ordered pathway for the assembly of fungal ESCRT-containing ambient pH signalling complexes at the plasma membrane. Journal of Cell Science, 125(7), 1784-1795. doi:10.1242/jcs.098897Goldstein, A. L., & McCusker, J. H. (1999). Three new dominant drug resistance cassettes for gene disruption inSaccharomyces cerevisiae. Yeast, 15(14), 1541-1553. doi:10.1002/(sici)1097-0061(199910)15:143.0.co;2-kHayashi, M., Fukuzawa, T., Sorimachi, H., & Maeda, T. (2005). Constitutive Activation of the pH-Responsive Rim101 Pathway in Yeast Mutants Defective in Late Steps of the MVB/ESCRT Pathway. Molecular and Cellular Biology, 25(21), 9478-9490. doi:10.1128/mcb.25.21.9478-9490.2005Herrador, A., Herranz, S., Lara, D., & Vincent, O. (2009). Recruitment of the ESCRT Machinery to a Putative Seven-Transmembrane-Domain Receptor Is Mediated by an Arrestin-Related Protein. Molecular and Cellular Biology, 30(4), 897-907. doi:10.1128/mcb.00132-09Herrador, A., Livas, D., Soletto, L., Becuwe, M., Léon, S., & Vincent, O. (2015). Casein kinase 1 controls the activation threshold of an α-arrestin by multisite phosphorylation of the interdomain hinge. Molecular Biology of the Cell, 26(11), 2128-2138. doi:10.1091/mbc.e14-11-1552Herranz, S., Rodriguez, J. M., Bussink, H.-J., Sanchez-Ferrero, J. C., Arst, H. N., Penalva, M. A., & Vincent, O. (2005). Arrestin-related proteins mediate pH signaling in fungi. Proceedings of the National Academy of Sciences, 102(34), 12141-12146. doi:10.1073/pnas.0504776102Hoya, M., Yanguas, F., Moro, S., Prescianotto-Baschong, C., Doncel, C., de León, N., … Valdivieso, M.-H. (2016). Traffic Through theTrans-Golgi Network and the Endosomal System Requires Collaboration Between Exomer and Clathrin Adaptors in Fission Yeast. Genetics, 205(2), 673-690. doi:10.1534/genetics.116.193458Huranova, M., Muruganandam, G., Weiss, M., & Spang, A. (2016). Dynamic assembly of the exomer secretory vesicle cargo adaptor subunits. EMBO reports, 17(2), 202-219. doi:10.15252/embr.201540795Kung, L. F., Pagant, S., Futai, E., D’Arcangelo, J. G., Buchanan, R., Dittmar, J. C., … Miller, E. A. (2011). Sec24p and Sec16p cooperate to regulate the GTP cycle of the COPII coat. The EMBO Journal, 31(4), 1014-1027. doi:10.1038/emboj.2011.444Lamb, T. M., & Mitchell, A. P. (2003). The Transcription Factor Rim101p Governs Ion Tolerance and Cell Differentiation by Direct Repression of the Regulatory Genes NRG1 and SMP1 in Saccharomyces cerevisiae. Molecular and Cellular Biology, 23(2), 677-686. doi:10.1128/mcb.23.2.677-686.2003Lamb, T. M., Xu, W., Diamond, A., & Mitchell, A. P. (2000). Alkaline Response Genes ofSaccharomyces cerevisiaeand Their Relationship to theRIM101Pathway. Journal of Biological Chemistry, 276(3), 1850-1856. doi:10.1074/jbc.m008381200Madrid, R., Gómez, M. J., Ramos, J., & Rodrı́guez-Navarro, A. (1998). Ectopic Potassium Uptake intrk1 trk2Mutants ofSaccharomyces cerevisiaeCorrelates with a Highly Hyperpolarized Membrane Potential. Journal of Biological Chemistry, 273(24), 14838-14844. doi:10.1074/jbc.273.24.14838Maresova, L., & Sychrova, H. (2004). Physiological characterization of Saccharomyces cerevisiae kha1 deletion mutants. Molecular Microbiology, 55(2), 588-600. doi:10.1111/j.1365-2958.2004.04410.xMarqués, M. C., Zamarbide-Forés, S., Pedelini, L., Llopis-Torregrosa, V., & Yenush, L. (2015). A functional Rim101 complex is required for proper accumulation of the Ena1 Na+-ATPase protein in response to salt stress in Saccharomyces cerevisiae. FEMS Yeast Research, 15(4). doi:10.1093/femsyr/fov017Mulet, J. M., Leube, M. P., Kron, S. J., Rios, G., Fink, G. R., & Serrano, R. (1999). A Novel Mechanism of Ion Homeostasis and Salt Tolerance in Yeast: the Hal4 and Hal5 Protein Kinases Modulate the Trk1-Trk2 Potassium Transporter. Molecular and Cellular Biology, 19(5), 3328-3337. doi:10.1128/mcb.19.5.3328Mulet, J. M., & Serrano, R. (2002). Simultaneous determination of potassium and rubidium content in yeast. Yeast, 19(15), 1295-1298. doi:10.1002/yea.909Murguía, J. R., Bellés, J. M., & Serrano, R. (1996). The YeastHAL2Nucleotidase Is anin VivoTarget of Salt Toxicity. Journal of Biological Chemistry, 271(46), 29029-29033. doi:10.1074/jbc.271.46.29029Obara, K., & Kihara, A. (2014). Signaling Events of the Rim101 Pathway Occur at the Plasma Membrane in a Ubiquitination-Dependent Manner. Molecular and Cellular Biology, 34(18), 3525-3534. doi:10.1128/mcb.00408-14Paczkowski, J. E., & Fromme, J. C. (2014). Structural Basis for Membrane Binding and Remodeling by the Exomer Secretory Vesicle Cargo Adaptor. Developmental Cell, 30(5), 610-624. doi:10.1016/j.devcel.2014.07.014Paczkowski, J. E., Richardson, B. C., & Fromme, J. C. (2015). Cargo adaptors: structures illuminate mechanisms regulating vesicle biogenesis. Trends in Cell Biology, 25(7), 408-416. doi:10.1016/j.tcb.2015.02.005Paczkowski, J. E., Richardson, B. C., Strassner, A. M., & Fromme, J. C. (2012). The exomer cargo adaptor structure reveals a novel GTPase-binding domain. The EMBO Journal, 31(21), 4191-4203. doi:10.1038/emboj.2012.268Parsons, A. B., Brost, R. L., Ding, H., Li, Z., Zhang, C., Sheikh, B., … Boone, C. (2003). Integration of chemical-genetic and genetic interaction data links bioactive compounds to cellular target pathways. Nature Biotechnology, 22(1), 62-69. doi:10.1038/nbt919Peñalva, M. A., Lucena-Agell, D., & Arst, H. N. (2014). Liaison alcaline: Pals entice non-endosomal ESCRTs to the plasma membrane for pH signaling. Current Opinion in Microbiology, 22, 49-59. doi:10.1016/j.mib.2014.09.005Ríos, G., Cabedo, M., Rull, B., Yenush, L., Serrano, R., & Mulet, J. M. (2013). Role of the yeast multidrug transporter Qdr2 in cation homeostasis and the oxidative stress response. FEMS Yeast Research, 13(1), 97-106. doi:10.1111/1567-1364.12013RIOS, G., FERRANDO, A., & SERRANO, R. (1997). Mechanisms of Salt Tolerance Conferred by Overexpression of theHAL1 Gene inSaccharomyces cerevisiae. Yeast, 13(6), 515-528. doi:10.1002/(sici)1097-0061(199705)13:63.0.co;2-xRitz, A. M., Trautwein, M., Grassinger, F., & Spang, A. (2014). The Prion-like Domain in the Exomer-Dependent Cargo Pin2 Serves as a trans-Golgi Retention Motif. Cell Reports, 7(1), 249-260. doi:10.1016/j.celrep.2014.02.026Rockenbauch, U., Ritz, A. M., Sacristan, C., Roncero, C., & Spang, A. (2012). The complex interactions of Chs5p, the ChAPs, and the cargo Chs3p. Molecular Biology of the Cell, 23(22), 4402-4415. doi:10.1091/mbc.e11-12-1015Roncero, C. (2002). The genetic complexity of chitin synthesis in fungi. Current Genetics, 41(6), 367-378. doi:10.1007/s00294-002-0318-7Rothfels, K., Tanny, J. C., Molnar, E., Friesen, H., Commisso, C., & Segall, J. (2005). Components of the ESCRT Pathway, DFG16, and YGR122w Are Required for Rim101 To Act as a Corepressor with Nrg1 at the Negative Regulatory Element of the DIT1 Gene of Saccharomyces cerevisiae. Molecular and Cellular Biology, 25(15), 6772-6788. doi:10.1128/mcb.25.15.6772-6788.2005Santos, B., & Snyder, M. (1997). Targeting of Chitin Synthase 3 to Polarized Growth Sites in Yeast Requires Chs5p and Myo2p. Journal of Cell Biology, 136(1), 95-110. doi:10.1083/jcb.136.1.95Sato, M., Dhut, S., & Toda, T. (2005). New drug-resistant cassettes for gene disruption and epitope tagging inSchizosaccharomyces pombe. Yeast, 22(7), 583-591. doi:10.1002/yea.1233Schekman, R., & Orci, L. (1996). Coat Proteins and Vesicle Budding. Science, 271(5255), 1526-1533. doi:10.1126/science.271.5255.1526Sopko, R., Huang, D., Preston, N., Chua, G., Papp, B., Kafadar, K., … Andrews, B. (2006). Mapping Pathways and Phenotypes by Systematic Gene Overexpression. Molecular Cell, 21(3), 319-330. doi:10.1016/j.molcel.2005.12.011Spang, A. (2008). Membrane traffic in the secretory pathway. Cellular and Molecular Life Sciences, 65(18), 2781-2789. doi:10.1007/s00018-008-8349-yStarr, T. L., Pagant, S., Wang, C.-W., & Schekman, R. (2012). Sorting Signals That Mediate Traffic of Chitin Synthase III between the TGN/Endosomes and to the Plasma Membrane in Yeast. PLoS ONE, 7(10), e46386. doi:10.1371/journal.pone.0046386Trautwein, M., Schindler, C., Gauss, R., Dengjel, J., Hartmann, E., & Spang, A. (2006). Arf1p, Chs5p and the ChAPs are required for export of specialized cargo from the Golgi. The EMBO Journal, 25(5), 943-954. doi:10.1038/sj.emboj.7601007Trilla, J. A., Durán, A., & Roncero, C. (1999). Chs7p, a New Protein Involved in the Control of Protein Export from the Endoplasmic Reticulum that Is Specifically Engaged in the Regulation of Chitin Synthesis in Saccharomyces cerevisiae. Journal of Cell Biology, 145(6), 1153-1163. doi:10.1083/jcb.145.6.1153Valdivia, R. H., Baggott, D., Chuang, J. S., & Schekman, R. W. (2002). The Yeast Clathrin Adaptor Protein Complex 1 Is Required for the Efficient Retention of a Subset of Late Golgi Membrane Proteins. Developmental Cell, 2(3), 283-294. doi:10.1016/s1534-5807(02)00127-2Wadskog, I., Forsmark, A., Rossi, G., Konopka, C., Öyen, M., Goksör, M., … Adler, L. (2006). The Yeast Tumor Suppressor Homologue Sro7p Is Required for Targeting of the Sodium Pumping ATPase to the Cell Surface. Molecular Biology of the Cell, 17(12), 4988-5003. doi:10.1091/mbc.e05-08-0798Wang, C.-W., Hamamoto, S., Orci, L., & Schekman, R. (2006). Exomer: a coat complex for transport of select membrane proteins from the trans-Golgi network to the plasma membrane in yeast. Journal of Cell Biology, 174(7), 973-983. doi:10.1083/jcb.200605106Weiskoff, A. M., & Fromme, J. C. (2014). Distinct N-terminal regions of the exomer secretory vesicle cargo Chs3 regulate its trafficking itinerary. Frontiers in Cell and Developmental Biology, 2. doi:10.3389/fcell.2014.00047Yahara, N., Ueda, T., Sato, K., & Nakano, A. (2001). Multiple Roles of Arf1 GTPase in the Yeast Exocytic and Endocytic Pathways. Molecular Biology of the Cell, 12(1), 221-238. doi:10.1091/mbc.12.1.221Yenush, L., Merchan, S., Holmes, J., & Serrano, R. (2005). pH-Responsive, Posttranslational Regulation of the Trk1 Potassium Transporter by the Type 1-Related Ppz1 Phosphatase. Molecular and Cellular Biology, 25(19), 8683-8692. doi:10.1128/mcb.25.19.8683-8692.2005Yenush, L. (2002). The Ppz protein phosphatases are key regulators of K+ and pH homeostasis: implications for salt tolerance, cell wall integrity and cell cycle progression. The EMBO Journal, 21(5), 920-929. doi:10.1093/emboj/21.5.920Zanolari, B., Rockenbauch, U., Trautwein, M., Clay, L., Barral, Y., & Spang, A. (2011). Transport to the plasma membrane is regulated differently early and late in the cell cycle in Saccharomyces cerevisiae. Journal of Cell Science, 124(7), 1055-1066. doi:10.1242/jcs.07237

    Genome-Wide Mutagenesis Reveals That ORF7 Is a Novel VZV Skin-Tropic Factor

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    The Varicella Zoster Virus (VZV) is a ubiquitous human alpha-herpesvirus that is the causative agent of chicken pox and shingles. Although an attenuated VZV vaccine (v-Oka) has been widely used in children in the United States, chicken pox outbreaks are still seen, and the shingles vaccine only reduces the risk of shingles by 50%. Therefore, VZV still remains an important public health concern. Knowledge of VZV replication and pathogenesis remains limited due to its highly cell-associated nature in cultured cells, the difficulty of generating recombinant viruses, and VZV's almost exclusive tropism for human cells and tissues. In order to circumvent these hurdles, we cloned the entire VZV (p-Oka) genome into a bacterial artificial chromosome that included a dual-reporter system (GFP and luciferase reporter genes). We used PCR-based mutagenesis and the homologous recombination system in the E. coli to individually delete each of the genome's 70 unique ORFs. The collection of viral mutants obtained was systematically examined both in MeWo cells and in cultured human fetal skin organ samples. We use our genome-wide deletion library to provide novel functional annotations to 51% of the VZV proteome. We found 44 out of 70 VZV ORFs to be essential for viral replication. Among the 26 non-essential ORF deletion mutants, eight have discernable growth defects in MeWo. Interestingly, four ORFs were found to be required for viral replication in skin organ cultures, but not in MeWo cells, suggesting their potential roles as skin tropism factors. One of the genes (ORF7) has never been described as a skin tropic factor. The global profiling of the VZV genome gives further insights into the replication and pathogenesis of this virus, which can lead to improved prevention and therapy of chicken pox and shingles

    A new era for understanding amyloid structures and disease

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    The aggregation of proteins into amyloid fibrils and their deposition into plaques and intracellular inclusions is the hallmark of amyloid disease. The accumulation and deposition of amyloid fibrils, collectively known as amyloidosis, is associated with many pathological conditions that can be associated with ageing, such as Alzheimer disease, Parkinson disease, type II diabetes and dialysis-related amyloidosis. However, elucidation of the atomic structure of amyloid fibrils formed from their intact protein precursors and how fibril formation relates to disease has remained elusive. Recent advances in structural biology techniques, including cryo-electron microscopy and solid-state NMR spectroscopy, have finally broken this impasse. The first near-atomic-resolution structures of amyloid fibrils formed in vitro, seeded from plaque material and analysed directly ex vivo are now available. The results reveal cross-β structures that are far more intricate than anticipated. Here, we describe these structures, highlighting their similarities and differences, and the basis for their toxicity. We discuss how amyloid structure may affect the ability of fibrils to spread to different sites in the cell and between organisms in a prion-like manner, along with their roles in disease. These molecular insights will aid in understanding the development and spread of amyloid diseases and are inspiring new strategies for therapeutic intervention

    Dynamics of PCR-based diagnosis in patients with invasive meningococcal disease

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    ABSTRACTInvasive meningococcal disease continues to be a life-threatening condition and rapid diagnosis is important for the administration of appropriate treatment. This study focused on the use of PCR for the diagnosis of meningococcal aetiology and the dynamics of PCR-based diagnosis over time in various biological samples. Sixty cerebrospinal fluid (CSF) and 144 serum samples collected during the first week of hospitalisation from 37 patients with laboratory-confirmed invasive meningococcal disease were investigated. Overall, 91.9% of CSF samples and 45.9% of serum samples were PCR-positive, while culture of CSF and blood was positive for only 35% and 39% samples, respectively. Positive PCR results were obtained until day 7 with CSF and until day 5 with serum. It is therefore recommended that samples for molecular diagnosis should be collected early in the course of suspected invasive meningococcal disease

    Immune response to E7 protein of human papillomavirus type 16 anchored on the cell surface

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    To target the E7 protein of human papilloma virus 16 to the cell surface, a fusion gene was constructed. It encodes the signal peptide, part of the immunoglobulin (IgG)-like domain, the transmembrane anchor of vaccinia virus (VV) hemagglutinin (HA), and the complete E7-coding sequence. The fusion gene was expressed under the HA late promoter by a recombinant VV, designated VV-E7-HA. The E7-HA protein was displayed on the surface of cells infected with the recombinant virus and was more stable than unmodified E7. The biological properties of the VV-E7-HA virus were compared with those of a VV-E7 virus that expressed the unmodified E7 and with a VV expressing the Sig-E7-LAMP fusion protein. While the first two of these recombinants were based on VV strain Praha, the third was derived from the WR strain of VV. Infection of mice with the VV-E7-HA virus induced the formation of E7-specific antibodies with the predominance of the IgG2a isotype, whereas the other two viruses did not induce the formation of E7-specific antibodies. Unlike the other two viruses, VV-E7-HA did not induce a response of cytotoxic T lymphocytes or Th1 cells and did not protect mice against the growth of E7-expressing tumors. Thus, VV-E7-HA induced a differently polarized immune response to the E7 protein than the other two viruses.status: publishe
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