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Zhu X, Wang Y, Shen C, Zhang S, Wang W. The participation of vacuoles and the regulation of various metabolic pathways under acid stress promote the differentiation of chlamydospore in Trichoderma harzianum T4. J Appl Microbiol 2023; 134:lxad203. [PMID: 37669895 DOI: 10.1093/jambio/lxad203] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/25/2023] [Accepted: 09/04/2023] [Indexed: 09/07/2023]
Abstract
AIMS Chlamydospores are a special, differentiated type with high environmental resistance. Consequently, the chlamydospores of Trichoderma harzianum T4 can used to industrialize the latter. This study aimed to investigate the key factors affecting the sporulation type of T. harzianum T4 and the mechanisms underlying this effect. METHODS AND RESULTS In the liquid fermentation of T. harzianum T4, ammonium sulfate (AS) inhibited conidia formation and chlamydospore production. Fermentation tests revealed that acid stress induced sporulation type alteration. Transcriptomic analysis was used to evaluate the adaptation strategy and mechanism underlying spore type alteration under acid stress. The fermentation experiments involving the addition of amino acids revealed that branched-chain amino acids benefited conidia production, whereas β-alanine benefited chlamydospore production. Confocal microscope fluorescence imaging and chloroquine intervention demonstrated that vacuole function was closely related to chlamydospore production. CONCLUSION The sporulation type of T. harzianum T4 can be controlled by adjusting the fermentation pH. T. harzianum T4 cells employ various self-protection measures against strong acid stress, including regulating their metabolism to produce a large number of chlamydospores for survival.
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Affiliation(s)
- Xiaochong Zhu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yaping Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Chao Shen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Songhan Zhang
- Agriculture Technology Extension Service Center of Shanghai, Shanghai 201103, China
| | - Wei Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
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2
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Geng X, Sun Y, Guo Y, Zhao Y, Zhang K, Xiao L, Qu L, Li Z. Fluorescent Carbon Dots for in Situ Monitoring of Lysosomal ATP Levels. Anal Chem 2020; 92:7940-7946. [PMID: 32406677 DOI: 10.1021/acs.analchem.0c01335] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Monitoring the ATP levels in lysosomes in situ is crucial for understanding their involvement in various biological processes but remains difficult due to the interference of ATP in other organelles or the cytoplasm. Here, we report a lysosome-specific fluorescent carbon dot (CD), which can be used to detect ATP in acidic lysosomes with "off-on" changes of yellow fluorescence. These CDs were successfully applied in real-time monitoring of the fluctuating concentration of lysosomal ATP induced by drug stimulation (e.g., chloroquine, etoposide, and oligomycin). Because of the excellent specificity, these CDs are promising agents for drug screening and medical diagnostics through lysosomal ATP monitoring.
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Affiliation(s)
- Xin Geng
- College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou University, Zhengzhou 450001, P.R. China
| | - Yuanqiang Sun
- College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou University, Zhengzhou 450001, P.R. China
| | - Yifei Guo
- College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou University, Zhengzhou 450001, P.R. China
| | - Yanmin Zhao
- College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou University, Zhengzhou 450001, P.R. China
| | - Ke Zhang
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Lehui Xiao
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, College of Chemistry, Nankai University, Tianjin 300071, P.R. China
| | - Lingbo Qu
- College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou University, Zhengzhou 450001, P.R. China
| | - Zhaohui Li
- College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou University, Zhengzhou 450001, P.R. China
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3
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Sampaio‐Marques B, Guedes A, Vasilevskiy I, Gonçalves S, Outeiro TF, Winderickx J, Burhans WC, Ludovico P. α-Synuclein toxicity in yeast and human cells is caused by cell cycle re-entry and autophagy degradation of ribonucleotide reductase 1. Aging Cell 2019; 18:e12922. [PMID: 30977294 PMCID: PMC6612645 DOI: 10.1111/acel.12922] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 12/21/2018] [Accepted: 01/20/2019] [Indexed: 12/22/2022] Open
Abstract
α‐Synuclein (aSyn) toxicity is associated with cell cycle alterations, activation of DNA damage responses (DDR), and deregulation of autophagy. However, the relationships between these phenomena remain largely unknown. Here, we demonstrate that in a yeast model of aSyn toxicity and aging, aSyn expression induces Ras2‐dependent growth signaling, cell cycle re‐entry, DDR activation, autophagy, and autophagic degradation of ribonucleotide reductase 1 (Rnr1), a protein required for the activity of ribonucleotide reductase and dNTP synthesis. These events lead to cell death and aging, which are abrogated by deleting RAS2, inhibiting DDR or autophagy, or overexpressing RNR1. aSyn expression in human H4 neuroglioma cells also induces cell cycle re‐entry and S‐phase arrest, autophagy, and degradation of RRM1, the human homologue of RNR1, and inhibiting autophagic degradation of RRM1 rescues cells from cell death. Our findings represent a model for aSyn toxicity that has important implications for understanding synucleinopathies and other age‐related neurodegenerative diseases.
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Affiliation(s)
- Belém Sampaio‐Marques
- School of Medicine, Life and Health Sciences Research Institute (ICVS) University of Minho Braga Portugal
- ICVS/3B’s ‐ PT Government Associate Laboratory Guimarães Portugal
| | - Ana Guedes
- School of Medicine, Life and Health Sciences Research Institute (ICVS) University of Minho Braga Portugal
- ICVS/3B’s ‐ PT Government Associate Laboratory Guimarães Portugal
| | - Igor Vasilevskiy
- School of Medicine, Life and Health Sciences Research Institute (ICVS) University of Minho Braga Portugal
- ICVS/3B’s ‐ PT Government Associate Laboratory Guimarães Portugal
| | - Susana Gonçalves
- Faculdade de Ciências Médicas, CEDOC – Chronic Diseases Research Center Universidade Nova de Lisboa Lisboa Portugal
| | - Tiago F. Outeiro
- Faculdade de Ciências Médicas, CEDOC – Chronic Diseases Research Center Universidade Nova de Lisboa Lisboa Portugal
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB) University Medical Center Göttingen Göttingen Germany
- Center for Biostructural Imaging of Neurodegeneration Göttingen Germany
- Max Planck Institute for Experimental Medicine Göttingen Germany
| | | | - William C. Burhans
- Department of Molecular and Cellular Biology Roswell Park Cancer Institute Buffalo New York
| | - Paula Ludovico
- School of Medicine, Life and Health Sciences Research Institute (ICVS) University of Minho Braga Portugal
- ICVS/3B’s ‐ PT Government Associate Laboratory Guimarães Portugal
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Unal E, Kinde B, Amon A. Gametogenesis eliminates age-induced cellular damage and resets life span in yeast. Science 2011; 332:1554-7. [PMID: 21700873 PMCID: PMC3923466 DOI: 10.1126/science.1204349] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Eukaryotic organisms age, yet detrimental age-associated traits are not passed on to progeny. How life span is reset from one generation to the next is not known. We show that in budding yeast resetting of life span occurs during gametogenesis. Gametes (spores) generated by aged cells show the same replicative potential as gametes generated by young cells. Age-associated damage is no longer detectable in mature gametes. Furthermore, transient induction of a transcription factor essential for later stages of gametogenesis extends the replicative life span of aged cells. Our results indicate that gamete formation brings about rejuvenation by eliminating age-induced cellular damage.
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Affiliation(s)
- Elçin Unal
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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6
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Limongi CL, Alviano CS, De Souza W, Rozental S. Isolation and partial characterization of an adhesin from Fonsecaea pedrosoi. Med Mycol 2001; 39:429-37. [PMID: 12054054 DOI: 10.1080/mmy.39.5.429.437] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
We showed previously that mannose and N-acetylglucosamine (GlcNAc) residues are involved in the process of adhesion of Fonsecaea pedrosoi, the causative agent of chromoblastomycosis, to epithelial cells. It was then suggested that lectin-like molecules would be involved in the interaction. In the present study, we used fluorescein isothiocyanate-labeled neoglycoproteins (bovine serum albumin [BSA]-mannose and BSA-GlcNAc) to analyze the presence of sugar-binding proteins on the surface of conidia of F. pedrosoi grown at 28 and 37 degrees C. Binding of the neoglycoproteins was measured using flow cytometry. Fungal conidia expressed high levels of binding sites for BSA-mannose and BSA-GlcNAc when grown at 37 degrees C rather than 28 degrees C. Binding was inhibited by previous incubation of the conidia in the presence of chloroquine and trypsin. Chloroquine treatment also inhibited the interaction of fungal conidia with Chinese hamster ovary cells. Extracts from the conidia, obtained using a mechanical cell homogenizer, were purified by affinity chromatography using mannose-agarose or GlcNAc-agarose column. Polyacrylamide gel electrophoresis of the purified material from both columns showed a single protein band of 50 kDa, suggesting that the same lectin-like protein recognizes both carbohydrates.
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Affiliation(s)
- C L Limongi
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
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7
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Kida K, Gent D, Colin Slaughter J. Effect of vacuoles on viability of Saccharomyces cerevisiae. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0922-338x(93)90195-e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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Wada Y, Ohsumi Y, Anraku Y. Genes for directing vacuolar morphogenesis in Saccharomyces cerevisiae. I. Isolation and characterization of two classes of vam mutants. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)37012-7] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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9
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Pringle JR, Preston RA, Adams AE, Stearns T, Drubin DG, Haarer BK, Jones EW. Fluorescence microscopy methods for yeast. Methods Cell Biol 1989; 31:357-435. [PMID: 2476649 DOI: 10.1016/s0091-679x(08)61620-9] [Citation(s) in RCA: 456] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- J R Pringle
- Department of Biology, University of Michigan, Ann Arbor 48109
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10
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Doi S, Tanabe K, Watanabe M, Yoshimura M. Chloroquine, a lysosomotropic agent, inhibits zygote formation in yeast. Arch Microbiol 1988; 151:20-5. [PMID: 2644907 DOI: 10.1007/bf00444663] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Haploid cells of opposite mating type of Saccharomyces cerevisiae conjugate to form zygote. During the conjugation process, the degradation or reorganization of the cell wall and the fusion of the two plasma membranes take place. Since chloroquine inhibits cellular events associated with the reorganization of the plasma membrane, the effect of the drug on conjugation was studied. Chloroquine at a concentration, at which cell growth was not retarded, inhibited zygote formation, while it did not affect other mating functions, such as sexual agglutination, production of and response to mating pheromone. Cells in a mating culture containing chloroquine formed no "prezygote" suggesting that they were not prepared for entering into fusion process. The inhibitory effect of chloroquine was reversible as cells formed zygote when they were washed after treatment with chloroquine. Zygote formation was unaffected in cells possessing chloroquine within vacuoles after incubation with the drug in complete medium (YPD) at pH 7.5, followed by washing. This suggests that chloroquine inhibits zygote formation by adsorbing to the plasma membrane of S. cerevisiae.
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Affiliation(s)
- S Doi
- Department of Legal Medicine, Kinki University School of Medicine, Osaka, Japan
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11
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Manhart A, Kalisz H, Holzer H. Sensitivity of yeast glycolytic enzymes to chloroquine. Arch Microbiol 1988; 150:309-12. [PMID: 2845878 DOI: 10.1007/bf00407797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Chloroquine at pH 8.0 and 1mM [corrected] concentration inhibits about 30% glucose consumption and ethanol formation in yeast cells. Out of the 11 glycolytic enzymes assayed, phosphoglycerate kinase and pyruvate decarboxylase have been found to be most sensitive to chloroquine. Next sensitive are hexokinase, glyceraldehyde-3-phosphate dehydrogenase and pyruvate kinase. Kinetic studies with the three kinases studied revealed competitive inhibition of chloroquine with ATP (hexokinase, phosphoglycerate kinase) or ADP (pyruvate kinase).
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Affiliation(s)
- A Manhart
- Biochemisches Institut der Universität Freiburg, Federal Republic of Germany
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12
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Kitamoto K, Yoshizawa K, Ohsumi Y, Anraku Y. Mutants of Saccharomyces cerevisiae with defective vacuolar function. J Bacteriol 1988; 170:2687-91. [PMID: 3131305 PMCID: PMC211189 DOI: 10.1128/jb.170.6.2687-2691.1988] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mutants of the yeast Saccharomyces cerevisiae that have a small vacuolar lysine pool were isolated and characterized. Mutant KL97 (lys1 slp1-1) and strain KL197-1A (slp1-1), a prototrophic derivative of KL97, did not grow well in synthetic medium supplemented with 10 mM lysine. Genetic studies indicated that the slp1-1 mutation (for small lysine pool) is recessive and is due to a single chromosomal mutation. Mutant KL97 shows the following pleiotropic defects in vacuolar functions. (i) It has small vacuolar pools for lysine, arginine, and histidine. (ii) Its growth is sensitive to lysine, histidine, Ca2+, heavy metal ions, and antibiotics. (iii) It has many small vesicles but no large central vacuole. (iv) It has a normal amount of the vacuolar membrane marker alpha-mannosidase but shows reduced activities of the vacuole sap markers proteinase A, proteinase B, and carboxypeptidase Y.
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Affiliation(s)
- K Kitamoto
- National Research Institute of Brewing, Tokyo, Japan
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13
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Satir BH, Busch G, Vuoso A, Murtaugh TJ. Aspects of signal transduction in stimulus exocytosis-coupling in Paramecium. J Cell Biochem 1988; 36:429-43. [PMID: 2454239 DOI: 10.1002/jcb.240360411] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This paper deals with the detailed mechanisms of signal transduction that lead to exocytosis during regulative secretion induced by specific secretagogues in a eukaryotic cell, Paramecium tetraurelia. There are at least three cellular compartments involved in the process: I) the plasma membrane, which contains secretagogue receptors and other transmembrane proteins, II) the cytoplasms, particularly in the region between the cell and secretory vesicle membranes, where molecules may influence interactions of the membranes, and III) the secretory vesicle itself. The ciliated protozoan Paramecium tetraurelia is very well suited for the study of signal transduction events associated with exocytosis because this eukaryotic cell contains thousands of docked secretory vesicles (trichocysts) below the cell membrane which can be induced to release synchronously when triggered with secretagogue. This ensures a high signal-to-noise ratio for events associated with this process. Upon release the trichocyst membrane fuses with the cell membrane and the trichocyst content undergoes a Ca2+-dependent irreversible expansion. Secretory mutants are available which are blocked at different points in the signal transduction pathway. Aspects of the three components mentioned above that will be discussed here include a) the properties of the vesicle content, its pH, and its membrane; b) the role of phosphorylation/dephosphorylation of a cytosolic 63-kilodalton (kDa)Mr protein in membrane fusion; and c) how influx of extracellular Ca2+ required for exocytosis may take place via exocytic Ca2+ channels which may be associated with specific membrane microdomains (fusion rosettes).
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Affiliation(s)
- B H Satir
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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Kotal P, Kotyk A, Jirsa M, Kordac V. Effect of chloroquine on membrane permeability in yeast--release of cellular coproporphyrin. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1988; 20:539-42. [PMID: 3286314 DOI: 10.1016/0020-711x(88)90503-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
1. The influx and efflux of labelled substances with and without chloroquine was studied in yeast cells. 2. The uptake of delta-aminolevulinic acid by Saccharomyces cerevisiae is characterized by a KT of 3-4 mM and Jmax of 1.0-1.2 mumol min-1 g dry weight-1. 3. A method for loading yeast with labelled coproporphyrin is suggested. 4. The uptake of sorbitol and coproporphyrin was slightly stimulated, while the uptake of 6-deoxyglucose was slightly, that of 2-aminoisobutyric acid and leucine strongly inhibited by chloroquine. 5. The efflux of coproporphyrin, 2-aminoisobutyric acid and sorbitol was stimulated while that of leucine was not influenced by chloroquine. 6. The result showed that chloroquine influenced directly but nonspecifically the membrane permeability, apparently mainly that of the vacuolar membrane.
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Affiliation(s)
- P Kotal
- 1st Medical Department, Charles University, Prague, Czechoslovakia
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15
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Detection and characterization of acidic compartments (vacuoles) in Chlorella vulgaris 11h cells by 31P-in vivo NMR spectroscopy and cytochemical techniques. Arch Microbiol 1987. [DOI: 10.1007/bf00425353] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
The rapid phase of fructose-1,6-bisphosphatase (FBPase) inactivation following glucose addition to starved yeast cells [reported previously] is inhibited on addition of 10 mM chloroquine (CQ) at about pH 8. This inhibition of inactivation was shown to be due to the prevention of phosphorylation of the enzyme. CQ was also found to inhibit general protein phosphorylation in the yeast cells. Glycolysis, as observed by changes in intracellular glucose-6-phosphate and extracellular glucose and ethanol concentrations, was shown to be significantly inhibited in cells treated with CQ. Similarly, a decrease in ATP concentrations was observed. However, during the early stages of phosphorylation of FBPase, levels of ATP were similar in cells containing CQ as in those without CQ. Thus, decrease in ATP levels is not thought to be significantly responsible for the inhibition of protein phosphorylation. However, the phosphorylating activity of cyclic AMP-dependent protein kinases is inhibited in vitro by relatively low concentrations of CQ. Thus, prevention of protein phosphorylation by CQ is believed to be due to inhibition of protein kinases in yeast cells.
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17
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Nicolay K, Veenhuis M, Douma AC, Harder W. A 31P NMR study of the internal pH of yeast peroxisomes. Arch Microbiol 1987; 147:37-41. [PMID: 3579461 DOI: 10.1007/bf00492902] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The internal pH of peroxisomes in the yeasts Hansenula polymorpha, Candida utilis and Trichosporon cutaneum X4 was estimated by 31P nuclear magnetic resonance (NMR) spectroscopy. 31P NMR spectra of suspensions of intact cells of these yeasts, grown under conditions of extensive peroxisomal proliferation, displayed two prominent Pi-peaks at different chemical shift positions. In control cells grown on glucose, which contain very few peroxisomes, only a single peak was observed. This latter peak, which was detected under all growth conditions, was assigned to cytosolic Pi at pH 7.1. The additional peak present in spectra of peroxisome-containing cells, reflected Pi at a considerably lower pH of approximately 5.8-6.0. Pi at a considerably lower pH of approximately 5.8-6.0. Experiments with the protonophore carbonyl cyanide m-chlorophenylhydrazon (CCCP) and the ionophores valinomycin and nigericin revealed that separation of the two Pi-peaks was caused by a pH-gradient across a membrane separating the two pools. Experiments with chloroquine confirmed the acidic nature of one of these pools. In a number of transfer experiments with the yeast H. polymorpha it was shown that the relative intensity of the Pi-signal at the low pH-position was correlated to the peroxisomal volume fraction. These results strongly suggest that this peak has to be assigned to Pi in peroxisomes, which therefore are acidic in nature. The presence of peroxisome-associated Pi was confirmed cytochemically.
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18
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Wettern M, Galling G. Degradation of the 32-kilodalton thylakoid-membrane polypeptide of Chlamydomonas reinhardi Y-1. PLANTA 1985; 166:474-482. [PMID: 24241612 DOI: 10.1007/bf00391271] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/1985] [Accepted: 08/01/1985] [Indexed: 06/02/2023]
Abstract
Isolated thylakoid membranes of Chlamydomonas reinhardi Y-1 with the 32-kDa polypeptide either radioactively labelled or unlabelled were incubated in vitro under various conditions in order to gain information about the degradation of the 32-kDa polypeptide. The degradation was higher at pH 6 compared with pH 7 and pH 8 and exhibited a temperature maximum between 20° C and 25° C (pH 6, pH 8). A light-dependent part of the total degradation was linearly dependent on white light of energy fluence rate between 1 and 20 mW·cm(-2) at 25° C and leveled out at higher fluence rates. The degradation in light was only slightly stimulated by ATP but was reduced by 3-(3'-4'-dichlorophenyl)-1,1-dimethylurea. Adenosine-5'-diphosphate and heparin (2.7 mM and 200 μg per 100 μl, respectively) known to inhibit kinases, caused a 50% decrease in degradation indicating that a phosphorylation step is involved in degradating the 32-kDa polypeptide. Out of various inhibitors specific for different types of proteases, only those for thiol- and endoproteases showed intense effects. These results point to a proteolytic degradation of the 32-kDa polypetide by a thylakoid-membrane-bound thiol-endoprotease. Its activity yields soluble breakdown products with relative molecular masses (Mrs) of 23, 16.5, 11.3 and 10.7 kDa, and these are accumulated in the in-vitro system. Partial proteolytic digestion of thylakoids with Staphylococcus aureus V8 protease results in at least two labelled breakdown products (Mrs 23, and 16.5 kDa). It is assumed that cleaving at identical amino-acid residues of the 32-kDa polypeptide by the thylakoid-membrane-bound thiolendoprotease and the V8 protease results in these two breakdown products. They are derived from subsequent cleavage at amino-acid residues 60-242 and 60-189 according to the deduced protein sequence (Erickson et al. 1984, EMBO J. 3, 2753-2762).
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Affiliation(s)
- M Wettern
- Botanisches Institut der Technischen Universität Braunschweig, Humboldtstrasse 1, D-3300, Braunschweig, Federal Republic of Germany
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19
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Cleavage of thiamine pyrophosphate by sulfite in saccharomyces cerevisiae. Eur Food Res Technol 1985. [DOI: 10.1007/bf01027410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Hinze H, Holzer H. Accumulation of nitrite and sulfite in yeast cells and synergistic depletion of the intracellular ATP content. ZEITSCHRIFT FUR LEBENSMITTEL-UNTERSUCHUNG UND -FORSCHUNG 1985; 180:117-20. [PMID: 3885619 DOI: 10.1007/bf01042634] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
When nitrite or sulfite are applied to yeast cells below pH 5.0, an enormous intracellular accumulation occurs. It is assumed that nitrite and sulfite penetrate the cell membrane in their undissociated forms as nitrous acid (pK = 3.3) or sulfurous acid (pK = 1.8), respectively. Due to the neutral intracellular pH they are trapped inside the cell in their anionic forms, which are impermeable to the cell membrane. It has previously been shown that sulfite causes a rapid depletion of the ATP content of yeast cells [Schimz, K.L. and Holzer, H. (1979) resp. Hinze et al. as above]. Similarly, millimolar concentrations of nitrite decrease the ATP level to less than 10% of the initial value. Nitrite and sulfite in combination deplete the ATP content of yeast cells much stronger than expected for the sum of the separate effects of these compounds ("synergistic effect").
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