Saccharomyces cerevisiae Vacuole in Zinc Storage and Intracellular Zinc Distribution

ABSTRACT Previous studies of the yeast Saccharomyces cerevisiae indicated that the vacuole is a major site of zinc storage in the cell. However, these studies did not address the absolute level of zinc that was stored in the vacuole nor did they examine the abundances of stored zinc in other compartments of the cell. In this report, we describe an analysis of the cellular distribution of zinc by use of both an organellar fractionation method and an electron probe X-ray microanalysis. With these methods, we determined that zinc levels in the vacuole vary with zinc status and can rise to almost 100 mM zinc (i.e., 7 × 108 atoms of vacuolar zinc per cell). Moreover, this zinc can be mobilized effectively to supply the needs of as many as eight generations of progeny cells under zinc starvation conditions. While the Zrc1 and Cot1 zinc transporters are essential for zinc uptake into the vacuole under steady-state growth conditions, additional transporters help mediate zinc uptake into the vacuole during “zinc shock,” when zinc-limited cells are resupplied with zinc. In addition, we found that other compartments of the cell do not provide significant stores of zinc. In particular, zinc accumulation in mitochondria is low and is homeostatically regulated independently of vacuolar zinc storage. Finally, we observed a strong correlation between zinc status and the levels of magnesium and phosphorus accumulated in cells. Our results implicate zinc as a major determinant of the ability of the cell to store these other important nutrients.

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Alterations in ZnT1 expression and function lead to impaired intracellular zinc homeostasis in cancer

Cell Death Discovery ◽

10.1038/s41420-019-0224-0 ◽

2019 ◽

Vol 5 (1) ◽

Cited By ~ 2

Author(s):

Adrian Israel Lehvy ◽

Guy Horev ◽

Yarden Golan ◽

Fabian Glaser ◽

Yael Shammai ◽

...

Keyword(s):

Malignant Tumors ◽

Zinc Homeostasis ◽

Healthy Population ◽

Missense Mutations ◽

Protein Alignment ◽

Loss Of Function ◽

Intracellular Zinc ◽

Dismal Prognosis ◽

Zinc Levels ◽

And Function

Abstract Zinc is vital for the structure and function of ~3000 human proteins and hence plays key physiological roles. Consequently, impaired zinc homeostasis is associated with various human diseases including cancer. Intracellular zinc levels are tightly regulated by two families of zinc transporters: ZIPs and ZnTs; ZIPs import zinc into the cytosol from the extracellular milieu, or from the lumen of organelles into the cytoplasm. In contrast, the vast majority of ZnTs compartmentalize zinc within organelles, whereas the ubiquitously expressed ZnT1 is the sole zinc exporter. Herein, we explored the hypothesis that qualitative and quantitative alterations in ZnT1 activity impair cellular zinc homeostasis in cancer. Towards this end, we first used bioinformatics to analyze inactivating mutations in ZIPs and ZNTs, catalogued in the COSMIC and gnomAD databases, representing tumor specimens and healthy population controls, respectively. ZnT1, ZnT10, ZIP8, and ZIP10 showed extremely high rates of loss of function mutations in cancer as compared to healthy controls. Analysis of the putative functional impact of missense mutations in ZnT1-ZnT10 and ZIP1-ZIP14, using homologous protein alignment and structural predictions, revealed that ZnT1 displays a markedly increased frequency of predicted functionally deleterious mutations in malignant tumors, as compared to a healthy population. Furthermore, examination of ZnT1 expression in 30 cancer types in the TCGA database revealed five tumor types with significant ZnT1 overexpression, which predicted dismal prognosis for cancer patient survival. Novel functional zinc transport assays, which allowed for the indirect measurement of cytosolic zinc levels, established that wild type ZnT1 overexpression results in low intracellular zinc levels. In contrast, overexpression of predicted deleterious ZnT1 missense mutations did not reduce intracellular zinc levels, validating eight missense mutations as loss of function (LoF) mutations. Thus, alterations in ZnT1 expression and LoF mutations in ZnT1 provide a molecular mechanism for impaired zinc homeostasis in cancer formation and/or progression.

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Ammonia regulation of amino acid permeases in Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.3.4.672-683.1983 ◽

1983 ◽

Vol 3 (4) ◽

pp. 672-683

Author(s):

W E Courchesne ◽

B Magasanik

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Cytoplasmic Membrane ◽

Nitrogen Sources ◽

Amino Acid Permease ◽

Inducer Exclusion ◽

Amino Acid Permeases ◽

General Amino Acid Permease ◽

State Growth ◽

And Control

The activities of the proline-specific permease (PUT4) and the general amino acid permease (GAP1) of Saccharomyces cerevisiae vary 70- to 140-fold in response to the nitrogen source of the growth medium. The PUT4 and GAP1 permease activities are regulated by control of synthesis and control of activity. These permeases are irreversibly inactivated by addition of ammonia or glutamine, lowering the activity to that found during steady-state growth on these nitrogen sources. Mutants altered in the regulation of the PUT4 permease (Per-) have been isolated. The mutations in these strains are pleiotropic and affect many other permeases, but have no direct effect on various cytoplasmic enzymes involved in nitrogen assimilation. In strains having one class of mutations (per1), ammonia inactivation of the PUT4 and GAP1 permeases did not occur, whereas glutamate and glutamine inactivation did. Thus, there appear to be two independent inactivation systems, one responding to ammonia and one responding to glutamate (or a metabolite of glutamate). The mutations were found to be nuclear and recessive. The inactivation systems are constitutive and do not require transport of the effector molecules per se, apparently operating on the inside of the cytoplasmic membrane. The ammonia inactivation was found not to require a functional glutamate dehydrogenase (NADP). These mutants were used to show that ammonia exerts control of arginase synthesis largely by inducer exclusion. This may be the primary mode of nitrogen regulation for most nitrogen-regulated enzymes of S. cerevisiae.

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B cell activation and proliferation increase intracellular zinc levels

The Journal of Nutritional Biochemistry ◽

10.1016/j.jnutbio.2018.10.008 ◽

2019 ◽

Vol 64 ◽

pp. 72-79 ◽

Cited By ~ 9

Author(s):

Johanna Ollig ◽

Veronika Kloubert ◽

Kathryn M. Taylor ◽

Lothar Rink

Keyword(s):

B Cell ◽

Cell Activation ◽

B Cell Activation ◽

Intracellular Zinc ◽

Zinc Levels

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Storage and Condition of Biomass Influence to Biosorption of Lead (II) and Zinc(II) by Saccharomyces cerevisiae Biomass

Indonesian Journal of Chemistry ◽

10.22146/ijc.21955 ◽

2010 ◽

Vol 1 (1) ◽

pp. 11-15

Author(s):

Jasmidi Jasmidi ◽

Eko Sugiharto ◽

Mudjiran Mudjiran

Keyword(s):

Saccharomyces Cerevisiae ◽

Atomic Absorption ◽

Room Temperature ◽

Final Concentration ◽

Biomass Storage ◽

Lead And Zinc ◽

The Difference ◽

Biomass Influence ◽

And Storage ◽

Zinc Storage

The influence of length and condition of Biomass Storage on the biosorption of lead and zinc that present together in a solution by Saccharomyces cerevisiae biomass were studied. In this experiment, variables of length and condition of biomass storage were examined. Concentration of lead and zinc were determined by atomic absorption spectrophotometric (AAS) using air-acetilene as atomizing flame. Loading of lead and zinc on the biomass were determined as the difference between the initial and the final concentration of lead and zinc in the solution. Biosorption of lead and zinc were influenced by condition and storage of the biomass. Storage of biomass in the room temperature for one week cause an increasing uptake. Storage for longer period result in decrease of lead and zinc uptake. Storage of biomass in a freezer up to 2 weeks increased the uptake of lead, but did not influence the uptake of zinc. Storage for longer period decreased the uptake of both of lead and zinc. For all condition the uptake of lead higher than the uptake of zinc by Saccharomyces cerevisiae.

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Size control models of Saccharomyces cerevisiae cell proliferation.

Molecular and Cellular Biology ◽

10.1128/mcb.2.4.361 ◽

1982 ◽

Vol 2 (4) ◽

pp. 361-368 ◽

Cited By ~ 52

Author(s):

A E Wheals

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Proliferation ◽

Critical Size ◽

Transition Probability ◽

Size Control ◽

Time Lapse ◽

Growth Conditions ◽

Yeast Cells ◽

Cycle Times ◽

The Individual

By using time-lapse photomicroscopy, the individual cycle times and sizes at bud emergence were measured for a population of saccharomyces cerevisiae cells growing exponentially under balanced growth conditions in a specially constructed filming slide. There was extensive variability in both parameters for daughter and parent cells. The data on 162 pairs of siblings were analyzed for agreement with the predictions of the transition probability hypothesis and the critical-size hypothesis of yeast cell proliferation and also with a model incorporating both of these hypotheses in tandem. None of the models accounted for all of the experimental data, but two models did give good agreement to all of the data. The wobbly tandem model proposes that cells need to attain a critical size, which is very variable, enabling them to enter a start state from which they exit with first order kinetics. The sloppy size control model suggests that cells have an increasing probability per unit time of traversing start as they increase in size, reaching a high plateau value which is less than one. Both models predict that the kinetics of entry into the cell division sequence will strongly depend on variability in birth size and thus will be quite different for daughters and parents of the asymmetrically dividing yeast cells. Mechanisms underlying these models are discussed.

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Effects of changes in ambient oxygen levels and hypoxia-reoxygenation on intracellular zinc levels in human coronary artery endothelial cells

Free Radical Biology and Medicine ◽

10.1016/j.freeradbiomed.2021.08.076 ◽

2021 ◽

Vol 177 ◽

pp. S72-S73

Author(s):

Matthew Smith ◽

Alexander Morrell ◽

Theodore Stewart ◽

Wolfgang Maret ◽

Ron Jacob ◽

...

Keyword(s):

Endothelial Cells ◽

Coronary Artery ◽

Human Coronary Artery ◽

Intracellular Zinc ◽

Oxygen Levels ◽

Ambient Oxygen ◽

Zinc Levels ◽

Hypoxia Reoxygenation

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Constitutive and inducible Saccharomyces cerevisiae promoters: evidence for two distinct molecular mechanisms

Molecular and Cellular Biology ◽

10.1128/mcb.6.11.3847-3853.1986 ◽

1986 ◽

Vol 6 (11) ◽

pp. 3847-3853

Author(s):

K Struhl

Keyword(s):

Saccharomyces Cerevisiae ◽

Molecular Mechanisms ◽

Normal Growth ◽

Regulatory Elements ◽

Growth Conditions ◽

Physical Structure ◽

Base Pairs ◽

Inducible Promoters ◽

Upstream Promoter ◽

Selection Of

his3 and pet56 are adjacent Saccharomyces cerevisiae genes that are transcribed in opposite directions from initiation sites that are separated by 200 base pairs. Under normal growth conditions, in which his3 and pet56 are transcribed at similar basal levels, a poly(dA-dT) sequence located between the genes serves as the upstream promoter element for both. In contrast, his3 but not pet56 transcription is induced during conditions of amino acid starvation, even though the critical regulatory site is located upstream of both respective TATA regions. Moreover, only one of the two normal his3 initiation sites is subject to induction. From genetic and biochemical evidence, I suggest that the his3-pet56 intergenic region contains constitutive and inducible promoters with different properties. In particular, two classes of TATA elements, constitutive (Tc) and regulatory (Tr), can be distinguished by their ability to respond to upstream regulatory elements, by their effects on the selection of initiation sites, and by their physical structure in nuclear chromatin. Constitutive and inducible his3 transcription is mediated by distinct promoters representing each class, whereas pet56 transcription is mediated by a constitutive promoter. Molecular mechanisms for these different kinds of S. cerevisiae promoters are proposed.

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Identification and Characterization ofMAE1, the Saccharomyces cerevisiae Structural Gene Encoding Mitochondrial Malic Enzyme

Journal of Bacteriology ◽

10.1128/jb.180.11.2875-2882.1998 ◽

1998 ◽

Vol 180 (11) ◽

pp. 2875-2882 ◽

Cited By ~ 101

Author(s):

Eckhard Boles ◽

Patricia de Jong-Gubbels ◽

Jack T. Pronk

Keyword(s):

Saccharomyces Cerevisiae ◽

Enzyme Activity ◽

Pyruvate Kinase ◽

Malic Enzyme ◽

Fold Increase ◽

Growth Conditions ◽

Anaerobic Growth ◽

Oxidative Decarboxylation ◽

Mrna Levels ◽

Malic Enzyme Activity

ABSTRACT Pyruvate, a precursor for several amino acids, can be synthesized from phosphoenolpyruvate by pyruvate kinase. Nevertheless, pyk1 pyk2 mutants of Saccharomyces cerevisiae devoid of pyruvate kinase activity grew normally on ethanol in defined media, indicating the presence of an alternative route for pyruvate synthesis. A candidate for this role is malic enzyme, which catalyzes the oxidative decarboxylation of malate to pyruvate. Disruption of open reading frame YKL029c, which is homologous to malic enzyme genes from other organisms, abolished malic enzyme activity in extracts of glucose-grown cells. Conversely, overexpression ofYKL029c/MAE1 from the MET25 promoter resulted in an up to 33-fold increase of malic enzyme activity. Growth studies with mutants demonstrated that presence of either Pyk1p or Mae1p is required for growth on ethanol. Mutants lacking both enzymes could be rescued by addition of alanine or pyruvate to ethanol cultures. Disruption of MAE1 alone did not result in a clear phenotype. Regulation of MAE1 was studied by determining enzyme activities and MAE1 mRNA levels in wild-type cultures and by measuring β-galactosidase activities in a strain carrying a MAE1::lacZ fusion. Both in shake flask cultures and in carbon-limited chemostat cultures,MAE1 was constitutively expressed. A three- to fourfold induction was observed during anaerobic growth on glucose. Subcellular fractionation experiments indicated that malic enzyme in S. cerevisiae is a mitochondrial enzyme. Its regulation and localization suggest a role in the provision of intramitochondrial NADPH or pyruvate under anaerobic growth conditions. However, since null mutants could still grow anaerobically, this function is apparently not essential.

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