scholarly journals Regulation of Copper Metabolism by Nitrogen Utilization in Saccharomyces cerevisiae

2021 ◽  
Vol 7 (9) ◽  
pp. 756
Author(s):  
Suzie Kang ◽  
Hyewon Seo ◽  
Min-Gyu Lee ◽  
Cheol-Won Yun
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Iron Uptake ◽  
Nitrogen Starvation ◽  
Copper Metabolism ◽  
Nitrogen Utilization ◽  
Deletion Mutants ◽  
Uptake System ◽  
Wild Type ◽  
High Affinity ◽  
Uptake Activity

To understand the relationship between carbon or nitrogen utilization and iron homeostasis, we performed an iron uptake assay with several deletion mutants with partial defects in carbon or nitrogen metabolism. Among them, some deletion mutants defective in carbon metabolism partially and the MEP2 deletion mutant showed lower iron uptake activity than the wild type. Mep2 is known as a high-affinity ammonia transporter in Saccharomyces cerevisiae. Interestingly, we found that nitrogen starvation resulted in lower iron uptake activity than that of wild-type cells without downregulation of the genes involved in the high-affinity iron uptake system FET3/FTR1. However, the gene expression of FRE1 and CTR1 was downregulated by nitrogen starvation. The protein level of Ctr1 was also decreased by nitrogen starvation, and addition of copper to the nitrogen starvation medium partially restored iron uptake activity. However, the expression of MAC1, which is a copper-responsive transcriptional activator, was not downregulated by nitrogen starvation at the transcriptional level but was highly downregulated at the translational level. Mac1 was downregulated dramatically under nitrogen starvation, and treatment with MG132, which is an inhibitor of proteasome-dependent protein degradation, partially attenuated the downregulation of Mac1. Taken together, these results suggest that nitrogen starvation downregulates the high-affinity iron uptake system by degrading Mac1 in a proteasome-dependent manner and eventually downregulates copper metabolism.

scholarly journals Genetic evidence that ferric reductase is required for iron uptake in Saccharomyces cerevisiae.

1990 ◽  
Vol 10 (5) ◽  
pp. 2294-2301 ◽  
Author(s):  
A Dancis ◽  
R D Klausner ◽  
A G Hinnebusch ◽  
J G Barriocanal
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Iron Uptake ◽  
Reductase Activity ◽  
Gene Transcript ◽  
Single Mutation ◽  
Uptake System ◽  
Ferric Reductase ◽  
Wild Type ◽  
Iron Starvation

The requirement for a reduction step in cellular iron uptake has been postulated, and the existence of plasma membrane ferric reductase activity has been described in both procaryotic and eucaryotic cells. In the yeast Saccharomyces cerevisiae, there is an externally directed reductase activity that is regulated by the concentration of iron in the growth medium; maximal activity is induced by iron starvation. We report here the isolation of a mutant of S. cerevisiae lacking the reductase activity. This mutant is deficient in the uptake of ferric iron and is extremely sensitive to iron deprivation. Genetic analysis of the mutant demonstrates that the reductase and ferric uptake deficiencies are due to a single mutation that we designate fre1-1. Both phenotypes cosegregate in meiosis, corevert with a frequency of 10(-7), and are complemented by a 3.5-kilobase fragment of genomic DNA from wild-type S. cerevisiae. This fragment contains FRE1, the wild-type allele of the mutant gene. The level of the gene transcript is regulated by iron in the same was as the reductase activity. The ferrous ion product of the reductase must traverse the plasma membrane. A high-affinity (Km = 5 microM) ferrous uptake system is present in both wild-type and mutant cells. Thus, iron uptake in S. cerevisiae is mediated by two plasma membrane components, a reductase and a ferrous transport system.

Genetic evidence that ferric reductase is required for iron uptake in Saccharomyces cerevisiae

1990 ◽  
Vol 10 (5) ◽  
pp. 2294-2301
Author(s):  
A Dancis ◽  
R D Klausner ◽  
A G Hinnebusch ◽  
J G Barriocanal
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Iron Uptake ◽  
Reductase Activity ◽  
Gene Transcript ◽  
Single Mutation ◽  
Uptake System ◽  
Ferric Reductase ◽  
Wild Type ◽  
Iron Starvation

The requirement for a reduction step in cellular iron uptake has been postulated, and the existence of plasma membrane ferric reductase activity has been described in both procaryotic and eucaryotic cells. In the yeast Saccharomyces cerevisiae, there is an externally directed reductase activity that is regulated by the concentration of iron in the growth medium; maximal activity is induced by iron starvation. We report here the isolation of a mutant of S. cerevisiae lacking the reductase activity. This mutant is deficient in the uptake of ferric iron and is extremely sensitive to iron deprivation. Genetic analysis of the mutant demonstrates that the reductase and ferric uptake deficiencies are due to a single mutation that we designate fre1-1. Both phenotypes cosegregate in meiosis, corevert with a frequency of 10(-7), and are complemented by a 3.5-kilobase fragment of genomic DNA from wild-type S. cerevisiae. This fragment contains FRE1, the wild-type allele of the mutant gene. The level of the gene transcript is regulated by iron in the same was as the reductase activity. The ferrous ion product of the reductase must traverse the plasma membrane. A high-affinity (Km = 5 microM) ferrous uptake system is present in both wild-type and mutant cells. Thus, iron uptake in S. cerevisiae is mediated by two plasma membrane components, a reductase and a ferrous transport system.

scholarly journals The Sinorhizobium meliloti ABC Transporter Cho Is Highly Specific for Choline and Expressed in Bacteroids from Medicago sativa Nodules

2004 ◽  
Vol 186 (18) ◽  
pp. 5988-5996 ◽  
Author(s):  
Laurence Dupont ◽  
Isabelle Garcia ◽  
Marie-Christine Poggi ◽  
Geneviève Alloing ◽  
Karine Mandon ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Abc Transporter ◽  
Sinorhizobium Meliloti ◽  
Lipid Membrane ◽  
Site Directed Mutagenesis ◽  
Choline Uptake ◽  
Uptake System ◽  
Choline Transport ◽  
High Affinity ◽  
Uptake Activity

ABSTRACT In Sinorhizobium meliloti, choline is the direct precursor of phosphatidylcholine, a major lipid membrane component in the Rhizobiaceae family, and glycine betaine, an important osmoprotectant. Moreover, choline is an efficient energy source which supports growth. Using a PCR strategy, we identified three chromosomal genes (choXWV) which encode components of an ABC transporter: ChoX (binding protein), ChoW (permease), and ChoV (ATPase). Whereas the best homology scores were obtained with components of betaine ProU-like systems, Cho is not involved in betaine transport. Site-directed mutagenesis of choX strongly reduced (60 to 75%) the choline uptake activity, and purification of ChoX, together with analysis of the ligand-binding specificity, showed that ChoX binds choline with a high affinity (K D , 2.7 μM) and acetylcholine with a low affinity (K D , 145 μM) but binds none of the betaines. Uptake competition experiments also revealed that ectoine, various betaines, and choline derivatives were not effective competitors for Cho-mediated choline transport. Thus, Cho is a highly specific high-affinity choline transporter. Choline transport activity and ChoX expression were induced by choline but not by salt stress. Western blotting experiments with antibodies raised against ChoX demonstrated the presence of ChoX in bacteroids isolated from nitrogen-fixing nodules obtained from Medicago sativa roots. The choX mutation did not have an effect on growth under standard conditions, and neither Nod nor Fix phenotypes were impaired in the mutant, suggesting that the remaining choline uptake system(s) still present in the mutant strain can compensate for the lack of Cho transporter.

scholarly journals Yeast protective response to arsenate involves the repression of the high affinity iron uptake system

2013 ◽  
Vol 1833 (5) ◽  
pp. 997-1005 ◽  
Author(s):  
Liliana Batista-Nascimento ◽  
Michel B. Toledano ◽  
Dennis J. Thiele ◽  
Claudina Rodrigues-Pousada
Keyword(s):  
Iron Uptake ◽  
Uptake System ◽  
Protective Response ◽  
High Affinity ◽  
Iron Uptake System

scholarly journals Dual Regulation of the Arabidopsis High-Affinity Root Iron Uptake System by Local and Long-Distance Signals

2003 ◽  
Vol 132 (2) ◽  
pp. 796-804 ◽  
Author(s):  
Grégory A. Vert ◽  
Jean-François Briat ◽  
Catherine Curie
Keyword(s):  
Iron Uptake ◽  
Uptake System ◽  
Long Distance ◽  
High Affinity ◽  
Iron Uptake System

The CaCTR1 gene is required for high-affinity iron uptake and is transcriptionally controlled by a copper-sensing transactivator encoded by CaMAC1

Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2197-2208 ◽  
Author(s):  
Marcus E. Marvin ◽  
Robert P. Mason ◽  
Annette M. Cashmore
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Iron Uptake ◽  
Invasive Growth ◽  
Hostile Environment ◽  
Null Mutant ◽  
Copper Uptake ◽  
Similar System ◽  
Copper Transporter ◽  
High Affinity ◽  
Null Strain

The ability of Candida albicans to acquire iron from the hostile environment of the host is known to be necessary for virulence and appears to be achieved using a similar system to that described for Saccharomyces cerevisiae. In S. cerevisiae, high-affinity iron uptake is dependent upon the acquisition of copper. The authors have previously identified a C. albicans gene (CaCTR1) that encodes a copper transporter. Deletion of this gene results in a mutant strain that grows predominantly as pseudohyphae and displays aberrant morphology in low-copper conditions. This paper demonstrates that invasive growth by C. albicans is induced by low-copper conditions and that this is augmented in a Cactr1-null strain. It also shows that deletion of CaCTR1 results in defective iron uptake. In S. cerevisiae, genes that facilitate high-affinity copper uptake are controlled by a copper-sensing transactivator, ScMac1p. The authors have now identified a C. albicans gene (CaMAC1) that encodes a copper-sensing transactivator. A Camac1-null mutant displays phenotypes similar to those of a Cactr1-null mutant and has no detectable CaCTR1 transcripts in low-copper conditions. It is proposed that high-affinity copper uptake by C. albicans is necessary for reductive iron uptake and is transcriptionally controlled by CaMac1p in a similar manner to that in S. cerevisiae.

scholarly journals High-Resolution Genetic Mapping With Ordered Arrays of Saccharomyces cerevisiae Deletion Mutants

Genetics ◽  
2002 ◽  
Vol 162 (3) ◽  
pp. 1091-1099 ◽  
Author(s):  
Paul Jorgensen ◽  
Bryce Nelson ◽  
Mark D Robinson ◽  
Yiqun Chen ◽  
Brenda Andrews ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Resolution ◽  
Genetic Mapping ◽  
Large Scale ◽  
Model Organisms ◽  
Deletion Mutants ◽  
Wild Type ◽  
Allele Specific ◽  
Single Allele ◽  
Kinase Signaling Pathway

Abstract We present a method for high-resolution genetic mapping that takes advantage of the ordered set of viable gene deletion mutants, which form a set of colinear markers covering almost every centimorgan of the Saccharomyces cerevisiae genome, and of the synthetic genetic array (SGA) system, which automates the construction of double mutants formed by mating and meiotic recombination. The Cbk1 kinase signaling pathway, which consists minimally of CBK1, MOB2, KIC1, HYM1, and TAO3 (PAG1), controls polarized morphogenesis and activation of the Ace2 transcription factor. Deletion mutations in the Cbk1 pathway genes are tolerated differently by common laboratory strains of S. cerevisiae, being viable in the W303 background but dead in the S288C background. Genetic analysis indicated that the lethality of Cbk1 pathway deletions in the S288C background was suppressed by a single allele specific to the W303 background. SGA mapping (SGAM) was used to locate this W303-specific suppressor to the SSD1 locus, which contains a known polymorphism that appears to compromise SSD1 function. This procedure should map any mutation, dominant or recessive, whose phenotype is epistatic to wild type, that is, a phenotype that can be scored from a mixed population of cells obtained by germination of both mutant and wild-type spores. In principle, SGAM should be applicable to the analysis of multigenic traits. Large-scale construction of ordered mutations in other model organisms would broaden the application of this approach.

Sequences and proteins required for iron-regulated expression ofsid1ofUstilago maydis

1995 ◽  
Vol 73 (S1) ◽  
pp. 140-147 ◽  
Author(s):  
S. A. Leong ◽  
Z. An ◽  
B. Mei ◽  
J. McEvoy ◽  
Q. Zhao ◽  
...  
Keyword(s):  
Iron Uptake ◽  
Cyclic Peptide ◽  
Ustilago Maydis ◽  
Uptake System ◽  
Wild Type ◽  
Iron Starvation ◽  
First Intron ◽  
Gata Transcription Factor ◽  
Regulated Expression ◽  
Translational Start

The molecular biology of the high affinity, siderophore-mediated iron uptake system of the basidiomycete fungus Ustilago maydis is under investigation. Ustilago maydis produces two cyclic peptide siderophores, ferrichrome and ferrichrome A. Biosynthesis of both siderophores is initiated by ornithine-N5-oxygenase, the product of sid1. sid1 mRNA accumulates only during growth under iron starvation conditions in wild-type cells or constitutively in urbs1 mutants, urbs1 encodes a 100-kDa protein with putative Zn finger domains that share sequence identity with those of the GATA family of transcription factors. The promoter region of sid1 was defined by deletion analysis of a 3.0-kb region 5′ to the translational start of sid1 using the Escherichia coli GUS gene as a reporter. Three regions were defined by this analysis to be critical to expression of sid1. These include (i) a 306-bp region containing two GATA sequences and mapping 2.4 kb from the start of translation; (ii) a 439-bp region immediately 5′ to the start of transcription; and (iii) a region encompassing the first intron of sid1. Deletion of the GATA sequences resulted in deregulated expression of sid1, while elimination of the latter two sequences ablated expression of the gene under all circumstances. Current efforts are focused on determining whether Urbsl interacts directly with the sid1 promoter via the GATA sequences and whether this interaction is dependent upon iron. Key words: GATA, transcription factor, siderophore, ferrichrome, iron, Urbs1.

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