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Welgemoed T, Duong TA, Barnes I, Stukenbrock EH, Berger DK. Population genomic analyses suggest recent dispersal events of the pathogen Cercospora zeina into East and Southern African maize cropping systems. G3 (BETHESDA, MD.) 2023; 13:jkad214. [PMID: 37738420 PMCID: PMC10627275 DOI: 10.1093/g3journal/jkad214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/03/2023] [Accepted: 09/06/2023] [Indexed: 09/24/2023]
Abstract
A serious factor hampering global maize production is gray leaf spot disease. Cercospora zeina is one of the causative pathogens, but population genomics analysis of C. zeina is lacking. We conducted whole-genome Illumina sequencing of a representative set of 30 C. zeina isolates from Kenya and Uganda (East Africa) and Zambia, Zimbabwe, and South Africa (Southern Africa). Selection of the diverse set was based on microsatellite data from a larger collection of the pathogen. Pangenome analysis of the C. zeina isolates was done by (1) de novo assembly of the reads with SPAdes, (2) annotation with BRAKER, and (3) protein clustering with OrthoFinder. A published long-read assembly of C. zeina (CMW25467) from Zambia was included and annotated using the same pipeline. This analysis revealed 790 non-shared accessory and 10,677 shared core orthogroups (genes) between the 31 isolates. Accessory gene content was largely shared between isolates from all countries, with a few genes unique to populations from Southern Africa (32) or East Africa (6). There was a significantly higher proportion of effector genes in the accessory secretome (44%) compared to the core secretome (24%). PCA, ADMIXTURE, and phylogenetic analysis using a neighbor-net network indicated a population structure with a geographical subdivision between the East African isolates and the Southern African isolates, although gene flow was also evident. The small pangenome and partial population differentiation indicated recent dispersal of C. zeina into Africa, possibly from 2 regional founder populations, followed by recurrent gene flow owing to widespread maize production across sub-Saharan Africa.
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Affiliation(s)
- Tanya Welgemoed
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Tuan A Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Irene Barnes
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Eva H Stukenbrock
- Environmental Genomics, Christian-Albrechts University of Kiel, Am Botanischen Garten 1-11, Kiel 24118, Germany
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, Plön 24306, Germany
| | - Dave K Berger
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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Tang Y, Yang X, Li H, Shuai Y, Chen W, Ma D, Lü Z. Uncovering the role of wheat magnesium transporter family genes in abiotic responses. FRONTIERS IN PLANT SCIENCE 2023; 14:1078299. [PMID: 36844102 PMCID: PMC9948656 DOI: 10.3389/fpls.2023.1078299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/23/2023] [Indexed: 05/13/2023]
Abstract
BACKGROUND The CorA / MGT / MRS2 family proteins are an important group of magnesium transporter proteins that maintain magnesium ion homeostasis in plant cells. However, little is known about the MGT functions in wheat. METHODS The known MGT sequences were used as queries to BlastP against wheat genome IWGSC RefSeq v2.1 assembly (E-value <10-5). Chromosome localization information for each TaMGT gene was obtained from the GFF3 file of the wheat genome data (IWGSCv2.1).The sequence of 1500 bp upstream of the TaMGT genes was extracted from the wheat genome data. The cis-elements were analyzed using PlantCARE online tool. RESULT A total of 24 MGT genes were identified on 18 chromosomes of wheat. After functional domain analysis, only TaMGT1A, TaMGT1B, and TaMGT1D had GMN mutations to AMN, while all the other genes had conserved GMN tripeptide motifs. Expression profiling showed that the TaMGT genes were differentially expressed under different stresses and at different growth and development stages. The expression levels of TaMGT4B and TaMGT4A were significantly up-regulated in cold damage. In addition, qRT-PCR results also confirmed that these TaMGT genes are involved in the wheat abiotic stress responses. CONCLUSION In conclusion, The results of our research provide a theoretical basis for further research on the function of TaMGT gene family in wheat.
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Affiliation(s)
- Yanhong Tang
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province)/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education/College of Agriculture, Yangtze University, Jingzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoyue Yang
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province)/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education/College of Agriculture, Yangtze University, Jingzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Han Li
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province)/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education/College of Agriculture, Yangtze University, Jingzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yating Shuai
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province)/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education/College of Agriculture, Yangtze University, Jingzhou, China
| | - Wang Chen
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province)/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education/College of Agriculture, Yangtze University, Jingzhou, China
- *Correspondence: Wang Chen, ; Dongfang Ma, ; Zhichuang Lü,
| | - Dongfang Ma
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province)/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education/College of Agriculture, Yangtze University, Jingzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- *Correspondence: Wang Chen, ; Dongfang Ma, ; Zhichuang Lü,
| | - Zhichuang Lü
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- *Correspondence: Wang Chen, ; Dongfang Ma, ; Zhichuang Lü,
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3
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Ge M, Zhong R, Sadeghnezhad E, Hakeem A, Xiao X, Wang P, Fang J. Genome-wide identification and expression analysis of magnesium transporter gene family in grape (Vitis vinifera). BMC PLANT BIOLOGY 2022; 22:217. [PMID: 35477360 PMCID: PMC9047265 DOI: 10.1186/s12870-022-03599-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 04/14/2022] [Indexed: 05/27/2023]
Abstract
BACKGROUND Magnesium ion is one of the essential mineral elements for plant growth and development, which participates in a variety of physiological and biochemical processes. Since there is no report on the research of magnesium ion transporter in grape, the study of the structure and function of magnesium ion transporters (MGT) is helpful to understand the dynamic balance mechanism of intracellular magnesium ions and their inter- or intra-cellular activities. RESULT In this study, we identified the members of MGT protein family in grape and performed the phylogenetic and expression analysis. We have identified nine VvMGT genes in grape genome, which are distributed on eight different chromosomes. Phylogenetic analysis showed that MGT family members of grapes were divided into five subfamilies and had obvious homology with Arabidopsis, maize, and pear. Based on transcriptome data from the web databases, we analyzed the expression patterns of VvMGTs at different development stages and in response to abiotic stresses including waterlogging, drought, salinity, and copper. Using qRT-PCR method, we tested the expression of grape VvMGTs under magnesium and aluminum treatments and found significant changes in VvMGTs expression. In addition, four of the MGT proteins in grape were located in the nucleus. CONCLUSION Overall, in this study we investigated the structural characteristics, evolution pattern, and expression analysis of VvMGTs in depth, which laid the foundation for further revealing the function of VvMGT genes in grape.
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Affiliation(s)
- Mengqing Ge
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Rong Zhong
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ehsan Sadeghnezhad
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Abdul Hakeem
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xin Xiao
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peipei Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jinggui Fang
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
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4
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Tang RJ, Meng SF, Zheng XJ, Zhang B, Yang Y, Wang C, Fu AG, Zhao FG, Lan WZ, Luan S. Conserved mechanism for vacuolar magnesium sequestration in yeast and plant cells. NATURE PLANTS 2022; 8:181-190. [PMID: 35087208 DOI: 10.1038/s41477-021-01087-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Magnesium (Mg2+) is an essential nutrient for all life forms. In fungal and plant cells, the majority of Mg2+ is stored in the vacuole but mechanisms for Mg2+ transport into the vacuolar store are not fully understood. Here we demonstrate that members of ancient conserved domain proteins (ACDPs) from Saccharomyces cerevisiae and Arabidopsis thaliana function in vacuolar Mg2+ sequestration that enables plant and yeast cells to cope with high levels of external Mg2+. We show that the yeast genome (as well as other fungal genomes) harbour a single ACDP homologue, referred to as MAM3, that functions specifically in vacuolar Mg2+ accumulation and is essential for tolerance to high Mg. In parallel, vacuolar ACDP homologues were identified from Arabidopsis and shown to complement the yeast mutant mam3Δ. An Arabidopsis mutant lacking one of the vacuolar ACDP homologues displayed hypersensitivity to high-Mg conditions and accumulated less Mg in the vacuole compared with the wild type. Taken together, our results suggest that conserved transporters mediate vacuolar Mg2+ sequestration in fungal and plant cells to maintain cellular Mg2+ homeostasis in response to fluctuating Mg2+ levels in the environment.
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Affiliation(s)
- Ren-Jie Tang
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Su-Fang Meng
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, State Key Laboratory for Pharmaceutical Biotechnology, College of Life Sciences, Nanjing University, Nanjing, China
| | - Xiao-Jiang Zheng
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- College of Life Sciences, Northwest University, Xi'an, China
| | - Bin Zhang
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, State Key Laboratory for Pharmaceutical Biotechnology, College of Life Sciences, Nanjing University, Nanjing, China
- College of Life Sciences, Northwest University, Xi'an, China
| | - Yang Yang
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, State Key Laboratory for Pharmaceutical Biotechnology, College of Life Sciences, Nanjing University, Nanjing, China
| | - Chao Wang
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- College of Life Sciences, Northwest University, Xi'an, China
| | - Ai-Gen Fu
- College of Life Sciences, Northwest University, Xi'an, China
| | - Fu-Geng Zhao
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, State Key Laboratory for Pharmaceutical Biotechnology, College of Life Sciences, Nanjing University, Nanjing, China
| | - Wen-Zhi Lan
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, State Key Laboratory for Pharmaceutical Biotechnology, College of Life Sciences, Nanjing University, Nanjing, China.
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.
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5
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Zhang X, Kebaara BW. Nonsense-mediated mRNA decay and metal ion homeostasis and detoxification in Saccharomyces cerevisiae. Biometals 2022; 35:1145-1156. [PMID: 36255607 PMCID: PMC9674712 DOI: 10.1007/s10534-022-00450-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/21/2022] [Indexed: 12/14/2022]
Abstract
The highly conserved Nonsense-mediated mRNA decay (NMD) pathway is a translation dependent mRNA degradation pathway. Although NMD is best known for its role in degrading mRNAs with premature termination codons (PTCs) generated during transcription, splicing, or damage to the mRNAs, NMD is now also recognized as a pathway with additional important functions. Notably, NMD precisely regulates protein coding natural mRNAs, hence controlling gene expression within several physiologically significant pathways. Such pathways affected by NMD include nutritional bio-metal homeostasis and metal ion detoxification, as well as crosstalk between these pathways. Here, we focus on the relationships between NMD and various metal homeostasis and detoxification pathways. We review the described role that the NMD pathway plays in magnesium, zinc, iron, and copper homeostasis, as well as cadmium detoxification.
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Affiliation(s)
- Xinyi Zhang
- grid.252890.40000 0001 2111 2894Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798 USA
| | - Bessie W. Kebaara
- grid.252890.40000 0001 2111 2894Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798 USA
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6
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Wing KM, Phillips MA, Baker AR, Burke MK. Consequences of Cryopreservation in Diverse Natural Isolates of Saccharomyces cerevisiae. Genome Biol Evol 2021; 12:1302-1312. [PMID: 32609330 DOI: 10.1093/gbe/evaa121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2020] [Indexed: 01/27/2023] Open
Abstract
Experimental evolution allows the observation of change over time as laboratory populations evolve in response to novel, controlled environments. Microbial evolution experiments take advantage of cryopreservation to archive experimental populations in glycerol media, creating a frozen, living "fossil" record. Prior research with Escherichia coli has shown that cryopreservation conditions can affect cell viability and that allele frequencies across the genome can change in response to a freeze-thaw event. We expand on these observations by characterizing fitness and genomic consequences of multiple freeze-thaw cycles in diploid yeast populations. Our study system is a highly recombinant Saccharomyces cerevisiae population (SGRP-4X) that harbors standing genetic variation that cryopreservation may threaten. We also investigate the four parental isogenic strains crossed to create the SGRP-4X. We measure cell viability over five consecutive freeze-thaw cycles; whereas we find that viability increases over time in the evolved recombinant populations, we observe no such viability improvements in the parental strains. We also collect genome-wide sequence data from experimental populations initially, after one freeze-thaw, and after five freeze-thaw cycles. In the recombinant evolved populations, we find a region of significant allele frequency change on chromosome 15 containing the ALR1 gene. In the parental strains, we find little evidence for new mutations. We conclude that cryopreserving yeast populations with standing genetic variation may have both phenotypic and genomic consequences, though the same cryopreservation practices may have only small impacts on populations with little or no initial variation.
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Affiliation(s)
- Kieslana M Wing
- Department of Integrative Biology, Oregon State University, Corvallis
| | - Mark A Phillips
- Department of Integrative Biology, Oregon State University, Corvallis
| | - Andrew R Baker
- Department of Integrative Biology, Oregon State University, Corvallis
| | - Molly K Burke
- Department of Integrative Biology, Oregon State University, Corvallis
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7
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Insights into the modulatory effect of magnesium on efflux mechanisms of Candida albicans reveal inhibition of ATP binding cassette multidrug transporters and dysfunctional mitochondria. Biometals 2021; 34:329-339. [PMID: 33394279 DOI: 10.1007/s10534-020-00282-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/21/2020] [Indexed: 10/22/2022]
Abstract
Candida infections pose a serious hazard to public health followed by widespread and prolonged deployment of antifungal drugs has which has led multidrug resistance (MDR) progress in prevalent human fungal pathogen, Candida albicans. Despite the fact that MDR is multifactorial phenomenon govern by several mechanisms in C. albicans, overexpression of drug efflux transporters by far remains the leading cause of MDR govern by ATP Binding Cassette (ABC) or major facilitator superfamily (MFS) transporters. Hence searching for strategies to target efflux pumps transporter still signifies a promising approach. In this study we analyzed the effect of magnesium (Mg) deprivation, on efflux pump action of C. albicans. We explored that Mg deprivation specially inhibits efflux of transporters (CaCdr1p and CaCdr2p) belonging to ABC superfamily as revealed by rhodamine 6G and Nile red accumulation. Furthermore, Mg deprivation causes mislocalization of CaCdr1p and CaCdr2p and reduced transcripts of CDR1 and CDR2 with no effect on CaMdr1p. Additionally, Mg deprivation causes depletion of ergosterol content in azole sensitive and resistant clinical matched pair of isolates Gu4/Gu5 and F2/F5 of C. albicans. Lastly, we observed that Mg deprivation impairs mitochondrial potential which could be the causal reason for abrogated efflux activity. With growing appreciation of manipulating metal homeostasis to combat MDR, inhibition of efflux activity under Mg deprivation warrants further studies to be utilized as an effective antifungal strategy.
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8
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Identification and functional analysis of the CorA/MGT/MRS2-type magnesium transporter in banana. PLoS One 2020; 15:e0239058. [PMID: 33001980 PMCID: PMC7529347 DOI: 10.1371/journal.pone.0239058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 08/28/2020] [Indexed: 01/20/2023] Open
Abstract
Magnesium (Mg) plays an irreplaceable role in plant growth and development. Mg
transporters, especially CorA/MGT/MRS2 family proteins, played a vital role in
regulating Mg content in plant cells. Although extensive work has been conducted
in model crops, such as Arabidopsis, rice, and maize, the relevant information
is scarce in tropical crops. In this study, 10 MaMRS2 genes in
banana (Musa acuminata) were isolated from its genome and
classified into five distinct clades. The putative physiochemical properties,
chromosome location, gene structure, cis-acting elements, and duplication
relationships in between these members were analyzed. Complementary experiments
revealed that three MaMRS2 gene members
(MaMRS2-1, MaMRS2-4,
MaMRS2-7), from three distinct phylogenetic branches, were
capable of restoring the function of Mg transport in Salmonella
typhimurium mutants. Semi-quantitative RT-PCR showed that
MaMRS2 genes were differentially expressed in banana
cultivar ‘Baxijiao’ (Musa spp. AAA Cavendish)
seedlings. The result was confirmed by real-time PCR analysis, in addition to
tissue specific expression, expression differences among MaMRS2
members were also observed under Mg deficiency conditions. These results showed
that Mg transporters may play a versatile role in banana growth and development,
and our work will shed light on the functional analysis of Mg transporters in
banana.
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9
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Abstract
CorA proteins belong to 2-TM-GxN family of membrane proteins, and play a major role in Mg2+ transport in prokaryotes and eukaryotic mitochondria. The selection of substrate is believed to occur via the signature motif GxN, however there is no consensus how strict this selection within the family. To answer this question, we employed fluorescence-based transport assays on three different family members, namely CorA from bacterium Thermotoga maritima, CorA from the archeon Methanocaldococcus jannaschii and ZntB from bacterium Escherichia coli, reconstituted into proteoliposomes. Our results show that all three proteins readily transport Mg2+, Co2+, Ni2+ and Zn2+, but not Al3+. Despite the similarity in cation specificity, ZntB differs from the CorA proteins, as in the former transport is stimulated by a proton gradient, but in the latter by the membrane potential, confirming the hypothesis that CorA and ZntB proteins diverged to different transport mechanisms within the same protein scaffold.
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10
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Niu H, Leng Y, Ran S, Amee M, Du D, Sun J, Chen K, Hong S. Toxicity of soil labile aluminum fractions and aluminum species in soil water extracts on the rhizosphere bacterial community of tall fescue. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 187:109828. [PMID: 31639644 DOI: 10.1016/j.ecoenv.2019.109828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Different forms of aluminum (Al) in soil can be toxic to plants and the bacterial community. In our previous study, the distribution and toxicity to plants of soil Al species and soil labile Al fractions were examined. However, the toxicity of different forms of Al on the bacterial community has not been completely studied. In this study, five soil samples (pH: 4.92, 6.17, 6.62, 6.70, 8.51) were collected from Lichuan, China. Tall fescue was planted in rhizosphere boxes with those soils for 120 days. The toxicity of soil Al species and soil labile Al fractions on the bacterial community of near-rhizosphere (NR) soils and far-rhizosphere (FR) soils were analyzed. The effect of different forms of Al on bacterial community between NR and FR soils was small, but the difference was obvious according to the different spatial distribution of samples. An individual bacterial community has eosinophilia, and most bacterial communities are tolerant of heavy metals (e.g., Cu, Zn, Cd). The toxicity of exchangeable Al has a strong effect on the bacterial community. Meanwhile, the toxicity of Al3+ to the bacterial community is strong. In this study, the key finding was that the toxicity of the Al-F- complex toward the bacterial community and plants was different. AlF2+, AlF2+, AlF3, and AlF4- are toxic for the bacterial community, and the correlation decreases with the addition of F-. This finding is of considerable significance to the treatment of acid-contaminated soil and the study of the tolerance mechanism of plants toward Al.
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Affiliation(s)
- Hong Niu
- College of Resources and Environmental Science, Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan, PR China
| | - Yifei Leng
- Key Laboratory of Aquatic Botany and Watershed Ecology & CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Shangmin Ran
- College of Resources and Environmental Science, Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan, PR China
| | - Maurice Amee
- Key Laboratory of Aquatic Botany and Watershed Ecology & CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Dongyun Du
- College of Resources and Environmental Science, Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan, PR China
| | - Jie Sun
- College of Resources and Environmental Science, Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan, PR China
| | - Ke Chen
- College of Resources and Environmental Science, Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan, PR China.
| | - Song Hong
- School of Resource and Environmental Sciences, Wuhan University, Wuhan, 430079, China.
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11
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Hanner AS, Dunworth M, Casero RA, MacDiarmid CW, Park MH. Elevation of cellular Mg 2+ levels by the Mg 2+ transporter, Alr1, supports growth of polyamine-deficient Saccharomyces cerevisiae cells. J Biol Chem 2019; 294:17131-17142. [PMID: 31548311 DOI: 10.1074/jbc.ra119.009705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/17/2019] [Indexed: 11/06/2022] Open
Abstract
The polyamines putrescine, spermidine, and spermine are required for normal eukaryotic cellular functions. However, the minimum requirement for polyamines varies widely, ranging from very high concentrations (mm) in mammalian cells to extremely low in the yeast Saccharomyces cerevisiae Yeast strains deficient in polyamine biosynthesis (spe1Δ, lacking ornithine decarboxylase, and spe2Δ, lacking SAM decarboxylase) require externally supplied polyamines, but supplementation with as little as 10-8 m spermidine restores their growth. Here, we report that culturing a spe1Δ mutant or a spe2Δ mutant in a standard polyamine-free minimal medium (SDC) leads to marked increases in cellular Mg2+ content. To determine which yeast Mg2+ transporter mediated this increase, we generated mutant strains with a deletion of SPE1 or SPE2 combined with a deletion of one of the three Mg2+ transporter genes, ALR1, ALR2, and MNR2, known to maintain cytosolic Mg2+ concentration. Neither Alr2 nor Mnr2 was required for increased Mg2+ accumulation, as all four double mutants (spe1Δ alr2Δ, spe2Δ alr2Δ, spe1Δ mnr2Δ, and spe2Δ mnr2Δ) exhibited significant Mg2+ accumulation upon polyamine depletion. In contrast, a spe2Δ alr1Δ double mutant cultured in SDC exhibited little increase in Mg2+ content and displayed severe growth defects compared with single mutants alr1Δ and spe2Δ under polyamine-deficient conditions. These findings indicate that Alr1 is required for the up-regulation of the Mg2+ content in polyamine-depleted cells and suggest that elevated Mg2+ can support growth of polyamine-deficient S. cerevisiae mutants. Up-regulation of cellular polyamine content in a Mg2+-deficient alr1Δ mutant provided further evidence for a cross-talk between Mg2+ and polyamine metabolism.
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Affiliation(s)
- Ashleigh S Hanner
- Molecular and Cellular Biochemistry Section, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Matthew Dunworth
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at The Johns Hopkins University, Baltimore, Maryland 21287
| | - Robert A Casero
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at The Johns Hopkins University, Baltimore, Maryland 21287
| | - Colin W MacDiarmid
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706
| | - Myung Hee Park
- Molecular and Cellular Biochemistry Section, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
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12
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Genome-wide analysis of magnesium transporter genes in Solanum lycopersicum. Comput Biol Chem 2019; 80:498-511. [DOI: 10.1016/j.compbiolchem.2019.05.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/21/2019] [Accepted: 05/29/2019] [Indexed: 11/18/2022]
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13
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Prasad D, Verma N, Bakshi M, Narayan OP, Singh AK, Dua M, Johri AK. Functional Characterization of a Magnesium Transporter of Root Endophytic Fungus Piriformospora indica. Front Microbiol 2019; 9:3231. [PMID: 30687249 PMCID: PMC6333687 DOI: 10.3389/fmicb.2018.03231] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/12/2018] [Indexed: 12/18/2022] Open
Abstract
Magnesium (Mg) is a crucial macronutrient required for the regular growth of plants. Here we report the identification, isolation and functional characterization of Mg-transporter PiMgT1 in root endophytic fungus Piriformospora indica. We also report the role of P. indica in the improvement of the Mg nutrition of the plant particularly under Mg deficiency condition. Protein BLAST (BLASTp) for conserved domains analysis showed that PiMgT1 belong to CorA like protein family of bacteria. We have also observed the presence of conserved 'GMN' signature sequence which suggests that PiMgT1 belongs to Mg transporter family. Phylogenetic analysis revealed that PiMgT1 clustered among fungal CorA family members nearer to basidiomycetes. Functionality of PiMgT1 was confirmed by complementation of a yeast magnesium transporter mutant CM66. We have observed that PiMgT1 restored the growth of mutant and showed comparable growth with that of WT. We found statistically significant (p < 0.05) two fold increase in the total intracellular Mg content of mutant complemented with PiMgT1 as compared to the mutant. These observations suggest that PiMgT1 is actively involved in Mg uptake by the fungus and may be helping in the nutritional status of the host plant.
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Affiliation(s)
- Durga Prasad
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Nidhi Verma
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Madhunita Bakshi
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | | | - Alok Kumar Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Meenakshi Dua
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Atul Kumar Johri
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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Ishijima S, Manabe Y, Shinkawa Y, Hotta A, Tokumasu A, Ida M, Sagami I. The homologous Arabidopsis MRS2/MGT/CorA-type Mg2+ channels, AtMRS2-10 and AtMRS2-1 exhibit different aluminum transport activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2184-2191. [DOI: 10.1016/j.bbamem.2018.08.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/24/2018] [Accepted: 08/29/2018] [Indexed: 11/30/2022]
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15
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Abstract
A wide variety of factors are required for the conversion of pre-tRNA molecules into the mature tRNAs that function in translation. To identify factors influencing tRNA biogenesis, we previously performed a screen for strains carrying mutations that induce lethality when combined with a sup61-T47:2C allele, encoding a mutant form of [Formula: see text]. Analyzes of two complementation groups led to the identification of Tan1 as a protein involved in formation of the modified nucleoside N4-acetylcytidine (ac4C) in tRNA and Bud13 as a factor controlling the levels of ac4C by promoting TAN1 pre-mRNA splicing. Here, we describe the remaining complementation groups and show that they include strains with mutations in genes for known tRNA biogenesis factors that modify (DUS2, MOD5 and TRM1), transport (LOS1), or aminoacylate (SES1) [Formula: see text]. Other strains carried mutations in genes for factors involved in rRNA/mRNA synthesis (RPA49, RRN3 and MOT1) or magnesium uptake (ALR1). We show that mutations in not only DUS2, LOS1 and SES1 but also in RPA49, RRN3 and MOT1 cause a reduction in the levels of the altered [Formula: see text]. These results indicate that Rpa49, Rrn3 and Mot1 directly or indirectly influence [Formula: see text] biogenesis.
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Affiliation(s)
- Fu Xu
- a Department of Molecular Biology , Umeå University , Umeå , Sweden
| | - Yang Zhou
- a Department of Molecular Biology , Umeå University , Umeå , Sweden
| | - Anders S Byström
- a Department of Molecular Biology , Umeå University , Umeå , Sweden
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Li H, Liu C, Zhou L, Zhao Z, Li Y, Qu M, Huang K, Zhang L, Lu Y, Cao M, Gao S, Zhang S. Molecular and functional characterization of the magnesium transporter gene ZmMGT12 in maize. Gene 2018; 665:167-173. [PMID: 29702186 DOI: 10.1016/j.gene.2018.04.068] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 04/04/2018] [Accepted: 04/23/2018] [Indexed: 11/30/2022]
Abstract
Magnesium (Mg) is an essential mineral element for normal plant growth and development, and the CorA/MRS2/MGT-type Mg transporters play a significant role in maintaining Mg homeostasis in plants. In total, 12 maize CorA-like Mg2+ transporters have been identified, but none of them had been functionally characterized. Accordingly, we cloned and functionally characterized ZmMGT12 from the maize CorA-like gene family. ZmMGT12 exhibited the structure typical of Mg2+ transporters, i.e., two conserved TM domains and a GMN tripeptide motif. ZmMGT12, Arabidopsis AtMGT6, and rice OsMRS2-6 shared high protein sequence identity and thus clustered in the same phylogenetic branch, suggesting that they could be homologs. A functional complementation assay in the Salmonella typhimurium MM281 mutant indicated that ZmMGT12 possessed Mg2+ transport ability. ZmMGT12 was expressed in roots, stems, and leaves, with the highest expression in leaves. Moreover, ZmMGT12 expression was induced by light and exhibited a circadian expression pattern. In addition, the expression level of ZmMGT12 in leaf tissue was related to chlorophyll synthesis. Overexpression of ZmMGT12 in Arabidopsis caused no phenotypic change in transgenic plants, including in fresh shoot weight, chlorophyll content, shoot Mg2+ content, and chloroplast Mg2+ content. Together, these results suggest that ZmMGT12 is a Mg2+ transporter and may play a role in Mg transport into chloroplasts.
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Affiliation(s)
- Hongyou Li
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China; Research Center of Buckwheat Industry Technology, Guizhou Normal University, Guiyang 550001, China
| | - Chan Liu
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Lina Zhou
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhuo Zhao
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Yihong Li
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Min Qu
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Kaifeng Huang
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Lu Zhang
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Yanli Lu
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Moju Cao
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Shibin Gao
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Suzhi Zhang
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest China of Agricultural Department, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
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Tekarslan-Sahin SH, Alkim C, Sezgin T. Physiological and transcriptomic analysis of a salt-resistant Saccharomyces cerevisiae mutant obtained by evolutionary engineering. Bosn J Basic Med Sci 2018; 18:55-65. [PMID: 28954203 PMCID: PMC5826675 DOI: 10.17305/bjbms.2017.2250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/07/2017] [Accepted: 08/08/2017] [Indexed: 12/19/2022] Open
Abstract
Salt-resistant yeast strains are highly demanded by industry due to the exposure of yeast cells to high concentrations of salt, in various industrial bioprocesses. The aim of this study was to perform a physiological and transcriptomic analysis of a salt-resistant Saccharomyces cerevisiae (S. cerevisiae) mutant generated by evolutionary engineering. NaCl-resistant S. cerevisiae strains were obtained by ethyl methanesulfonate (EMS) mutagenesis followed by successive batch cultivations in the presence of gradually increasing NaCl concentrations, up to 8.5% w/v of NaCl (1.45 M). The most probable number (MPN) method, high-performance liquid chromatography (HPLC), and glucose oxidase/peroxidase method were used for physiological analysis, while Agilent yeast DNA microarray systems were used for transcriptome analysis. NaCl-resistant mutant strain T8 was highly cross-resistant to LiCl and highly sensitive to AlCl3. In the absence of NaCl stress, T8 strain had significantly higher trehalose and glycogen levels compared to the reference strain. Global transcriptome analysis by means of DNA microarrays showed that the genes related to stress response, carbohydrate transport, glycogen and trehalose biosynthesis, as well as biofilm formation, were upregulated. According to gene set enrichment analysis, 548 genes were upregulated and 22 downregulated in T8 strain, compared to the reference strain. Among the 548 upregulated genes, the highest upregulation was observed for the FLO11 (MUC1) gene (92-fold that of the reference strain). Overall, evolutionary engineering by chemical mutagenesis and increasing NaCl concentrations is a promising approach in developing industrial strains for biotechnological applications.
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Affiliation(s)
- Seyma Hande Tekarslan-Sahin
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, Istanbul, Turkey; Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (ITU-MOBGAM), Istanbul Technical University, Istanbul, Turkey; Department of Pharmaceutical Technology, Faculty of Pharmacy, Istanbul University, Istanbul, Turkey.
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Decreased aluminium tolerance in the growth of Saccharomyces cerevisiae with SSO2 gene disruption. Biometals 2018; 31:203-215. [PMID: 29383568 DOI: 10.1007/s10534-017-0069-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 11/20/2017] [Indexed: 01/06/2023]
Abstract
Aluminium ions inhibit growth of the budding yeast Saccharomyces cerevisiae. Disruption of the SSO2 gene increased the susceptibility to aluminium. Sso2p belongs to the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) family. SSO2 has one paralogue, SSO1, which encodes Sso1p. The SNARE complex containing Sso1/2p plays a role in the recognition of plasma membrane targeted vesicle transport. The susceptibility to aluminium stress was not increased in the Δsso1 strain. The phenotype of aluminium ion influx between the wild-type and Δsso2 strains was not different, suggesting that Sso2p was involved in the elimination of cellular aluminium. However, the cellular lipid constitution of Δsso2 was richer in unsaturated fatty acids than the wild type, indicating that Sso2p is associated with lipid homeostasis of the plasma membrane. Aluminium treatment increased the production of reactive oxygen species (ROS) during proliferation. ROS production was increased in the Δsso2 strain after 3 h of aluminium treatment compared with the wild type. These results suggested that Sso2p plays a role in maintaining the lipid composition of the plasma membrane and the increase in unsaturated fatty acids amplified the production of ROS in the acute phase of aluminium stress. ROS derived from aluminium stress inhibited growth and resulted in the susceptibility of the Δsso2 strain.
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Magnesium uptake by connecting fluid-phase endocytosis to an intracellular inorganic cation filter. Nat Commun 2017; 8:1879. [PMID: 29192218 PMCID: PMC5709425 DOI: 10.1038/s41467-017-01930-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 10/24/2017] [Indexed: 12/03/2022] Open
Abstract
Cells acquire free metals through plasma membrane transporters. But, in natural settings, sequestering agents often render metals inaccessible to transporters, limiting metal bioavailability. Here we identify a pathway for metal acquisition, allowing cells to cope with this situation. Under limited bioavailability of Mg2+, yeast cells upregulate fluid-phase endocytosis and transfer solutes from the environment into their vacuole, an acidocalcisome-like compartment loaded with highly concentrated polyphosphate. We propose that this anionic inorganic polymer, which is an avid chelator of Mg2+, serves as an immobilized cation filter that accumulates Mg2+ inside these organelles. It thus allows the vacuolar exporter Mnr2 to efficiently transfer Mg2+ into the cytosol. Leishmania parasites also employ acidocalcisomal polyphosphate to multiply in their Mg2+-limited habitat, the phagolysosomes of inflammatory macrophages. This suggests that the pathway for metal uptake via endocytosis, acidocalcisomal polyphosphates and export into the cytosol, which we term EAPEC, is conserved. Metal bioavailability is frequently limited by sequestering agents which makes them inaccessible to cells. Here the authors show that cells can increase Mg2+ uptake via fluid phase endocytosis and accumulate this metal in their vacuole loaded with polyphosphate, and later can be exported to the cytosol.
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Zhao XQ, Bao XM, Wang C, Xiao ZY, Hu ZM, Zheng CL, Shen RF. Hydroxy-Al and cell-surface negativity are responsible for the enhanced sensitivity of Rhodotorula taiwanensis to aluminum by increased medium pH. Arch Microbiol 2017; 199:1185-1194. [PMID: 28540503 DOI: 10.1007/s00203-017-1387-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 05/04/2017] [Accepted: 05/15/2017] [Indexed: 11/24/2022]
Abstract
Aluminum (Al) is ubiquitous and toxic to microbes. High Al3+ concentration and low pH are two key factors responsible for Al toxicity, but our present results contradict this idea. Here, an Al-tolerant yeast strain Rhodotorula taiwanensis RS1 was incubated in glucose media containing Al with a continuous pH gradient from pH 3.1-4.2. The cells became more sensitive to Al and accumulated more Al when pH increased. Calculations using an electrostatic model Speciation Gouy Chapman Stern indicated that, the increased Al sensitivity of cells was associated with AlOH2+ and Al(OH) 2+ rather than Al3+. The alcian blue (a positively charged dye) adsorption and zeta potential determination of cell surface indicated that, higher pH than 3.1 increased the negative charge and Al adsorption at the cell surface. Taken together, the enhanced sensitivity of R. taiwanensis RS1 to Al from pH 3.1-4.2 was associated with increased hydroxy-Al and cell-surface negativity.
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Affiliation(s)
- Xue Qiang Zhao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China
| | - Xue Min Bao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China.,School of Environment and Energy, Inner Mongolia University of Science and Technology, 014010, Baotou, China
| | - Chao Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China
| | - Zuo Yi Xiao
- School of Environment and Energy, Inner Mongolia University of Science and Technology, 014010, Baotou, China
| | - Zhen Min Hu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Chun Li Zheng
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China. .,School of Life Science and Technology, Inner Mongolia University of Science and Technology, 014010, Baotou, China.
| | - Ren Fang Shen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China.
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Johansson MJO. Determining if an mRNA is a Substrate of Nonsense-Mediated mRNA Decay in Saccharomyces cerevisiae. Methods Mol Biol 2017; 1507:169-177. [PMID: 27832540 DOI: 10.1007/978-1-4939-6518-2_13] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) is a conserved eukaryotic quality control mechanism which triggers decay of mRNAs harboring premature translation termination codons. In this chapter, I describe methods for monitoring the influence of NMD on mRNA abundance and decay rates in Saccharomyces cerevisiae. The descriptions include detailed methods for growing yeast cells, total RNA isolation, and Northern blotting. Although the chapter focuses on NMD, the methods can be easily adapted to assess the effect of other mRNA decay pathways.
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Nestedness in Arbuscular Mycorrhizal Fungal Communities along Soil pH Gradients in Early Primary Succession: Acid-Tolerant Fungi Are pH Generalists. PLoS One 2016; 11:e0165035. [PMID: 27755574 PMCID: PMC5068792 DOI: 10.1371/journal.pone.0165035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 10/05/2016] [Indexed: 12/20/2022] Open
Abstract
Soil acidity is a major constraint on plant productivity. Arbuscular mycorrhizal (AM) fungi support plant colonization in acidic soil, but soil acidity also constrains fungal growth and diversity. Fungi in extreme environments generally evolve towards specialists, suggesting that AM fungi in acidic soil are acidic-soil specialists. In our previous surveys, however, some AM fungi detected in strongly acidic soils could also be detected in a soil with moderate pH, which raised a hypothesis that the fungi in acidic soils are pH generalists. To test the hypothesis, we conducted a pH-manipulation experiment and also analyzed AM fungal distribution along a pH gradient in the field using a synthesized dataset of the previous and recent surveys. Rhizosphere soils of the generalist plant Miscanthus sinensis were collected both from a neutral soil and an acidic soil, and M. sinensis seedlings were grown at three different pH. For the analysis of field communities, rhizosphere soils of M. sinensis were collected from six field sites across Japan, which covered a soil pH range of 3.0-7.4, and subjected to soil trap culture. AM fungal community compositions were determined based on LSU rDNA sequences. In the pH-manipulation experiment the acidification of medium had a significant impact on the compositions of the community from the neutral soil, but the neutralization of the medium had no effect on those of the community from the acidic soil. Furthermore, the communities in lower -pH soils were subsets of (nested in) those in higher-pH soils. In the field communities a significant nestedness pattern was observed along the pH gradient. These observations suggest that the fungi in strongly acidic soils are pH generalists that occur not only in acidic soil but also in wide ranges of soil pH. Nestedness in AM fungal community along pH gradients may have important implications for plant community resilience and early primary succession after disturbance in acidic soils.
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Magnesium Uptake by CorA Transporters Is Essential for Growth, Development and Infection in the Rice Blast Fungus Magnaporthe oryzae. PLoS One 2016; 11:e0159244. [PMID: 27416318 PMCID: PMC4945025 DOI: 10.1371/journal.pone.0159244] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/29/2016] [Indexed: 11/29/2022] Open
Abstract
Magnaporthe oryzae, the causative organism of rice blast, infects cereal crops and grasses at various stages of plant development. A comprehensive understanding of its metabolism and the implications on pathogenesis is necessary for countering this devastating crop disease. We present the role of the CorA magnesium transporters, MoAlr2 and MoMnr2, in development and pathogenicity of M. oryzae. The MoALR2 and MoMNR2 genes individually complement the Mg2+ uptake defects of a S. cerevisiae CorA transporter double mutant. MoALR2 and MoMNR2 respond to extracellular Mg2+ and Ca2+ levels and their expression is elevated under Mg2+ scarce conditions. RNA silencing mediated knockdown of MoALR2 (WT+siALR2, Δmnr2+siALR2 and ALR2+MNR2 simultaneous silencing) drastically alters intracellular cation concentrations and sensitivity to metal ions. MoALR2 silencing is detrimental to vegetative growth and surface hydrophobicity of mycelia, and the transformants display loss of cell wall integrity. MoALR2 is required for conidiogenesis and appressorium development, and is essential for infection. Investigation of knockdown transformants reveal low cAMP levels and altered expression of genes encoding proteins involved in MoMps1 cell wall integrity and cAMP MoPmk1 driven MAP Kinase signaling pathways. In contrast to MoALR2 knockdowns, the MoMNR2 deletion (Δmnr2) shows increased sensitivity to CorA inhibitors as well as altered cation sensitivity, but has limited effect on surface hydrophobicity and severity of plant infection. Interestingly, MoALR2 expression is elevated in Δmnr2. Impairment of development and infectivity of knockdown transformants and altered intracellular cation composition suggest that CorA transporters are essential for Mg2+ homeostasis within the cell, and are crucial to maintaining normal gene expression associated with cell structure, signal transduction and surface hydrophobicity in M. oryzae. We suggest that CorA transporters, and especially MoALR2, constitute an attractive target for the development of antifungal agents against this pathogen.
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Sade H, Meriga B, Surapu V, Gadi J, Sunita MSL, Suravajhala P, Kavi Kishor PB. Toxicity and tolerance of aluminum in plants: tailoring plants to suit to acid soils. Biometals 2016; 29:187-210. [PMID: 26796895 DOI: 10.1007/s10534-016-9910-z] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 01/14/2016] [Indexed: 10/22/2022]
Abstract
Aluminum (Al) stress is one of the serious limiting factors in plant productivity in acidic soils, which constitute about 50 % of the world's potentially arable lands and causes anywhere between 25 and 80 % of yield losses depending upon the species. The mechanism of Al toxicity and tolerance has been examined in plants, which is vital for crop improvement and enhanced food production in the future. Two mechanisms that facilitate Al tolerance in plants are Al exclusion from the roots and the ability to tolerate Al in the symplast or both. Although efforts have been made to unravel Al-resistant factors, many aspects remain unclear. Certain gene families such as MATE, ALMT, ASR, and ABC transporters have been implicated in some plants for resistance to Al which would enhance the opportunities for creating crop plants suitable to grow in acidic soils. Though QTLs have been identified related to Al-tolerance, no crop plant that is tolerant to Al has been evolved so far using breeding or molecular approaches. The remarkable changes that plants experience at the physiological, biochemical and molecular level under Al stress, the vast array of genes involved in Al toxicity-tolerance, the underlying signaling events and the holistic image of the molecular regulation, and the possibility of creating transgenics for Al tolerance are discussed in this review.
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Affiliation(s)
- Hemalatha Sade
- Department of Biochemistry, S.V. University, Tirupati, 517 502, India
| | - Balaji Meriga
- Department of Biochemistry, S.V. University, Tirupati, 517 502, India.
| | | | - Jogeswar Gadi
- AU College of Pharmaceutical Sciences, Andhra University, Visakhapatnam, 530 017, India
| | - M S L Sunita
- Department of Genetics, Osmania University, Hyderabad, 500 007, India
| | | | - P B Kavi Kishor
- Department of Genetics, Osmania University, Hyderabad, 500 007, India
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Barros de Souza R, Silva RK, Ferreira DS, de Sá Leitão Paiva Junior S, de Barros Pita W, de Morais Junior MA. Magnesium ions in yeast: setting free the metabolism from glucose catabolite repression. Metallomics 2016; 8:1193-1203. [DOI: 10.1039/c6mt00157b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Ezaki B, Higashi A, Nanba N, Nishiuchi T. An S-adenosyl Methionine Synthetase (SAMS) Gene from Andropogon virginicus L. Confers Aluminum Stress Tolerance and Facilitates Epigenetic Gene Regulation in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2016; 7:1627. [PMID: 27877178 PMCID: PMC5099669 DOI: 10.3389/fpls.2016.01627] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 10/14/2016] [Indexed: 05/22/2023]
Abstract
Candidate clones which conferred Al tolerance to yeast transformants (TFs) were obtained from a cDNA library derived from a highly Al-tolerant poaceae, Andropogon virginicus L. One such clone, AL3A-4, encoded an S-adenosyl methionine synthetase (SAMS) gene. A full-length cDNA was obtained by 5'-RACE, designated AvSAMS1, and introduced into Arabidopsis thaliana to investigate its biological functions under Al stress. Two TF plant lines both showed higher tolerance than the Col-0 ecotype (non-TF) not only for Al stress, but also for Cu, Pb, Zn and diamide stresses, suggesting the AvSAMS1 was a multiple tolerance gene. More than 40 of A. thaliana Al response-genes (Al induced genes and Al repressed genes) were selected from microarray results and then used for investigations of DNA or histone methylation status under Al stress in Col-0 and the AvSAMS1 TF line. The results indicated that Al stress caused alterations of methylation status in both DNA and histone H3 (H3K4me3 and H3K9me3) and that these alterations were different between the AvSAMS1 TF and Col-0, suggesting the differences were AvSAMS1-gene dependent. These results suggested the existence of AvSAMS1-related epigenetic gene-regulation under Al stress.
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Affiliation(s)
- Bunichi Ezaki
- Institute of Plant Science and Resources, Okayama UniversityKurashiki, Japan
- *Correspondence: Bunichi Ezaki
| | - Aiko Higashi
- Institute of Plant Science and Resources, Okayama UniversityKurashiki, Japan
| | - Norie Nanba
- Institute of Plant Science and Resources, Okayama UniversityKurashiki, Japan
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Mariano-da-Silva S, Ducatti RDB, Murari IP, Pilon F. Magnesium capability to attenuate the toxicity of aluminum on the growth of Saccharomyces cerevisiae PE-2. BRAZILIAN JOURNAL OF FOOD TECHNOLOGY 2016. [DOI: 10.1590/1981-6723.9415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Summary The magnesium (Mg) capability to attenuate the toxicity of aluminum (Al) for the trehalose content, anaerobic growth, viability and budding rate of Saccharomyces cerevisiae, was studied in this work. Fermentations were carried out in triplicate with sterilized and diluted sugar cane media (4% total reducing sugars/pH 4.0) containing different Al (0.0, 50, 100 and 150 mg L-1) and Mg (0.0, 50 and 100 mg L-1) concentrations. The media were inoculated with 1 mL of 1% (wet basis) yeast suspension and incubated at 30ºC, 70 rpm for 20 hours in orbital shaker. At specific times during fermentation portions of cell suspension were taken out and the biomass concentration, yeast viability, budding rate and trehalose content on cells determined. The increase of Al levels, from 0.0 up to 150 mg L-1, showed a reduction on the yeast growth of approximately 95%, 55% and 18% as Mg increased from 0.0 to 50 and 100 mg L-1, respectively. The trehalose content experienced its lowest reduction when greater amounts of Mg were added to the fermentation process. Cell viability showed greater reductions as the content of Al in the media increased. Magnesium effectively protected yeast cells against the deleterious effects of Al on cell growth, viability, budding and trehalose content.
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Affiliation(s)
| | | | | | - Fabio Pilon
- Universidade Federal da Fronteira Sul, Brazil
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Abstract
Calcium is an essential cation for a cell. This cation participates in the regulation of numerous processes in either prokaryotes or eukaryotes, from bacteria to humans. Saccharomyces cerevisiae has served as a model organism to understand calcium homeostasis and calcium-dependent signaling in fungi. In this chapter it will be reviewed known and predicted transport mechanisms that mediate calcium homeostasis in the yeast. How and when calcium enters the cell, how and where it is stored, when is reutilized, and finally secreted to the environment to close the cycle. As a second messenger, maintenance of a controlled free intracellular calcium concentration is important for mediating transcriptional regulation. Many environmental stimuli modify the concentration of cytoplasmic free calcium generating the "calcium signal". This is sensed and transduced through the calmodulin/calcineurin pathway to a transcription factor, named calcineurin-responsive zinc finger, CRZ, also known as "crazy", to mediate transcriptional regulation of a large number of genes of diverse pathways including a negative feedback regulation of the calcium homeostasis system.
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Affiliation(s)
- Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, 9, 28040, Madrid, Spain.
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Xu XF, Wang B, Lou Y, Han WJ, Lu JY, Li DD, Li LG, Zhu J, Yang ZN. Magnesium Transporter 5 plays an important role in Mg transport for male gametophyte development in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:925-36. [PMID: 26478267 DOI: 10.1111/tpj.13054] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/22/2015] [Accepted: 10/01/2015] [Indexed: 05/27/2023]
Abstract
During anther development the male gametophyte develops inside the locule and the tapetal cells provide all nutrients for its development. Magnesium Transporter 5 (MGT5) is a member of the MGT family and has dual functions of Mg export and import. Here, we show that male gametophyte mitosis and intine formation are defective in a mgt5 mutant. The transient expression of GFP-MGT5 revealed that MGT5 is localized in the plasma membrane. These findings suggest that in the male gametophyte MGT5 plays a role in importing Mg from the locule and that Mg is essential for male gametophyte development. The expression of MGT5 in the knockout ABORTED MICROSPORES (AMS) mutant (AMS being an essential regulator of tapetum) is tremendously reduced. Chromatin immunoprecipitation and mobility shift assay experiments demonstrated that AMS can directly bind the promoter of MGT5. An immunoelectron microscopy assay revealed that MGT5-His is localized to the plasma membrane of the tapetum. These findings suggest that AMS directly regulates MGT5 in the tapetum and thus induces export of Mg into the locule. The mgt5 plant exhibits severe male sterility while the expression of MGT5 under the tapetum-specific promoter A9 partly rescued mgt5 fertility. mgt5 fertility was restored under high-Mg conditions. These findings suggest that the mgt5 tapetum still has the ability to export Mg and that a sufficient supply of Mg from the tapetum can improve the importation of Mg in the mgt5 male gametophyte. Therefore, MGT5 plays an important role in Mg transport from the tapetum to the microspore.
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Affiliation(s)
- Xiao-Feng Xu
- Department of Molecular and Cell Biology, School of Life Science and Technology, Tongji University, Shanghai, 200092, China
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Bo Wang
- Department of Molecular and Cell Biology, School of Life Science and Technology, Tongji University, Shanghai, 200092, China
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Yue Lou
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Wen-Jian Han
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Jie-Yang Lu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Dan-Dan Li
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Le-Gong Li
- College of Life Sciences, Capital Normal University, Beijing, 100048, China
| | - Jian Zhu
- Department of Molecular and Cell Biology, School of Life Science and Technology, Tongji University, Shanghai, 200092, China
| | - Zhong-Nan Yang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
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Zhang J, Zhang L, Qiu J, Nian H. Isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis of Cryptococcus humicola response to aluminum stress. J Biosci Bioeng 2015; 120:359-63. [DOI: 10.1016/j.jbiosc.2015.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 02/05/2015] [Accepted: 02/07/2015] [Indexed: 02/03/2023]
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Kobayashi NI, Tanoi K. Critical Issues in the Study of Magnesium Transport Systems and Magnesium Deficiency Symptoms in Plants. Int J Mol Sci 2015; 16:23076-93. [PMID: 26404266 PMCID: PMC4613352 DOI: 10.3390/ijms160923076] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 08/27/2015] [Accepted: 09/06/2015] [Indexed: 12/16/2022] Open
Abstract
Magnesium (Mg) is the second most abundant cation in living cells. Over 300 enzymes are known to be Mg-dependent, and changes in the Mg concentration significantly affects the membrane potential. As Mg becomes deficient, starch accumulation and chlorosis, bridged by the generation of reactive oxygen species, are commonly found in Mg-deficient young mature leaves. These defects further cause the inhibition of photosynthesis and finally decrease the biomass. Recently, transcriptome analysis has indicated the transcriptinal downregulation of chlorophyll apparatus at the earlier stages of Mg deficiency, and also the potential involvement of complicated networks relating to hormonal signaling and circadian oscillation. However, the processes of the common symptoms as well as the networks between Mg deficiency and signaling are not yet fully understood. Here, for the purpose of defining the missing pieces, several problems are considered and explained by providing an introduction to recent reports on physiological and transcriptional responses to Mg deficiency. In addition, it has long been unclear whether the Mg deficiency response involves the modulation of Mg2+ transport system. In this review, the current status of research on Mg2+ transport and the relating transporters are also summarized. Especially, the rapid progress in physiological characterization of the plant MRS2 gene family as well as the fundamental investigation about the molecular mechanism of the action of bacterial CorA proteins are described.
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Affiliation(s)
- Natsuko I Kobayashi
- Graduate School of Agricultural and Life Sciences, the University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
| | - Keitaro Tanoi
- Graduate School of Agricultural and Life Sciences, the University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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Kern B, Jain U, Utsch C, Otto A, Busch B, Jiménez-Soto L, Becher D, Haas R. Characterization of Helicobacter pylori VacA-containing vacuoles (VCVs), VacA intracellular trafficking and interference with calcium signalling in T lymphocytes. Cell Microbiol 2015; 17:1811-32. [PMID: 26078003 DOI: 10.1111/cmi.12474] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 05/27/2015] [Accepted: 06/11/2015] [Indexed: 12/11/2022]
Abstract
The human pathogen Helicobacter pylori colonizes half of the global population. Residing at the stomach epithelium, it contributes to the development of diseases such as gastritis, duodenal and gastric ulcers, and gastric cancer. A major factor is the secreted vacuolating toxin VacA, which forms anion-selective channels in the endosome membrane that cause the compartment to swell, but the composition and purpose of the resulting VacA-containing vacuoles (VCVs) are still unknown. VacA exerts influence on the host immune response in various ways, including inhibition of T-cell activation and proliferation and suppression of the host immune response. In this study, for the first time the composition of VCVs from T cells was comprehensively analysed to investigate VCV function. VCVs were successfully isolated via immunomagnetic separation, and the purified vacuoles were analysed by mass spectrometry. We detected a set of 122 VCV-specific proteins implicated among others in immune response, cell death and cellular signalling processes, all of which VacA is known to influence. One of the individual proteins studied further was stromal interaction molecule (STIM1), a calcium sensor residing in the endoplasmic reticulum (ER) that is important in store-operated calcium entry. Live cell imaging microscopy data demonstrated colocalization of VacA with STIM1 in the ER and indicated that VacA may interfere with the movement of STIM1 towards the plasma membrane-localized calcium release activated calcium channel protein ORAI1 in response to Ca(2+) store depletion. Furthermore, VacA inhibited the increase of cytosolic-free Ca(2+) in the Jurkat E6-1 T-cell line and human CD4(+) T cells. The presence of VacA in the ER and its trafficking to the Golgi apparatus was confirmed in HeLa cells, identifying these two cellular compartments as novel VacA target structures.
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Affiliation(s)
- Beate Kern
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Utkarsh Jain
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Ciara Utsch
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Andreas Otto
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Greifswald, Germany
| | - Benjamin Busch
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Luisa Jiménez-Soto
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Dörte Becher
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Greifswald, Germany
| | - Rainer Haas
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany.,German Center for Infection Research (DZIF), Munich, Germany
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Milne N, Luttik MAH, Cueto Rojas HF, Wahl A, van Maris AJA, Pronk JT, Daran JM. Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae. Metab Eng 2015; 30:130-140. [PMID: 26037463 DOI: 10.1016/j.ymben.2015.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/18/2015] [Accepted: 05/21/2015] [Indexed: 12/31/2022]
Abstract
In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential platform for production of nitrogen-containing chemicals, uptake and assimilation of ammonium requires 1 ATP per incorporated NH3. Urea assimilation by this yeast is more energy efficient but still requires 0.5 ATP per NH3 produced. To decrease ATP costs for nitrogen assimilation, the S. cerevisiae gene encoding ATP-dependent urease (DUR1,2) was replaced by a Schizosaccharomyces pombe gene encoding ATP-independent urease (ure2), along with its accessory genes ureD, ureF and ureG. Since S. pombe ure2 is a Ni(2+)-dependent enzyme and Saccharomyces cerevisiae does not express native Ni(2+)-dependent enzymes, the S. pombe high-affinity nickel-transporter gene (nic1) was also expressed. Expression of the S. pombe genes into dur1,2Δ S. cerevisiae yielded an in vitro ATP-independent urease activity of 0.44±0.01 µmol min(-1) mg protein(-1) and restored growth on urea as sole nitrogen source. Functional expression of the Nic1 transporter was essential for growth on urea at low Ni(2+) concentrations. The maximum specific growth rates of the engineered strain on urea and ammonium were lower than those of a DUR1,2 reference strain. In glucose-limited chemostat cultures with urea as nitrogen source, the engineered strain exhibited an increased release of ammonia and reduced nitrogen content of the biomass. Our results indicate a new strategy for improving yeast-based production of nitrogen-containing chemicals and demonstrate that Ni(2+)-dependent enzymes can be functionally expressed in S. cerevisiae.
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Affiliation(s)
- N Milne
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - M A H Luttik
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - H F Cueto Rojas
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - A Wahl
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - A J A van Maris
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - J T Pronk
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - J M Daran
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
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Li J, Huang Y, Tan H, Yang X, Tian L, Luan S, Chen L, Li D. An endoplasmic reticulum magnesium transporter is essential for pollen development in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 231:212-20. [PMID: 25576006 DOI: 10.1016/j.plantsci.2014.12.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/11/2014] [Accepted: 12/08/2014] [Indexed: 05/21/2023]
Abstract
Magnesium is one of the essential macro-elements for plant growth and development, participated in photosynthesis and various metabolic processes. The Mg-transport abilities of the AtMGT (Magnesium Transporter) genes were identified in bacteria or yeast mutant system. In our previous studies, both the AtMGT5 and AtMGT9 were found essential for pollen development in Arabidopsis. Here we report another AtMGT member, AtMGT4, which was localized to the endoplasmic reticulum, was essential for pollen development as well. AtMGT4 expressed notably in pollen grains from bicellular pollen stage to mature pollen stage. A T-DNA insertional mutant of the gene, named mgt4-1, showed pollen abortive phenotype, thus we could not get any homozygous mutant from progenies of self-crossed +/mgt4-1 plants. Meanwhile, nearly half of pollens in AtMGT4-RNAi transgenic lines were sterile, consistent with the phenotype of +/mgt4-1 mutant. Transgenic plants expressing AtMGT4 in the mgt4-1 background could recover the pollen fertility to the wild type. Together, our findings demonstrated that the disruption of AtMGT4 in Arabidopsis could cause a defect of pollen development. The visible pollen abortion appeared at bicellular pollen stage in +/mgt4-1.
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Affiliation(s)
- Jian Li
- College of Life Sciences, Hunan Normal University, Changsha 410081, PR China
| | - Yuan Huang
- College of Life Sciences, Hunan Normal University, Changsha 410081, PR China
| | - Hong Tan
- College of Life Sciences, Hunan Normal University, Changsha 410081, PR China
| | - Xiao Yang
- College of Life Sciences, Hunan Normal University, Changsha 410081, PR China
| | - Lianfu Tian
- College of Life Sciences, Hunan Normal University, Changsha 410081, PR China
| | - Sheng Luan
- NJU-NJFU Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing 210093, PR China; Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Liangbi Chen
- College of Life Sciences, Hunan Normal University, Changsha 410081, PR China.
| | - Dongping Li
- College of Life Sciences, Hunan Normal University, Changsha 410081, PR China.
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35
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A novel mitochondrial carrier protein Mme1 acts as a yeast mitochondrial magnesium exporter. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:724-32. [PMID: 25585246 DOI: 10.1016/j.bbamcr.2014.12.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/28/2014] [Accepted: 12/22/2014] [Indexed: 11/23/2022]
Abstract
The homeostasis of magnesium (Mg2+), an abundant divalent cation indispensable for many biological processes including mitochondrial functions, is underexplored. Previously, two mitochondrial Mg2+ importers, Mrs2 and Lpe10, were characterized for mitochondrial Mg2+ uptake. We now show that mitochondrial Mg2+ homeostasis is accurately controlled through the combined effects of previously known importers and a novel exporter, Mme1 (mitochondrial magnesium exporter 1). Mme1 belongs to the mitochondrial carrier family and was isolated for its mutation that is able to suppress the mrs2Δ respiration defect. Deletion of MME1 significantly increased steady-state mitochondrial Mg2+ concentration, while overexpression decreased it. Measurements of Mg2+ exit from proteoliposomes reconstituted with purified Mme1 provided definite evidence for Mme1 as an Mg2+ exporter. Our studies identified, for the first time, a mitochondrial Mg2+ exporter that works together with mitochondrial importers to ensure the precise control of mitochondrial Mg2+ homeostasis.
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36
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Specificity of Ion Uptake and Homeostasis Maintenance During Acid and Aluminium Stresses. ALUMINUM STRESS ADAPTATION IN PLANTS 2015. [DOI: 10.1007/978-3-319-19968-9_12] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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37
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Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
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38
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Bleackley MR, Hayes BM, Parisi K, Saiyed T, Traven A, Potter ID, van der Weerden NL, Anderson MA. Bovine pancreatic trypsin inhibitor is a new antifungal peptide that inhibits cellular magnesium uptake. Mol Microbiol 2014; 92:1188-97. [DOI: 10.1111/mmi.12621] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Mark R. Bleackley
- La Trobe Institute for Molecular Science; Melbourne Vic. 3086 Australia
| | - Brigitte M. Hayes
- La Trobe Institute for Molecular Science; Melbourne Vic. 3086 Australia
| | - Kathy Parisi
- La Trobe Institute for Molecular Science; Melbourne Vic. 3086 Australia
| | - Tamana Saiyed
- La Trobe Institute for Molecular Science; Melbourne Vic. 3086 Australia
| | - Ana Traven
- Department of Biochemistry and Molecular Biology; Monash University; Clayton Vic. 3800 Australia
| | - Ian D. Potter
- La Trobe Institute for Molecular Science; Melbourne Vic. 3086 Australia
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Assessment of the requirements for magnesium transporters in Bacillus subtilis. J Bacteriol 2014; 196:1206-14. [PMID: 24415722 DOI: 10.1128/jb.01238-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Magnesium is the most abundant divalent metal in cells and is required for many structural and enzymatic functions. For bacteria, at least three families of proteins function as magnesium transporters. In recent years, it has been shown that a subset of these transport proteins is regulated by magnesium-responsive genetic control elements. In this study, we investigated the cellular requirements for magnesium homeostasis in the model microorganism Bacillus subtilis. Putative magnesium transporter genes were mutationally disrupted, singly and in combination, in order to assess their general importance. Mutation of only one of these genes resulted in strong dependency on supplemental extracellular magnesium. Notably, this transporter gene, mgtE, is known to be under magnesium-responsive genetic regulatory control. This suggests that the identification of magnesium-responsive genetic mechanisms may generally denote primary transport proteins for bacteria. To investigate whether B. subtilis encodes yet additional classes of transport mechanisms, suppressor strains that permitted the growth of a transporter-defective mutant were identified. Several of these strains were sequenced to determine the genetic basis of the suppressor phenotypes. None of these mutations occurred in transport protein homologues; instead, they affected housekeeping functions, such as signal recognition particle components and ATP synthase machinery. From these aggregate data, we speculate that the mgtE protein provides the primary route of magnesium import in B. subtilis and that the other putative transport proteins are likely to be utilized for more-specialized growth conditions.
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Sponder G, Svidová S, Khan MB, Kolisek M, Schweyen RJ, Carugo O, Djinović-Carugo K. The G-M-N motif determines ion selectivity in the yeast magnesium channel Mrs2p. Metallomics 2013; 5:745-52. [PMID: 23686104 DOI: 10.1039/c3mt20201a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The highly conserved G-M-N motif of the CorA-Mrs2-Alr1 family of Mg(2+) channels has been shown to be essential for Mg(2+) transport. We performed random mutagenesis of the G-M-N sequence of Saccharomyces cerevisiae Mrs2p in an unbiased genetic screen. A large number of mutants still capable of Mg(2+) influx, albeit below the wild-type level, were generated. Growth complementation assays, performed in media supplemented with Ca(2+) or Co(2+) or Mn(2+) or Zn(2+) at varying concentrations, lead to identification of mutants with reduced growth in the presence of Mn(2+) and Zn(2+). We hereby conclude that (1) at least two, but predominantly all three amino acids of the G-M-N motif must be replaced by certain combinations of other amino acids to remain functional, (2) replacement of any single amino acid within the G-M-N motif always impairs the function of Mrs2p, and (3) we show that the G-M-N motif determines ion selectivity, likely in concurrence with the negatively charged loop at the entrance of the channel thereby forming the Mrs2p selectivity filter.
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Affiliation(s)
- Gerhard Sponder
- Department of Microbiology, Immunobiology, Genetics, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
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41
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Fates of Microcystis aeruginosa cells and associated microcystins in sediment and the effect of coagulation process on them. Toxins (Basel) 2013; 6:152-67. [PMID: 24380974 PMCID: PMC3920254 DOI: 10.3390/toxins6010152] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 12/21/2013] [Accepted: 12/23/2013] [Indexed: 11/22/2022] Open
Abstract
During toxic Microcystis aeruginosa blooms, large amounts of cells can enter sediment through natural settlement, and coagulation treatment used to control water blooms can enhance the accumulation of cells. However, the current understanding of the fates of these cells and associated microcystins (MCs), as well as the effect of coagulation treatment on these factors, is limited. The results of the present study show that Microcystis aeruginosa cells in sediment were steadily decomposed under experimental conditions, and that they completely disappeared within 28 days. The major MCs released from settled cells were immediately degraded in sediment, and microbial degradation may be the main mechanism involved in this process. Coagulation treatment with PAC (polyaluminium chloride) + sepiolite can efficiently remove Microcystis aeruginosa cells from the water column and prevent their re-invasion. Furthermore, coagulation treatment with PAC + sepiolite had no significant effect on the release and decomposition of MCs and, thus, will not enhance the MCs pollution. However, coagulation treatment can accelerate the nutrient cycle by enhancing the settlement of cells. More attention should be paid to the effect on nutrient cycle when coagulation treatment is used for restoration of aquatic ecosystems.
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Groisman EA, Hollands K, Kriner MA, Lee EJ, Park SY, Pontes MH. Bacterial Mg2+ homeostasis, transport, and virulence. Annu Rev Genet 2013; 47:625-46. [PMID: 24079267 DOI: 10.1146/annurev-genet-051313-051025] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Organisms must maintain physiological levels of Mg(2+) because this divalent cation is critical for the stabilization of membranes and ribosomes, for the neutralization of nucleic acids, and as a cofactor in a variety of enzymatic reactions. In this review, we describe the mechanisms that bacteria utilize to sense the levels of Mg(2+) both outside and inside the cytoplasm. We examine how bacteria achieve Mg(2+) homeostasis by adjusting the expression and activity of Mg(2+) transporters and by changing the composition of their cell envelope. We discuss the connections that exist between Mg(2+) sensing, Mg(2+) transport, and bacterial virulence. Additionally, we explore the logic behind the fact that bacterial genomes encode multiple Mg(2+) transporters and distinct sensing systems for cytoplasmic and extracytoplasmic Mg(2+). These analyses may be applicable to the homeostatic control of other cations.
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Affiliation(s)
- Eduardo A Groisman
- Department of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale School of Medicine, New Haven, Connecticut 06536; , , , , ,
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Uptake and subcellular partitioning of trivalent metals in a green alga: comparison between Al and Sc. Biometals 2013; 26:989-1001. [DOI: 10.1007/s10534-013-9675-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/06/2013] [Indexed: 01/04/2023]
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44
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Li C, Xu Y, Jiang W, Dong X, Wang D, Liu B. Effect of NaCl on the heavy metal tolerance and bioaccumulation of Zygosaccharomyces rouxii and Saccharomyces cerevisiae. BIORESOURCE TECHNOLOGY 2013; 143:46-52. [PMID: 23774294 DOI: 10.1016/j.biortech.2013.05.114] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 05/27/2013] [Accepted: 05/28/2013] [Indexed: 06/02/2023]
Abstract
Application of microorganisms as bioremediators for heavy metal removal in high salt environment is usually restricted by high salt concentrations. The effect of NaCl on the heavy metal tolerance and bioaccumulation of Zygosaccharomyces rouxii and Saccharomyces cerevisiae was investigated. For both yeasts, NaCl improved the cadmium and zinc tolerance, reduced the copper tolerance, and showed no obvious effect on the lead and iron tolerance. The bioaccumulation capacities of copper, zinc, and iron increased but the cadmium bioaccumulation capacities decreased after the addition of NaCl. NaCl obviously affected the amount of heavy metals removed intracellularly and on the cell surface. The heavy metal removal was not overwhelmingly inhibited by elevated NaCl concentrations, especially for Z. rouxii, and in some cases NaCl improved their removal ability. The salt-tolerant Z. rouxii that showed more powerful heavy metal tolerance and removal ability might be more suitable for heavy metal removal in high salt environment.
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Affiliation(s)
- Chunsheng Li
- Laboratory of Food Chemistry and Nutrition, College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
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45
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Schmitz J, Tierbach A, Lenz H, Meschenmoser K, Knoop V. Membrane protein interactions between different Arabidopsis thaliana MRS2-type magnesium transporters are highly permissive. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2032-40. [DOI: 10.1016/j.bbamem.2013.05.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 05/06/2013] [Accepted: 05/22/2013] [Indexed: 12/25/2022]
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Payandeh J, Pfoh R, Pai EF. The structure and regulation of magnesium selective ion channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2778-92. [PMID: 23954807 DOI: 10.1016/j.bbamem.2013.08.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 10/26/2022]
Abstract
The magnesium ion (Mg(2+)) is the most abundant divalent cation within cells. In man, Mg(2+)-deficiency is associated with diseases affecting the heart, muscle, bone, immune, and nervous systems. Despite its impact on human health, little is known about the molecular mechanisms that regulate magnesium transport and storage. Complete structural information on eukaryotic Mg(2+)-transport proteins is currently lacking due to associated technical challenges. The prokaryotic MgtE and CorA magnesium transport systems have recently succumbed to structure determination by X-ray crystallography, providing first views of these ubiquitous and essential Mg(2+)-channels. MgtE and CorA are unique among known membrane protein structures, each revealing a novel protein fold containing distinct arrangements of ten transmembrane-spanning α-helices. Structural and functional analyses have established that Mg(2+)-selectivity in MgtE and CorA occurs through distinct mechanisms. Conserved acidic side-chains appear to form the selectivity filter in MgtE, whereas conserved asparagines coordinate hydrated Mg(2+)-ions within the selectivity filter of CorA. Common structural themes have also emerged whereby MgtE and CorA sense and respond to physiologically relevant, intracellular Mg(2+)-levels through dedicated regulatory domains. Within these domains, multiple primary and secondary Mg(2+)-binding sites serve to staple these ion channels into their respective closed conformations, implying that Mg(2+)-transport is well guarded and very tightly regulated. The MgtE and CorA proteins represent valuable structural templates to better understand the related eukaryotic SLC41 and Mrs2-Alr1 magnesium channels. Herein, we review the structure, function and regulation of MgtE and CorA and consider these unique proteins within the expanding universe of ion channel and transporter structural biology.
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Affiliation(s)
- Jian Payandeh
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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Bose J, Babourina O, Shabala S, Rengel Z. Low-pH and aluminum resistance in arabidopsis correlates with high cytosolic magnesium content and increased magnesium uptake by plant roots. PLANT & CELL PHYSIOLOGY 2013; 54:1093-104. [PMID: 23620479 DOI: 10.1093/pcp/pct064] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Low-pH stress and Al(3+) toxicity affect root growth in acid soils. It was hypothesized that the capacity of genotypes to maintain Mg(2+) uptake in acidic environments may contribute to low-pH and Al resistance, but explicit evidence is lacking. In this work, an Al-resistant alr104 mutant and two Al-sensitive mutants (als5 and als3) of Arabidopsis thaliana were compared with the wild type (Col-0) for Mg(2+) uptake and intracellular Mg(2+) concentration under low-pH and combined low-pH/Al stresses. Magnesium accumulation in roots was measured in long-term (7 d) experiments. The Mg(2+) fluxes were measured using ion-sensitive microelectrodes at the distal elongation and the mature root zones in short-term (0-60 min) experiments. Intracellular Mg(2+) concentrations were measured in intact root cells at the distal elongation zone using magnesium-specific fluorescent dye and fluorescent lifetime imaging (FLIM) analysis. Under low-pH stress, Arabidopsis mutants als5 and alr104 maintained a higher Mg concentration in roots, and had greater Mg(2+) influx than the wild type and the als3 mutant. Under combined low-pH/Al treatment, Al-resistant genotypes (wild type and alr104) maintained a higher Mg(2+) accumulation, and had a higher Mg(2+) influx and higher intracellular Mg(2+) concentration than Al-sensitive genotypes (als3 and als5). Overall, these results show that increased Mg(2+) uptake correlates with an enhanced capacity of Arabidopsis genotypes to cope with low-pH and combined low-pH/Al stresses.
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Affiliation(s)
- Jayakumar Bose
- School of Earth and Environment, University of Western Australia, Crawley, WA 6009, Australia.
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Gupta N, Gaurav SS, Kumar A. Molecular Basis of Aluminium Toxicity in Plants: A Review. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ajps.2013.412a3004] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Pakrashi S, Dalai S, Ritika, Sneha B, Chandrasekaran N, Mukherjee A. A temporal study on fate of Al2O3 nanoparticles in a fresh water microcosm at environmentally relevant low concentrations. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2012; 84:70-77. [PMID: 22819567 DOI: 10.1016/j.ecoenv.2012.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 06/20/2012] [Accepted: 06/21/2012] [Indexed: 05/16/2023]
Abstract
This study on a microcosm, brings out the temporal changes in physico-chemical behavior of aluminum oxide nanoparticles (for a period of 210 days), at environmentally relevant concentrations (1000 μg/L and below). The dynamics of particle behavior in terms of mean hydrodynamic diameter, specific surface area and dissolution of soluble aluminum and, their possible ecological implications have been presented in this study. A thorough statistical analysis brings out nanoparticle behavior, where a rapid aggregation of particles (79±13 nm at 0 h to 1464±80 nm at 48 h), with a decrease in specific surface area (32 m2/g at 0 h to 1.7 m2/g at 48 h) was observed. Ion release profile indicated a significant increase in soluble aluminum concentration only after 36 h (277±15 μg/L at 0 h to 462±3 μg/L at 36 h) which reduced over a period of 60 days (279±20 μg/L). A differential response at 1000 μg/L concentration was observed, short term exposure (5 days) showed an immediate effect on the resident algal population (∼25% decreased viability) and the long term (7 months/210 days) exposure showed a gradual recovery. Thus, nanomaterials may not have the stipulated toxic response, at low concentration and longer standing period, presumably owing to the complexity of the natural systems.
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Functional reconstitution and characterization of the Arabidopsis Mg2+ transporter AtMRS2-10 in proteoliposomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2202-8. [DOI: 10.1016/j.bbamem.2012.04.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 04/05/2012] [Accepted: 04/19/2012] [Indexed: 11/24/2022]
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