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Tod NP, Vogelauer M, Cheng C, Karimian A, Schmollinger S, Camacho D, Kurdistani SK. The role of histone H3 leucine 126 in fine-tuning the copper reductase activity of nucleosomes. J Biol Chem 2024; 300:107314. [PMID: 38657861 PMCID: PMC11134540 DOI: 10.1016/j.jbc.2024.107314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 04/08/2024] [Accepted: 04/17/2024] [Indexed: 04/26/2024] Open
Abstract
The copper reductase activity of histone H3 suggests undiscovered characteristics within the protein. Here, we investigated the function of leucine 126 (H3L126), which occupies an axial position relative to the copper binding. Typically found as methionine or leucine in copper-binding proteins, the axial ligand influences the reduction potential of the bound ion, modulating its tendency to accept or yield electrons. We found that mutation of H3L126 to methionine (H3L126M) enhanced the enzymatic activity of native yeast nucleosomes in vitro and increased intracellular levels of Cu1+, leading to improved copper-dependent activities including mitochondrial respiration and growth in oxidative media with low copper. Conversely, H3L126 to histidine (H3L126H) mutation decreased nucleosome's enzymatic activity and adversely affected copper-dependent activities in vivo. Our findings demonstrate that H3L126 fine-tunes the copper reductase activity of nucleosomes and highlights the utility of nucleosome enzymatic activity as a novel paradigm to uncover previously unnoticed features of histones.
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Affiliation(s)
- Nataliya P Tod
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Maria Vogelauer
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Chen Cheng
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Ansar Karimian
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Stefan Schmollinger
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| | - Dimitrios Camacho
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| | - Siavash K Kurdistani
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA; Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
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2
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Ejmalian N, Mirzaei S, Mirzaie-Asl A, Chaichi M. A Potential Involvement of Metallothionein in the Zinc Tolerance of Trichoderma harzianum: Experimental Findings. Protein J 2024; 43:503-512. [PMID: 38488956 DOI: 10.1007/s10930-024-10185-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2024] [Indexed: 03/17/2024]
Abstract
Metallothioneins are a group of cysteine-rich proteins that play an important role in the homeostasis and detoxification of heavy metals. The objective of this research was to explore the significance of metallothionein in Trichoderma harzianum tolerance to zinc. At the inhibitory concentration of 1000 ppm, the fungus adsorbed 16.7 ± 0.4 mg/g of metal. The HPLC and SDS-PAGE electrophoresis data suggested that the fungus production of metallothionein was twice as high in the presence of zinc as in the control group. The examination of the genes; metallothionein expression activator (MEA) and Cu fist revealed that the MEA, with a C2H2 zinc finger domain, increased significantly in the presence of zinc. It was observed that in T. harzianum, the enhanced expression of the metallothionein gene was managed by the metallothionein activator under zinc overload conditions. According to our knowledge, this is the first report on the role of metallothionein in the resistance of T. harzianum to zinc.
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Affiliation(s)
- Negin Ejmalian
- Department of Plant Protection, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
| | - Soheila Mirzaei
- Department of Plant Protection, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.
| | - Asghar Mirzaie-Asl
- Department of Biotechnology, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
| | - Mehrdad Chaichi
- Department of Seed and Plant Improvement Research, Hamedan Agricultural and Natural Resources, Research and Education Center, Agricultural Research, Education and Extension Organization, Hamedan, Iran
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3
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Springer C, Humayun D, Skouta R. Cuproptosis: Unraveling the Mechanisms of Copper-Induced Cell Death and Its Implication in Cancer Therapy. Cancers (Basel) 2024; 16:647. [PMID: 38339398 PMCID: PMC10854864 DOI: 10.3390/cancers16030647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
Copper, an essential element for various biological processes, demands precise regulation to avert detrimental health effects and potential cell toxicity. This paper explores the mechanisms of copper-induced cell death, known as cuproptosis, and its potential health and disease implications, including cancer therapy. Copper ionophores, such as elesclomol and disulfiram, increase intracellular copper levels. This elevation triggers oxidative stress and subsequent cell death, offering potential implications in cancer therapy. Additionally, copper ionophores disrupt mitochondrial respiration and protein lipoylation, further contributing to copper toxicity and cell death. Potential targets and biomarkers are identified, as copper can be targeted to those proteins to trigger cuproptosis. The role of copper in different cancers is discussed to understand targeted cancer therapies using copper nanomaterials, copper ionophores, and copper chelators. Furthermore, the role of copper is explored through diseases such as Wilson and Menkes disease to understand the physiological mechanisms of copper. Exploring cuproptosis presents an opportunity to improve treatments for copper-related disorders and various cancers, with the potential to bring significant advancements to modern medicine.
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Affiliation(s)
- Chloe Springer
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA;
| | - Danish Humayun
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA;
| | - Rachid Skouta
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA;
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA;
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4
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Vogelauer M, Cheng C, Karimian A, Iranpour HG, Kurdistani SK. Zinc is Essential for the Copper Reductase Activity of Yeast Nucleosomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.14.557765. [PMID: 37745536 PMCID: PMC10515886 DOI: 10.1101/2023.09.14.557765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The histone H3-H4 tetramer is a copper reductase enzyme, facilitating the production of cuprous (Cu1+) ions for distribution to copper-dependent enzymes. It was, however, unknown if this enzymatic activity occurred within nucleosomes. To investigate this, we obtained native nucleosomes from Saccharomyces cerevisiae using micrococcal nuclease digestion of chromatin in isolated nuclei and ion-exchange chromatographic purification. The purified nucleosomal fragments robustly reduced Cu2+ to Cu1+ ions, with the optimal activity dependent on the presence of zinc ions. Mutation of the histone H3 histidine 113 (H3H113) residue at the active site substantially reduced the enzymatic activity of nucleosomes, underscoring the catalytic role of histone H3. Consistently, limiting zinc ions reduced intracellular Cu1+ levels and compromised growth, phenotypes that were mitigated by genetically enhancing the copper reductase activity of histone H3. These results indicate that yeast nucleosomes possess copper reductase activity, suggesting that the fundamental unit of eukaryotic chromatin is an enzyme complex.
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Affiliation(s)
- Maria Vogelauer
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Chen Cheng
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Ansar Karimian
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Hooman Golshan Iranpour
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Siavash K. Kurdistani
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
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5
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Yu Y, Liu H, Xia H, Chu Z. Double- or Triple-Tiered Protection: Prospects for the Sustainable Application of Copper-Based Antimicrobial Compounds for Another Fourteen Decades. Int J Mol Sci 2023; 24:10893. [PMID: 37446071 DOI: 10.3390/ijms241310893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/23/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Copper (Cu)-based antimicrobial compounds (CBACs) have been widely used to control phytopathogens for nearly fourteen decades. Since the first commercialized Bordeaux mixture was introduced, CBACs have been gradually developed from highly to slightly soluble reagents and from inorganic to synthetic organic, with nanomaterials being a recent development. Traditionally, slightly soluble CBACs form a physical film on the surface of plant tissues, separating the micro-organisms from the host, then release divalent or monovalent copper ions (Cu2+ or Cu+) to construct a secondary layer of protection which inhibits the growth of pathogens. Recent progress has demonstrated that the release of a low concentration of Cu2+ may elicit immune responses in plants. This supports a triple-tiered protection role of CBACs: break contact, inhibit microorganisms, and stimulate host immunity. This spatial defense system, which is integrated both inside and outside the plant cell, provides long-lasting and broad-spectrum protection, even against emergent copper-resistant strains. Here, we review recent findings and highlight the perspectives underlying mitigation strategies for the sustainable utilization of CBACs.
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Affiliation(s)
- Yue Yu
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072, China
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an 271018, China
| | - Haifeng Liu
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an 271018, China
| | - Haoran Xia
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhaohui Chu
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072, China
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6
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Moraes D, Rodrigues JGC, Silva MG, Soares LW, Soares CMDA, Bailão AM, Silva-Bailão MG. Copper acquisition and detoxification machineries are conserved in dimorphic fungi. FUNGAL BIOL REV 2023. [DOI: 10.1016/j.fbr.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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7
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He S, Zhang Z, Lu W. Natural promoters and promoter engineering strategies for metabolic regulation in Saccharomyces cerevisiae. J Ind Microbiol Biotechnol 2023; 50:6986260. [PMID: 36633543 PMCID: PMC9936215 DOI: 10.1093/jimb/kuac029] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 12/19/2022] [Indexed: 01/13/2023]
Abstract
Sharomyces cerevisiae is currently one of the most important foreign gene expression systems. S. cerevisiae is an excellent host for high-value metabolite cell factories due to its advantages of simplicity, safety, and nontoxicity. A promoter, as one of the basic elements of gene transcription, plays an important role in regulating gene expression and optimizing metabolic pathways. Promoters control the direction and intensity of transcription, and the application of promoters with different intensities and performances will largely determine the effect of gene expression and ultimately affect the experimental results. Due to its significant role, there have been many studies on promoters for decades. While some studies have explored and analyzed new promoters with different functions, more studies have focused on artificially modifying promoters to meet their own scientific needs. Thus, this article reviews current research on promoter engineering techniques and related natural promoters in S. cerevisiae. First, we introduce the basic structure of promoters and the classification of natural promoters. Then, the classification of various promoter strategies is reviewed. Finally, by grouping related articles together using various strategies, this review anticipates the future development direction of promoter engineering.
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Affiliation(s)
| | - Zhanwei Zhang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China
| | - Wenyu Lu
- Correspondence should be addressed to: W. Y. Lu, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China. Phone: +86-22-853-56523. Fax: +86-22-274-00973. E-mail:
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8
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Wang L, Yang HZ, Ma WL, Chen CM, Wang L. Study on metal binding capacity of the freshwater crab Sinopotamon henanense's recombinant copper specific binding metallothionein expressed in Escherichia coli. ECOTOXICOLOGY (LONDON, ENGLAND) 2022; 31:149-160. [PMID: 34751855 DOI: 10.1007/s10646-021-02470-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
The copper specific binding metallothionein (CuMT) is a type of cysteine-rich, metal-binding, small protein which plays an important role in Cu2+ metabolism in vertebrates. In this study, we investigated the metal tolerance and removing ability of recombinant strains harboring CuMT obtained in vivo from the freshwater crab Sinopotamon henanense (ShCuMT) in order to study its physiological functions and metal binding capacity. We performed a 3D modeling of ShCuMT and created its structural and functional models using the I-TASSER program. The shCumt gene was inserted into a pGEX-4t-1 vector and recombinant soluble ShCuMT was expressed in Escherichia coli. In addition, in order to characterize the tolerance and removing ability of heavy metals in E. coli with ShCuMT expression, the recombinant strains harboring ShCuMT were exposed to various concentrations of Cd2+, Cu2+ and Zn2+, respectively. The results showed that ShCuMT contains transition metal binding sites. In addition, E. coli cells expressing ShCuMT exhibited enhanced metal tolerance and higher removing ability of metal ions than control cells. However, compared with Cd2+ and Zn2+, E. coli cells expressing ShCuMT have stronger tolerance and higher removing ability of Cu2+. In general, ShCuMT contains multiple transition metal binding sites, and it could enhance tolerance and removing ability of metal ions. Therefore, ShCuMT can provide potential candidates for heavy metal bioremediation. This research on the metal binding properties of ShCuMT provides a scientific basis for bioremediation of heavy metal pollution by the recombinant strains.
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Affiliation(s)
- Lu Wang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Hui Zhen Yang
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi Province, 030600, China
| | - Wen Li Ma
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Chien Min Chen
- Department of Environmental Resources Management, Chia Nan University of Pharmacy & Science, Tainan City, Taiwan
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China.
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9
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Singh S, Sahu RK, Sugathan A, Tomar RS. The H2A N-terminal tail is required to alleviate copper-induced stress in Saccharomyces cerevisiae. FEMS Yeast Res 2021; 21:6459723. [PMID: 34894216 DOI: 10.1093/femsyr/foab061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 12/09/2021] [Indexed: 11/13/2022] Open
Abstract
Histone tail residues drive many biological processes by regulating genome-wide transcription. Functions of histone H3 and H4 tail residues in stress-responsive gene transcriptional programs have been extensively studied. The H2A tail residues have been shown to regulate DNA damage repair and oxidative stress response, but the involvement of N-terminal tail of H2A (H2ANtT) in proteostasis regulation is unknown. The unfolded protein response pathway (UPR) is an essential mechanism adopted by cells to prevent protein toxicity in response to ER stress. The disturbance in ER can occur by various factors such as heat stress, redox imbalance, exposure to xenobiotics and metals. Copper is utilized as a cofactor by cellular enzymes, but excessive copper affects ER homeostasis. We found that cells lacking 1-20 residues of H2ANtT are intolerant to copper stress, owing to the accumulation of misfolded proteins in the mutant cells. H2A 1-20 truncation also reduces the physiological UPR, and copper exposure further aggravates this effect. Furthermore, the expression of a spliced version of HAC1 mRNA in H2A∆(1-20) cells, encoding the downstream transcription factor of UPR signalling, rescues their growth under copper stress. Altogether these results provide evidence that H2ANtT reduces copper-induced ER stress by regulating UPR signalling.
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Affiliation(s)
- Sakshi Singh
- Laboratory of Chromatin Biology, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Rd, Bhauri, Madhya Pradesh 462066, India
| | - Rakesh Kumar Sahu
- Laboratory of Chromatin Biology, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Rd, Bhauri, Madhya Pradesh 462066, India
| | - Anaswara Sugathan
- Laboratory of Chromatin Biology, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Rd, Bhauri, Madhya Pradesh 462066, India
| | - Raghuvir Singh Tomar
- Laboratory of Chromatin Biology, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Rd, Bhauri, Madhya Pradesh 462066, India
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10
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The N-Terminal Tail of Histone H3 Regulates Copper Homeostasis in Saccharomyces cerevisiae. Mol Cell Biol 2021; 41:MCB.00210-20. [PMID: 33257505 DOI: 10.1128/mcb.00210-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/22/2020] [Indexed: 11/20/2022] Open
Abstract
Copper homeostasis is crucial for various cellular processes. The balance between nutritional and toxic copper levels is maintained through the regulation of its uptake, distribution, and detoxification via antagonistic actions of two transcription factors, Ace1 and Mac1. Ace1 responds to toxic copper levels by transcriptionally regulating detoxification genes CUP1 and CRS5 Cup1 metallothionein confers protection against toxic copper levels. CUP1 gene regulation is a multifactorial event requiring Ace1, TATA-binding protein (TBP), chromatin remodeler, acetyltransferase (Spt10), and histones. However, the role of histone H3 residues has not been fully elucidated. To investigate the role of the H3 tail in CUP1 transcriptional regulation, we screened the library of histone mutants in copper stress. We identified mutations in H3 (K23Q, K27R, K36Q, Δ5-16, Δ13-16, Δ13-28, Δ25-28, Δ28-31, and Δ29-32) that reduce CUP1 expression. We detected reduced Ace1 occupancy across the CUP1 promoter in K23Q, K36Q, Δ5-16, Δ13-28, Δ25-28, and Δ28-31 mutations correlating with the reduced CUP1 transcription. The majority of these mutations affect TBP occupancy at the CUP1 promoter, augmenting the CUP1 transcription defect. Additionally, some mutants displayed cytosolic protein aggregation upon copper stress. Altogether, our data establish previously unidentified residues of the H3 N-terminal tail and their modifications in CUP1 regulation.
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11
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Culbertson EM, Culotta VC. Copper in infectious disease: Using both sides of the penny. Semin Cell Dev Biol 2021; 115:19-26. [PMID: 33423931 DOI: 10.1016/j.semcdb.2020.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/28/2020] [Accepted: 12/08/2020] [Indexed: 12/17/2022]
Abstract
The transition metal Cu is an essential micronutrient that serves as a co-factor for numerous enzymes involved in redox and oxygen chemistry. However, Cu is also a potentially toxic metal, especially to unicellular microbes that are in direct contact with their environment. Since 400 BCE, Cu toxicity has been leveraged for its antimicrobial properties and even today, Cu based materials are being explored as effective antimicrobials against human pathogens spanning bacteria, fungi, and viruses, including the SARS-CoV-2 agent of the 2019-2020 pandemic. Given that Cu has the double-edged property of being both highly toxic and an essential micronutrient, it plays an active and complicated role at the host-pathogen interface. Humans have evolved methods of incorporating Cu into innate and adaptive immune processes and both sides of the penny (Cu toxicity and Cu as a nutrient) are employed. Here we review the evolution of Cu in biology and its multi-faceted roles in infectious disease, from the viewpoints of the microbial pathogens as well as the animal hosts they infect.
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Affiliation(s)
- Edward M Culbertson
- The Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Valeria C Culotta
- The Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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12
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Otsuka F. [Transcription Factor MTF-1 Involved in the Cellular Response to Zinc]. YAKUGAKU ZASSHI 2021; 141:857-867. [PMID: 34078794 DOI: 10.1248/yakushi.20-00247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heavy metals, both toxic and essential, have long been an important research focus in life science. To investigate the intracellular actions of heavy metals at the molecular level, I have been exploring protein factors involved in induction of metallothionein (MT) genes by heavy metals that specifically bind to a metal responsive element (MRE) in the region upstream of the human MT-IIA gene. Purification of a zinc-dependent MRE-binding factor, and cloning of its cDNA identified a sequence identical to that of metal-responsive transcription factor-1 (MTF-1). MTF-1, which is characterized by six tandem repeats of the C2H2 type zinc finger motif, is indispensable for induction of MT gene expression by multiple types of heavy metal, but zinc is the only metal that can directly activate MTF-1 binding to the MRE, indicating that other heavy metal signals act through zinc as a second messenger. Functional analysis of various MTF-1 point mutants revealed several cysteine (Cys) residues critical for DNA binding and/or transactivation activity. Interestingly, six finger motifs seem to mediate several MTF-1 functions other than DNA binding. Immunohistochemical analyses of various mouse tissues revealed selective expression of MTF-1 in spermatocytes among the testicular cells, suggesting roles relevant to spermatogenesis. The zinc regulon, under the control of MTF-1, will likely provide good clues to aid in unraveling novel functions of intracellular zinc ions.
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Affiliation(s)
- Fuminori Otsuka
- Laboratory of Molecular Environmental Health, Faculty of Pharma-Sciences, Teikyo University
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13
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Kassem S, Ferrari P, Hughes AL, Soudet J, Rando OJ, Strubin M. Histone exchange is associated with activator function at transcribed promoters and with repression at histone loci. SCIENCE ADVANCES 2020; 6:6/36/eabb0333. [PMID: 32917590 PMCID: PMC7467701 DOI: 10.1126/sciadv.abb0333] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 07/15/2020] [Indexed: 05/14/2023]
Abstract
Transcription in eukaryotes correlates with major chromatin changes, including the replacement of old nucleosomal histones by new histones at the promoters of genes. The role of these histone exchange events in transcription remains unclear. In particular, the causal relationship between histone exchange and activator binding, preinitiation complex (PIC) assembly, and/or subsequent transcription remains unclear. Here, we provide evidence that histone exchange at gene promoters is not simply a consequence of PIC assembly or transcription but instead is mediated by activators. We further show that not all activators up-regulate gene expression by inducing histone turnover. Thus, histone exchange does not simply correlate with transcriptional activity, but instead reflects the mode of action of the activator. Last, we show that histone turnover is not only associated with activator function but also plays a role in transcriptional repression at the histone loci.
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Affiliation(s)
- Sari Kassem
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), 1211 Geneva 4, Switzerland
| | - Paolo Ferrari
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), 1211 Geneva 4, Switzerland
| | - Amanda L Hughes
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Julien Soudet
- Department of Cell Biology, University of Geneva, 1211 Genève 4, Switzerland
| | - Oliver J Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Michel Strubin
- Department of Microbiology and Molecular Medicine, University Medical Centre (C.M.U.), 1211 Geneva 4, Switzerland.
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14
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Kim MS, Cho KH, Park KH, Jang J, Hahn JS. Activation of Haa1 and War1 transcription factors by differential binding of weak acid anions in Saccharomyces cerevisiae. Nucleic Acids Res 2019; 47:1211-1224. [PMID: 30476185 PMCID: PMC6379682 DOI: 10.1093/nar/gky1188] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 10/31/2018] [Accepted: 11/07/2018] [Indexed: 01/03/2023] Open
Abstract
In Saccharomyces cerevisiae, Haa1 and War1 transcription factors are involved in cellular adaptation against hydrophilic weak acids and lipophilic weak acids, respectively. However, it is unclear how these transcription factors are differentially activated depending on the identity of the weak acid. Using a field-effect transistor (FET)-type biosensor based on carbon nanofibers, in the present study we demonstrate that Haa1 and War1 directly bind to various weak acid anions with different affinities. Haa1 is most sensitive to acetate, followed by lactate, whereas War1 is most sensitive to benzoate, followed by sorbate, reflecting their differential activation during weak acid stresses. We show that DNA binding by Haa1 is induced in the presence of acetic acid and that the N-terminal Zn-binding domain is essential for this activity. Acetate binds to the N-terminal 150-residue region, and the transcriptional activation domain is located between amino acid residues 230 and 483. Our data suggest that acetate binding converts an inactive Haa1 to the active form, which is capable of DNA binding and transcriptional activation.
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Affiliation(s)
- Myung Sup Kim
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Kyung Hee Cho
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Kwang Hyun Park
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jyongsik Jang
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Ji-Sook Hahn
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
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15
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Pakdee O, Songnuan W, Panvisavas N, Pokethitiyook P, Yokthongwattana K, Meetam M. Functional characterization of metallothionein-like genes from Physcomitrella patens: expression profiling, yeast heterologous expression, and disruption of PpMT1.2a gene. PLANTA 2019; 250:427-443. [PMID: 31037485 DOI: 10.1007/s00425-019-03173-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/22/2019] [Indexed: 06/09/2023]
Abstract
Physcomitrella patens contains four metallothionein-like genes. Three were shown to confer metal tolerance in yeast. Transcript profiling suggests their roles in senescence and reproductive development or cadmium and oxidative stress. Metallothioneins (MTs) have been suggested to play various roles including metal detoxification, nutrient remobilization, ROS scavenging, stress tolerance, and plant development. However, little is known about the forms and functions of MTs in bryophytes. The moss Physcomitrella patens genome was found to contain four MT-like genes. Amino acid sequence composition showed that the P. patens MTs (PpMTs) were clustered with Type 1 plant MTs, and could be further classified into two sub-types, herein referred to as sub-type 1: PpMT1.1a and PpMT1.1b and sub-type 2: PpMT1.2a and PpMT1.2b. Transcript abundance of PpMT1.1b and PpMT1.2b was upregulated in the gametophore compared to protonema, and all, except PpMT1.2a, were highly induced in senescing gametophytes. PpMT1.1a and PpMT1.1b transcripts were upregulated in protonema treated with cadmium and hydrogen peroxide. Unlike many higher plant MTs, the PpMT transcript abundance was not strongly induced in response to copper and zinc. These results suggest that PpMTs may play a role in protecting P. patens from cadmium and oxidative stress and may be involved in tissues senescence and reproductive development. The PpMTs, except PpMT1.2b, were also able to confer metal tolerance and accumulation when heterologously expressed in the ∆cup1 yeast. A P. patens mutant lacking PpMT1.2a through targeted gene disruption was generated. However, it did not show any alteration in growth phenotypes under senescence-induced conditions or hypersensitivity to cadmium, copper, zinc, H2O2, and NaCl stresses. Further characterization of additional P. patens mutants lacking single or multiple PpMTs may provide insight into the physiological roles of bryophytic MTs.
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Affiliation(s)
- Orathai Pakdee
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
- Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Bangkok, 10400, Thailand
| | - Wisuwat Songnuan
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Nathinee Panvisavas
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Prayad Pokethitiyook
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
- Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Bangkok, 10400, Thailand
| | | | - Metha Meetam
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
- Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Bangkok, 10400, Thailand.
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16
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Song J, Li R, Jiang J. Copper Homeostasis in Aspergillus fumigatus: Opportunities for Therapeutic Development. Front Microbiol 2019; 10:774. [PMID: 31031736 PMCID: PMC6473158 DOI: 10.3389/fmicb.2019.00774] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/26/2019] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus can cause severe invasive aspergillosis in immunocompromised individuals. Copper, an essential but potentially toxic trace element for A. fumigatus, plays a critical role at the host-pathogen axis during infection. Accumulating evidence demonstrates that the host utilizes copper compartmentalization within macrophages to combat A. fumigatus infection. To survive under host-imposed copper toxicity, A. fumigatus has evolved sophisticated machinery to regulate copper homeostasis. Thus, targeting molecular pathways critical for copper homeostasis regulation provides an opportunity to improve therapeutic options for aspergillosis caused by A. fumigatus. In this review, we describe the copper homeostatic mechanisms by which A. fumigatus acquires and controls copper levels and explores the responses of the pathogen to alter copper levels in the host. Finally, we discuss the regulatory mechanisms of copper homeostasis that could be targeted for antifungal drug development.
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Affiliation(s)
- Jinxing Song
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, China
| | - Rongpeng Li
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, China
| | - Jihong Jiang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, China
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17
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Copper Utilization, Regulation, and Acquisition by Aspergillus fumigatus. Int J Mol Sci 2019; 20:ijms20081980. [PMID: 31018527 PMCID: PMC6514546 DOI: 10.3390/ijms20081980] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 01/01/2023] Open
Abstract
Copper is an essential micronutrient for the opportunistic human pathogen, Aspergillus fumigatus. Maintaining copper homeostasis is critical for survival and pathogenesis. Copper-responsive transcription factors, AceA and MacA, coordinate a complex network responsible for responding to copper in the environment and determining which response is necessary to maintain homeostasis. For example, A. fumigatus uses copper exporters to mitigate the toxic effects of copper while simultaneously encoding copper importers and small molecules to ensure proper supply of the metal for copper-dependent processes such a nitrogen acquisition and respiration. Small molecules called isocyanides recently found to be produced by A. fumigatus may bind copper and partake in copper homeostasis similarly to isocyanide copper chelators in bacteria. Considering that the host uses copper as a microbial toxin and copper availability fluctuates in various environmental niches, understanding how A. fumigatus maintains copper homeostasis will give insights into mechanisms that facilitate the development of invasive aspergillosis and its survival in nature.
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18
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The Role of Copper Homeostasis at the Host-Pathogen Axis: From Bacteria to Fungi. Int J Mol Sci 2019; 20:ijms20010175. [PMID: 30621285 PMCID: PMC6337107 DOI: 10.3390/ijms20010175] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/28/2018] [Accepted: 12/29/2018] [Indexed: 02/01/2023] Open
Abstract
Copper is an essential trace element participating in many vital biological processes, however it becomes a toxic agent when in excess. Thus, precise and tight regulation of copper homeostasis processes, including transport, delivery, storage, detoxification, and efflux machineries, is important, ensuring that only the amount needed to sustain basic biological functions and simultaneously prevent copper toxicity in the cell is maintained. Numerous exciting studies have revealed that copper plays an indispensable role at the microbial pathogen-host axis for entities ranging from pathogenic bacteria to deadly fungal species. Analyses of copper homeostases in bacteria and fungi extensively demonstrate that copper is utilized by the host immune system as an anti-microbial agent. The expression of copper efflux and detoxification from microbial pathogens is induced to counteract the host's copper bombardment, which in turn disrupts these machineries, resulting in the attenuation of microbial survival in host tissue. We hereby review the latest work in copper homeostases in pathogenic bacteria and fungi and focus on the maintenance of a copper balance at the pathogen-host interaction axis.
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19
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Dennison C. The Coordination Chemistry of Copper Uptake and Storage for Methane Oxidation. Chemistry 2018; 25:74-86. [PMID: 30281847 DOI: 10.1002/chem.201803444] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Indexed: 11/09/2022]
Abstract
Methanotrophs are remarkable bacteria that utilise large quantities of copper (Cu) to oxidize the potent greenhouse gas methane. To assist in providing the Cu they require for this process some methanotrophs can secrete the Cu-sequestering modified peptide methanobactin. These small molecules bind CuI with very high affinity and crystal structures have given insight into why this is the case, and also how the metal ion may be released within the cell. A much greater proportion of methanotrophs, genomes of which have been sequenced, possess a member of a newly discovered bacterial family of copper storage proteins (the Csps). These are tetramers of four-helix bundles whose cores are lined with Cys residues enabling the binding of large numbers of CuI ions. In methanotrophs, a Csp exported from the cytosol stores CuI for the active site of the ubiquitous enzyme that catalyses the oxidation of methane. The presence of cytosolic Csps, not only in methanotrophs but in a wide range of bacteria, challenges the dogma that these organisms have no requirement for Cu in this location. The properties of the Csps, with an emphasis on CuI binding and the structures of the sites formed, are the primary focus of this review.
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Affiliation(s)
- Christopher Dennison
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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20
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Mehta GD, Ball DA, Eriksson PR, Chereji RV, Clark DJ, McNally JG, Karpova TS. Single-Molecule Analysis Reveals Linked Cycles of RSC Chromatin Remodeling and Ace1p Transcription Factor Binding in Yeast. Mol Cell 2018; 72:875-887.e9. [PMID: 30318444 DOI: 10.1016/j.molcel.2018.09.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/08/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022]
Abstract
It is unknown how the dynamic binding of transcription factors (TFs) is molecularly linked to chromatin remodeling and transcription. Using single-molecule tracking (SMT), we show that the chromatin remodeler RSC speeds up the search process of the TF Ace1p for its response elements (REs) at the CUP1 promoter. We quantified smFISH mRNA data using a gene bursting model and demonstrated that RSC regulates transcription bursts of CUP1 only by modulating TF occupancy but does not affect initiation and elongation rates. We show by SMT that RSC binds to activated promoters transiently, and based on MNase-seq data, that RSC does not affect the nucleosomal occupancy at CUP1. Therefore, transient binding of Ace1p and rapid bursts of transcription at CUP1 may be dependent on short repetitive cycles of nucleosome mobilization. This type of regulation reduces the transcriptional noise and ensures a homogeneous response of the cell population to heavy metal stress.
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Affiliation(s)
- Gunjan D Mehta
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David A Ball
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter R Eriksson
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Razvan V Chereji
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - David J Clark
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - James G McNally
- Institute for Soft Matter and Functional Materials, Helmholtz Center Berlin, Berlin 12489, Germany
| | - Tatiana S Karpova
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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21
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Garcia-Santamarina S, Festa RA, Smith AD, Yu CH, Probst C, Ding C, Homer CM, Yin J, Noonan JP, Madhani H, Perfect JR, Thiele DJ. Genome-wide analysis of the regulation of Cu metabolism in Cryptococcus neoformans. Mol Microbiol 2018; 108:473-494. [PMID: 29608794 PMCID: PMC5980777 DOI: 10.1111/mmi.13960] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2018] [Indexed: 12/13/2022]
Abstract
The ability of the human fungal pathogen Cryptococcus neoformans to adapt to variable copper (Cu) environments within the host is key for successful dissemination and colonization. During pulmonary infection, host alveolar macrophages compartmentalize Cu into the phagosome and C. neoformans Cu-detoxifying metallothioneins, MT1 and MT2, are required for survival of the pathogen. In contrast, during brain colonization the C. neoformans Cu+ importers Ctr1 and Ctr4 are required for virulence. Central for the regulation and expression of both the Cu detoxifying MT1/2 and the Cu acquisition Ctr1/4 proteins is the Cu-metalloregulatory transcription factor Cuf1, an established C. neoformans virulence factor. Due to the importance of the distinct C. neoformans Cu homeostasis mechanisms during host colonization and virulence, and to the central role of Cuf1 in regulating Cu homeostasis, we performed a combination of RNA-Seq and ChIP-Seq experiments to identify differentially transcribed genes between conditions of high and low Cu. We demonstrate that the transcriptional regulation exerted by Cuf1 is intrinsically complex and that Cuf1 also functions as a transcriptional repressor. The Cu- and Cuf1-dependent regulon in C. neoformans reveals new adaptive mechanisms for Cu homeostasis in this pathogenic fungus and identifies potential new pathogen-specific targets for therapeutic intervention in fungal infections.
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Affiliation(s)
- Sarela Garcia-Santamarina
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Richard A. Festa
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Aaron D. Smith
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Chen-Hsin Yu
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Corinna Probst
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Chen Ding
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Christina M. Homer
- Department of Biochemistry and Biophysics, UCSF, San Francisco, California, USA
| | - Jun Yin
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - James P. Noonan
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Hiten Madhani
- Department of Biochemistry and Biophysics, UCSF, San Francisco, California, USA
| | - John R. Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Dennis J. Thiele
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina, USA
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22
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Garcia Silva-Bailão M, Lobato Potenciano da Silva K, Raniere Borges dos Anjos L, de Sousa Lima P, de Melo Teixeira M, Maria de Almeida Soares C, Melo Bailão A. Mechanisms of copper and zinc homeostasis in pathogenic black fungi. Fungal Biol 2018; 122:526-537. [DOI: 10.1016/j.funbio.2017.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 02/08/2023]
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23
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Lai YH, Kuo C, Kuo MT, Chen HHW. Modulating Chemosensitivity of Tumors to Platinum-Based Antitumor Drugs by Transcriptional Regulation of Copper Homeostasis. Int J Mol Sci 2018; 19:ijms19051486. [PMID: 29772714 PMCID: PMC5983780 DOI: 10.3390/ijms19051486] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/10/2018] [Accepted: 05/12/2018] [Indexed: 12/21/2022] Open
Abstract
Platinum (Pt)-based antitumor agents have been effective in treating many human malignancies. Drug importing, intracellular shuffling, and exporting—carried out by the high-affinity copper (Cu) transporter (hCtr1), Cu chaperone (Ato x1), and Cu exporters (ATP7A and ATP7B), respectively—cumulatively contribute to the chemosensitivity of Pt drugs including cisplatin and carboplatin, but not oxaliplatin. This entire system can also handle Pt drugs via interactions between Pt and the thiol-containing amino acid residues in these proteins; the interactions are strongly influenced by cellular redox regulators such as glutathione. hCtr1 expression is induced by acute Cu deprivation, and the induction is regulated by the transcription factor specific protein 1 (Sp1) which by itself is also regulated by Cu concentration variations. Copper displaces zinc (Zn) coordination at the zinc finger (ZF) domains of Sp1 and inactivates its DNA binding, whereas Cu deprivation enhances Sp1-DNA interactions and increases Sp1 expression, which in turn upregulates hCtr1. Because of the shared transport system, chemosensitivity of Pt drugs can be modulated by targeting Cu transporters. A Cu-lowering agent (trientine) in combination with a Pt drug (carboplatin) has been used in clinical studies for overcoming Pt-resistance. Future research should aim at further developing effective Pt drug retention strategies for improving the treatment efficacy.
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Affiliation(s)
- Yu-Hsuan Lai
- Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70428, Taiwan.
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70428, Taiwan.
| | - Chin Kuo
- Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70428, Taiwan.
| | - Macus Tien Kuo
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA.
| | - Helen H W Chen
- Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70428, Taiwan.
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan 70101, Taiwan.
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24
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Abstract
Fungal cells colonize and proliferate in distinct niches, from soil and plants to diverse tissues in human hosts. Consequently, fungi are challenged with the goal of obtaining nutrients while simultaneously elaborating robust regulatory mechanisms to cope with a range of availability of nutrients, from scarcity to excess. Copper is essential for life but also potentially toxic. In this review we describe the sophisticated homeostatic mechanisms by which fungi acquire, utilize, and control this biochemically versatile trace element. Fungal pathogens, which can occupy distinct host tissues that have their own intrinsic requirements for copper homeostasis, have evolved mechanisms to acquire copper to successfully colonize the host, disseminate to other tissues, and combat host copper bombardment mechanisms that would otherwise mitigate virulence.
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Affiliation(s)
| | | | - Dennis J Thiele
- Department of Pharmacology and Cancer Biology.,Department of Molecular Genetics and Microbiology, and.,Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710;
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25
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Ottoz DSM, Rudolf F. Constitutive and Regulated Promoters in Yeast: How to Design and Make Use of Promoters in S. cerevisiae. Synth Biol (Oxf) 2018. [DOI: 10.1002/9783527688104.ch6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Diana S. M. Ottoz
- ETH Zurich; Department of Biosystems Science and Engineering; Mattenstrasse 26 4058 Basel Switzerland
- Yale University; Department of Molecular Biophysics and Biochemistry; 333 Cedar street SHM C-111 New Haven CT 06520 USA
| | - Fabian Rudolf
- ETH Zurich; Department of Biosystems Science and Engineering; Mattenstrasse 26 4058 Basel Switzerland
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26
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Fonseca M, Molina M, Winnik D, Busi M, Fariña J, Villalba L, Zapata P. Isolation of a laccase-coding gene from the lignin-degrading fungusPhlebia brevisporaBAFC 633 and heterologous expression inPichia pastoris. J Appl Microbiol 2018; 124:1454-1468. [DOI: 10.1111/jam.13720] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/26/2018] [Accepted: 01/29/2018] [Indexed: 11/28/2022]
Affiliation(s)
- M.I. Fonseca
- Laboratorio de Biotecnología Molecular; Instituto de Biotecnología Misiones; Facultad de Ciencias Exactas Químicas y Naturales; Universidad Nacional de Misiones; Posadas Misiones Argentina
| | - M.A. Molina
- Laboratorio de Biotecnología Molecular; Instituto de Biotecnología Misiones; Facultad de Ciencias Exactas Químicas y Naturales; Universidad Nacional de Misiones; Posadas Misiones Argentina
| | - D.L. Winnik
- Laboratorio de Biotecnología Molecular; Instituto de Biotecnología Misiones; Facultad de Ciencias Exactas Químicas y Naturales; Universidad Nacional de Misiones; Posadas Misiones Argentina
| | - M.V. Busi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET); Universidad Nacional de Rosario; Rosario Argentina
| | - J.I. Fariña
- Laboratorio de Biotecnología Fúngica; PROIMI-CONICET; Tucumán Argentina
| | - L.L. Villalba
- Laboratorio de Biotecnología Molecular; Instituto de Biotecnología Misiones; Facultad de Ciencias Exactas Químicas y Naturales; Universidad Nacional de Misiones; Posadas Misiones Argentina
| | - P.D. Zapata
- Laboratorio de Biotecnología Molecular; Instituto de Biotecnología Misiones; Facultad de Ciencias Exactas Químicas y Naturales; Universidad Nacional de Misiones; Posadas Misiones Argentina
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27
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Generation of an arginine-tRNA-adapted Saccharomyces cerevisiae strain for effective heterologous protein expression. Curr Genet 2017; 64:589-598. [PMID: 29098364 DOI: 10.1007/s00294-017-0774-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/30/2017] [Accepted: 10/27/2017] [Indexed: 10/18/2022]
Abstract
The tRNA population reflects the codon bias of the organism and affects the translation of heterologous target mRNA molecules. In this study, Saccharomyces cerevisiae strains with modified levels of rare tRNA were engineered, that allowed efficient generation of recombinant proteins with unfavorable codon usage. We established a novel synthetic tRNA expression cassette and verified functional nonsense suppressor tRNAGlnSCUA generation in a stop codon read-through assay with a modified β-galactosidase reporter gene. Correlation between altered tRNA and protein level was shown by survival of copper sensitive S. cerevisiae cells in the presence of copper ions by an increased transcription of tRNAArgCCG molecules, recognizing rare codons in a modified CUP1 gene. Genome integration of tRNA expression cassette led to the generation of arginine-tRNA-adapted S. cerevisiae strains, which showed elevated tRNA levels (tRNAArgCCG, tRNAArgGCG and tRNAArgUCG) pairing to rare codons. The modified strain MNY3 revealed a considerably improved monitoring of protein-protein interaction from Aspergillus fumigatus bait and prey sequences in yeast two-hybrid experiments. In future, this principle to overcome limited recombinant protein expression by tRNA adaption of expression strains instead of codon adaption might provide new designer yeast cells for an efficient protein production and for improved genome-wide protein-protein interaction analyses.
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28
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Yuan S, Chen S, Xi Z, Liu Y. Copper-finger protein of Sp1: the molecular basis of copper sensing. Metallomics 2017; 9:1169-1175. [PMID: 28759062 DOI: 10.1039/c7mt00184c] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The cellular copper level is strictly regulated since excessive copper is harmful to cells. It has been proposed that the expression of copper transport protein hCtr1 is transcriptionally regulated by specificity protein 1 (Sp1) in response to the cellular copper level. However, it is not known how Sp1, a zinc-finger-protein (ZFP), can sense copper ions in cells. Here we found that Sp1 demonstrates high binding affinity to cuprous ions, even stronger than Cu-Atox1 binding. Cu(i) can displace Zn(ii) in Sp1, resulting in a well-folded 'Copper-Finger-Protein' (CFP). Although only very little structural alteration occurs upon copper binding, CFP cannot recognize the promoter of hCtr1, therefore copper binding interrupts the transcription. This result indicates that, in addition to apo-to-holo alteration, metal substitution can also lead to transcriptional switch in metal sensing. This work provides insight into the copper sensing mechanism of Sp1 at the molecular level.
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Affiliation(s)
- Siming Yuan
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
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29
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Antsotegi-Uskola M, Markina-Iñarrairaegui A, Ugalde U. Copper Resistance in Aspergillus nidulans Relies on the P I-Type ATPase CrpA, Regulated by the Transcription Factor AceA. Front Microbiol 2017; 8:912. [PMID: 28611736 PMCID: PMC5447758 DOI: 10.3389/fmicb.2017.00912] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 05/04/2017] [Indexed: 01/17/2023] Open
Abstract
Copper homeostasis has been extensively studied in mammals, bacteria, and yeast, but it has not been well-documented in filamentous fungi. In this report, we investigated the basis of copper tolerance in the model fungus Aspergillus nidulans. Three genes involved in copper homeostasis have been characterized. First, crpA the A. nidulans ortholog of Candida albicans CaCRP1 gene encoding a PI-type ATPase was identified. The phenotype of crpA deletion led to a severe sensitivity to Cu+2 toxicity and a characteristic morphological growth defect in the presence of high copper concentration. CrpA displayed some promiscuity regarding metal species response. The expression pattern of crpA showed an initial strong elevation of mRNA and a low continuous gene expression in response to long term toxic copper levels. Coinciding with maximum protein expression level, CrpA was localized close to the cellular surface, however protein distribution across diverse organelles suggests a complex regulated trafficking process. Secondly, aceA gene, encoding a transcription factor was identified and deleted, resulting in an even more extreme copper sensitivity than the ΔcrpA mutant. Protein expression assays corroborated that AceA was necessary for metal inducible expression of CrpA, but not CrdA, a putative metallothionein the function of which has yet to be elucidated.
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Affiliation(s)
- Martzel Antsotegi-Uskola
- Microbial Biochemistry Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque CountrySan Sebastian, Spain
| | - Ane Markina-Iñarrairaegui
- Microbial Biochemistry Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque CountrySan Sebastian, Spain
| | - Unai Ugalde
- Microbial Biochemistry Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque CountrySan Sebastian, Spain
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30
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Calvo J, Jung H, Meloni G. Copper metallothioneins. IUBMB Life 2017; 69:236-245. [PMID: 28296007 DOI: 10.1002/iub.1618] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 02/16/2017] [Indexed: 11/10/2022]
Abstract
Metallothioneins (MTs) are a class of low molecular weight and cysteine-rich metal binding proteins present in all the branches of the tree of life. MTs efficiently bind with high affinity several essential and toxic divalent and monovalent transition metals by forming characteristic polynuclear metal-thiolate clusters within their structure. MTs fulfil multiple biological functions related to their metal binding properties, with essential roles in both Zn(II) and Cu(I) homeostasis as well as metal detoxification. Depending on the organism considered, the primary sequence, and the specific physiological and metabolic status, Cu(I)-bound MT isoforms have been isolated, and their chemistry and biology characterized. Besides the recognized role in the biochemistry of divalent metals, it is becoming evident that unique biological functions in selectively controlling copper levels, its reactivity as well as copper-mediated biochemical processes have evolved in some members of the MT superfamily. Selected examples are reviewed to highlight the peculiar chemical properties and biological functions of copper MTs. © 2016 IUBMB Life, 69(4):236-245, 2017.
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Affiliation(s)
- Jenifer Calvo
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX, USA
| | - Hunmin Jung
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX, USA
| | - Gabriele Meloni
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX, USA
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Yoshioka H, Tanaka M, Fujii H, Nonogaki T. Sasa veitchii extract suppresses carbon tetrachloride-induced hepato- and nephrotoxicity in mice. Environ Health Prev Med 2016; 21:554-562. [PMID: 27738877 DOI: 10.1007/s12199-016-0581-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 10/04/2016] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE The aim of this study was to investigate the therapeutic effects of a Sasa veitchii leaf extract (SE) on carbon tetrachloride (CCl4)-induced hepato- and nephrotoxicity. METHODS Seven-week-old male ddy mice were orally administered SE or saline for seven days. Twenty-four hours after the last SE or saline administration, the mice were intraperitoneally injected with 3 g/kg CCl4 or olive oil. The mice from each group were euthanized and bled for plasma analysis 24 h after the CCl4/olive oil injection. RESULTS We found that pretreatment with SE completely abolished the CCl4-induced mortality in the mice after 24 h. The mice pretreated with SE exhibited significantly decreased levels of functional markers, and reduced histological damage in both the liver and the kidney. Furthermore, we found that the SE pretreatment decreased lipid peroxidation and calcium levels in the liver. Although SE could not induce the free radical-scavenging metallothioneins, the plasma biological antioxidant power was significantly increased in the mice pretreated with SE. CONCLUSION Our findings demonstrate that prophylactic treatment with SE protects mice from CCl4-induced lethal toxicity by decreasing oxidative stress in the liver and kidney, presumably by increasing biological antioxidant power.
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Affiliation(s)
- Hiroki Yoshioka
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyamaku, Nagoya, Aichi, 463-8521, Japan.
| | - Miki Tanaka
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyamaku, Nagoya, Aichi, 463-8521, Japan
| | - Hirohisa Fujii
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyamaku, Nagoya, Aichi, 463-8521, Japan
| | - Tsunemasa Nonogaki
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyamaku, Nagoya, Aichi, 463-8521, Japan.
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Ball DA, Mehta GD, Salomon-Kent R, Mazza D, Morisaki T, Mueller F, McNally JG, Karpova TS. Single molecule tracking of Ace1p in Saccharomyces cerevisiae defines a characteristic residence time for non-specific interactions of transcription factors with chromatin. Nucleic Acids Res 2016; 44:e160. [PMID: 27566148 PMCID: PMC5137432 DOI: 10.1093/nar/gkw744] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/05/2016] [Accepted: 08/15/2016] [Indexed: 12/26/2022] Open
Abstract
In vivo single molecule tracking has recently developed into a powerful technique for measuring and understanding the transient interactions of transcription factors (TF) with their chromatin response elements. However, this method still lacks a solid foundation for distinguishing between specific and non-specific interactions. To address this issue, we took advantage of the power of molecular genetics of yeast. Yeast TF Ace1p has only five specific sites in the genome and thus serves as a benchmark to distinguish specific from non-specific binding. Here, we show that the estimated residence time of the short-residence molecules is essentially the same for Hht1p, Ace1p and Hsf1p, equaling 0.12-0.32 s. These three DNA-binding proteins are very different in their structure, function and intracellular concentration. This suggests that (i) short-residence molecules are bound to DNA non-specifically, and (ii) that non-specific binding shares common characteristics between vastly different DNA-bound proteins and thus may have a common underlying mechanism. We develop new and robust procedure for evaluation of adverse effects of labeling, and new quantitative analysis procedures that significantly improve residence time measurements by accounting for fluorophore blinking. Our results provide a framework for the reliable performance and analysis of single molecule TF experiments in yeast.
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Affiliation(s)
- David A Ball
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gunjan D Mehta
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ronit Salomon-Kent
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Davide Mazza
- Istituto Scientifico Ospedale San Raffaele, Centro di Imaging Sperimentale e Università Vita-Salute San Raffaele, Milan 20132, Italy
| | - Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Florian Mueller
- Institut Pasteur, Computation Imaging and Modeling Unit, CNRS, URA 2582, Paris 75015, France
| | - James G McNally
- Institute for Soft Matter and Functional Materials, Helmholtz Center Berlin, Berlin 12489, Germany
| | - Tatiana S Karpova
- CCR/LRBGE Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Santos AK, Parreira RC, Resende RR. Expression System Based on an MTIIa Promoter to Produce hPSA in Mammalian Cell Cultures. Front Microbiol 2016; 7:1280. [PMID: 27582737 PMCID: PMC4987383 DOI: 10.3389/fmicb.2016.01280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/03/2016] [Indexed: 11/30/2022] Open
Abstract
Because of the limitations of standard culture techniques, the development of new recombinant protein expression systems with biotechnological potential is a key challenge. Ideally, such systems should be able to effectively and accurately synthesize a protein of interest with intrinsic metabolic capacity. Here, we describe such a system that was designed based on a plasmid vector containing promoter elements derived from the metallothionein MTIIa promoter, as well as processing and purification elements. This promoter can be induced by heavy metals in a culture medium to induce the synthesis of human prostate-specific antigen (hPSA), which has been modified to insert elements for purification, proteolysis, and secretion. We optimized hPSA production in this system by comparing the effects and contributions of ZnCl2, CdCl2, and CuSO4 in HEK293FT, HeLa, BHK-21, and CHO-K1 cells. We also compared the effectiveness of three different transfection agents: multi-walled carbon nanotubes, Lipofectamine 2000, and X-tremeGENE HP Reagent. hPSA production was confirmed via the detection of enhanced green fluorescent protein fluorescence, and cell viability was determined. The expression of hPSA was compared with that of the native protein produced by LNCaP cells, using enzyme-linked immunosorbent assay and sodium dodecyl sulfate polyacrylamide gel electrophoresis. X-tremeGENE reagent, the BHK-21 cell line, and CuSO4 showed the highest hPSA production rates. Furthermore, BHK-21 cells were more resistant to the oxidative stress caused by 100 μM CuSO4. These results suggest that the proposed optimized inducible expression system can effectively produce recombinant proteins with desired characteristics for a wide range of applications in molecular biology.
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Affiliation(s)
- Anderson K Santos
- Laboratório de Sinalização Celular e Nanobiotecnologia, Departamento de Bioquímica e Imunologia, Universidade Federal de Minas GeraisBelo Horizonte, Brazil; Instituto NanocellDivinópolis, Brazil
| | - Ricardo C Parreira
- Laboratório de Sinalização Celular e Nanobiotecnologia, Departamento de Bioquímica e Imunologia, Universidade Federal de Minas GeraisBelo Horizonte, Brazil; Instituto NanocellDivinópolis, Brazil
| | - Rodrigo R Resende
- Laboratório de Sinalização Celular e Nanobiotecnologia, Departamento de Bioquímica e Imunologia, Universidade Federal de Minas GeraisBelo Horizonte, Brazil; Instituto NanocellDivinópolis, Brazil
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Kullik I, Storz G. Transcriptional regulators of the oxidative stress response in prokaryotes and eukaryotes. Redox Rep 2016; 1:23-9. [DOI: 10.1080/13510002.1994.11746951] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Smith N, Wei W, Zhao M, Qin X, Seravalli J, Kim H, Lee J. Cadmium and Secondary Structure-dependent Function of a Degron in the Pca1p Cadmium Exporter. J Biol Chem 2016; 291:12420-31. [PMID: 27059957 DOI: 10.1074/jbc.m116.724930] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Indexed: 11/06/2022] Open
Abstract
Protein turnover is a critical cellular process regulating biochemical pathways and destroying terminally misfolded or damaged proteins. Pca1p, a cadmium exporter in the yeast Saccharomyces cerevisiae, is rapidly degraded by the endoplasmic reticulum-associated degradation (ERAD) system via a cis-acting degron that exists at the 250-350 amino acid region of Pca1p and is transferable to other proteins to serve as a degradation signal. Cadmium stabilizes Pca1p in a manner dependent on the degron. This suggested that cadmium-mediated masking of the degron impedes its interaction with the molecular factors involved in the ERAD. The characteristics and mechanisms of action of the degron in Pca1p and most of those in other proteins however remain to be determined. The results presented here indicate that specific cysteine residues in a degron of Pca1p sense cadmium. An unbiased approach selecting non-functional degrons indicated a critical role of hydrophobic amino acids in the degron for its function. A secondary structure modeling predicted the formation of an amphipathic helix. Site-directed mutagenesis confirmed the functional significance of the hydrophobic patch. Last, hydrophobic amino acids in the degron- and cadmium-binding region affected the interaction of Pca1p with the Ssa1p molecular chaperone, which is involved in ERAD. These results reveal the mechanism of action of the degron, which might be useful for the identification and characterization of other degrons.
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Affiliation(s)
- Nathan Smith
- From the Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska, 68588-0664 and
| | - Wenzhong Wei
- From the Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska, 68588-0664 and
| | - Miaoyun Zhao
- From the Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska, 68588-0664 and
| | - Xiaojuan Qin
- From the Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska, 68588-0664 and the College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Javier Seravalli
- From the Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska, 68588-0664 and
| | - Heejeong Kim
- From the Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska, 68588-0664 and
| | - Jaekwon Lee
- From the Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska, 68588-0664 and
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Singh S, Parihar P, Singh R, Singh VP, Prasad SM. Heavy Metal Tolerance in Plants: Role of Transcriptomics, Proteomics, Metabolomics, and Ionomics. FRONTIERS IN PLANT SCIENCE 2016; 6:1143. [PMID: 26904030 PMCID: PMC4744854 DOI: 10.3389/fpls.2015.01143] [Citation(s) in RCA: 422] [Impact Index Per Article: 52.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 12/02/2015] [Indexed: 05/18/2023]
Abstract
Heavy metal contamination of soil and water causing toxicity/stress has become one important constraint to crop productivity and quality. This situation has further worsened by the increasing population growth and inherent food demand. It has been reported in several studies that counterbalancing toxicity due to heavy metal requires complex mechanisms at molecular, biochemical, physiological, cellular, tissue, and whole plant level, which might manifest in terms of improved crop productivity. Recent advances in various disciplines of biological sciences such as metabolomics, transcriptomics, proteomics, etc., have assisted in the characterization of metabolites, transcription factors, and stress-inducible proteins involved in heavy metal tolerance, which in turn can be utilized for generating heavy metal-tolerant crops. This review summarizes various tolerance strategies of plants under heavy metal toxicity covering the role of metabolites (metabolomics), trace elements (ionomics), transcription factors (transcriptomics), various stress-inducible proteins (proteomics) as well as the role of plant hormones. We also provide a glance of some strategies adopted by metal-accumulating plants, also known as "metallophytes."
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Affiliation(s)
- Samiksha Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Parul Parihar
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Rachana Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Vijay P. Singh
- Department of Botany, Government Ramanuj Pratap Singhdev Post Graduate College, Sarguja UniversityBaikunthpur, India
| | - Sheo M. Prasad
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
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Liu J, Zhang QM, Feng Y, Zhou Z, Shih K. Solvent-Switching Gelation and Orange-Red Emission of Ultrasmall Copper Nanoclusters. Chemphyschem 2015; 17:225-31. [DOI: 10.1002/cphc.201500969] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Jinhua Liu
- Innovation Center for Advanced Materials; Nanjing Tech University; Nanjing 211816 China
- Department of Civil Engineering; University of HongKong; Porkfulam Road HongKong China
| | - Qiang Matthew Zhang
- Department of Chemistry; University of Alberta; Edmonton Alberta T6G 2G2 Canada
| | - Yong Feng
- Department of Civil Engineering; University of HongKong; Porkfulam Road HongKong China
| | - Zhengyuan Zhou
- Department of Civil Engineering; University of HongKong; Porkfulam Road HongKong China
| | - Kaimin Shih
- Department of Civil Engineering; University of HongKong; Porkfulam Road HongKong China
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Chen HHW, Chen WC, Liang ZD, Tsai WB, Long Y, Aiba I, Fu S, Broaddus R, Liu J, Feun LG, Savaraj N, Kuo MT. Targeting drug transport mechanisms for improving platinum-based cancer chemotherapy. Expert Opin Ther Targets 2015; 19:1307-17. [PMID: 26004625 DOI: 10.1517/14728222.2015.1043269] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Platinum (Pt)-based antitumor agents remain important chemotherapeutic agents for treating many human malignancies. Elevated expression of the human high-affinity copper transporter 1 (hCtr1), resulting in enhanced Pt drug transport into cells, has been shown to be associated with improved treatment efficacy. Thus, targeting hCtr1 upregulation is an attractive strategy for improving the treatment efficacy of Pt-based cancer chemotherapy. AREA COVERED Regulation of hCtr1 expression by cellular copper homeostasis is discussed. Association of elevated hCtr1 expression with intrinsic sensitivity of ovarian cancer to Pt drugs is presented. Mechanism of copper-lowering agents in enhancing hCtr1-mediated cis-diamminedichloroplatinum (II) (cisplatin, cDDP) transport is reviewed. Applications of copper chelation strategy in overcoming cDDP resistance through enhanced hCtr1 expression are evaluated. EXPERT OPINION While both transcriptional and post-translational mechanisms of hCtr1 regulation by cellular copper bioavailability have been proposed, detailed molecular insights into hCtr1 regulation by copper homeostasis remain needed. Recent clinical study using a copper-lowering agent in enhancing hCtr1-mediated drug transport has achieved incremental improvement in overcoming Pt drug resistance. Further improvements in identifying predictive measures in the subpopulation of patients that can benefit from the treatment are needed.
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Affiliation(s)
- Helen H W Chen
- a 1 National Cheng Kung University, National Cheng Kung University Hospital, College of Medicine, Department of Radiation Oncology , Tainan, Taiwan
| | - Wen-Chung Chen
- b 2 National Cheng Kung University, National Cheng Kung University Hospital, College of Medicine, Department of Pathology , Tainan, Taiwan
| | - Zhang-Dong Liang
- c 3 The University of Texas MD Anderson Cancer Center, Department of Translational Molecular Pathology , Houston, TX 77030, USA
| | - Wen-Bin Tsai
- c 3 The University of Texas MD Anderson Cancer Center, Department of Translational Molecular Pathology , Houston, TX 77030, USA
| | - Yan Long
- d 4 The University of Texas MD Anderson Cancer Center, Department of Translational Molecular Pathology , Houston, TX 77030, USA
| | - Isamu Aiba
- e 5 The University of Texas MD Anderson Cancer Center, Department of Translational Molecular Pathology , Houston, TX 77030, USA
| | - Siqing Fu
- f 6 The University of Texas MD Anderson Cancer Center, Departments of Investigative Cancer Therapeutics , Houston, TX, USA
| | - Russell Broaddus
- g 7 The University of Texas MD Anderson Cancer Center, Departments of Pathology , Houston, TX, USA
| | - Jinsong Liu
- g 7 The University of Texas MD Anderson Cancer Center, Departments of Pathology , Houston, TX, USA
| | - Lynn G Feun
- h 8 University of Miami, Sylvester Comprehensive Cancer Center , 1475 NW 12th Avenue, Miami, FL 33136, USA
| | - Niramol Savaraj
- h 8 University of Miami, Sylvester Comprehensive Cancer Center , 1475 NW 12th Avenue, Miami, FL 33136, USA
| | - Macus Tien Kuo
- i 9 The University of Texas MD Anderson Cancer Center, Department of Translational Molecular Pathology , Unit 2951, LSP 9.4206, 2130 W. Holcombe Blvd, Houston, TX 77030, USA +1 713 834 6038 ; +1 713 834 6085 ;
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Kalubi KN, Mehes-Smith M, Narendrula R, Michael P, Omri A. Molecular analysis of red maple (Acer rubrum) populations from a reclaimed mining region in Northern Ontario (Canada): soil metal accumulation and translocation in plants. ECOTOXICOLOGY (LONDON, ENGLAND) 2015; 24:636-647. [PMID: 25560741 DOI: 10.1007/s10646-014-1411-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/27/2014] [Indexed: 06/04/2023]
Abstract
Red maple (Acer rubrum) species is one of the most widespread deciduous (hardwood) trees of eastern North America. It is among the dominant tree species in the Northern Ontario after land reclamation. To date, the effects of heavy metal contamination from the mining activities on terrestrial ecosystems are not well understood. The main objectives of the present study are (1) to determine the level of phytoavailable metal in soil and accumulation in A. rubrum, and (2) to compare the levels of genetic variation among and within A. rubrum populations from areas with different metal contents in a Northern Ontario region. The total heavy metal levels were found to be high but the availability of these metals were much lower. We found that red maple does not accumulate heavy metals in their leaves as other hardwood species. The translocation factors were 0.05, 0.21, 0.38, 0.90, and 2.8 for Cu, Ni, Fe, Zn, and Mg, respectively. The levels of genetic variation in red maple populations from reclaimed lands in Northern Ontario were moderate to high since the percentage of polymorphic loci varied between 51 and 67%. The mean values for observed number of alleles (Na), effective number of alleles (Ne), Nei's gene diversity (h), and Shannon's information index (I) were 1.60, 1.24, 0.15 and 0.24, respectively. The population differentiation (GST) among the fragmented populations was high (0.28) despite a high level of gene flow (Nm = 1.28). Nevertheless, all the populations within the targeted region were genetically closely related. A specific ISSR marker that was identified in all the samples from the reference sites was absent in most samples from metal contaminated. This specific band was cloned and sequenced. Overall, the present study confirms that red maple populations in Northern Ontario are genetically sustainable despite the high level of total metal content in soil.
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Affiliation(s)
- K N Kalubi
- Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E-2C6, Canada
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Wimalarathna RN, Pan PY, Shen CH. Co-dependent recruitment of Ino80p and Snf2p is required for yeast CUP1 activation. Biochem Cell Biol 2014; 92:69-75. [DOI: 10.1139/bcb-2013-0097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In yeast, Ace1p-dependent induction of CUP1 is responsible for protecting cells from copper toxicity. Although the mechanism of yeast CUP1 induction has been studied intensively, it is still uncertain which chromatin remodelers are involved in CUP1 transcriptional activation. Here, we show that yeast cells are inviable in the presence of copper when either chromatin remodeler, Ino80p or Snf2p, is not present. This inviability is due to the lack of CUP1 expression in ino80Δ and snf2Δ cells. Subsequently, we observe that both Ino80p and Snf2p are present at the promoter and they are responsible for recruiting chromatin remodeling activity to the CUP1 promoter under induced conditions. These results suggest that they directly participate in CUP1 transcriptional activation. Furthermore, the codependent recruitment of both INO80 and SWI/SNF depends on the presence of the transcriptional activator, Ace1p. We also demonstrate that both remodelers are required to recruit RNA polymerase II and targeted histone acetylation, indicating that remodelers are recruited to the CUP1 promoter before RNA polymerase II and histone acetylases. These observations provide evidence for the mechanism of CUP1 induction. As such, we propose a model that describes novel insight into the order of events in CUP1 activation.
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Affiliation(s)
- Roshini N. Wimalarathna
- Department of Biology, College of Staten Island, City University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA
- PhD Program in Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, NY 10016, USA
| | - Po Yun Pan
- Department of Biology, College of Staten Island, City University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA
| | - Chang-Hui Shen
- Department of Biology, College of Staten Island, City University of New York, 2800 Victory Blvd., Staten Island, NY 10314, USA
- PhD Program in Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, NY 10016, USA
- Institute for Macromolecular Assemblies, City University of New York, 2800 Victory Blvd, Staten Island, NY 10314, USA
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Natural and modified promoters for tailored metabolic engineering of the yeast Saccharomyces cerevisiae. Methods Mol Biol 2014; 1152:17-42. [PMID: 24744025 DOI: 10.1007/978-1-4939-0563-8_2] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The ease of highly sophisticated genetic manipulations in the yeast Saccharomyces cerevisiae has initiated numerous initiatives towards development of metabolically engineered strains for novel applications beyond its traditional use in brewing, baking, and wine making. In fact, baker's yeast has become a key cell factory for the production of various bulk and fine chemicals. Successful metabolic engineering requires fine-tuned adjustments of metabolic fluxes and coordination of multiple pathways within the cell. This has mostly been achieved by controlling gene expression at the transcriptional level, i.e., by using promoters with appropriate strengths and regulatory properties. Here we present an overview of natural and modified promoters, which have been used in metabolic pathway engineering of S. cerevisiae. Recent developments in creating promoters with tailor-made properties are also discussed.
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Saijo T, Nagasawa A. Development of a tightly regulated and highly responsive copper-inducible gene expression system and its application to control of flowering time. PLANT CELL REPORTS 2014; 33:47-59. [PMID: 24097281 DOI: 10.1007/s00299-013-1511-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 09/09/2013] [Accepted: 09/20/2013] [Indexed: 06/02/2023]
Abstract
KEY MESSAGE A newly developed copper-inducible gene expression system overcame the mixed results reported earlier, worked well both in cultured cells and a whole plant, and enabled to control flowering timing. Copper is one of the essential microelements and is readily taken up by plants. However, to date, it has rarely been used to control the expression of genes of interest, probably due to the inefficiency of the gene expression systems. In this study, we successfully developed a copper-inducible gene expression system that is based on the regulation of the yeast metallothionein gene. This system can be applied in the field and regulated at approximately one-hundredth of the rate used for registered copper-based fungicides. In the presence of copper, a translational fusion of the ACE1 transcription factor with the VP16 activation domain (VP16AD) of herpes simplex virus strongly activated transcription of the GFP gene in transgenic Arabidopsis. Interestingly, insertion of the To71 sequence, a 5'-untranslated region of the 130k/180k gene of tomato mosaic virus, upstream of the GFP gene reduced the basal expression of GFP in the absence of copper to almost negligible levels, even in soil-grown plants that were supplemented with ordinary liquid nutrients. Exposure of plants to 100 μM copper resulted in an over 1,000-fold induction ratio at the transcriptional level of GFP. This induction was copper-specific and dose-dependent with rapid and reversible responses. Using this expression system, we also succeeded in regulating floral transition by copper treatment. These results indicate that our newly developed copper-inducible system can accelerate gene functional analysis in model plants and can be used to generate novel agronomic traits in crop species.
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Affiliation(s)
- Takanori Saijo
- Biology Group, Discovery, Health & Crop Sciences Research Laboratory, Sumitomo Chemical Co., Ltd., 4-2-1, Takatsukasa, Takarazuka, Hyogo, 665-8555, Japan,
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Dong D, Xu X, Yin W, Kang YJ. Changes in copper concentrations affect the protein levels but not the mRNA levels of copper chaperones in human umbilical vein endothelial cells. Metallomics 2013; 6:554-9. [PMID: 24343031 DOI: 10.1039/c3mt00138e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Copper chaperones are critical regulators of intracellular copper metabolism and distribution. The present study was undertaken to investigate the effects of changes in copper concentrations on the abundance of copper chaperones. Human umbilical vein endothelial cells (HUVECs) were treated with siRNA targeting copper transporter 1 (CTR1) or tetraethylenepentamine (TEPA) to decrease, or with copper sulfide to increase, intracellular copper concentrations, assayed using an atomic absorption spectrophotometer. Western blot analyses showed that CTR1 silencing or TEPA treatment increased the protein levels of copper chaperone ATOX1 and copper chaperone for superoxide dismutase 1 (CCS-1), but decreased copper chaperone for cytochrome c oxidase (COX17). In contrast, copper supplementation decreased the protein levels of ATOX1 and CCS-1 and increased COX17. Real-time RT-PCR analyses found no difference in the mRNA levels of the copper chaperones examined under the conditions defined above. This study thus demonstrated that changes in copper concentrations alter the protein levels, but not the mRNA levels, of copper chaperones, suggesting a role of copper in the post-translational modification of these proteins.
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Affiliation(s)
- Daoyin Dong
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P. R. China.
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Effective induction of pblac1 laccase by copper ion in Polyporus brumalis ibrc05015. Fungal Biol 2012; 117:52-61. [PMID: 23332833 DOI: 10.1016/j.funbio.2012.11.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 11/06/2012] [Accepted: 11/23/2012] [Indexed: 11/24/2022]
Abstract
Polyporus brumalis ibrc05015 is a strain capable of high laccase (Lac) production. Among several inducers, 0.25 mM copper was most effective for Lac production. One of the Lacs induced by copper was PbLac1, and its transcription was induced within 60 min after copper addition. The promoter region of pblac1 contained six putative metal response elements and one Ace1 consensus cis-element. We cloned the P. brumalis PbAce1 transcription factor, a homologue of Saccharomyces cerevisiae transcription factor Ace1, which regulates metallothionein genes in response to excess copper. PbAce1 complemented the function of Ace1 in an S. cerevisiae Δace strain. The conserved N-terminal copper-fist DNA binding domain of PbAce1 was required for complementation. In the PbAce1 complemented Δace1 strain, the pblac1 promoter was constitutively expressed at a high level, independent of copper concentration. PbAce1 has two Cys-rich repeat motifs (PbC1 and PbC2), which are similar to the Cys-rich repeat domain in metallothionein proteins, and are uniquely conserved in the C-terminal domain of basidiomycetous Ace1 sequences. These C-terminal domains could be involved in copper sensing and concentration-dependent Lac production in basidiomycetous fungi.
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Bi WX, Kong F, Hu XY, Cui X. Role of glutathione in detoxification of copper and cadmium by yeast cells having different abilities to express cup1 protein. Toxicol Mech Methods 2012; 17:371-8. [PMID: 20020960 DOI: 10.1080/15376510601091392] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
ABSTRACT Although copper is an essential metal and cadmium is an environmental pollutant, both are toxic when present in excess. Metallothionein and glutathione are two of the key components that participate in detoxification of copper and cadmium. In the present study the role of glutathione in resistance to copper and cadmium was investigated with the yeast Saccharomyces cerevisiae. The yeast cells used in this study have different abilities to produce glutathione and Cup1 protein, the yeast metallothionein homolog encoded by CUP1 gene. It was demonstrated that Cup1 protein plays a dominant role in buffering excess copper, and yeast does not depend on glutathione to reduce copper toxicity whether it possesses single or multiple copies of CUP1. In fact, excess copper can cause glutathione oxidation and depletion and damage the glutathione system. On the other hand, it was indicated that Cup1 protein is an important cadmium-detoxifying component, and the glutathione system can positively respond to cadmium. In yeast containing single or multiple copies of CUP1, glutathione is an indispensable line of defense against cadmium. Yeast having glutathione and no Cup1 protein is not able to grow in medium containing excess copper, but can tolerate higher concentrations of cadmium. In addition, it was found that yeast, independent of glutathione, can efficiently remove excess copper, whereas it cannot promptly eliminate accumulated cadmium regardless of having glutathione or not.
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Affiliation(s)
- W X Bi
- Department of Biochemistry, Wakayama Medical University, Kimiidera, Wakayama, Japan
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Chromatin repositioning activity and transcription machinery are both recruited by Ace1p in yeast CUP1 activation. Biochem Biophys Res Commun 2012; 422:658-63. [PMID: 22609398 DOI: 10.1016/j.bbrc.2012.05.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 05/09/2012] [Indexed: 11/22/2022]
Abstract
The relationship among transcriptional activators, nucleosome repositioning activity and transcription machinery at the yeast CUP1 gene was addressed. CUP1 encodes a cysteine-rich, copper-binding metallothionein that protects cells against copper toxicity through its ability to sequester copper. The induction of CUP1 requires the presence of Ace1p and the binding of Ace1p at the CUP1 promoter during activation provides evidence that Ace1p is directly involved in CUP1 induction. Furthermore, transcriptional activation of CUP1 resulted in nucleosome repositioning at the CUP1 promoter and sequences further downstream in the coding region, suggesting a gene-wide chromatin remodeling activity. Such remodeling activity depends on the presence of transcription activator Ace1p. The recruitment of RNA polymerase II also requires the presence of Ace1p. Therefore, these observations provide insight into the molecular mechanism of CUP1 activation.
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Coordination chemistry of copper proteins: How nature handles a toxic cargo for essential function. J Inorg Biochem 2012; 107:129-43. [DOI: 10.1016/j.jinorgbio.2011.11.024] [Citation(s) in RCA: 232] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/25/2011] [Accepted: 11/15/2011] [Indexed: 01/16/2023]
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Kobayashi T, Itai RN, Aung MS, Senoura T, Nakanishi H, Nishizawa NK. The rice transcription factor IDEF1 directly binds to iron and other divalent metals for sensing cellular iron status. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:81-91. [PMID: 21880076 DOI: 10.1111/j.1365-313x.2011.04772.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Iron is essential for most living organisms and its availability often determines survival and proliferation. The Oryza sativa (rice) transcription factor IDEF1 plays a crucial role in regulating iron deficiency-induced genes involved in iron homeostasis. In the present report, we found characteristic histidine-asparagine repeat and proline-rich regions in IDEF1 and its homolog in Hordeum vulgare (barley), HvIDEF1. An immobilized metal ion affinity chromatography assay revealed that IDEF1 and HvIDEF1 bind to various divalent metals, including Fe(2+) and Ni(2+) . Recombinant IDEF1 protein expressed in Escherichia coli contained mainly Fe and Zn. This metal-binding activity of IDEF1 was almost abolished by deletion of the histidine-asparagine and proline-rich regions, but DNA-binding and trans-activation functions were not impaired by the deletion. Transgenic rice plants constitutively overexpressing IDEF1 without these metal-binding domains failed to cause pleiotropic effects conferred by overexpression of full-length IDEF1, including a low germination rate, impaired seedling growth, tolerance to iron deficiency in hydroponic culture, and enhanced expression of various iron deficiency-inducible genes. Impairment of the transcriptional regulation of IDEF1 by deletion of the metal-binding domains occurred primarily at an early stage of iron deficiency. These results suggest that the histidine-asparagine and proline-rich regions in rice IDEF1 directly bind to divalent metals and sense the cellular metal ion balance caused by changes in iron availability.
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Affiliation(s)
- Takanori Kobayashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Liang ZD, Tsai WB, Lee MY, Savaraj N, Kuo MT. Specificity protein 1 (sp1) oscillation is involved in copper homeostasis maintenance by regulating human high-affinity copper transporter 1 expression. Mol Pharmacol 2011; 81:455-64. [PMID: 22172574 DOI: 10.1124/mol.111.076422] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Copper is an essential micronutrient for cell growth but is toxic in excess. Copper transporter (Ctr1) plays an important role in regulating adequate copper levels in mammalian cells. We have shown previously that expression of the human high-affinity copper transporter (hCtr1) was transcriptionally up-regulated under copper-depleted conditions and down-regulated under replete conditions; moreover, elevated hCtr1 levels suppress hCtr1 expression. Specificity protein 1 (Sp1) regulates expression of hCtr1 under copper-stressed conditions. In this study, we made the following important observations: 1) Sp1 expression is down-regulated under copper-replete conditions but up-regulated under copper-depleted conditions. These up- and down-regulations of Sp1 in turn regulate hCtr1 expression to control copper homeostasis. 2) Copper-regulated Sp1 expression involved Sp1 binding to its own promoter as demonstrated by the chromatin immunoprecipitation assay; therefore, Sp1 is also transcriptionally self-regulated via hCtr1/copper intermediation. 3) Both zinc finger and glutamine-rich transactivation domains of Sp1 are involved in the Sp1-mediated hCtr1 and Sp1 regulation by copper stresses. 4) Although Sp3 expression is also regulated by copper availability, Sp3 does not regulate hCtr1 homeostasis. Collectively, our results demonstrated that mammalian cells use Sp1 oscillation in response to copper availability to regulate copper homeostasis through hCtr1 expression in a tripartite inter-regulatory relationship. These findings have important implications in mammalian copper physiology regulation.
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Affiliation(s)
- Zheng D Liang
- Department of Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
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