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Yu X, Li Y, Tian X, Zang X, Yang S, Qiao H, Zhu C, Moussian B, Wang Y. Pb exposure causes non-linear accumulation of Pb in D. melanogaster controlled by metallothionein B and exerts ecological effects. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 900:165680. [PMID: 37499811 DOI: 10.1016/j.scitotenv.2023.165680] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023]
Abstract
Pb pollution can harm human health and the ecosystem. Therefore, it is worthwhile to study the metabolic processes of heavy metals in individual bodies and their influence on ecological systems. In this work, we analyzed the genetic responses and physiological changes of D. melanogaster which took diets exposed to different doses of Pb using transcriptomic analysis, ICP-MS, and various other physiological methods. We found that the Pb accumulated in D. melanogaster in a nonlinear pattern with the increase of Pb content in food. Metallothioneins (Mtns), especially the MtnB directly affects the accumulation and excretion of metal Pb in D. melanogaster, and causes the nonlinear accumulation. Metal regulatory transcription factor-1 (MTF-1) is involved in the regulation of Pb-induced high expressions of Mtns. Furthermore, an interaction between the metal metabolism pathway and xenobiotic response pathway leads to the cross-tolerances of Pb-exposed D. melanogaster to insecticides and other toxins. The oxidative stress induced by Pb toxicity may be the bridge between them. Our findings provide a physiological and molecular genetic basis for further study of the accumulation and metabolism of Pb in D. melanogaster.
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Affiliation(s)
- Xiaoyu Yu
- School of Pharmaceutical Science and Technology, Tianjin University, 300072 Tianjin, China
| | - Ying Li
- School of Pharmaceutical Science and Technology, Tianjin University, 300072 Tianjin, China
| | - Xiaohan Tian
- School of Pharmaceutical Science and Technology, Tianjin University, 300072 Tianjin, China
| | - Xiya Zang
- School of Pharmaceutical Science and Technology, Tianjin University, 300072 Tianjin, China
| | - Shuyu Yang
- School of Pharmaceutical Science and Technology, Tianjin University, 300072 Tianjin, China
| | - Huanhuan Qiao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, 300072 Tianjin, China
| | - Chunfeng Zhu
- School of Life Sciences, Tianjin University, 300072 Tianjin, China
| | - Bernard Moussian
- Animal Genetics, Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany.
| | - Yiwen Wang
- School of Pharmaceutical Science and Technology, Tianjin University, 300072 Tianjin, China.
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2
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Yiwen W, Xiaohan T, Chunfeng Z, Xiaoyu Y, Yaodong M, Huanhuan Q. Genetics of metallothioneins in Drosophilamelanogaster. CHEMOSPHERE 2022; 288:132562. [PMID: 34653491 DOI: 10.1016/j.chemosphere.2021.132562] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Metallothioneins (MTs) are ubiquitous metal-chelating proteins involved in cellular metal homeostasis. MTs were found to be related with almost all the biological processes and their malfunctioning is responsible for a lot of important human diseases. Invertebrate MTs were also used broadly as biomarkers of metal contamination due to their inducible expression by metal exposure. MT system plays a significant role in maintaining human health and ecological stability. Drosophila melanogaster, the vinegar fly, is a perfect model for studying insect MT systems. Six MTs were identified in D. melanogaster, and were designated MtnA to F. All the MTs are considered as Cu-thioneins except for MtnF, which is putatively a Zn-thionein. Expression of all the MTs are regulated by MTF-1/MRE system, thus being able to be induced by heavy metal exposure. The expression pattern and function of separated MTs are partially overlapped and partially distinct. In this work, we made a summary of all the studies on D. melanogaster MTs. From this review, we noted that, compared with studies on mammalian MTs, the understanding of the MT system of D. melanogaster and other invertebrates, especially the regulation mechanism for MT expression and protein-protein interaction with them, is still in a low level.
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Affiliation(s)
- Wang Yiwen
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China
| | - Tian Xiaohan
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China
| | - Zhu Chunfeng
- School of Life Sciences, Tianjin University, 300072, Tianjin, China
| | - Yu Xiaoyu
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China
| | - Miao Yaodong
- Second Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, 300250, Tianjin, China
| | - Qiao Huanhuan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, 300072, Tianjin, China.
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3
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Ditta SA, Yaqub A, Tanvir F, Ullah R, Rashid M, Bilal M. Histopathological evaluation of amino acid capped silver nanoconjugates in albino mice. BIOINSPIRED BIOMIMETIC AND NANOBIOMATERIALS 2021. [DOI: 10.1680/jbibn.21.00033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Various molecules may modify the surface chemistry of commonly used nanomaterials (NMs), resulting in the synthesis of novel and safer NMs. The current study was delineated to evaluate the in vivo toxicity profiling of the silver nanoconjugates (AgNCs) conjugated with different amino acids. The L-glycine capped-AgNCs exhibited toxicity and caused tissue damage, while L-cystine- and L-tyrosine-capped AgNCs showed protective effects against cadmium-induced toxicity. L-cystine-capped AgNCs performed well as compared to other amino-acid AgNCs. The level of serum creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and blood urea increased (p < 0.05) in G2, G3 and G5 in comparison to G1 (control group), while an increase in bilirubin for G2 was statistically non-significant (p > 0.05). The ALT and AST elevated (p < 0.05) in G4; however, other serological parameters in G4 and G6 did not show any noticeable change in their values. Histological analysis showed disturbed and deformed cellular structures in liver and kidney tissues of G2, G3 and G5. However, G4 and G6 samples demonstrated minute changes in comparison to G1. It is concluded that L-cystine- and L-tyrosine-capped AgNCs exhibited protective effects and should be tested further for developing safer nanoconjugates for biomedical uses.
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Affiliation(s)
| | - Atif Yaqub
- Department of Zoology, Government College University, Lahore, Pakistan
| | - Fouzia Tanvir
- Department of Zoology, University of Okara, Okara, Pakistan
| | - Rehan Ullah
- Department of Zoology, Government College University, Lahore, Pakistan
| | - Muhammad Rashid
- Department of Zoology, Government College University, Lahore, Pakistan
| | - Muhammad Bilal
- Department of Zoology, Government College University, Lahore, Pakistan
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4
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Purać J, Čelić TV, Vukašinović EL, Đorđievski S, Milić S, Ninkov J, Kojić D. Identification of a metallothionein gene and the role of biological thiols in stress induced by short-term Cd exposure in Ostrinia nubilalis. Comp Biochem Physiol C Toxicol Pharmacol 2021; 250:109148. [PMID: 34343701 DOI: 10.1016/j.cbpc.2021.109148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/15/2021] [Accepted: 07/23/2021] [Indexed: 01/05/2023]
Abstract
Cadmium (Cd) is a non-essential metal that is highly toxic to all living forms, characterized by an extremely high affinity for thiol (SH) groups. The aim of this work was to identify and experimentally verify metallothionein gene and to analyze the role of biological thiols in stress induced by short-term Cd exposure in Ostrinia nubilalis, one of the most important corn pests. The coding region of a metallothionein (MT) gene in O. nubilalis was identified, encoding protein, OnMT1, which contains 46 amino acids, including 12 cysteine residues, and has no aromatic amino acids. Phylogenetic analysis revealed that OnMT1 clustered together with metallothionein from Bombyx mori. Structural bioinformatics analysis strongly suggests that OnMT1 is a metallothionein with affinity for multiple transition metals. Further, in order to elucidate the role of biological thiols, O. nubilalis L5 larvae were exposed to increasing Cd concentrations in diet (6.85, 41.71, 77.35 mg kg-1) during a 48 h period, after which Cd concentration in larvae was measured (3.50, 12.02, 47.37 mg kg-1, respectively). Due to short-term Cd exposure, concentration of free protein SH groups and relative expression of OnMT1 and thioredoxin (Trx) genes was elevated, while the reduced glutathione content remained unchanged. The presented results provide evidence that OnMT1 plays a role in Cd detoxification and homeostasis, and confirm the importance of biological thiols, especially OnMT1 and Trx, in the early response of O. nubilalis to Cd poisoning, indicating interaction between Cd and thiol-linked redox reactions. Insects provide valuable insight into molecular adaptations to metals.
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Affiliation(s)
- Jelena Purać
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia
| | - Tatjana V Čelić
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia.
| | - Elvira L Vukašinović
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia
| | - Srđana Đorđievski
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia
| | - Stanko Milić
- Institute of Field and Vegetable Crops, National Institute of the Republic of Serbia, Laboratory for Soil and Agroecology, Maksima Gorkog 30, 21000 Novi Sad, Serbia
| | - Jordana Ninkov
- Institute of Field and Vegetable Crops, National Institute of the Republic of Serbia, Laboratory for Soil and Agroecology, Maksima Gorkog 30, 21000 Novi Sad, Serbia
| | - Danijela Kojić
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia
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Ramnarine TJS, Grath S, Parsch J. Natural variation in the transcriptional response of Drosophila melanogaster to oxidative stress. G3-GENES GENOMES GENETICS 2021; 12:6409858. [PMID: 34747443 PMCID: PMC8727983 DOI: 10.1093/g3journal/jkab366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/15/2021] [Indexed: 11/26/2022]
Abstract
Broadly distributed species must cope with diverse and changing environmental conditions, including various forms of stress. Cosmopolitan populations of Drosophila melanogaster are more tolerant to oxidative stress than those from the species’ ancestral range in sub-Saharan Africa, and the degree of tolerance is associated with an insertion/deletion polymorphism in the 3′ untranslated region of the Metallothionein A (MtnA) gene that varies clinally in frequency. We examined oxidative stress tolerance and the transcriptional response to oxidative stress in cosmopolitan and sub-Saharan African populations of D. melanogaster, including paired samples with allelic differences at the MtnA locus. We found that the effect of the MtnA polymorphism on oxidative stress tolerance was dependent on the genomic background, with the deletion allele increasing tolerance only in a northern, temperate population. Genes that were differentially expressed under oxidative stress included MtnA and other metallothioneins, as well as those involved in glutathione metabolism and other genes known to be part of the oxidative stress response or the general stress response. A gene coexpression analysis revealed further genes and pathways that respond to oxidative stress including those involved in additional metabolic processes, autophagy, and apoptosis. There was a significant overlap among the genes induced by oxidative and cold stress, which suggests a shared response pathway to these two stresses. Interestingly, the MtnA deletion was associated with consistent changes in the expression of many genes across all genomic backgrounds, regardless of the expression level of the MtnA gene itself. We hypothesize that this is an indirect effect driven by the loss of microRNA binding sites within the MtnA 3′ untranslated region.
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Affiliation(s)
- Timothy J S Ramnarine
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität (LMU) München, Planegg-Martinsried 82152, Germany
| | - Sonja Grath
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität (LMU) München, Planegg-Martinsried 82152, Germany
| | - John Parsch
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität (LMU) München, Planegg-Martinsried 82152, Germany
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6
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Slobodian MR, Petahtegoose JD, Wallis AL, Levesque DC, Merritt TJS. The Effects of Essential and Non-Essential Metal Toxicity in the Drosophila melanogaster Insect Model: A Review. TOXICS 2021; 9:269. [PMID: 34678965 PMCID: PMC8540122 DOI: 10.3390/toxics9100269] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/08/2021] [Accepted: 10/14/2021] [Indexed: 02/07/2023]
Abstract
The biological effects of environmental metal contamination are important issues in an industrialized, resource-dependent world. Different metals have different roles in biology and can be classified as essential if they are required by a living organism (e.g., as cofactors), or as non-essential metals if they are not. While essential metal ions have been well studied in many eukaryotic species, less is known about the effects of non-essential metals, even though essential and non-essential metals are often chemically similar and can bind to the same biological ligands. Insects are often exposed to a variety of contaminated environments and associated essential and non-essential metal toxicity, but many questions regarding their response to toxicity remain unanswered. Drosophila melanogaster is an excellent insect model species in which to study the effects of toxic metal due to the extensive experimental and genetic resources available for this species. Here, we review the current understanding of the impact of a suite of essential and non-essential metals (Cu, Fe, Zn, Hg, Pb, Cd, and Ni) on the D. melanogaster metal response system, highlighting the knowledge gaps between essential and non-essential metals in D. melanogaster. This review emphasizes the need to use multiple metals, multiple genetic backgrounds, and both sexes in future studies to help guide future research towards better understanding the effects of metal contamination in general.
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Affiliation(s)
| | | | | | | | - Thomas J. S. Merritt
- Faculty of Science and Engineering, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON P3E 2C6, Canada; (M.R.S.); (J.D.P.); (A.L.W.); (D.C.L.)
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7
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Zhang J, Shi Z, Gao Z, Wen Y, Wang W, Liu W, Wang X, Zhu F. Identification of three metallothioneins in the black soldier fly and their functions in Cd accumulation and detoxification. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 286:117146. [PMID: 34438505 DOI: 10.1016/j.envpol.2021.117146] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 03/30/2021] [Accepted: 04/11/2021] [Indexed: 06/13/2023]
Abstract
The black soldier fly (BSF) Hermetia illucens has a strong tolerance to cadmium stress. This helps to use BSF in entomoremediation of heavy metal pollution. Rich metallothionein (MT) proteins were thought to be important for some insects to endure the toxicity of heavy metal. We identified and characterized three MTs genes in BSF (BSFMTs), including BSFMT1, BSFMT2A, and BSFMT2B. Molecular modeling was used to predict metal binding sites. Phylogenetic analysis was used to identify gene families. Overexpression of the recombinant black soldier fly metallothioneins was found to confer Cd tolerance in Escherichia coli. Finally, functions of BSFMTs in BSF were explored through RNA interference (RNAi). RNAi results of BSFMT2B showed that the larval fresh weight decreased significantly, and the larvae mortality increased significantly. This study suggests that BSFMTs have important properties in Cd detoxification and tolerance in BSF. Further characterization analyses of physiological function about metallothioneins are necessary in BSF and other insects.
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Affiliation(s)
- Jie Zhang
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion By Insects, Huazhong Agricultural University, Wuhan, 430070, China; Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Zhihui Shi
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion By Insects, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Zhenghui Gao
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion By Insects, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Yiting Wen
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion By Insects, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Wanqiang Wang
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion By Insects, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Wen Liu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Xiaoping Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Fen Zhu
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion By Insects, Huazhong Agricultural University, Wuhan, 430070, China; Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
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8
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Jia R, Song Z, Lin J, Li Z, Shan G, Huang C. Gawky modulates MTF-1-mediated transcription activation and metal discrimination. Nucleic Acids Res 2021; 49:6296-6314. [PMID: 34107019 PMCID: PMC8216474 DOI: 10.1093/nar/gkab474] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 02/07/2023] Open
Abstract
Metal-induced genes are usually transcribed at relatively low levels under normal conditions and are rapidly activated by heavy metal stress. Many of these genes respond preferentially to specific metal-stressed conditions. However, the mechanism by which the general transcription machinery discriminates metal stress from normal conditions and the regulation of MTF-1-meditated metal discrimination are poorly characterized. Using a focused RNAi screening in Drosophila Schneider 2 (S2) cells, we identified a novel activator, the Drosophila gawky, of metal-responsive genes. Depletion of gawky has almost no effect on the basal transcription of the metallothionein (MT) genes, but impairs the metal-induced transcription by inducing the dissociation of MTF-1 from the MT promoters and the deficient nuclear import of MTF-1 under metal-stressed conditions. This suggests that gawky serves as a 'checkpoint' for metal stress and metal-induced transcription. In fact, regular mRNAs are converted into gawky-controlled transcripts if expressed under the control of a metal-responsive promoter, suggesting that whether transcription undergoes gawky-mediated regulation is encrypted therein. Additionally, lack of gawky eliminates the DNA binding bias of MTF-1 and the transcription preference of metal-specific genes. This suggests a combinatorial control of metal discrimination by gawky, MTF-1, and MTF-1 binding sites.
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Affiliation(s)
- Ruirui Jia
- School of Life Sciences, Chongqing University, Chongqing 401331, China
- Center of Plant Functional Genomics, Institute of Advanced Interdisciplinary Studies, Chongqing University, Chongqing 401331, China
| | - Zhenxing Song
- School of Life Sciences, Chongqing University, Chongqing 401331, China
- Center of Plant Functional Genomics, Institute of Advanced Interdisciplinary Studies, Chongqing University, Chongqing 401331, China
| | - Jiamei Lin
- School of Life Sciences, Chongqing University, Chongqing 401331, China
- Center of Plant Functional Genomics, Institute of Advanced Interdisciplinary Studies, Chongqing University, Chongqing 401331, China
| | - Zhengguo Li
- School of Life Sciences, Chongqing University, Chongqing 401331, China
- Center of Plant Functional Genomics, Institute of Advanced Interdisciplinary Studies, Chongqing University, Chongqing 401331, China
| | - Ge Shan
- School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Chuan Huang
- School of Life Sciences, Chongqing University, Chongqing 401331, China
- Center of Plant Functional Genomics, Institute of Advanced Interdisciplinary Studies, Chongqing University, Chongqing 401331, China
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9
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Essential (Mg, Fe, Zn and Cu) and Non-Essential (Cd and Pb) Elements in Predatory Insects ( Vespa crabro and Vespa velutina): A Molecular Perspective. Int J Mol Sci 2020; 22:ijms22010228. [PMID: 33379365 PMCID: PMC7797950 DOI: 10.3390/ijms22010228] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 11/17/2022] Open
Abstract
The recent introduction of the Asian yellow-legged hornet, Vespa velutina, into Europe has raised concern regarding the threat to honeybees and the competition with the European hornet, Vespa crabro. The aim of this study was to investigated essential (Mg, Fe, Zn, Cu) and non-essential (Cd and Pb) elements in these two species. Element concentrations were determined in the whole body and separately in the head, thorax and abdomen using atomic absorption spectrometry (AAS). The changes in essential element concentration and speciation during metamorphosis were also studied using size exclusion chromatography followed by AAS and proteomic analysis. In both species, the essential elements were more concentrated in the abdomen due to the presence of fat bodies. Magnesium, Fe and Zn concentrations were significantly higher in V. crabro than in V. velutina and could have been related to the higher aerobic energy demand of the former species required to sustain foraging flight. Low concentrations of Cd and Pb were indicative of low environmental exposure. The concentration and speciation of essential elements, particularly Fe, varied among the developmental stages, indicating a modification of ligand preferences during metamorphosis. Overall, the results in the present study provide a better understanding of the hornet metal metabolism and a foundation for additional studies.
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Wang Z, Li X, Zhou B. Drosophila ZnT1 is essential in the intestine for dietary zinc absorption. Biochem Biophys Res Commun 2020; 533:1004-1011. [PMID: 33012507 DOI: 10.1016/j.bbrc.2020.09.077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 09/20/2020] [Indexed: 12/12/2022]
Abstract
Zinc is an essential trace element and participates in a variety of biological processes. ZnT (SLC30) family members are generally responsible for zinc efflux across the membrane regulating zinc homeostasis. In mammals, the only predominantly plasma membrane resident ZnT has been reported to be ZnT1, and ZnT1-/ZnT1- mice die at the embryonic stage. In Drosophila, knock down of ZnT1 homologue (dZnT1//ZnT63C/CG17723) results in growth arrest under zinc-limiting conditions. To investigate the essentiality of dZnT1 for zinc homeostasis, as well as its role in dietary zinc uptake especially under normal physiological conditions, we generated dZnT1 mutants by the CRISPER/Cas9 method. Homozygous mutant dZnT1 is lethal, with substantial zinc accumulation in the iron cell region, posterior midgut as well as gastric caeca. Expression of human ZnT1 (hZnT1), in the whole body or in the entire midgut, fully rescued the dZnT1 mutant lethality, whereas tissue-specific expression of hZnT1 in the iron cell region and posterior midgut partially rescued the developmental defect of the dZnT1 mutant. Supplementation of zinc together with clioquinol or hinokitiol conferred a limited but observable rescue upon dZnT1 loss. Our work demonstrated the absolute requirement of dZnT1 in Drosophila survival and indicated that the most essential role of dZnT1 is in the gut.
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Affiliation(s)
- Zhiqing Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Xinxin Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Bing Zhou
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China.
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11
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Luo M, Finet C, Cong H, Wei HY, Chung H. The evolution of insect metallothioneins. Proc Biol Sci 2020; 287:20202189. [PMID: 33109013 DOI: 10.1098/rspb.2020.2189] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Metallothioneins (MTs) are a family of cysteine-rich metal-binding proteins that are important in the chelating and detoxification of toxic heavy metals. Until now, the short length and the low sequence complexity of MTs have hindered the inference of robust phylogenies, hampering the study of their evolution. To address this longstanding question, we applied an iterative BLAST search pipeline that allowed us to build a unique dataset of more than 300 MT sequences in insects. By combining phylogenetics and synteny analysis, we reconstructed the evolutionary history of MTs in insects. We show that the MT content in insects has been shaped by lineage-specific tandem duplications from a single ancestral MT. Strikingly, we also uncovered a sixth MT, MtnF, in the model organism Drosophila melanogaster. MtnF evolves faster than other MTs and is characterized by a non-canonical length and higher cysteine content. Our methodological framework not only paves the way for future studies on heavy metal detoxification but can also allow us to identify other previously unidentified genes and other low complexity genomic features.
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Affiliation(s)
- Mei Luo
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA.,College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, People's Republic of China
| | - Cédric Finet
- Yale-NUS College, 16 College Avenue West, Singapore 138527, Republic of Singapore
| | - Haosu Cong
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Hong-Yi Wei
- College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, People's Republic of China
| | - Henry Chung
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA.,Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI 48824, USA
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12
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Nanda KP, Kumari C, Dubey M, Firdaus H. Chronic lead (Pb) exposure results in diminished hemocyte count and increased susceptibility to bacterial infection in Drosophila melanogaster. CHEMOSPHERE 2019; 236:124349. [PMID: 31326753 DOI: 10.1016/j.chemosphere.2019.124349] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Heavy metal Pb is a common toxic pollutant present in our environment adversely affecting health of the living organisms. Recent studies suggest positive correlation between heavy metal exposure and immune dysfunction and present work utilizes Drosophila to address this issue in relation to Pb exposure. In-vivo Pb toxicity was established by dietary intake where essential parameters like development and life span were found to be hampered and augmented upon metallothionein B (mtnB) downregulation hinting towards potential role of mtnB in Pb detoxification. Further response of Drosophila to B. subtilis bacterial infection was monitored by carrying out oral infections. Pb fed flies showed increased susceptibility to infection as compared to their controls. Since Drosophila hemocytes play dual role as immune cells, we checked for the total hemocyte count and found significant decrease in hemocyte numbers in Pb fed larvae. Both crystal cells and plasmatocytes, the two major hemocytes in third instar larval hemolymph were reduced. However we did not find any visible morphological changes in Giemsa stained hemocytes. Crystal cells are crucial for synthesis and release of phenoloxidase (PO), an enzyme required for melanin clot synthesis and deposition. PO activity assessed from total hemolymph protein isolates was found to be substantially decreased in Pb raised animals. Results were also confirmed by spot test and native gel activity assay of PO. Overall our results suggest immunotoxic effect of Pb through decrease in hemocyte count including crystal cell which in turn leads to decreased PO activity and increased susceptibility to B. subtilis.
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Affiliation(s)
- Kumari Pragati Nanda
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India
| | - Chandani Kumari
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India
| | - Madhavi Dubey
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India
| | - Hena Firdaus
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India.
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13
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Purać J, Nikolić TV, Kojić D, Ćelić AS, Plavša JJ, Blagojević DP, Petri ET. Identification of a metallothionein gene in honey bee Apis mellifera and its expression profile in response to Cd, Cu and Pb exposure. Mol Ecol 2019; 28:731-745. [PMID: 30575191 DOI: 10.1111/mec.14984] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 11/29/2018] [Indexed: 12/01/2022]
Abstract
Metallothioneins are ubiquitous proteins important in metal homeostasis and detoxification. However, they have not previously been identified in honey bees or other Hymenoptera, where metallothioneins could be of ecophysiological and ecotoxicological significance. Better understanding of the molecular responses to stress induced by toxic metals could contribute to honey bee conservation. In addition, honey bee metallothionein could represent a biomarker for monitoring environmental quality. Here we identify and characterize a metallothionein gene in Apis mellifera (AmMT). AmMT is 1,680 bp long and encodes a 48 amino acids protein with 15 cysteines and no aromatic residues. A metal response element upstream of the start codon, coupled with numerous cis-regulatory elements indicate the functional context of AmMT. Molecular modelling predicts several transition metal binding sites, and comparative phylogenetic analysis revealed five putative metallothionein proteins in three other hymenoptera species. AmMT was characterized by cloning the full-length coding sequence of the putative metallothionein. Recombinant AmMT was found to increase metal tolerance upon overexpression in Escherichia coli supplemented with Cd, Cu or Pb. Finally, in laboratory tests on honey bees, gene expression profiles showed a dose-dependant relationship between Cd, Cu and Pb concentrations present in food and AmMT expression, while field experiments showed induction of AmMT in bees from an industrial site compared to those from an urban area. These studies suggest that AmMT has metal binding properties in agreement with a possible role in metal homeostasis. Further functional and structural characterization of metallothionein in honey bees and other Hymenoptera are necessary.
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Affiliation(s)
- Jelena Purać
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Tatjana V Nikolić
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Danijela Kojić
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Anđelka S Ćelić
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Jovana J Plavša
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Duško P Blagojević
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia
| | - Edward T Petri
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
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14
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Miguel-Aliaga I, Jasper H, Lemaitre B. Anatomy and Physiology of the Digestive Tract of Drosophila melanogaster. Genetics 2018; 210:357-396. [PMID: 30287514 PMCID: PMC6216580 DOI: 10.1534/genetics.118.300224] [Citation(s) in RCA: 245] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/26/2018] [Indexed: 12/15/2022] Open
Abstract
The gastrointestinal tract has recently come to the forefront of multiple research fields. It is now recognized as a major source of signals modulating food intake, insulin secretion and energy balance. It is also a key player in immunity and, through its interaction with microbiota, can shape our physiology and behavior in complex and sometimes unexpected ways. The insect intestine had remained, by comparison, relatively unexplored until the identification of adult somatic stem cells in the Drosophila intestine over a decade ago. Since then, a growing scientific community has exploited the genetic amenability of this insect organ in powerful and creative ways. By doing so, we have shed light on a broad range of biological questions revolving around stem cells and their niches, interorgan signaling and immunity. Despite their relatively recent discovery, some of the mechanisms active in the intestine of flies have already been shown to be more widely applicable to other gastrointestinal systems, and may therefore become relevant in the context of human pathologies such as gastrointestinal cancers, aging, or obesity. This review summarizes our current knowledge of both the formation and function of the Drosophila melanogaster digestive tract, with a major focus on its main digestive/absorptive portion: the strikingly adaptable adult midgut.
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Affiliation(s)
- Irene Miguel-Aliaga
- Medical Research Council London Institute of Medical Sciences, Imperial College London, W12 0NN, United Kingdom
| | - Heinrich Jasper
- Buck Institute for Research on Aging, Novato, California 94945-1400
- Immunology Discovery, Genentech, Inc., San Francisco, California 94080
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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15
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Tejeda-Guzmán C, Rosas-Arellano A, Kroll T, Webb SM, Barajas-Aceves M, Osorio B, Missirlis F. Biogenesis of zinc storage granules in Drosophila melanogaster. J Exp Biol 2018; 221:jeb168419. [PMID: 29367274 PMCID: PMC5897703 DOI: 10.1242/jeb.168419] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/17/2018] [Indexed: 12/16/2022]
Abstract
Membrane transporters and sequestration mechanisms concentrate metal ions differentially into discrete subcellular microenvironments for use in protein cofactors, signalling, storage or excretion. Here we identify zinc storage granules as the insect's major zinc reservoir in principal Malpighian tubule epithelial cells of Drosophila melanogaster The concerted action of Adaptor Protein-3, Rab32, HOPS and BLOC complexes as well as of the white-scarlet (ABCG2-like) and ZnT35C (ZnT2/ZnT3/ZnT8-like) transporters is required for zinc storage granule biogenesis. Due to lysosome-related organelle defects caused by mutations in the homologous human genes, patients with Hermansky-Pudlak syndrome may lack zinc granules in beta pancreatic cells, intestinal paneth cells and presynaptic vesicles of hippocampal mossy fibers.
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Affiliation(s)
- Carlos Tejeda-Guzmán
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, C.P. 07360, México
| | - Abraham Rosas-Arellano
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, C.P. 07360, México
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Samuel M Webb
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Martha Barajas-Aceves
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, C.P. 07360, México
| | - Beatriz Osorio
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, C.P. 07360, México
| | - Fanis Missirlis
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, C.P. 07360, México
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16
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Navarro JA, Schneuwly S. Copper and Zinc Homeostasis: Lessons from Drosophila melanogaster. Front Genet 2017; 8:223. [PMID: 29312444 PMCID: PMC5743009 DOI: 10.3389/fgene.2017.00223] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/11/2017] [Indexed: 01/19/2023] Open
Abstract
Maintenance of metal homeostasis is crucial for many different enzymatic activities and in turn for cell function and survival. In addition, cells display detoxification and protective mechanisms against toxic accumulation of metals. Perturbation of any of these processes normally leads to cellular dysfunction and finally to cell death. In the last years, loss of metal regulation has been described as a common pathological feature in many human neurodegenerative diseases. However, in most cases, it is still a matter of debate whether such dyshomeostasis is a primary or a secondary downstream defect. In this review, we will summarize and critically evaluate the contribution of Drosophila to model human diseases that involve altered metabolism of metals or in which metal dyshomeostasis influence their pathobiology. As a prerequisite to use Drosophila as a model, we will recapitulate and describe the main features of core genes involved in copper and zinc metabolism that are conserved between mammals and flies. Drosophila presents some unique strengths to be at the forefront of neurobiological studies. The number of genetic tools, the possibility to easily test genetic interactions in vivo and the feasibility to perform unbiased genetic and pharmacological screens are some of the most prominent advantages of the fruitfly. In this work, we will pay special attention to the most important results reported in fly models to unveil the role of copper and zinc in cellular degeneration and their influence in the development and progression of human neurodegenerative pathologies such as Parkinson's disease, Alzheimer's disease, Huntington's disease, Friedreich's Ataxia or Menkes, and Wilson's diseases. Finally, we show how these studies performed in the fly have allowed to give further insight into the influence of copper and zinc in the molecular and cellular causes and consequences underlying these diseases as well as the discovery of new therapeutic strategies, which had not yet been described in other model systems.
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Affiliation(s)
- Juan A. Navarro
- Department of Developmental Biology, Institute of Zoology, University of Regensburg, Regensburg, Germany
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17
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Merritt TJS, Bewick AJ. Genetic Diversity in Insect Metal Tolerance. Front Genet 2017; 8:172. [PMID: 29163639 PMCID: PMC5673992 DOI: 10.3389/fgene.2017.00172] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 10/23/2017] [Indexed: 12/20/2022] Open
Abstract
Insects encounter a variety of metals in their environment, many of which are required at some concentration for normal organismal homeostasis, but essentially all of which are toxic at higher concentrations. Insects have evolved a variety of genetic, and likely epigenetic, mechanisms to deal with metal stress. A recurring theme in all these systems is complexity and diversity; even simple, single gene, cases are complex. Of the known gene families, the metallothioneins are perhaps the best understood and provide good examples of how diverse metal response is. Interestingly, there is considerable diversity across taxa in these metal-responsive systems, including duplications to form small gene families and complex expression of single loci. Strikingly, different species have evolved different mechanisms to cope with the same, or similar, stress suggesting both independent derivation of, and plasticity in, the pathways involved. It is likely that some metal-response systems evolved early in evolutionary time and have been conserved, while others have diverged, and still others evolved more recently and convergently. In addition to conventional genetics, insects likely respond to environmental metal through a variety of epigenetic systems, but direct tests are lacking. Ultimately, it is likely that classical genetic and epigenetic factors interact in regulating insect metal responses. In light of this diversity across species, future studies including a broad-based examination of gene expression in non-model species in complex environments will likely uncover additional genes and genetic and epigenetic mechanisms.
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Affiliation(s)
- Thomas J S Merritt
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada
| | - Adam J Bewick
- Department of Genetics, University of Georgia, Athens, GA, United States
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18
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Calap-Quintana P, González-Fernández J, Sebastiá-Ortega N, Llorens JV, Moltó MD. Drosophila melanogaster Models of Metal-Related Human Diseases and Metal Toxicity. Int J Mol Sci 2017; 18:E1456. [PMID: 28684721 PMCID: PMC5535947 DOI: 10.3390/ijms18071456] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 06/27/2017] [Accepted: 06/30/2017] [Indexed: 12/21/2022] Open
Abstract
Iron, copper and zinc are transition metals essential for life because they are required in a multitude of biological processes. Organisms have evolved to acquire metals from nutrition and to maintain adequate levels of each metal to avoid damaging effects associated with its deficiency, excess or misplacement. Interestingly, the main components of metal homeostatic pathways are conserved, with many orthologues of the human metal-related genes having been identified and characterized in Drosophila melanogaster. Drosophila has gained appreciation as a useful model for studying human diseases, including those caused by mutations in pathways controlling cellular metal homeostasis. Flies have many advantages in the laboratory, such as a short life cycle, easy handling and inexpensive maintenance. Furthermore, they can be raised in a large number. In addition, flies are greatly appreciated because they offer a considerable number of genetic tools to address some of the unresolved questions concerning disease pathology, which in turn could contribute to our understanding of the metal metabolism and homeostasis. This review recapitulates the metabolism of the principal transition metals, namely iron, zinc and copper, in Drosophila and the utility of this organism as an experimental model to explore the role of metal dyshomeostasis in different human diseases. Finally, a summary of the contribution of Drosophila as a model for testing metal toxicity is provided.
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Affiliation(s)
- Pablo Calap-Quintana
- Department of Genetics, University of Valencia, Campus of Burjassot, 46100 Valencia, Spain.
| | - Javier González-Fernández
- Department of Genetics, University of Valencia, Campus of Burjassot, 46100 Valencia, Spain.
- Biomedical Research Institute INCLIVA, 46010 Valencia, Spain.
| | - Noelia Sebastiá-Ortega
- Department of Genetics, University of Valencia, Campus of Burjassot, 46100 Valencia, Spain.
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Spain.
| | - José Vicente Llorens
- Department of Genetics, University of Valencia, Campus of Burjassot, 46100 Valencia, Spain.
| | - María Dolores Moltó
- Department of Genetics, University of Valencia, Campus of Burjassot, 46100 Valencia, Spain.
- Biomedical Research Institute INCLIVA, 46010 Valencia, Spain.
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Spain.
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19
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Qiang W, Huang Y, Wan Z, Zhou B. Metal-metal interaction mediates the iron induction of Drosophila MtnB. Biochem Biophys Res Commun 2017; 487:646-652. [DOI: 10.1016/j.bbrc.2017.04.109] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 04/20/2017] [Indexed: 02/07/2023]
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20
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Balinski MA, Woodruff RC. Differential sexual survival of Drosophila melanogaster on copper sulfate. Genetica 2017; 145:131-137. [PMID: 28154959 DOI: 10.1007/s10709-017-9951-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/16/2017] [Indexed: 12/16/2022]
Abstract
Based on studies of the influence of X-chromosomes on the viability of Drosophila melanogaster exposed to cadmium, and on the role of X-linked genes on copper homeostasis, we examined the effect of copper sulfate (CuSO4) on offspring viability using three independent, inbred D. melanogaster crosses (ensuring identical autosomes for males and females within each cross). Each cross was performed with attached X-chromosome females and males with a single X-chromosome. As female D. melanogaster have less metallothionein RNA expression than males, we predicted fewer female offspring than male offspring in crosses exposed to CuSO4, even though females have two copies of X-chromosome genes, possibly resulting in overdominant heterozygosity. In two of three crosses, CuSO4 caused significantly higher numbers of male offspring compared to female offspring. We hypothesized that these gender-based viability differences to copper exposure are caused by X-chromosome ploidy and X-linked genetic variation affecting metallothionein expression. Observed differential offspring viability responses among crosses to copper exposure also showed that different genetic backgrounds (autosomal and/or X-chromosome) can result in significant differences in heavy metal and metallothionein regulation. These results suggest that the effect of copper on offspring viability depends on both genetic background and gender, as both factors can affect the regulation of metallothionein proteins as well as homeostasis of biologically necessary heavy metals.
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Affiliation(s)
- Michael A Balinski
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, 43403, USA.
| | - Ronny C Woodruff
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, 43403, USA
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21
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Le Manh H, Guio L, Merenciano M, Rovira Q, Barrón MG, González J. Natural and laboratory mutations in kuzbanian are associated with zinc stress phenotypes in Drosophila melanogaster. Sci Rep 2017; 7:42663. [PMID: 28218276 PMCID: PMC5316978 DOI: 10.1038/srep42663] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 01/13/2017] [Indexed: 11/09/2022] Open
Abstract
Organisms must cope with altered environmental conditions such as high concentrations of heavy metals. Stress response to heavy metals is mediated by the metal-responsive transcription factor 1 (MTF-1), which is conserved from Drosophila to humans. MTF-1 binds to metal response elements (MREs) and changes the expression of target genes. kuzbanian (kuz), a metalloendopeptidase that activates the evolutionary conserved Notch signaling pathway, has been identified as an MTF-1 target gene. We have previously identified a putatively adaptive transposable element in the Drosophila melanogaster genome, named FBti0019170, inserted in a kuz intron. In this work, we investigated whether a laboratory mutant stock overexpressing kuz is associated with zinc stress phenotypes. We found that both embryos and adult flies overexpressing kuz are more tolerant to zinc compared with wild-type flies. On the other hand, we found that the effect of FBti0019170 on zinc stress tolerance depends on developmental stage and genetic background. Moreover, in the majority of the genetic backgrounds analyzed, FBti0019170 has a deleterious effect in unpolluted environments in pre-adult stages. These results highlight the complexity of natural mutations and suggest that besides laboratory mutations, natural mutations should be studied in order to accurately characterize gene function and evolution.
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Affiliation(s)
- Hung Le Manh
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49. 08003 Barcelona. Spain
- Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet st, Hanoi, Vietnam
| | - Lain Guio
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49. 08003 Barcelona. Spain
| | - Miriam Merenciano
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49. 08003 Barcelona. Spain
| | - Quirze Rovira
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49. 08003 Barcelona. Spain
| | - Maite G. Barrón
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49. 08003 Barcelona. Spain
| | - Josefa González
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49. 08003 Barcelona. Spain
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22
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Yin S, Qin Q, Zhou B. Functional studies of Drosophila zinc transporters reveal the mechanism for zinc excretion in Malpighian tubules. BMC Biol 2017; 15:12. [PMID: 28196538 PMCID: PMC5309981 DOI: 10.1186/s12915-017-0355-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 01/25/2017] [Indexed: 11/10/2022] Open
Abstract
Background Zinc is an essential metal involved in many physiological processes. Previous work has identified a set of zinc transporters involved in Drosophila dietary zinc absorption. However, zinc excretion and reabsorption, the other two important processes to maintain zinc homeostasis, are not as well understood. In this work, we screened all the potential zinc transporter Zip (SLC39) and ZnT (SLC30) members for their likely roles in zinc excretion in Malpighian tubules, an insect organ functionally analogous to mammalian kidneys. Results Zip71B (CG10006, most homologous to hZIP5), in addition to the previously characterized ZnT35C (CG3994), was identified as being critical in zinc excretion. Tubule-specific knockdown of Zip71B/dZip5 reduces zinc accumulation in the tubules, but increases zinc levels in the body, resulting in survival defect under zinc excess conditions. Zip71B/dZip5 is localized to the plasma membrane at the basolateral side of the tubules, and is functionally epistatic to the apically localized ZnT35C in regulating the tubule zinc homeostasis. Our results indicate that Zip71B/dZip5 is involved in zinc import into the tubular cells from the circulation, and ZnT35C in turn effluxes the tubular zinc out. Notably, mammalian ZIP5, which is expressed in the kidney, functions analogously to Zip71B/dZip5 in the fly while hZIP4 cannot complement the loss of Zip71B/dZip5 function. Furthermore, Zip71B/dZip5 expression is regulated by zinc so that, in response to toxic levels of zinc, the tubules can increase zinc efflux capability. We also characterized the role of dZnT1 (CG17723) in zinc reabsorption in Malpighian tubules. Finally, using a tubule calcification model, we were able to show that knockdown of Zip71B/dZip5 or ZnT35C was able to mitigate stone formation, consistent with their roles in tubular zinc homeostasis. Conclusions Our results start to sketch out a relatively complete picture of the zinc excretion process in Drosophila Malpighian tubules, and may provide a reference for relevant mammalian studies. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0355-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sai Yin
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiuhong Qin
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Bing Zhou
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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23
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Polykretis P, Delfino G, Petrocelli I, Cervo R, Tanteri G, Montori G, Perito B, Branca JJV, Morucci G, Gulisano M. Evidence of immunocompetence reduction induced by cadmium exposure in honey bees (Apis mellifera). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 218:826-834. [PMID: 27528187 DOI: 10.1016/j.envpol.2016.08.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 07/21/2016] [Accepted: 08/03/2016] [Indexed: 06/06/2023]
Abstract
In the last decades a dramatic loss of Apis mellifera hives has been reported in both Europe and USA. Research in this field is oriented towards identifying a synergy of contributing factors, i.e. pathogens, pesticides, habitat loss and pollution to the weakening of the hive. Cadmium (Cd) is a hazardous anthropogenic pollutant whose effects are proving to be increasingly lethal. Among the multiple damages related to Cd contamination, some studies report that it causes immunosuppression in various animal species. The aim of this paper is to determine whether contamination by Cd, may have a similar effect on the honey bees' immunocompetence. Our results, obtained by immune challenge experiments and confirmed by structural and ultrastructural observations show that such metal causes a reduction in immunocompetence in 3 days Cd exposed bees. As further evidence of honey bee response to Cd treatment, Energy Dispersive X-ray Spectroscopy (X-EDS) has revealed the presence of zinc (Zn) in peculiar electron-dense granules in fat body cells. Zn is a characteristic component of metallothioneins (MTs), which are usually synthesized as anti-oxidant and scavenger tools against Cd contamination. Our findings suggest that honey bee colonies may have a weakened immune system in Cd polluted areas, resulting in a decreased ability in dealing with pathogens.
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Affiliation(s)
- P Polykretis
- Magnetic Resonance Center - CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy.
| | - G Delfino
- Department of Biology, University of Florence, Via La Pira 4, 50121, Florence, Italy
| | - I Petrocelli
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Florence, Italy
| | - R Cervo
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Florence, Italy
| | - G Tanteri
- Department of Biology, University of Florence, Via La Pira 4, 50121, Florence, Italy
| | - G Montori
- Department of Biology, University of Florence, Via La Pira 4, 50121, Florence, Italy
| | - B Perito
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Florence, Italy
| | - J J V Branca
- Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - G Morucci
- Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - M Gulisano
- Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 3, 50134, Florence, Italy.
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Smulders S, Larue C, Sarret G, Castillo-Michel H, Vanoirbeek J, Hoet PH. Lung distribution, quantification, co-localization and speciation of silver nanoparticles after lung exposure in mice. Toxicol Lett 2015; 238:1-6. [DOI: 10.1016/j.toxlet.2015.07.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 06/30/2015] [Accepted: 07/02/2015] [Indexed: 11/28/2022]
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Kalajdzic P, Kenig B, Andjelkovic M. Drosophila subobscura flies adapted to low lead concentration carry no fitness cost. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 204:90-98. [PMID: 25935609 DOI: 10.1016/j.envpol.2015.04.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 06/04/2023]
Abstract
As a response to the long-term presence of heavy metals in the environment, populations can evolve resistance. Its maintenance may have detrimental effect on population's fitness, causing a fitness cost. Lead is one of the widely distributed elements in the environment exhibiting high toxicity on organisms. By analyzing developmental stages viability and developmental time, we evaluated fitness cost in Drosophila subobscura flies adapted to low lead concentration and control flies derived from the same wild population, as well as their hybrids. Significant changes in specific developmental stages viability were detected in both lines, as well as their hybrids, suggesting complex response to low lead concentration. The results show that a long-term exposure to low lead concentration may have a significant impact on a population's survival, especially in a changing environment conditions.
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Affiliation(s)
- Predrag Kalajdzic
- Institute for Biological Research, University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia; Justus-Liebig-University Gießen, Winchesterstr. 2, 35394 Gießen, Germany.
| | - Bojan Kenig
- Institute for Biological Research, University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia.
| | - Marko Andjelkovic
- Institute for Biological Research, University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia; Faculty of Biology, University of Belgrade, Belgrade, Serbia; Serbian Academy of Sciences and Arts, Knez Mihailova 35, 11000 Belgrade, Serbia.
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26
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Liu Y, Wu H, Kou L, Liu X, Zhang J, Guo Y, Ma E. Two metallothionein genes in Oxya chinensis: molecular characteristics, expression patterns and roles in heavy metal stress. PLoS One 2014; 9:e112759. [PMID: 25391131 PMCID: PMC4229212 DOI: 10.1371/journal.pone.0112759] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 10/14/2014] [Indexed: 11/17/2022] Open
Abstract
Metallothioneins (MTs) are small, cysteine-rich, heavy metal-binding proteins involved in metal homeostasis and detoxification in living organisms. In the present study, we cloned two MT genes (OcMT1 and OcMT2) from Oxya chinensis, analyzed the expression patterns of the OcMT transcripts in different tissues and at varying developmental stages using real-time quantitative PCR (RT-qPCR), evaluated the functions of these two MTs using RNAi and recombinant proteins in an E. coli expression system. The full-length cDNAs of OcMT1 and OcMT2 encoded 40 and 64 amino acid residues, respectively. We found Cys-Cys, Cys-X-Cys and Cys-X-Y-Z-Cys motifs in OcMT1 and OcMT2. These motifs might serve as primary chelating sites, as in other organisms. These characteristics suggest that OcMT1 and OcMT2 may be involved in heavy metal detoxification by capturing the metals. Two OcMT were expressed at all developmental stages, and the highest levels were found in the eggs. Both transcripts were expressed in all eleven tissues examined, with the highest levels observed in the brain and optic lobes, followed by the fat body. The expression of OcMT2 was also relatively high in the ovaries. The functions of OcMT1 and OcMT2 were explored using RNA interference (RNAi) and different concentrations and treatment times for the three heavy metals. Our results indicated that mortality increased significantly from 8.5% to 16.7%, and this increase was both time- and dose-dependent. To evaluate the abilities of these two MT proteins to confer heavy metal tolerance to E. coli, the bacterial cells were transformed with pET-28a plasmids containing the OcMT genes. The optical densities of both the MT-expressing and control cells decreased with increasing concentrations of CdCl2. Nevertheless, the survival rates of the MT-overexpressing cells were higher than those of the controls. Our results suggest that these two genes play important roles in heavy metal detoxification in O. chinensis.
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Affiliation(s)
- Yaoming Liu
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Haihua Wu
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Lihua Kou
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Xiaojian Liu
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Jianzhen Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Yaping Guo
- College of Life Science, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Enbo Ma
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
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Nguyen AH, Altomare LE, McElwain MC. Decreased accumulation of cadmium in Drosophila selected for resistance suggests a mechanism independent of metallothionein. Biol Trace Elem Res 2014; 160:245-9. [PMID: 24929542 DOI: 10.1007/s12011-014-0037-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
Abstract
Heavy metals, including cadmium, are common contaminants in environments subject to human activity. Responses to exposure in the fruit fly, Drosophila melanogaster, are dosage-dependent and resistance is selectable. While metallothionein-mediated sequestration has been extensively studied as a mechanism of cadmium resistance, a link between selection for resistance and an increased accumulation of cadmium has yet to be demonstrated. To address this need, we have selected wild-type flies for cadmium resistance for 20 generations and tested metal content using mass spectrometry. Resistant flies were observed to contain lower levels of cadmium, arguing for a mechanism of cadmium resistance that is not mediated by increased sequestration. This, coupled with genetic evidence suggesting the involvement of factors located on the X chromosome, suggests a gene other than metallothionein may be involved in resistance in this line.
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Affiliation(s)
- Austin H Nguyen
- Department of Biology, Loyola Marymount University, 1 LMU Dr, Los Angeles, CA, 90045, USA
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Abstract
Copper (Cu) is an essential redox active metal that is potentially toxic in excess. Multicellular organisms acquire Cu from the diet and must regulate uptake, storage, distribution and export of Cu at both the cellular and organismal levels. Systemic Cu deficiency can be fatal, as seen in Menkes disease patients. Conversely Cu toxicity occurs in patients with Wilson disease. Cu dyshomeostasis has also been implicated in neurodegenerative disorders such as Alzheimer's disease. Over the last decade, the fly Drosophila melanogaster has become an important model organism for the elucidation of eukaryotic Cu regulatory mechanisms. Gene discovery approaches with Drosophila have identified novel genes with conserved protein functions relevant to Cu homeostasis in humans. This review focuses on our current understanding of Cu uptake, distribution and export in Drosophila and the implications for mammals.
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Affiliation(s)
- Adam Southon
- Department of Genetics, University of Melbourne, Parkville, Australia.
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Isani G, Carpenè E. Metallothioneins, unconventional proteins from unconventional animals: a long journey from nematodes to mammals. Biomolecules 2014; 4:435-57. [PMID: 24970224 PMCID: PMC4101491 DOI: 10.3390/biom4020435] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/19/2014] [Accepted: 03/21/2014] [Indexed: 12/19/2022] Open
Abstract
Metallothioneins (MTs) are ubiquitous low molecular weight cysteine-rich proteins characterized by high affinity for d10 electron configuration metals, including essential (Zn and Cu) and non-essential (Cd and Hg) trace elements. The biological role of these ancient and well-conserved multifunctional proteins has been debated since MTs were first discovered in 1957. Their main hypothesized functions are: (1) homeostasis of Zn and Cu; (2) detoxification of Cd, and Hg; and (3) free radical scavenging. This review will focus on MTs in unconventional animals, those not traditionally studied in veterinary medicine but of increasing interest in this field of research. Living in different environments, these animals represent an incredible source of physiological and biochemical adaptations still partly unexplored. The study of metal-MT interactions is of great interest for clinicians and researchers working in veterinary medicine, food quality and endangered species conservation.
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Affiliation(s)
- Gloria Isani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, via Tolara di sopra, 50, Ozzano Emilia, Bologna 40064, Italy.
| | - Emilio Carpenè
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, via Tolara di sopra, 50, Ozzano Emilia, Bologna 40064, Italy.
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Afshar N, Argunhan B, Bettedi L, Szular J, Missirlis F. A recessive X-linked mutation causes a threefold reduction of total body zinc accumulation in Drosophila melanogaster laboratory strains. FEBS Open Bio 2013; 3:302-4. [PMID: 23951551 PMCID: PMC3741916 DOI: 10.1016/j.fob.2013.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 07/10/2013] [Accepted: 07/15/2013] [Indexed: 11/25/2022] Open
Abstract
A newly identified human locus on chromosome 15 was recently associated with zinc accumulation. Based on a prior report of a threefold difference in zinc accumulation between fumble1 heterozygous mutants and control fly strains, it was suggested that phosphopantothenoylcysteine decarboxylase might affect zinc status through its effects on vitamin B5 (pantothenate) metabolism. We report here that outcrossed fumble1 heterozygous mutant flies with low zinc content have been recovered, suggesting that pantothenate metabolism did not alter zinc homeostasis in fumble1 heterozygous flies. We show instead that the Drosophila condition of low body zinc accumulation is an X-chromosome-linked recessive trait. Flies with a threefold reduction in zinc accumulation remain viable and fertile. There is no causal association between zinc accumulation and fly pantothenate kinase mutants. A widespread X-linked mutation causes a threefold reduction in zinc accumulation in Drosophila.
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Affiliation(s)
- Negar Afshar
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
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Mandilaras K, Pathmanathan T, Missirlis F. Iron absorption in Drosophila melanogaster. Nutrients 2013; 5:1622-47. [PMID: 23686013 PMCID: PMC3708341 DOI: 10.3390/nu5051622] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/03/2013] [Accepted: 05/07/2013] [Indexed: 12/20/2022] Open
Abstract
The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration.
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Affiliation(s)
- Konstantinos Mandilaras
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK; E-Mail:
| | - Tharse Pathmanathan
- Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN, IPN Avenue 2508, Zacatenco, 07360, Mexico City, Mexico; E-Mail:
| | - Fanis Missirlis
- Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN, IPN Avenue 2508, Zacatenco, 07360, Mexico City, Mexico; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +52-55-5747-3963; Fax: +52-55-5747-5713
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Günther V, Lindert U, Schaffner W. The taste of heavy metals: gene regulation by MTF-1. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1823:1416-25. [PMID: 22289350 DOI: 10.1016/j.bbamcr.2012.01.005] [Citation(s) in RCA: 234] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 01/08/2012] [Accepted: 01/11/2012] [Indexed: 11/22/2022]
Abstract
The metal-responsive transcription factor-1 (MTF-1, also termed MRE-binding transcription factor-1 or metal regulatory transcription factor-1) is a pluripotent transcriptional regulator involved in cellular adaptation to various stress conditions, primarily exposure to heavy metals but also to hypoxia or oxidative stress. MTF-1 is evolutionarily conserved from insects to humans and is the main activator of metallothionein genes, which encode small cysteine-rich proteins that can scavenge toxic heavy metals and free radicals. MTF-1 has been suggested to act as an intracellular metal sensor but evidence for direct metal sensing was scarce. Here we review recent advances in our understanding of MTF-1 regulation with a focus on the mechanism underlying heavy metal responsiveness and transcriptional activation mediated by mammalian or Drosophila MTF-1. This article is part of a Special Issue entitled: Cell Biology of Metals.
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Affiliation(s)
- Viola Günther
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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Marr SK, Pennington KL, Marr MT. Efficient metal-specific transcription activation by Drosophila MTF-1 requires conserved cysteine residues in the carboxy-terminal domain. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1819:902-12. [PMID: 22484022 PMCID: PMC3378919 DOI: 10.1016/j.bbagrm.2012.03.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 03/02/2012] [Accepted: 03/06/2012] [Indexed: 11/21/2022]
Abstract
MTF-1 is a sequence-specific DNA binding protein that activates the transcription of metal responsive genes. The extent of activation is dependent on the nature of the metal challenge. Here we identify separate regions within the Drosophila MTF-1 (dMTF-1) protein that are required for efficient copper- versus cadmium-induced transcription. dMTF-1 contains a number of potential metal binding regions that might allow metal discrimination including a DNA binding domain containing six zinc fingers and a highly conserved cysteine-rich C-terminus. We find that four of the zinc fingers in the DNA binding domain are essential for function but the DNA binding domain does not contribute to the metal discrimination by dMTF-1. We find that the conserved C-terminus of the cysteine-rich domain provides cadmium specificity while copper specificity maps to the previously described copper-binding region (Chen et al.). In addition, both metal specific domains are autorepressive in the absence of metal and contribute to the low level of basal transcription from metal inducible promoters.
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Affiliation(s)
- Sharon K. Marr
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA
| | - Katie L. Pennington
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA
| | - Michael T. Marr
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454, USA
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Filipiak M, Tylko G, Pyza E. Zinc induces caspase-dependent mitochondrial pathway of the programmed cell death in haemocytes of Drosophila melanogaster. Biometals 2012; 25:507-16. [PMID: 22367497 PMCID: PMC3349848 DOI: 10.1007/s10534-012-9530-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 02/09/2012] [Indexed: 01/11/2023]
Abstract
Zinc is an essential trace element in cells. However, its high level in cytoplasm promotes activation of stress signaling pathways and may lead to cell death. In the present study we used Drosophila melanogaster blood cells (haemocytes), obtained from the third instar larvae, to study the effects of high concentrations of Zn(2+) on programmed cell death (PCD). We analyzed the activity of caspases, the level of caspase inhibitor protein DIAP1 and metallothioneins, as well as calcium concentrations and activity of mitochondria in haemocytes exposed to 0.35 and 1.7 mM concentrations of Zn. The obtained results showed that rapid increase of [Zn(2+)]( i ) in the cytoplasm up-regulates metallothionein MtnB but not MtnA gene expression in cells treated with Zn(2+) in both concentrations. Excess of Zn(2+) also induced activation of the initiator caspase Dronc, associated with the mitochondrial pathway of PCD, and the effector caspase DrICE. In turn, the activity of receptor-regulated Dredd caspase was not changed. The level of DIAP1 decreased significantly in haemocytes in the presence of high Zn(2+) concentration in comparison to untreated cells. Moreover, mitochondrial membrane potential was significantly decreased after exposure to Zn ions. These results indicate that high concentration of Zn(2+) in the cytoplasm of haemocytes induces PCD via a mitochondrial pathway and that caspases play a pivotal role in this process.
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Affiliation(s)
- Marta Filipiak
- Department of Cell Biology and Imaging, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
| | - Grzegorz Tylko
- Department of Cell Biology and Imaging, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
| | - Elzbieta Pyza
- Department of Cell Biology and Imaging, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
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Pérez-Rafael S, Kurz A, Guirola M, Capdevila M, Palacios Ò, Atrian S. Is MtnE, the fifth Drosophila metallothionein, functionally distinct from the other members of this polymorphic protein family? Metallomics 2012; 4:342-9. [DOI: 10.1039/c2mt00182a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Vašák M. Metallothioneins: chemical and biological challenges. J Biol Inorg Chem 2011; 16:975-6. [DOI: 10.1007/s00775-011-0832-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 08/08/2011] [Indexed: 10/17/2022]
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