Industrial activities such as smelting emissions,mineral combustion and industrial wastewater discharge might lead to copper pollution in the environment.This kind of copper pollution has harmful effects on aquatic o ...Industrial activities such as smelting emissions,mineral combustion and industrial wastewater discharge might lead to copper pollution in the environment.This kind of copper pollution has harmful effects on aquatic o rganisms,plants and animals through direct or indirect exposure.However,the current understanding of the toxicity of copper is rather limited.Copper overload can perturb intracellular homeostasis and induce oxidative stress and e ven cell death.Recently,cuproptosis has been identified as a copper-dependent form of cell death induced by o xidative stress in mitochondria.We uncover here that zinc transporter 1(ZNT1)is an important regulator involved in cuproptosis.Firstly,we established the copper overload-induced cell death model with the overexpression of copper importer SLC31A1 in HeLa cells.Using this model,we conducted unbiased genome-wide CRISPR-Cas9 screens in cells treated with copper.Our results revealed a significant enrichment of ZNT1 gene in both library A and library B plasmids.Knocking out of ZNT1 in HeLa cells notably prevented cuproptosis.Subsequent knockout of metal transcription factor 1(MTF1)in ZNT1-deficient cells nearly abolished their ability to resist copper-induced cell death.However,overexpression of metallothionein 1X(MT1X)in the double-knockout cells could p artially restored the resistance to cuproptosis by loss of MTF1.Mechanistically,knockout of ZNT1 could promote MT1X expression by activating MTF1.As a consequence,the interaction between MT1X and copper was e nhanced,reducing the flow of copper into mitochondria and eliminating mitochondria damage.Taken together,this study reveals the important role of ZNT1 in cuproptosis and shows MTF1-MT1X axis mediated resistance to c uproptosis.Moreover,our study will help to understand the regulatory mechanism of cellular and systemic copper homeostasis under copper overload,and present insights into novel treatments for damages caused by both genetic copper overload diseases and environmental copper contamination.展开更多
We measured the concentrations of heavy metal elements,i.e.,V,Cr,Mn,Ni,Cu,Zn,Cd,Se and Pb and the semi-metal element As in feces of Chinese Egret(Egretta eulophotes)on Caiyu Island in Zhangpu County,Fujian Province,Ch...We measured the concentrations of heavy metal elements,i.e.,V,Cr,Mn,Ni,Cu,Zn,Cd,Se and Pb and the semi-metal element As in feces of Chinese Egret(Egretta eulophotes)on Caiyu Island in Zhangpu County,Fujian Province,China using inductively coupled plasma-mass spectrometry(ICP-MS) and compared the differences between the topsoil of their nesting and non-nesting areas before and after breeding.The results show that no Se and Cd was detected in any of the samples,including feces and soil,while heavy metal concentrations in the non-nesting soil were not significantly different before and after breeding(p > 0.05),but the differences in concentrations of Zn and Pb in the nesting soil were highly significant before and after breeding(p < 0.01).A comparison of the concentrations of the elements in the nesting and non-nesting soils also reveals that before breeding,the concentration of Zn in these two soils were significantly different(p < 0.01).After breeding,concentrations of Cu,Zn,As and Pb in the nesting and non-nesting soil were significantly different(p < 0.01) while V and Ni concentrations showed merely significant differences(p < 0.05).These findings indicate that the colonial breeding activities of E.eulophotes play an important role in the transfer of heavy metals between wetland and island eco-systems and that such activities may,over time,result in heavy metal contamination of the heronry soil on the island.展开更多
A novel cDNA sequencehtMT2, which encodes a type 2 metallothionein_like protein, was isolated from Helianthus tuberosus L. tuber cDNA library. The whole sequence is 509 bp, including an open reading frame (ORF) of 240...A novel cDNA sequencehtMT2, which encodes a type 2 metallothionein_like protein, was isolated from Helianthus tuberosus L. tuber cDNA library. The whole sequence is 509 bp, including an open reading frame (ORF) of 240 bp, a 5′ UTR of 62 bp and a 3′ UTR of 207 bp. Two genomic sequences covering the coding region ofhtMT2were cloned by PCR reaction. Sequence analysis revealed that the genomic sequences htMTG_1 of 986 bp and htMTG_2 of 982 bp were both composed of three exons and two introns. The deduced protein consisted of 79 amino acid residues with a predicted molecular weight of 7.8 ku (kD). Amino_terminal and carboxy_terminal domains contained 8 and 7 cysteine residues respectively, separated by a central cysteine free spacer. Sequence alignment revealed that the predicted protein ofhtMT2 was homologous to type 2 metallothioneins (MTs) of plants. Southern blotting analysis indicated that htMT2was encoded by a small multi_gene family in H. tuberosus genome. Northern blotting analysis showed that htMT2 transcripts were detected in stems, leaves and leafstalks, but no transcripts were detected in roots. The expression level in stems was the highest among the above tissues. Transcripts in stems were significantly reduced by Cu 2+ treatment. Judging from the homologies between the deduced HtMT2 and other type 2 plant metallothioneins as well as responses to metal ions, we believe thatwere cloned by PCR reaction. Sequence analysis revealed that the genomic sequences htMTG_1 of 986 bp and htMTG_2 of 982 bp were both composed of three exons and two introns. The deduced protein consisted of 79 amino acid residues with a predicted molecular weight of 7.8 ku (kD). Amino_terminal and carboxy_terminal domains contained 8 and 7 cysteine residues respectively, separated by a central cysteine free spacer. Sequence alignment revealed that the predicted protein ofhtMT2 was homologous to type 2 metallothioneins (MTs) of plants. Southern blotting analysis indicated that htMT2was encoded by a small multi_gene family in H. tuberosus genome. Northern blotting analysis showed that htMT2 transcripts were detected in stems, leaves and leafstalks, but no transcripts were detected in roots. The expression level in stems was the highest among the above tissues. Transcripts in stems were significantly reduced by Cu 2+ treatment. Judging from the homologies between the deduced HtMT2 and other type 2 plant metallothioneins as well as responses to metal ions, we believe that[ShtMT2 encodes a new type 2 metallothionein.展开更多
[Objective] The aim of this study was to study effects of metal ions on the protease activities in digestive tissues and gland of red-white ornamental carp（Cyprinus carpio L）.[Method] Effects of four kinds of metal ...[Objective] The aim of this study was to study effects of metal ions on the protease activities in digestive tissues and gland of red-white ornamental carp（Cyprinus carpio L）.[Method] Effects of four kinds of metal ions （K＋,Na＋,Mg2＋ and Ca2＋） on protease activities in hepatopancreas,foregut,midgut,hindgut of red-white ornamental carp were studied by enzyme analysis method.[Result] Effects of four kinds of metal ions on protease activities of red-white ornamental carp were different in the range of experimental concentration from 25 mmol/L to 150 mmol/L.K＋ could promote protease activities in hepatopancreas and hindgut at different levels.Especially,K＋ had the promoting effect at low-concentration level,but the inhibitory effect at high-concentration level in midgut and the inhibitory effect in foregut.Na＋ had the promoting effect on protease activities in hepatopancreas,foregut and hindgut at different levels,but the inhibitory effect in midgut.Mg2＋ and Ca2＋ had the inhibitory effect on protease activities in intestinal and hepatopancreas at different levels.[Conclusion] This study provides basic data and theoretical foundation for researches on the digestive physiology of red-white ornamental carp or the development and optimization of compound feed.展开更多
Aim To synthesize a new prodrug, resveratrol trinicotinate. Methods Inpresence of lithium and a catalytic amount of naphthalene, the reaction of p-methoxybenzyltrimethylsilyl ether and 3,5-dimethoxylbenzaldehyde gave ...Aim To synthesize a new prodrug, resveratrol trinicotinate. Methods Inpresence of lithium and a catalytic amount of naphthalene, the reaction of p-methoxybenzyltrimethylsilyl ether and 3,5-dimethoxylbenzaldehyde gave resveratrol after a series of translation.Resveratrol trinicotinate was obtained by the reaction of resveratrol and nicotinoyl chloridehydrochloride. Results A mutual prodrug resveratrol trinicotinate was designed and synthesized.Conclusion A novel method for synthesis of resveratrol and resveratrol trinicotinate has beenafforded. The E-isomer is selectivily obtained by dehydration of the compound 2 with KHSO_4 .展开更多
[Objective] This study aimed to analyze the bioinformatics information of Betula phatyphylla metallothionein for subsequent investigation of the important func- tions of metallothionein gene. [Method] The physical and...[Objective] This study aimed to analyze the bioinformatics information of Betula phatyphylla metallothionein for subsequent investigation of the important func- tions of metallothionein gene. [Method] The physical and chemical properties, trans- membrane domains, hydrophobicity / hydrophilicity, secondary structure, functional domains and functional classification of B. phatyphylla metallothionein were analyzed and predicted using bioinformatics methods and tools. [Result] The relative molecular mass of B. phatyphylla metallothionein is 7.75 kD and isoelectric point is 5.66; there is a strong hydrophobic region in the center of B. phatyphylla metallothionein and hydrophilic regions in both ends; B. phatyphylla metallothionein may be a non-trans- membrane protein and is mainly constituted by random coil without enzymatic activi- ty, suggesting that it belongs to Metallothio_2 protein family. [Conclusion] This study provided reference for further functional research of B. phatyphylla metallothionein gene.展开更多
Rice metallothionein-like protein (rgMT) shows characteristics of a three-section pattern composed of two highly conserved cysteine rich (CR) domains in the terminals and a spacer without cysteine (cys) residues in th...Rice metallothionein-like protein (rgMT) shows characteristics of a three-section pattern composed of two highly conserved cysteine rich (CR) domains in the terminals and a spacer without cysteine (cys) residues in the center of the molecule. In this paper, the two CR domains and the spacer region were modeled by the distance geometry and homology methods separately. For the CR domains, twenty random models were generated for each cys combination based on the constraint conditions of CXC (C represents cys, X represents any amino acid other than cys), and CXXC motifs and a metal-sulfur chelating cluster. Four models for the N-terminal and two for C-terminal CR domain containing metal chelating structures formed by different combinations of cys were selected from 900 possible conformations. The GOR method was used to predict the secondary structure of the spacer region and its model was built by the homology method. After three parts of the protein were modeled, they were connected to form a three-dimensional structure model of rgMT. The whole conformation showed that rgMT could form two independent metal-sulfur chelating structures connected by a spacer peptide, without a structural or energy barrier for them to form two independent metal-chelating clusters just as mammalian metallothionein (MT) proteins. As all plant metallothionein-like (MT-L) proteins have the same primary structural characteristic, two CR domains connected by a spacer region, and many have the same cys arrangement pattern as rgMT, the three-dimensional structure model of rgMT will provide an important reference for the structural study of other plant MT-L proteins.展开更多
文摘Industrial activities such as smelting emissions,mineral combustion and industrial wastewater discharge might lead to copper pollution in the environment.This kind of copper pollution has harmful effects on aquatic o rganisms,plants and animals through direct or indirect exposure.However,the current understanding of the toxicity of copper is rather limited.Copper overload can perturb intracellular homeostasis and induce oxidative stress and e ven cell death.Recently,cuproptosis has been identified as a copper-dependent form of cell death induced by o xidative stress in mitochondria.We uncover here that zinc transporter 1(ZNT1)is an important regulator involved in cuproptosis.Firstly,we established the copper overload-induced cell death model with the overexpression of copper importer SLC31A1 in HeLa cells.Using this model,we conducted unbiased genome-wide CRISPR-Cas9 screens in cells treated with copper.Our results revealed a significant enrichment of ZNT1 gene in both library A and library B plasmids.Knocking out of ZNT1 in HeLa cells notably prevented cuproptosis.Subsequent knockout of metal transcription factor 1(MTF1)in ZNT1-deficient cells nearly abolished their ability to resist copper-induced cell death.However,overexpression of metallothionein 1X(MT1X)in the double-knockout cells could p artially restored the resistance to cuproptosis by loss of MTF1.Mechanistically,knockout of ZNT1 could promote MT1X expression by activating MTF1.As a consequence,the interaction between MT1X and copper was e nhanced,reducing the flow of copper into mitochondria and eliminating mitochondria damage.Taken together,this study reveals the important role of ZNT1 in cuproptosis and shows MTF1-MT1X axis mediated resistance to c uproptosis.Moreover,our study will help to understand the regulatory mechanism of cellular and systemic copper homeostasis under copper overload,and present insights into novel treatments for damages caused by both genetic copper overload diseases and environmental copper contamination.
基金supported by the National Natural Science Foundation of China (Grant Nos.40876077,30970380)the Fujian Natural Science Foundation of China (2008S0007,2009J01195)
文摘We measured the concentrations of heavy metal elements,i.e.,V,Cr,Mn,Ni,Cu,Zn,Cd,Se and Pb and the semi-metal element As in feces of Chinese Egret(Egretta eulophotes)on Caiyu Island in Zhangpu County,Fujian Province,China using inductively coupled plasma-mass spectrometry(ICP-MS) and compared the differences between the topsoil of their nesting and non-nesting areas before and after breeding.The results show that no Se and Cd was detected in any of the samples,including feces and soil,while heavy metal concentrations in the non-nesting soil were not significantly different before and after breeding(p > 0.05),but the differences in concentrations of Zn and Pb in the nesting soil were highly significant before and after breeding(p < 0.01).A comparison of the concentrations of the elements in the nesting and non-nesting soils also reveals that before breeding,the concentration of Zn in these two soils were significantly different(p < 0.01).After breeding,concentrations of Cu,Zn,As and Pb in the nesting and non-nesting soil were significantly different(p < 0.01) while V and Ni concentrations showed merely significant differences(p < 0.05).These findings indicate that the colonial breeding activities of E.eulophotes play an important role in the transfer of heavy metals between wetland and island eco-systems and that such activities may,over time,result in heavy metal contamination of the heronry soil on the island.
文摘A novel cDNA sequencehtMT2, which encodes a type 2 metallothionein_like protein, was isolated from Helianthus tuberosus L. tuber cDNA library. The whole sequence is 509 bp, including an open reading frame (ORF) of 240 bp, a 5′ UTR of 62 bp and a 3′ UTR of 207 bp. Two genomic sequences covering the coding region ofhtMT2were cloned by PCR reaction. Sequence analysis revealed that the genomic sequences htMTG_1 of 986 bp and htMTG_2 of 982 bp were both composed of three exons and two introns. The deduced protein consisted of 79 amino acid residues with a predicted molecular weight of 7.8 ku (kD). Amino_terminal and carboxy_terminal domains contained 8 and 7 cysteine residues respectively, separated by a central cysteine free spacer. Sequence alignment revealed that the predicted protein ofhtMT2 was homologous to type 2 metallothioneins (MTs) of plants. Southern blotting analysis indicated that htMT2was encoded by a small multi_gene family in H. tuberosus genome. Northern blotting analysis showed that htMT2 transcripts were detected in stems, leaves and leafstalks, but no transcripts were detected in roots. The expression level in stems was the highest among the above tissues. Transcripts in stems were significantly reduced by Cu 2+ treatment. Judging from the homologies between the deduced HtMT2 and other type 2 plant metallothioneins as well as responses to metal ions, we believe thatwere cloned by PCR reaction. Sequence analysis revealed that the genomic sequences htMTG_1 of 986 bp and htMTG_2 of 982 bp were both composed of three exons and two introns. The deduced protein consisted of 79 amino acid residues with a predicted molecular weight of 7.8 ku (kD). Amino_terminal and carboxy_terminal domains contained 8 and 7 cysteine residues respectively, separated by a central cysteine free spacer. Sequence alignment revealed that the predicted protein ofhtMT2 was homologous to type 2 metallothioneins (MTs) of plants. Southern blotting analysis indicated that htMT2was encoded by a small multi_gene family in H. tuberosus genome. Northern blotting analysis showed that htMT2 transcripts were detected in stems, leaves and leafstalks, but no transcripts were detected in roots. The expression level in stems was the highest among the above tissues. Transcripts in stems were significantly reduced by Cu 2+ treatment. Judging from the homologies between the deduced HtMT2 and other type 2 plant metallothioneins as well as responses to metal ions, we believe that[ShtMT2 encodes a new type 2 metallothionein.
文摘[Objective] The aim of this study was to study effects of metal ions on the protease activities in digestive tissues and gland of red-white ornamental carp（Cyprinus carpio L）.[Method] Effects of four kinds of metal ions （K＋,Na＋,Mg2＋ and Ca2＋） on protease activities in hepatopancreas,foregut,midgut,hindgut of red-white ornamental carp were studied by enzyme analysis method.[Result] Effects of four kinds of metal ions on protease activities of red-white ornamental carp were different in the range of experimental concentration from 25 mmol/L to 150 mmol/L.K＋ could promote protease activities in hepatopancreas and hindgut at different levels.Especially,K＋ had the promoting effect at low-concentration level,but the inhibitory effect at high-concentration level in midgut and the inhibitory effect in foregut.Na＋ had the promoting effect on protease activities in hepatopancreas,foregut and hindgut at different levels,but the inhibitory effect in midgut.Mg2＋ and Ca2＋ had the inhibitory effect on protease activities in intestinal and hepatopancreas at different levels.[Conclusion] This study provides basic data and theoretical foundation for researches on the digestive physiology of red-white ornamental carp or the development and optimization of compound feed.
文摘Aim To synthesize a new prodrug, resveratrol trinicotinate. Methods Inpresence of lithium and a catalytic amount of naphthalene, the reaction of p-methoxybenzyltrimethylsilyl ether and 3,5-dimethoxylbenzaldehyde gave resveratrol after a series of translation.Resveratrol trinicotinate was obtained by the reaction of resveratrol and nicotinoyl chloridehydrochloride. Results A mutual prodrug resveratrol trinicotinate was designed and synthesized.Conclusion A novel method for synthesis of resveratrol and resveratrol trinicotinate has beenafforded. The E-isomer is selectivily obtained by dehydration of the compound 2 with KHSO_4 .
基金Supported by Youth Academic Backbone Project of Mudanjiang Normal College(G201210)~~
文摘[Objective] This study aimed to analyze the bioinformatics information of Betula phatyphylla metallothionein for subsequent investigation of the important func- tions of metallothionein gene. [Method] The physical and chemical properties, trans- membrane domains, hydrophobicity / hydrophilicity, secondary structure, functional domains and functional classification of B. phatyphylla metallothionein were analyzed and predicted using bioinformatics methods and tools. [Result] The relative molecular mass of B. phatyphylla metallothionein is 7.75 kD and isoelectric point is 5.66; there is a strong hydrophobic region in the center of B. phatyphylla metallothionein and hydrophilic regions in both ends; B. phatyphylla metallothionein may be a non-trans- membrane protein and is mainly constituted by random coil without enzymatic activi- ty, suggesting that it belongs to Metallothio_2 protein family. [Conclusion] This study provided reference for further functional research of B. phatyphylla metallothionein gene.
文摘Rice metallothionein-like protein (rgMT) shows characteristics of a three-section pattern composed of two highly conserved cysteine rich (CR) domains in the terminals and a spacer without cysteine (cys) residues in the center of the molecule. In this paper, the two CR domains and the spacer region were modeled by the distance geometry and homology methods separately. For the CR domains, twenty random models were generated for each cys combination based on the constraint conditions of CXC (C represents cys, X represents any amino acid other than cys), and CXXC motifs and a metal-sulfur chelating cluster. Four models for the N-terminal and two for C-terminal CR domain containing metal chelating structures formed by different combinations of cys were selected from 900 possible conformations. The GOR method was used to predict the secondary structure of the spacer region and its model was built by the homology method. After three parts of the protein were modeled, they were connected to form a three-dimensional structure model of rgMT. The whole conformation showed that rgMT could form two independent metal-sulfur chelating structures connected by a spacer peptide, without a structural or energy barrier for them to form two independent metal-chelating clusters just as mammalian metallothionein (MT) proteins. As all plant metallothionein-like (MT-L) proteins have the same primary structural characteristic, two CR domains connected by a spacer region, and many have the same cys arrangement pattern as rgMT, the three-dimensional structure model of rgMT will provide an important reference for the structural study of other plant MT-L proteins.
