Abstract For mercury phytoextraction, we previously demonstrated in Arabidopsis thaliana that a constitutive and ubiquitous promoter-driven expression of bacterial transporter MerC fused with SYP121, plant SNARE for plasma membrane protein trafficking increases accumulation. To advance regulation ectopic the system, present study examined whether merC-SYP121 driven by root epidermis specific promoter (pEpi) is sufficient to enhance accumulation tissues. We generated five independent...

Phytochelatin (PC) synthesis has been well demonstrated as a major metal tolerance mechanism in Arabidopsis thaliana, whereas its contribution to long-distance element transport especially monocots remains elusive. Using rice cereal model, we examined physiological roles of Oryza sativa phytochelatin synthase 1 (OsPCS1) the distribution and detoxification arsenic (As) cadmium (Cd), two toxic elements associated with food safety concerns. First, isolated four different transcript variants...

In order to clarify the physiological role of merE gene transposon Tn 21 , a pE4 plasmid that contained merR pMR26 from Pseudomonas strain K‐62, and Shigella flexneri NR1 (R100) was constructed. Bacteria with ( ‐o/p‐ ) were more hypersensitive CH 3 Hg(I) Hg(II), took up significantly than isogenic strain. The MerE protein encoded by localized in membrane cell fraction, but not soluble fraction. Based on these experimental results, we suggest for first time is broad mercury transporter...

The characteristics of bacteria take up mercury into cells via membrane potential-dependent sequence-divergent members the mercuric ion (Mer) superfamily, i.e., a periplasmic scavenging protein (MerP) and one or more inner membrane-spanning proteins (MerC, MerE, MerF, MerT), which transport ions cytoplasm, have been applied in engineering bioreactor used for mercurial bioremediation. We engineered to express MerC, MerT with without MerP clarify their individual role potential mercurial. By...

Abstract We report the complete nucleotide sequence of plasmid pMR68, isolated from Pseudomonas strain K-62, two plasmids contribute to broad-spectrum mercury resistance and that mer operon one them (pMR26) has been previously characterized. The was 71,020 bp in length contained 75 coding regions. Three gene clusters were identified. first comprised merR-orf4-orf5-merT1-merP1-merF-merA-merB1 , which confers bacterial mercuric ions organomercury. second third merT2-merP2 encodes a transport...

IscU serves as a scaffold for the de novo assembly of [2Fe–2S] cluster prior to its delivery recipient protein. It has also been proposed that on one dimer bacterial IscU, two clusters can be converted into single [4Fe–4S] cluster. However, lack structural information about dimeric state hindered our understanding underlying mechanisms. In this study, we determine X-ray crystal structure from thermophilic archaeon Methanothrix thermoacetophila and demonstrate in which are facing each other...

Phytochelatins (PCs) are major chelators of toxic elements including inorganic arsenic (As) in plant cells. Their synthesis confers tolerance and influences within-plant mobility. Previous studies had shown that various metal/metalloid ions differentially activate PC synthesis. Here we identified C-terminal parts involved arsenite- [As(III)] dependent activation AtPCS1, the primary Arabidopsis synthase. The T-DNA insertion AtPCS1 mutant cad1-6 causes a truncation regulatory domain affects by...

Cysteine desulfurases are pyridoxal-5'-phosphate (PLP)-dependent enzymes that mobilize sulfur derived from the l-cysteine substrate to partner acceptor proteins. Three cysteine desulfurases, IscS, NifS, and SufS, have been identified in ISC, NIF, SUF/SUF-like systems for iron-sulfur (Fe-S) cluster biosynthesis, respectively. These investigated over decades, providing insights into shared/distinct catalytic processes based on two types of (type I: IscS type II: SufS). This review summarizes...

Cysteine desulfurase enzymes catalyze sulfur mobilization from l-cysteine to sulfur-containing biomolecules such as iron-sulfur (Fe-S) clusters and thio-tRNAs. The utilize the cofactor pyridoxal-5'-phosphate (PLP), which forms external substrate- product-aldimines ketimines during catalysis are grouped into two types (I II) based on their different catalytic loops. To clarify structure-based mechanisms for each group, we determined structures of intermediates NifS (type I) SufS that involved...

In order to clarify the physiological roles played by MerP, MerT and MerE in Gram-negative bacteria, we constructed plasmids pTP4 pTPE21, which contained genes merR, merT merP, from Pseudomonas K-62 plasmid pMR26, or same with merE gene of Tn21 Shigella flexneri NR1 (R100), respectively. Cells containing showed increased hypersensitivity Hg(II), but maintained a normal sensitivity CH3Hg(I). However, cells pTPE21 exhibited Hg(II) accumulated appreciably more than control cells, no significant...

The bacterial merE gene derived from the Tn21 mer operon encodes a broad-spectrum mercury transporter that governs transport of methylmercury and mercuric ions across cytoplasmic membranes, this is potential molecular tool for improving efficiency phytoremediation. A transgenic Arabidopsis engineered to express MerE was constructed impact expression on accumulation evaluated. subcellular localization transiently expressed GFP-tagged examined in suspension-cultured cells. GFP-MerE found...

Abstract —Although many studies have reported that nitroaromatics such as 2,4,6‐trinitrotoluene (TNT) strong mutagenicity, the mechanism of mutagenic activity in these compounds has not yet been reported. We examined mutagenicity versus reactivity and biodegradation by bacteria using TNT its analogs (1,3,5‐trinitrobenzene [TNB], 2,4,6‐trinitroaniline [TNA], 2,4,6‐trinitrophenol [TNP], N ,2,4,6‐tetranitro‐ ‐methyl‐aniline [tetryl], 2,4‐dinitrotoluene [24DNT], 2,6‐dinitrotoluene [26DNT])....

The epithelial–mesenchymal transition (EMT) is a crucial morphological event that occurs during epithelial tumor progression. ZEB1/2 are EMT transcription factors positively correlated with phenotypes and breast cancer aggressiveness. regulate the alternative splicing hence isoform switching of fibroblast growth factor receptors (FGFRs) by repressing regulatory proteins, ESRP1 ESRP2. Here, we show mesenchymal-like oral squamous cell carcinoma (OSCC) cells dependent on autocrine FGF–FGFR...

MerC, encoded by merC in the transposon Tn21 mer operon, is a heavy metal transporter with potential applications for phytoremediation of metals such as mercuric ion and cadmium. In this study, we demonstrate that MerC also acts methylmercury. When was expressed Escherichia coli XL1-Blue, cells became hypersensitive to CH3Hg(I) uptake these higher than isogenic strain. Moreover, transgenic Arabidopsis plants expressing bacterial or fused plant soluble N-ethylmaleimide-sensitive factor...

Mercury superfamily proteins, i.e. inner membrane-spanning proteins (MerC, MerE, MerF and MerT) a periplasmic mercury-binding protein (MerP), transport mercury into the cytoplasm. A previous study demonstrated that Mer transporter homolog exhibits cadmium activity; based on this, present aimed to evaluate activity of MerC, MerT effects MerP co-expression in Escherichia coli. Bacteria expressing or without were more sensitive significantly absorbed than did control strain. Expression...

Methylmercury (MeHg) is a widely distributed environmental pollutant that causes series of cytotoxic effects. However, molecular mechanisms underlying MeHg toxicity are not fully understood. Here, we report sequestosome1/p62 protects mouse embryonic fibroblasts (MEFs) against low-dose cytotoxicity via clearance MeHg-induced ubiquitinated proteins. p62 mRNA and protein expression in MEFs were temporally induced by exposure p62-deficient exhibited higher sensitivity to compared their wild-type...

Abstract Some methylmercury (MeHg) is converted to inorganic mercury (Hg2+) after incorporation into human and animal tissues, where it can remain for a long time. To determine the overall toxicity of MeHg in studies should evaluate low concentrations Hg2+. Although demethylation involved, participating enzymes or underlying mechanisms are unknown; addition, cell membrane permeability Hg2+ makes these analyses challenging. We established model lines assess toxicities using bacterial...