Human Copper Chaperone Atox1 Translocates to the Nucleus but does not Bind DNA In Vitro

2015 ◽  
Vol 22 (6) ◽  
pp. 532-538 ◽  
Author(s):  
Dana Kahra ◽  
Tanumoy Mondol ◽  
Moritz Niemiec ◽  
Pernilla Wittung-Stafshede
Keyword(s):  
Copper Chaperone

scholarly journals A putative nuclear copper chaperone promotes plant immunity in Arabidopsis

2020 ◽  
Vol 71 (20) ◽  
pp. 6684-6696 ◽  
Author(s):  
Long-Xiang Chai ◽  
Kai Dong ◽  
Song-Yu Liu ◽  
Zhen Zhang ◽  
Xiao-Peng Zhang ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Immunity ◽  
Copper Chaperone ◽  
Copper Binding ◽  
Nuclear Speckles ◽  
Defense Gene Expression ◽  
Copper Chaperones ◽  
Plant Nucleus

Abstract Copper is essential for many metabolic processes but must be sequestrated by copper chaperones. It is well known that plant copper chaperones regulate various physiological processes. However, the functions of copper chaperones in the plant nucleus remain largely unknown. Here, we identified a putative copper chaperone induced by pathogens (CCP) in Arabidopsis thaliana. CCP harbors a classical MXCXXC copper-binding site (CBS) at its N-terminus and a nuclear localization signal (NLS) at its C-terminus. CCP mainly formed nuclear speckles in the plant nucleus, which requires the NLS and CBS domains. Overexpression of CCP induced PR1 expression and enhanced resistance against Pseudomonas syringae pv. tomato DC3000 compared with Col-0 plants. Conversely, two CRISPR/Cas9-mediated ccp mutants were impaired in plant immunity. Further biochemical analyses revealed that CCP interacted with the transcription factor TGA2 in vivo and in vitro. Moreover, CCP recruits TGA2 to the PR1 promoter sequences in vivo, which induces defense gene expression and plant immunity. Collectively, our results have identified a putative nuclear copper chaperone required for plant immunity and provided evidence for a potential function of copper in the salicylic pathway.

scholarly journals Copper chaperone blocks amyloid formation via ternary complex

2018 ◽  
Vol 51 ◽  
Author(s):  
Istvan Horvath ◽  
Tony Werner ◽  
Ranjeet Kumar ◽  
Pernilla Wittung-Stafshede
Keyword(s):  
Control Systems ◽  
Protein Misfolding ◽  
Ternary Complex ◽  
Copper Ions ◽  
Copper Chaperone ◽  
Amyloid Formation ◽  
Cellular Environment ◽  
Copper Site ◽  
Amyloidogenic Protein

AbstractProtein misfolding in cells is avoided by a network of protein chaperones that detect misfolded or partially folded species. When proteins escape these control systems, misfolding may result in protein aggregation and amyloid formation. We here show that aggregation of the amyloidogenic protein α-synuclein (αS), the key player in Parkinson's disease, is controlled by the copper transport protein Atox1 in vitro. Copper ions are not freely available in the cellular environment, but when provided by Atox1, the resulting copper-dependent ternary complex blocks αS aggregation. Because the same inhibition was found for a truncated version of αS, lacking the C-terminal part, it appears that Atox1 interacts with the N-terminal copper site in αS. Metal-dependent chaperoning may be yet another manner in which cells control its proteome.

scholarly journals Functional and Expression Analyses of the cop Operon, Required for Copper Resistance in Agrobacterium tumefaciens

2009 ◽  
Vol 191 (16) ◽  
pp. 5159-5168 ◽  
Author(s):  
Sirikan Nawapan ◽  
Nisanart Charoenlap ◽  
Anchalee Charoenwuttitam ◽  
Panatda Saenkham ◽  
Skorn Mongkolsuk ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Copper Ions ◽  
Protein A ◽  
Copper Resistance ◽  
Copper Chaperone ◽  
Phytopathogenic Bacterium ◽  
Ion Concentrations ◽  
Increased Sensitivity ◽  
Cop Operon

ABSTRACT The copper resistance determinant copARZ, which encodes a CPx-type copper ATPase efflux protein, a transcriptional regulator, and a putative intracellular copper chaperone, was functionally characterized for the phytopathogenic bacterium Agrobacterium tumefaciens. These genes are transcribed as an operon, and their expression is induced in response to increasing copper and silver ion concentrations in a copR-dependent fashion. Analysis of the copARZ promoter revealed a putative CopR binding box located within the spacer of the −35 and −10 promoter motifs. In vitro, purified CopR could specifically bind to the box. The inactivation of the copARZ operon or copZ reduces the level of resistance to copper but not to other metal ions. Also, the copARZ operon mutant shows increased sensitivity to the superoxide generators menadione and plumbagin. In addition, the loss of functional copZ does not affect the ability of copper ions to induce the copARZ promoter, indicating that CopZ is not involved in the copper-sensing mechanism of CopR. Altogether, the results demonstrate a crucial role for the copARZ operon as a component of the copper resistance machinery in A. tumefaciens.

scholarly journals Rules of Expansion: an Updated Consensus Operator Site for the CopR-CopY Family of Bacterial Copper Exporter System Repressors

mSphere ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Henrik O’Brien ◽  
Joseph W. Alvin ◽  
Sanjay V. Menghani ◽  
Yamil Sanchez-Rosario ◽  
Koenraad Van Doorslaer ◽  
...  
Keyword(s):  
Dna Binding ◽  
Consensus Sequence ◽  
Species Interaction ◽  
Copper Stress ◽  
Copper Chaperone ◽  
Binding Studies ◽  
Content Type ◽  
Operator Sequence ◽  
Export System

ABSTRACT Copper is broadly toxic to bacteria. As such, bacteria have evolved specialized copper export systems (cop operons) often consisting of a DNA-binding/copper-responsive regulator (which can be a repressor or activator), a copper chaperone, and a copper exporter. For those bacteria using DNA-binding copper repressors, few studies have examined the regulation of this operon regarding the operator DNA sequence needed for repressor binding. In Streptococcus pneumoniae (the pneumococcus), CopY is the copper repressor for the cop operon. Previously, homologs of pneumococcal CopY have been characterized to bind a 10-base consensus sequence T/GACANNTGTA known as the cop box. Using this motif, we sought to determine whether genes outside the cop operon are also regulated by the CopY repressor, which was previously shown in Lactococcus lactis. We found that S. pneumoniae CopY did not bind to cop operators upstream of these candidate genes in vitro. During this process, we found that the cop box sequence is necessary but not sufficient for CopY binding. Here, we propose an updated operator sequence for the S. pneumoniae cop operon to be ATTGACAAATGTAGAT binding CopY with a dissociation constant (Kd) of ∼28 nM. We demonstrate strong cross-species interaction between some CopY proteins and CopY operators, suggesting strong evolutionary conservation. Taken together with our binding studies and bioinformatics data, we propose the consensus operator RNYKACANNYGTMRNY for the bacterial CopR-CopY copper repressor homologs. IMPORTANCE Many Gram-positive bacteria respond to copper stress by upregulating a copper export system controlled by a copper-sensitive repressor, CopR-CopY. The previous operator sequence for this family of proteins had been identified as TACANNTGTA. Here, using several recombinant proteins and mutations in various DNA fragments, we define those 10 bases as necessary but not sufficient for binding and in doing so, refine the cop operon operator to the 16-base sequence RNYKACANNTGTMRNY. Due to the sheer number of repressors that have been said to bind to the original 10 bases, including many antibiotic resistance repressors such as BlaI and MecI, we feel that this study highlights the need to reexamine many of these sites of the past and use added stringency for verifying operators in the future.

scholarly journals Tumorigenic Poxviruses Up-Regulate Intracellular Superoxide To Inhibit Apoptosis and Promote Cell Proliferation

2005 ◽  
Vol 79 (9) ◽  
pp. 5799-5811 ◽  
Author(s):  
Melissa L. T. Teoh ◽  
Patricia V. Turner ◽  
David H. Evans
Keyword(s):  
Cell Proliferation ◽  
Clinical Manifestations ◽  
Myxoma Virus ◽  
Jurkat Cells ◽  
Copper Chaperone ◽  
Dependent Manner ◽  
Wild Type ◽  
Promote Cell Proliferation

ABSTRACT Tumorigenic leporipoxviruses encode catalytically inactive homologs of cellular Cu-Zn superoxide dismutase (SOD1). The function of the orthologous myxoma virus M131R and Shope fibroma virus S131R gene products is uncertain, but they inhibit SOD1 activity by a process linked to binding its copper chaperone. Using a superoxide-sensitive dye (hydroethidine), we observed that virus infection increased intracellular superoxide levels in an M/S131R-dependent manner. To see whether this effect promotes infection, we deleted the Shope fibroma virus S131R gene and compared the clinical manifestations of wild-type and mutant virus infections in rabbits. S131RΔ virus produced significantly smaller fibroxanthosarcoma-like growths in vivo and, at a point where these growths were already receding, wild-type infections still showed extensive leukocyte infiltration, necrosis, and fibromatous cell proliferation. Coincidentally, whereas Jurkat cells are protected from mitochondria- and Fas-mediated apoptosis by wild-type myxoma virus in vitro, M131RΔ virus could not block Fas-initiated apoptosis as judged by DNA laddering, terminal deoxynucleotidyltransferase-mediated dUTP-fluorescein nick end labeling, and caspase 3 cleavage assays. These data suggest that tumorigenic poxviruses can modulate intracellular redox status to their advantage to stimulate infected cell growth and inhibit programmed cell death.

scholarly journals Structure and Function of CinD (YtjD) of Lactococcus lactis, a Copper-Induced Nitroreductase Involved in Defense against Oxidative Stress

2010 ◽  
Vol 192 (16) ◽  
pp. 4172-4180 ◽  
Author(s):  
Mélanie Mermod ◽  
Frédéric Mourlane ◽  
Sandro Waltersperger ◽  
Anselm E. Oberholzer ◽  
Ulrich Baumann ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lactococcus Lactis ◽  
Copper Chaperone ◽  
Knockout Mutant ◽  
X Ray ◽  
Real Time Quantitative Pcr ◽  
Copper Atpases ◽  
And Function

ABSTRACT In Lactococcus lactis IL1403, 14 genes are under the control of the copper-inducible CopR repressor. This so-called CopR regulon encompasses the CopR regulator, two putative CPx-type copper ATPases, a copper chaperone, and 10 additional genes of unknown function. We addressed here the function of one of these genes, ytjD, which we renamed cinD ( c opper- i nduced n itroreductase). Copper, cadmium, and silver induced cinD in vivo, as shown by real-time quantitative PCR. A knockout mutant of cinD was more sensitive to oxidative stress exerted by 4-nitroquinoline-N-oxide and copper. Purified CinD is a flavoprotein and reduced 2,6-dichlorophenolindophenol and 4-nitroquinoline-N-oxide with k cat values of 27 and 11 s−1, respectively, using NADH as a reductant. CinD also exhibited significant catalase activity in vitro. The X-ray structure of CinD was resolved at 1.35 Å and resembles those of other nitroreductases. CinD is thus a nitroreductase which can protect L. lactis against oxidative stress that could be exerted by nitroaromatic compounds and copper.

scholarly journals Mammalian Copper Chaperone Cox17p Has an Essential Role in Activation of Cytochrome c Oxidase and Embryonic Development

2002 ◽  
Vol 22 (21) ◽  
pp. 7614-7621 ◽  
Author(s):  
Yoshinori Takahashi ◽  
Koichiro Kako ◽  
Shin-ichi Kashiwabara ◽  
Akio Takehara ◽  
Yoshiko Inada ◽  
...  
Keyword(s):  
Essential Role ◽  
Copper Ions ◽  
Mouse Embryos ◽  
Copper Chaperone ◽  
Succinate Dehydrogenase Activity ◽  
Copper Transporter ◽  
A Cell ◽  
Deficient Mice ◽  
Mammalian System

ABSTRACT Cox17p is essential for the assembly of functional cytochrome c oxidase (CCO) and for delivery of copper ions to the mitochondrion for insertion into the enzyme in yeast. Although this small protein has already been cloned or purified from humans, mice, and pigs, the function of Cox17p in the mammalian system has not yet been elucidated. In vitro biochemical data for mammalian Cox17p indicate that the copper binds to the sequence -KPCCAC-. Although mouse embryos homozygous for COX17 disruption die between embryonic days E8.5 and E10, they develop normally until E6.5. This phenotype is strikingly similar to embryos of Ctr1(−/−), a cell surface copper transporter, in its lethality around the time of gastrulation. COX17-deficient embryos exhibit severe reductions in CCO activity at E6.5. Succinate dehydrogenase activity and immunoreactivities for anti-COX subunit antibodies were normal in the COX17(−/−) embryos, indicating that this defect was not caused by the deficiency of other complexes and/or subunits but was caused by impaired CCO activation by Cox17p. Since other copper chaperone (Atox1 and CCS)-deficient mice show a more moderate defect, the disruption of the COX17 locus causes the expression of only the phenotype of Ctr1(−/−). We found that the activity of lactate dehydrogenase was also normal in E6.5 embryos, implying that the activation of CCO by Cox17p may not be essential to the progress of embryogenesis before gastrulation.

scholarly journals Cisplatin binds human copper chaperone Atox1 and promotes unfolding in vitro

2011 ◽  
Vol 108 (17) ◽  
pp. 6951-6956 ◽  
Author(s):  
M. E. Palm ◽  
C. F. Weise ◽  
C. Lundin ◽  
G. Wingsle ◽  
Y. Nygren ◽  
...  
Keyword(s):  
Copper Chaperone

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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