An Expanding Range of Functions for the Copper Chaperone/Antioxidant Protein Atox1

Hatori, Yoshinori; Lutsenko, Svetlana

doi:10.1089/ars.2012.5086

Cited by 68 publications

(81 citation statements)

References 103 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The eluted fractions were concentrated with centrifugal filters to reach a concentration of monomeric and dimeric Atox1 of 100 and 50 μM, respectively. To characterize the two fractions, we applied band-selective optimized flip-angle short-transient (SOFAST)-HMQC spectroscopy to obtain a two-dimensional 1 H, 15 N-correlation spectrum of the protein in a few seconds and with a high signal-to-noise ratio.…”

Section: Separation Of Atox1 Monomer and Dimer Andmentioning

confidence: 99%

“…33 The 1 H, 15 Figure SI4). The spectrum of the monomeric Atox1 fraction displayed no peaks relative to 15 Figure SI4). This result supports binding of both Pt atoms to the CXXC motif.…”

Section: Separation Of Atox1 Monomer and Dimer Andmentioning

confidence: 99%

“…15 (25 mM, pH 7.0) at 25°C, and after 48 h of incubation, the reaction was analyzed by SEC following the procedure previously described. The protein fractions corresponding to peaks of Atox1 monomer and dimer were collected, concentrated with Amicon Ultra centrifugal filters (3 kDa cutoff), and analyzed by 1 H and 15 N HSQC NMR experiments.…”

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Oxaliplatin Binding to Human Copper Chaperone Atox1 and Protein Dimerization

et al. 2016

View full text Add to dashboard Cite

Copper trafficking proteins have been implicated in the cellular response to platinum anticancer drugs. We investigated the reaction of the chaperone Atox1 with an activated form of oxaliplatin, the third platinum drug to reach worldwide approval. Unlike cisplatin, which contains monodentate ammines, oxaliplatin contains chelated 1,2-diaminocyclohexane (DACH), which is more resistant to displacement by nucleophiles. In solution, one or two {Pt(DACH)(2+)} moieties bind to the conserved CXXC metal-binding motif of Atox1; in the latter case the two sulfur atoms likely bridging the two platinum units. At longer reaction times, a dimeric species is formed whose composition, Atox12·Pt(2+)2, indicates complete loss of the diamine ligands. Such a dimerization process is accompanied by partial unfolding of the protein. Crystallization experiments aiming at the characterization of the monomeric species have afforded, instead, a dimeric species resembling that already obtained by Boal and Rosenzweig in a similar reaction performed with cisplatin. However, while in the latter case there was only one Pt-binding site (0.4 occupancy) made of four sulfur atoms of the CXXC motifs of the two Atox1 chains in a tetrahedral arrangement, we found, in addition, a secondary Pt-binding site involving Cys41 of the B chain (0.25 occupancy). Moreover, both platinum atoms have lost their diamines. Thus, there appears to be little relationship between what is observed in solution and what is formed in the solid state. Since full occupancy of the tetrahedral cavity is a common feature of all Atox1 dimeric structures obtained with other metal ions (Cu(+), Cd(2+), and Hg(2+)), we propose that in the case of platinum, where the occupancy is only 0.4, the remaining cavities are occupied by Cu(+) ions. Experimental evidence is reported in support of the latter hypothesis. Our proposal represents a meeting point between the initial proposal of Boal and Rosenzweig (0.4 Pt occupancy) and the reinterpretation of the original crystallographic data put forward by Shabalin et al. (1 Cu occupancy), and could apply to other cases.

show abstract

Section: Separation Of Atox1 Monomer and Dimer Andmentioning

confidence: 99%

“…33 The 1 H, 15 Figure SI4). The spectrum of the monomeric Atox1 fraction displayed no peaks relative to 15 Figure SI4). This result supports binding of both Pt atoms to the CXXC motif.…”

Section: Separation Of Atox1 Monomer and Dimer Andmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Oxaliplatin Binding to Human Copper Chaperone Atox1 and Protein Dimerization

et al. 2016

View full text Add to dashboard Cite

show abstract

“…In many reviews on Cu transport, the three cytoplasmic Cu transfer pathways are depicted as independent, and studies have shown that Atox1 cannot replace CCS in Cu loading of SOD1 and CCS cannot replace Atox1 in Cu loading of ATP7B (Festa and Thiele 2011;Hatori and Lutsenko 2013;O'Halloran and Culotta 2000;Puig and Thiele 2002;Robinson and Winge 2010). However, the possibility of cross-reactivity between the two chaperones has not been specifically assessed, expect for a note in a recent study (in the discussion part, without showing raw data) in favor of an interaction (Allen et al 2012).…”

mentioning

confidence: 99%

Human cytoplasmic copper chaperones Atox1 and CCS exchange copper ions in vitro

et al. 2015

View full text Add to dashboard Cite

After Ctr1-mediated copper ion (Cu) entry into the human cytoplasm, chaperones Atox1 and CCS deliver Cu to P1B-type ATPases and to superoxide dismutase, respectively, via direct protein-protein interactions. Although the two Cu chaperones are presumed to work along independent pathways, we here assessed cross-reactivity between Atox1 and the first domain of CCS (CCS1) using biochemical and biophysical methods in vitro. By NMR we show that CCS1 is monomeric although it elutes differently from Atox1 in size exclusion chromatography (SEC). This property allows separation of Atox1 and CCS1 by SEC and, combined with the 254/280 nm ratio as an indicator of Cu loading, we demonstrate that Cu can be transferred from one protein to the other. Cu exchange also occurs with full-length CCS and, as expected, the interaction involves the metal binding sites since mutation of Cu-binding cysteine in Atox1 eliminates Cu transfer from CCS1. Cross-reactivity between CCS and Atox1 may aid in regulation of Cu distribution in the cytoplasm.

show abstract

“…The biological role of association with peroxisomes of the majority of transcripts detected in our microarray analysis is unclear, however for some of them the potential significance can be speculated about. For example, among the highly enriched transcripts in peroxisomal fractions was Atox1 , which encodes copper chaperone involved in protection from oxidative stress [36, 37]. The oxidase enzymatic activity in peroxisomes directly leads to production of high quantities of H 2 O 2 , which pose a risk to cause oxidative damage to the cell.…”

Section: Discussionmentioning

confidence: 99%

Genome-wide analysis of mRNAs associated with mouse peroxisomes

et al. 2016

View full text Add to dashboard Cite

BackgroundRNA is often targeted to be localized to the specific subcellular compartments. Specific localization of mRNA is believed to be an important mechanism for targeting their protein products to the locations, where their function is required.ResultsIn this study we performed the genome wide transcriptome analysis of peroxisome preparations from the mouse liver using microarrays. We demonstrate that RNA is absent inside peroxisomes, however it is associated at their exterior via the noncovalent contacts with the membrane proteins. We detect enrichment of specific sets of transcripts in two preparations of peroxisomes, purified with different degrees of stringency. Importantly, among these were mRNAs encoding bona fide peroxisomal proteins, such as peroxins and peroxisomal matrix enzymes involved in beta-oxidation of fatty acids and bile acid biosynthesis. The top-most enriched mRNA, whose association with peroxisomes we confirm microscopically was Hmgcs1, encoding 3-hydroxy-3-methylglutaryl-CoA synthase, a crucial enzyme of cholesterol biosynthesis pathway. We observed significant representation of mRNAs encoding mitochondrial and secreted proteins in the peroxisomal fractions.ConclusionsThis is a pioneer genome-wide study of localization of mRNAs to peroxisomes that provides foundation for more detailed dissection of mechanisms of RNA targeting to subcellular compartments.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3330-x) contains supplementary material, which is available to authorized users.

show abstract

An Expanding Range of Functions for the Copper Chaperone/Antioxidant Protein Atox1

Cited by 68 publications

References 103 publications

Oxaliplatin Binding to Human Copper Chaperone Atox1 and Protein Dimerization

Oxaliplatin Binding to Human Copper Chaperone Atox1 and Protein Dimerization

Human cytoplasmic copper chaperones Atox1 and CCS exchange copper ions in vitro

Genome-wide analysis of mRNAs associated with mouse peroxisomes

Contact Info

Product

Resources

About