The Arabidopsis thaliana CUTA gene encodes an evolutionarily conserved copper binding chloroplast pro-tein. Plant J 34: 856-867

Biology Department, Colorado State University, Room E 416, Fort Collins, CO 80523, USA.
The Plant Journal (Impact Factor: 5.97). 07/2003; 34(6):856-67. DOI: 10.1046/j.1365-313X.2003.01769.x
Source: PubMed

ABSTRACT The Arabidopsis thaliana CUTA gene encodes a 182-amino-acid-long putative precursor of a chloroplast protein with high sequence similarity to evolutionarily conserved prokaryotic proteins implicated in copper tolerance. Northern analysis indicates that AtCUTA mRNA is expressed in all major tissue types. Analysis of cDNA clones and RT-PCR with total mRNA revealed alternative splicing of AtCUTA by retention of an intron. The intron-containing mRNA encodes a truncated 156-amino-acid protein as a result of stop codons in the included intron. The sequence of AtCutAp encoded by the fully spliced transcript suggests that the precursor consists of three domains: an N-terminal chloroplast transit sequence of 70 residues, followed by a domain with prokaryotic signal-sequence-like characteristics and finally the most conserved C-terminal domain. The N-terminal chloroplast transit sequence was functional to route a passenger protein into isolated pea chloroplasts with possible sorting to the envelope. Chloroplast localization was confirmed by Western blot analysis of isolated and fractionated chloroplasts. Recombinant AtCutA protein was expressed in Escherichia coli without the N-terminal 70-amino-acid chloroplast transit sequence. This recombinant AtCutAp was routed to the bacterial periplasm of E. coli. Purified recombinant AtCutAp is tetrameric and selectively binds Cu(II) ions with an affinity comparable to that reported for mammalian prion proteins.

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Available from: Jason Lee Burkhead, Sep 26, 2015
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    • "Arabidopsis has a homolog of the conserved CutA protein (Burkhead et al., 2003) and CutA has some structural resemblance to ATX (Arnesano et al., 2003). CutA binds Cu(II) in vitro and was detected in chloroplasts of overexpressing plants (Burkhead et al., 2003), but its location has not yet been verified by GFP fusions and a T-DNA knockout does not affect plastocyanin function. Research in Synechocystis PCC 6803 on Atx1 has shed light on the role of metallochaperones (Borrely et al., 2004). "
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    ABSTRACT: Copper (Cu) is a cofactor in proteins that are involved in electron transfer reactions and is an essential micronutrient for plants. Copper delivery is accomplished by the concerted action of a set of evolutionarily conserved transporters and metallochaperones. As a result of regulation of transporters in the root and the rarity of natural soils with high Cu levels, very few plants in nature will experience Cu in toxic excess in their tissues. However, low Cu bioavailability can limit plant productivity and plants have an interesting response to impending Cu deficiency, which is regulated by an evolutionarily conserved master switch. When Cu supply is insufficient, systems to increase uptake are activated and the available Cu is utilized with economy. A number of Cu-regulated small RNA molecules, the Cu-microRNAs, are used to downregulate Cu proteins that are seemingly not essential. On low Cu, the Cu-microRNAs are upregulated by the master Cu-responsive transcription factor SPL7, which also activates expression of genes involved in Cu assimilation. This regulation allows the most important proteins, which are required for photo-autotrophic growth, to remain active over a wide range of Cu concentrations and this should broaden the range where plants can thrive.
    New Phytologist 05/2009; 182(4):799-816. DOI:10.1111/j.1469-8137.2009.02846.x · 7.67 Impact Factor
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    • "It has been also shown that the Arabidopsis gene, AtCOX17, encoding a protein that shares sequence similarity to the copper yeast chaperone COX17, might serve as a copper delivery protein in the assembly of a functional cytochrome oxidase complex in the mitochondria (Balandin & Castesana, 2002). More recently, the specific interaction with Cu(II) ions and its presence in the chloroplast has suggest that AtCutAp , derived from alternative splicing of the gene AtCUTA of Arabidopsis, has a role as a typical copper chaperone in the control of metal homeostasis in chloroplasts (Burkhead et al., 2003). In addition, the gene PAA1, a P-Type ATPase of Arabidopsis, has been demonstrated to be a critical component of a copper transport system responsible for cofactor delivery to chloroplast Cu/Zn superoxide dismutase (Shikanai et al., 2003), whereas PAA2 has been more recently shown to localize at the thylakoid membranes and mediate transport of copper to plastocyanin (Abdel-Ghany et al., 2005). "
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    ABSTRACT: Copper is a vital component of electron transfer reactions mediated by proteins such as superoxide dismutase, cytochrome c oxidase and plastocyanin, but its concentrations in the cells needs to be maintained at low levels. In fact, the same ability of this essential metal ion to transfer electrons can also make it toxic to cells when present in excess. In vitro cultured explants of Nicotiana have been extensively used as a model to analyse metal-DNA interactions. In this report, we examined the effect of copper (1, 10 and 100 μM CuSO4) on callus growth and protein synthesis of in vitro-cultured pith explants of Nicotiana glauca. In addition, a N. glauca cDNA library from Cu-treated (100 μM CuSO4) pith explants cultured in vitro for 24 h was analysed by mRNA differential screening. The copper treatments inhibited callus growth of pith explants. The extent of inhibition was directly correlated to metal concentration. One and 10 μM CuSO4 induced a notable increase of proteins synthesis relative to control explants. By contrast, 100 μM CuSO4 inhibited protein synthesis relative to control extracts. The SDS-PAGE fluorography of pith proteins revealed, in Cu-treated extracts qualitative and/or quantitative differences in the synthesis of some polypeptides compared with control explants. Copper-modulated patterns of gene expression were also analysed by mRNA differential screening. The N. glauca genes isolated from Cu-treated pith explants shared common identities with other genes known to be elicited by diverse stresses, including pathogenesis and abiotic stress. In particular, the cDNAs were homologues to genes encoding cell wall proteins (i.e., extensin, and arabinogalactan-protein) and pathogenesis-related proteins (i.e., osmotin, endochitinase and a member of the Systemic Acquired Resistance gene family). In addition, an MD-2-related lipid-recognition (ML) domain protein and the enzyme S-adenosyl-L-homocysteine (AdoHcy) hydrolase appeared involved in the response to copper stress. In animal cells, AdoHcy hydrolase is a copper binding protein in vivo, which suggests that, also in plant tissues, this enzyme may play an important role in regulating the levels and intracellular distribution of copper.
    Plant Biosystems 07/2007; 141(2):194-203. DOI:10.1080/11263500701401521 · 1.92 Impact Factor
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    • "within the plant . The presence of putative Cu 2+ transporters in plants ( e . g . HMA1 ) suggests that additional mechanisms may exist for proper Cu delivery . In this sense , the Arabidopsis CUTA protein , which binds Cu 2+ and localizes to the intermem - brane chloroplastic space , has been proposed as a candidate for a Cu 2+ metallochaperone ( Burkhead et al . 2003 ) ."
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    ABSTRACT: Plants have developed sophisticated mechanisms to tightly control the acquisition and distribution of copper and iron in response to environmental fluctuations. Recent studies with Arabidopsis thaliana are allowing the characterization of the diverse families and components involved in metal uptake, such as metal-chelate reductases and plasma membrane transporters. In parallel, emerging data on both intra- and intercellular metal distribution, as well as on long-distance transport, are contributing to the understanding of metal homeostatic networks in plants. Furthermore, gene expression analyses are deciphering coordinated mechanisms of regulation and response to copper and iron limitation. Prioritizing the use of metals in essential versus dispensable processes, and substituting specific metalloproteins by other metal counterparts, are examples of plant strategies to optimize copper and iron utilization. The metabolic links between copper and iron homeostasis are well documented in yeast, algae and mammals. In contrast, interactions between both metals in vascular plants remain controversial, mainly owing to the absence of copper-dependent iron acquisition. This review describes putative interactions between both metals at different levels in plants. The characterization of plant copper and iron homeostasis should lead to biotechnological applications aimed at the alleviation of iron deficiency and copper contamination and, thus, have a beneficial impact on agricultural and human health problems.
    Plant Cell and Environment 04/2007; 30(3):271-90. DOI:10.1111/j.1365-3040.2007.01642.x · 6.96 Impact Factor
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