Os12g0438600
Contents
Annotated Information
Function
AtCLC-a, a member of the CLC family of anion transporters, is involved mainly in nitrate storage in the vacuole. CLCa (AtCLCa) is localized to an intracellular membrane, the tonoplast of the plant vacuole, with anion transport ability. AtCLCa is able to accumulate specifically nitrate in the vacuole and behaves as a NO32-/H+ exchanger. electrophysiological studies show that, at physiological membrane potentials, AtCLCa-mediated current is able to transport NO3 2 into the vacuole (negative current), when cytosolic [NO3 2-] is in a physiological range. Nevertheless, there is a clear discrepancy between the measured Erev and the Nernst potential for NO3 2. This observation demonstrates that other ions are transported by AtCLCa[1].. The high selectivity of AtCLCa for nitrate ions compared with chloride ions seems to be a peculiarity of this plant CLC and is in agreement with the clca knockout mutant phenotype. Finally, the present findings illustrate the exchanger mechanism of a CLC protein in the native membrane system and answer the biological question regarding CLC antiporter function in an intracellular organelle.
Representation of the AtCLCaNO32/Ht antiporter in a plant cell
By monitoring AtCLCa activity in its native environment, Stefanie Wege found that if proline 160 in AtCLCa is changed to a serine (AtCLCaP160S), the transporter loses its nitrate selectivity, but the anion proton exchange mechanism is unaffected. The results confirm the significance of this amino acid in the conserved selectivity filter of CLC proteins and highlight the importance of nitrate metabolism in Arabidopsis.[2].
Vacuolar chloride is transported differently by native AtCLCaWT andthe mutant AtCLCaP160S. Thus, compared with AtCLCaWT, AtCLCaP160S shows adecrease of the anion conductance directed to the vacuoleupon exchange of the cytosolic solution from Cl) to NO3 This indicates that alteration of proline at position 160 to serine in the selectivity filter impairs NO3) import into the vacuole, and thus P160 may be important for the physiological function of AtCLCa in NO3 ) accumulation in vacuoles.
ATP reversibly inhibits AtCLCa by interacting with the C-terminal domain[3].. Applying the patch clamp technique to isolated Arabidopsis thaliana vacuoles, Alexis De Angeli demonstrate that ATP reduces AtCLCa activity with a maximum inhibition of 60%. ATP inhibition of nitrate influx into the vacuole at cytosolic physiological nitrate concentrations suggests that ATP modulation is physiologically relevant. ADP and AMP do not decrease the AtCLCa transport activity; nonetheless, AMP (but not ADP) competes with ATP, preventing inhibition.
Homology model of the AtCLCa C-terminal region. a, the alignment used for the homology modeling of AtCLCa C-terminal region on the hCLC-5 C-terminal region. b, detail of the region putatively involved in the ATP-AtCLCa interaction.
In this study, analyses of T-DNA insertion mutants within the AtClCa and AtClCe genes revealed common phenotypic traits: a lower endogenous nitrate content; a higher nitrite content; a reduced nitrate influx into the root; and a decreased expression of several genes encoding nitrate transporters. This set of nitrate-related phenotypes, displayed by clca and clce mutant plants, showed interconnecting roles of AtClCa and AtClCe in nitrate homeostasis involving two different endocellular membranes.[4].
Expression
The rice genome has been completely sequenced and comprises five CLC homologues, but only two members from Oryza sativa L., OsClC-1 and OsClC-2 have been characterized . The highest homology with the plant subgroup comprising AtClC-a to –g, OsClC-1 is expressed in most tissues, whereas OsClC-2 is expressed only in roots, nodes, internodes and leaf sheaths, but for both of them vacuolar localization has been suggested.[5].
To determine the subcellular localization of the AtCLCa protein, green fluorescent protein (GFP) fusion proteins were transiently expressed in protoplasts from Arabidopsis cell suspensions. Confocal microscopy studies revealed a green fluorescent labelling that coincided with the tonoplast[1].。
Transient expression of AtCLCa–GFP fusion proteins in protoplasts. Laser-scanning images of GFP fluorescence (left), transmitted light (centre) and merge of both (right); scale bars correspond to 16 mm.
Evolution
Phylogeny of predicted AtCLC proteins. (A) Scaled graphic representation of different domains of CLCs from Arabidopsis as well as from E. Coli (EcCLC-a, EcCLCb) and Torpedo marmorata (CLC-0). The relative position of each TM region and CBS domain is modified according to PRED-TMR and SMART, respectively. Each black bar stands for a TM region and gray boxes correspond to CBS domains as indicated inside. Accession numbers of the CLC protein sequences are available in Supplemental Tables 2–4. (B) Plant CLC proteins are grouped into two distinct subclasses. Neighbor-joining protein sequence phylogeny was performed using MEGA4.0. Bootstrap values are shown on the branch points of the tree. Subclass Iand II are indicated by two curves separately. Accession numbers of the sequences included are provided in Supplemental Tables 2–4. (C) Amino acid sequence alignments of two CBS domains of AtCLCs. The corresponding CBS domain was lined on the top of the sequences.
Labs working on this gene
Institute for Plant Biology, University of Zurich, CH-8008 Zurich, Switzerland. Alexis De Angeli Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, France. Geneviève Ephritikhine School of Life Science and Technology, Tongji University, Shanghai, China. Zhixue Liu National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China. Hong-xia Zhang Universite Paris 7-Denis Diderot, UFR Biologie Sciences de la Nature, France. G. Ephritikhine
References
- ↑ 1.0 1.1 De Angeli A, Monachello D, Ephritikhine G, Frachisse JM, Thomine S, Gambale F and Barbier-Brygoo H (2006) The nitrate/proton antiporter AtCLCa mediates nitrate accumulation in plant vacuoles. Nature 442:939-942.
- ↑ Wege S, Jossier M, Filleur S, Thomine S, Barbier-Brygoo H, Gambale F and De Angeli A (2010) The proline 160 in the selectivity filter of the Arabidopsis NO(3)(-)/H(+) exchanger AtCLCa is essential for nitrate accumulation in planta. The Plant journal : for cell and molecular biology 63:861-869.
- ↑ De Angeli A, Moran O, Wege S, Filleur S, Ephritikhine G, Thomine S, Barbier-Brygoo H and Gambale F (2009) ATP binding to the C terminus of the Arabidopsis thaliana nitrate/proton antiporter, AtCLCa, regulates nitrate transport into plant vacuoles. The Journal of biological chemistry 284:26526-26532.
- ↑ Monachello D, Allot M, Oliva S, Krapp A, Daniel-Vedele F, Barbier-Brygoo H and Ephritikhine G (2009) Two anion transporters AtClCa and AtClCe fulfil interconnecting but not redundant roles in nitrate assimilation pathways. The New phytologist 183:88-94.
- ↑ Zifarelli G and Pusch M (2010) CLC transport proteins in plants. FEBS letters 584:2122-2127.
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Structured Information
| Gene Name |
Os12g0438600 |
|---|---|
| Description |
Similar to Chloride channel protein CLC-a (AtCLC-a) |
| Version |
NM_001073224.1 GI:115488409 GeneID:4352132 |
| Length |
3607 bp |
| Definition |
Oryza sativa Japonica Group Os12g0438600, complete gene. |
| Source |
Oryza sativa Japonica Group ORGANISM Oryza sativa Japonica Group
Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
Spermatophyta; Magnoliophyta; Liliopsida; Poales; Poaceae; BEP
clade; Ehrhartoideae; Oryzeae; Oryza.
|
| Chromosome | |
| Location |
Chromosome 12:14635483..14639089 |
| Sequence Coding Region |
14635749..14635847,14636418..14638079,14638194..14638371,14638457..14638641 |
| Expression | |
| Genome Context |
<gbrowseImage1> name=NC_008405:14635483..14639089 source=RiceChromosome12 preset=GeneLocation </gbrowseImage1> |
| Gene Structure |
<gbrowseImage2> name=NC_008405:14635483..14639089 source=RiceChromosome12 preset=GeneLocation </gbrowseImage2> |
| Coding Sequence |
<cdnaseq>tctgttcaagcacgactggaggaggcgatcgaacgtggaggtgctgcagtacatcttcctcaagtgggccatggcgttcctcgtcggcctcctcaccggcgtcatcgcgtcgctcatcaacctcgccatcgagaacatctccggcctcaagatgctccacatggtgcagctcgtccgcaagaaaaatactgggccggtttcttgtatttcgccggcgtcaacttcggcctgacgttcatcgccgccatgctctgcgtcgtcttcgccccgaccgccgccggccccggcatcccggagatcaaggcctacctcaacggcgtcgacacgcccaacatgttcggcgcgccgcagctcattgtcaagatcatcggtagcatctgcgcggtgtcgtcggggctggatctcgggaaggaagggccactggtgcacatcggcgcgtgcctggcgaacttgctgagccagggcggctccggccggcaccgcctccggttgcggtggctgcgctacttcgacaacgaccgcgaccggcgcgacctgatcacctgcggcgcgtcgtcgggcgtgtgcgcggcgttccgggcgcccgtcggcggcgtgctgttcgcgctggaggaggtggcgacgtggtggcggagcgcgctgctgtggcgcaccttcttcagcacggccaccgtcgtcgtcgtcctccgcgggttcatcgaggtgtgcaggaacgggcggtgcggtctgttcggcgagggcgggctcatcctgttcgacgtcggcgacgtcgccgtccggtaccacgccggcgacctcctcccggtgaccatcgtcggcgtgcttggcggcgtcctcggcgcgctgtacaaccacgtcctccacaaggtgctccgcgtgtacaacctcatcaacgagaagggccgcgccgcgaagctcgccctggcgctcgccgtgtgcgcgctcacgtcggcgctgctgtacgtgacgccgttcgccgtgccgtgcacgccgtgcgacccggcgttcggcggcgcgtgcccgacgctggggaagagcggcaacttcaagcggttcaactgccccgagggccactacaacgacctcgccaccctcctccacgccaccaacgtcgacgcgacgcggaacatcttctccacgggcaccgccggcgagttcaggctcgactcgctgctcatcttcttcgccgtctactgcgtcctgggcctcttcaccttcggcatcgccgtcccctcggggctcttcctccccatcatcctcatgggctccgcctacggccgcgtcacggcgctcgtgctgtcgcggttcgcccgcatcgaccacggcctatacgccgtgctcggcgcggcggcgctcatgtcggggtccatgcggatgaccgtgtcgctcgtcgtcatcttcctcgagctcaccaacaacctcctcctcctcccaatcaccatgttcgtcctcctcatcgccaagaccgtcggcgacgcgttcaaccccagcatctacgagatcatcctcgacctcaagggcctcccgttcctggaggcgaagccggagccgtggatgaaggacctcaccgtcggcgagctcgccgccgccaagccccgcgccgtggcgctccaggtggtggagcgcgtgtccacggtggtggaggcgctccgggcgacgcggcacaacgggttcccggtgctggaccggccgcggcccggggtatcggagctgcacgggctggtgctccggtcgcacctcgtcgccgcgctgaggaagcggtggttcctgccggagaggaggaggacggaggagtgggaggcccgcgagatgttcagctcggcggagctcgcggacaagtgcggcggcgtggacgagctggagatctcgccggaggagatggggatgtacgtggacctccacccgctgacgaacacgacgccgtacaccgtggtggagaccatgtcggtggcgaaggccgtcgtgctgttccgctccgtcgcgctccgccacatgctcatcatgcccaagttccaaggacccgagatatctccaattgtggggatcttgacaaggcaggacctgatagcacacaacatcctcggtgcatttccacaccttgcaagcaagaggaaaacacattga</cdnaseq> |
| Protein Sequence |
<aaseq>SVQARLEEAIERGGAAVHLPQVGHGVPRRPPHRRHRVAHQPRHR EHLRPQDAPHGAARPQEKYWAGFLYFAGVNFGLTFIAAMLCVVFAPTAAGPGIPEIKA YLNGVDTPNMFGAPQLIVKIIGSICAVSSGLDLGKEGPLVHIGACLANLLSQGGSGRH RLRLRWLRYFDNDRDRRDLITCGASSGVCAAFRAPVGGVLFALEEVATWWRSALLWRT FFSTATVVVVLRGFIEVCRNGRCGLFGEGGLILFDVGDVAVRYHAGDLLPVTIVGVLG GVLGALYNHVLHKVLRVYNLINEKGRAAKLALALAVCALTSALLYVTPFAVPCTPCDP AFGGACPTLGKSGNFKRFNCPEGHYNDLATLLHATNVDATRNIFSTGTAGEFRLDSLL IFFAVYCVLGLFTFGIAVPSGLFLPIILMGSAYGRVTALVLSRFARIDHGLYAVLGAA ALMSGSMRMTVSLVVIFLELTNNLLLLPITMFVLLIAKTVGDAFNPSIYEIILDLKGL PFLEAKPEPWMKDLTVGELAAAKPRAVALQVVERVSTVVEALRATRHNGFPVLDRPRP GVSELHGLVLRSHLVAALRKRWFLPERRRTEEWEAREMFSSAELADKCGGVDELEISP EEMGMYVDLHPLTNTTPYTVVETMSVAKAVVLFRSVALRHMLIMPKFQGPEISPIVGI LTRQDLIAHNILGAFPHLASKRKTH</aaseq> |
| Gene Sequence |
<dnaseqindica>3243..3341#1011..2672#719..896#449..633#acacatacacacacatatctcatcttgttgtttctgagctgctccaagaagcagagctctgtccatggaggaggagcagagcccgaggctcgccgccggcgagccggagcgcaagctcgaggacggagtcaccgacgccgaggaccccgggtgcacgggcaatgcggccatgagctcgctggagcagccgcttctgaagcggagcaacacgctaacggccagccacctcgccatggttggcgccaaggtctcccacatcgagagcctcgactacgagtgagcattttctcctcctcctcctccatgtctaattcaccgtgctcgatcacgagtccatcaattcttggattcttgatttgttgattctcgatcggttggtttaattaatctgttcttgcattttttttcaatttgtgatgtgtgaatttggtagaattatcgagaatgatctgttcaagcacgactggaggaggcgatcgaacgtggaggtgctgcagtacatcttcctcaagtgggccatggcgttcctcgtcggcctcctcaccggcgtcatcgcgtcgctcatcaacctcgccatcgagaacatctccggcctcaagatgctccacatggtgcagctcgtccgcaagaaaagttaagcccacaactcctccttcttcttcctcatcgccggcgacgagttcttgatggtgaaaaatttgccgtcaccctactgcagatactgggccggtttcttgtatttcgccggcgtcaacttcggcctgacgttcatcgccgccatgctctgcgtcgtcttcgccccgaccgccgccggccccggcatcccggagatcaaggcctacctcaacggcgtcgacacgcccaacatgttcggcgcgccgcagctcattgtcaaggtcacaaaaaaaaaatgtcacacttctccaacgtgtcggaacaacatttttttttcgattaaacggcagacgcgcacacactgacgagtagaaaaaaatgtatgatcatcgcagatcatcggtagcatctgcgcggtgtcgtcggggctggatctcgggaaggaagggccactggtgcacatcggcgcgtgcctggcgaacttgctgagccagggcggctccggccggcaccgcctccggttgcggtggctgcgctacttcgacaacgaccgcgaccggcgcgacctgatcacctgcggcgcgtcgtcgggcgtgtgcgcggcgttccgggcgcccgtcggcggcgtgctgttcgcgctggaggaggtggcgacgtggtggcggagcgcgctgctgtggcgcaccttcttcagcacggccaccgtcgtcgtcgtcctccgcgggttcatcgaggtgtgcaggaacgggcggtgcggtctgttcggcgagggcgggctcatcctgttcgacgtcggcgacgtcgccgtccggtaccacgccggcgacctcctcccggtgaccatcgtcggcgtgcttggcggcgtcctcggcgcgctgtacaaccacgtcctccacaaggtgctccgcgtgtacaacctcatcaacgagaagggccgcgccgcgaagctcgccctggcgctcgccgtgtgcgcgctcacgtcggcgctgctgtacgtgacgccgttcgccgtgccgtgcacgccgtgcgacccggcgttcggcggcgcgtgcccgacgctggggaagagcggcaacttcaagcggttcaactgccccgagggccactacaacgacctcgccaccctcctccacgccaccaacgtcgacgcgacgcggaacatcttctccacgggcaccgccggcgagttcaggctcgactcgctgctcatcttcttcgccgtctactgcgtcctgggcctcttcaccttcggcatcgccgtcccctcggggctcttcctccccatcatcctcatgggctccgcctacggccgcgtcacggcgctcgtgctgtcgcggttcgcccgcatcgaccacggcctatacgccgtgctcggcgcggcggcgctcatgtcggggtccatgcggatgaccgtgtcgctcgtcgtcatcttcctcgagctcaccaacaacctcctcctcctcccaatcaccatgttcgtcctcctcatcgccaagaccgtcggcgacgcgttcaaccccagcatctacgagatcatcctcgacctcaagggcctcccgttcctggaggcgaagccggagccgtggatgaaggacctcaccgtcggcgagctcgccgccgccaagccccgcgccgtggcgctccaggtggtggagcgcgtgtccacggtggtggaggcgctccgggcgacgcggcacaacgggttcccggtgctggaccggccgcggcccggggtatcggagctgcacgggctggtgctccggtcgcacctcgtcgccgcgctgaggaagcggtggttcctgccggagaggaggaggacggaggagtgggaggcccgcgagatgttcagctcggcggagctcgcggacaagtgcggcggcgtggacgagctggagatctcgccggaggagatggggatgtacgtggacctccacccgctgacgaacacgacgccgtacaccgtggtggagaccatgtcggtggcgaaggccgtcgtgctgttccgctccgtcgcgctccgccacatgctcatcatgcccaagttccaaggacccgaggtcagcgccaaaacacagactgaattttactccctggttacaagacgatccaagtcaaactgttttaagtttgattaaagtttatagaaaaaataataataacattttcaaccaagacaaatttattataaatatatattcaattattggtttgatgaaacttatttagtattataaatattatcatatttgtctatgaatttagtcaaacttgaaacagtttaactttgattaaagtcaaagcgttttataacctgaaacggagtaagtatttgtttattaatttacttattattttccaactacattcctggatcacaatgcaagtaaatgttgttctaagatcacaataatctctggattctgtatgtgcttgataaatcagatatgtgcagaatctgtgttctgtcctggtcttttgttacagaactggggatttagtgtcttatcagtgtcttatcatttctagaattttgctttgctttgtagaatacgggttagtgatcatttgttgaactcaatttgtgcatagttcggtgatgaaacttatgtttttttttttaatttcagatatctccaattgtggggatcttgacaaggcaggacctgatagcacacaacatcctcggtgcatttccacaccttgcaagcaagaggaaaacacattgagaggaaccatttttgagagttaatccatctttattgtcttgaagccaaatatcagagtcacctgcatatacagcttttatgaggctttgagttttttttcttttttttttcagttatcctcttctctgtaagtagattcaggattattatttgctgctcttctgagagtgcttgaataattgctgccaatgtaaaatcacacatgtaactatgccagatgtaatcaaaagggacacaaccatgatgcaatagagcaattctttttt</dnaseqindica> |
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