CHX21_ARATH
ID CHX21_ARATH Reviewed; 832 AA.
AC Q9SKA9;
DT 15-JUN-2010, integrated into UniProtKB/Swiss-Prot.
DT 15-JUN-2010, sequence version 2.
DT 03-AUG-2022, entry version 115.
DE RecName: Full=Cation/H(+) antiporter 21;
DE AltName: Full=Protein CATION/H+ EXCHANGER 21;
DE Short=AtCHX21;
GN Name=CHX21; OrderedLocusNames=At2g31910; ORFNames=F20M17.5;
OS Arabidopsis thaliana (Mouse-ear cress).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis.
OX NCBI_TaxID=3702;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=cv. Columbia;
RX PubMed=10617197; DOI=10.1038/45471;
RA Lin X., Kaul S., Rounsley S.D., Shea T.P., Benito M.-I., Town C.D.,
RA Fujii C.Y., Mason T.M., Bowman C.L., Barnstead M.E., Feldblyum T.V.,
RA Buell C.R., Ketchum K.A., Lee J.J., Ronning C.M., Koo H.L., Moffat K.S.,
RA Cronin L.A., Shen M., Pai G., Van Aken S., Umayam L., Tallon L.J.,
RA Gill J.E., Adams M.D., Carrera A.J., Creasy T.H., Goodman H.M.,
RA Somerville C.R., Copenhaver G.P., Preuss D., Nierman W.C., White O.,
RA Eisen J.A., Salzberg S.L., Fraser C.M., Venter J.C.;
RT "Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana.";
RL Nature 402:761-768(1999).
RN [2]
RP GENOME REANNOTATION.
RC STRAIN=cv. Columbia;
RX PubMed=27862469; DOI=10.1111/tpj.13415;
RA Cheng C.Y., Krishnakumar V., Chan A.P., Thibaud-Nissen F., Schobel S.,
RA Town C.D.;
RT "Araport11: a complete reannotation of the Arabidopsis thaliana reference
RT genome.";
RL Plant J. 89:789-804(2017).
RN [3]
RP GENE FAMILY, AND NOMENCLATURE.
RX PubMed=11500563; DOI=10.1104/pp.126.4.1646;
RA Maeser P., Thomine S., Schroeder J.I., Ward J.M., Hirschi K., Sze H.,
RA Talke I.N., Amtmann A., Maathuis F.J.M., Sanders D., Harper J.F.,
RA Tchieu J., Gribskov M., Persans M.W., Salt D.E., Kim S.A., Guerinot M.L.;
RT "Phylogenetic relationships within cation transporter families of
RT Arabidopsis.";
RL Plant Physiol. 126:1646-1667(2001).
RN [4]
RP GENE FAMILY, AND NOMENCLATURE.
RX PubMed=15347787; DOI=10.1104/pp.104.046003;
RA Sze H., Padmanaban S., Cellier F., Honys D., Cheng N.-H., Bock K.W.,
RA Conejero G., Li X., Twell D., Ward J.M., Hirschi K.D.;
RT "Expression patterns of a novel AtCHX gene family highlight potential roles
RT in osmotic adjustment and K+ homeostasis in pollen development.";
RL Plant Physiol. 136:2532-2547(2004).
RN [5]
RP FUNCTION, DISRUPTION PHENOTYPE, SUBCELLULAR LOCATION, AND TISSUE
RP SPECIFICITY.
RX PubMed=16513816; DOI=10.1093/jxb/erj092;
RA Hall D., Evans A.R., Newbury H.J., Pritchard J.;
RT "Functional analysis of CHX21: a putative sodium transporter in
RT Arabidopsis.";
RL J. Exp. Bot. 57:1201-1210(2006).
RN [6]
RP FUNCTION, TISSUE SPECIFICITY, AND DISRUPTION PHENOTYPE.
RC STRAIN=cv. Columbia;
RX PubMed=21239645; DOI=10.1105/tpc.110.080499;
RA Lu Y., Chanroj S., Zulkifli L., Johnson M.A., Uozumi N., Cheung A., Sze H.;
RT "Pollen tubes lacking a pair of K+ transporters fail to target ovules in
RT Arabidopsis.";
RL Plant Cell 23:81-93(2011).
RN [7]
RP RETRACTED PAPER.
RX PubMed=21976771; DOI=10.1093/jxb/err271;
RA Evans A.R., Hall D., Pritchard J., Newbury H.J.;
RT "The roles of the cation transporters CHX21 and CHX23 in the development of
RT Arabidopsis thaliana.";
RL J. Exp. Bot. 63:59-67(2012).
RN [8]
RP RETRACTION NOTICE OF PUBMED:21976771.
RX PubMed=33428752; DOI=10.1093/jxb/eraa530;
RA Evans A.R., Hall D., Pritchard J., Newbury H.J.;
RL J. Exp. Bot. 72:775-775(2021).
CC -!- FUNCTION: Operates as a Na(+)/H(+) antiporter that plays a role in
CC regulation of xylem Na(+) concentration and, consequently, Na(+)
CC accumulation in the leaf. Required for pollen tube guidance, but not
CC for normal pollen development. May also be involved in the development
CC or function of the female gametophyte. {ECO:0000269|PubMed:16513816,
CC ECO:0000269|PubMed:21239645}.
CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000269|PubMed:16513816};
CC Multi-pass membrane protein {ECO:0000269|PubMed:16513816}.
CC -!- TISSUE SPECIFICITY: Specifically expressed in root endodermal cells
CC (PubMed:16513816). Expressed in seedlings, roots, leaves, flowers,
CC flower buds and pollen. {ECO:0000269|PubMed:16513816,
CC ECO:0000269|PubMed:21239645}.
CC -!- DISRUPTION PHENOTYPE: Mutants display a reduced rosette width, a later
CC flowering time and an altered leaf K(+) and Na(+) contents
CC (PubMed:16513816). No defect in male fertility, due to redundancy with
CC CHX23. Chx21 and chx23 double mutants are male sterile
CC (PubMed:21239645). {ECO:0000269|PubMed:16513816,
CC ECO:0000269|PubMed:21239645}.
CC -!- SIMILARITY: Belongs to the monovalent cation:proton antiporter 2 (CPA2)
CC transporter (TC 2.A.37) family. CHX (TC 2.A.37.4) subfamily.
CC {ECO:0000305}.
CC -!- CAUTION: The article by Evans et al was retracted by the editors due to
CC concerns over image manipulation, which raised sufficient doubts
CC regarding the credibility of the study. {ECO:0000305|PubMed:33428752}.
CC -!- SEQUENCE CAUTION:
CC Sequence=AAD32281.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};
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DR EMBL; AC006533; AAD32281.1; ALT_SEQ; Genomic_DNA.
DR EMBL; CP002685; AEC08602.1; -; Genomic_DNA.
DR PIR; F84726; F84726.
DR RefSeq; NP_001324588.1; NM_001336356.1.
DR RefSeq; NP_001324589.1; NM_001336355.1.
DR RefSeq; NP_180750.2; NM_128749.2.
DR AlphaFoldDB; Q9SKA9; -.
DR SMR; Q9SKA9; -.
DR STRING; 3702.AT2G31910.1; -.
DR PaxDb; Q9SKA9; -.
DR PRIDE; Q9SKA9; -.
DR EnsemblPlants; AT2G31910.1; AT2G31910.1; AT2G31910.
DR GeneID; 817749; -.
DR Gramene; AT2G31910.1; AT2G31910.1; AT2G31910.
DR KEGG; ath:AT2G31910; -.
DR Araport; AT2G31910; -.
DR TAIR; locus:2045283; AT2G31910.
DR eggNOG; KOG1650; Eukaryota.
DR HOGENOM; CLU_005126_6_2_1; -.
DR InParanoid; Q9SKA9; -.
DR OMA; IHEMADC; -.
DR OrthoDB; 336706at2759; -.
DR PhylomeDB; Q9SKA9; -.
DR PRO; PR:Q9SKA9; -.
DR Proteomes; UP000006548; Chromosome 2.
DR ExpressionAtlas; Q9SKA9; baseline and differential.
DR Genevisible; Q9SKA9; AT.
DR GO; GO:0012505; C:endomembrane system; IBA:GO_Central.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0005451; F:monovalent cation:proton antiporter activity; IEA:InterPro.
DR GO; GO:0010183; P:pollen tube guidance; IGI:TAIR.
DR GO; GO:0006813; P:potassium ion transport; IEA:UniProtKB-KW.
DR GO; GO:0006885; P:regulation of pH; IBA:GO_Central.
DR GO; GO:0006814; P:sodium ion transport; IEA:InterPro.
DR Gene3D; 1.20.1530.20; -; 1.
DR InterPro; IPR006153; Cation/H_exchanger.
DR InterPro; IPR030153; CHX21/CHX23.
DR InterPro; IPR038770; Na+/solute_symporter_sf.
DR PANTHER; PTHR32468:SF128; PTHR32468:SF128; 1.
DR Pfam; PF00999; Na_H_Exchanger; 1.
PE 2: Evidence at transcript level;
KW Antiport; Cell membrane; Ion transport; Membrane; Potassium;
KW Potassium transport; Reference proteome; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..832
FT /note="Cation/H(+) antiporter 21"
FT /id="PRO_0000394991"
FT TRANSMEM 33..55
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 61..81
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 99..119
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 132..152
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 161..181
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 200..220
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 236..256
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 278..298
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 319..339
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 352..372
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 379..399
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 413..433
FT /note="Helical"
FT /evidence="ECO:0000255"
FT REGION 792..832
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ SEQUENCE 832 AA; 91982 MW; 2C389C3EA9173FB6 CRC64;
MADPAAESID ASSSRFGRVV CYNQTAMHGS NTISAAAPFF MTQLSVANLT YRILYYFLKP
LCLPPFVAQI LCGLLFSPTV LGNNEVVLKL IFPYKYTMLL ETFANLALVY NVFLLGLGLD
LRMIKIKDIK PVIIAIVGLL AALLAGAGLY YLPSNGEADK ILAGCMYWSI AFGCTNFPDL
ARILADLKLL RTDMGHTAMC AAVVTDLCTW ILFIFGMAIF SKSGVRNEML PYSLASTIAF
VLLCYFVIQP GVAWIFNNTV EGGQVGDTHV WYTLAGVIIC SLITEVCGVH SITGAFLFGL
SIPHDHIIRK MIEEKLHDFL SGMLMPLFYI ICGLRADIGY MNRTVSVGMM AVVTSASVMV
KILSTMFCSI FLRIPLRDGL AIGALMNTKG TMALVILNAG RDTKALDVIM YTHLTLAFLV
MSMVVQPLLA IAYKPKKKLI FYKNRTIQKH KGESELCVLT CVHVLPNVSG ITNLLQLSNP
TKKSPLNVFA IHLVELTGRT TASLLIMNDE AKPKANFADR VRAESDQIAE MFTALEVNND
GVMVQTITAV SPYATMDEDI CLLAEDKQAC FILLPYHKNM TSDGRLNEGN AVHAEINQNV
MSHAPCSVGI LVDRGMTTVR FESFMFQGET TKKEIAMLFL GGRDDREALA YAWRMVGQEM
VQLTVVRFVP SQEALVSAGE AADEYEKDKH VDEESIYEFN FKTMNDPSVT YVEKVVKNGQ
ETITAILELE DNNSYDLYIV GRGYQVETPV TSGLTDWNST PDLGIIGDTL ISSNFTMQAS
VLVVQQYSSA NRQTAENNNQ EPVQGKAKTD HEATPFMEDE DDEVEHQYSM RR
