POT1A_ARATH
ID POT1A_ARATH Reviewed; 467 AA.
AC Q56Y52; Q4W6W9; Q4W6X0; Q52VR7; Q6Q835; Q9SJ37;
DT 18-APR-2012, integrated into UniProtKB/Swiss-Prot.
DT 10-MAY-2005, sequence version 1.
DT 03-AUG-2022, entry version 132.
DE RecName: Full=Protection of telomeres protein 1a {ECO:0000303|PubMed:17627276};
DE Short=AtPOT1a {ECO:0000303|PubMed:17627276};
DE Short=AtPot1 {ECO:0000303|PubMed:16107718};
DE AltName: Full=Protection of telomeres protein 1 {ECO:0000303|PubMed:16107718};
GN Name=POT1A {ECO:0000303|PubMed:17627276};
GN Synonyms=POT1 {ECO:0000303|PubMed:16107718};
GN OrderedLocusNames=At2g05210 {ECO:0000312|Araport:AT2G05210}; ORFNames=F5G3;
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 [MRNA] (ISOFORM 1).
RX PubMed=15589838; DOI=10.1016/j.febslet.2004.11.021;
RA Kuchar M., Fajkus J.;
RT "Interactions of putative telomere-binding proteins in Arabidopsis
RT thaliana: identification of functional TRF2 homolog in plants.";
RL FEBS Lett. 578:311-315(2004).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND ALTERNATIVE SPLICING (ISOFORMS 1; 2
RP AND 3).
RC STRAIN=cv. Columbia;
RX PubMed=15824455; DOI=10.1266/ggs.80.41;
RA Tani A., Murata M.;
RT "Alternative splicing of Pot1 (Protection of telomere)-like genes in
RT Arabidopsis thaliana.";
RL Genes Genet. Syst. 80:41-48(2005).
RN [3]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), FUNCTION, AND TISSUE SPECIFICITY.
RX PubMed=16107718; DOI=10.1128/mcb.25.17.7725-7733.2005;
RA Shakirov E.V., Surovtseva Y.V., Osbun N., Shippen D.E.;
RT "The Arabidopsis Pot1 and Pot2 proteins function in telomere length
RT homeostasis and chromosome end protection.";
RL Mol. Cell. Biol. 25:7725-7733(2005).
RN [4]
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 [5]
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 [6]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
RC STRAIN=cv. Columbia;
RA Totoki Y., Seki M., Ishida J., Nakajima M., Enju A., Kamiya A.,
RA Narusaka M., Shin-i T., Nakagawa M., Sakamoto N., Oishi K., Kohara Y.,
RA Kobayashi M., Toyoda A., Sakaki Y., Sakurai T., Iida K., Akiyama K.,
RA Satou M., Toyoda T., Konagaya A., Carninci P., Kawai J., Hayashizaki Y.,
RA Shinozaki K.;
RT "Large-scale analysis of RIKEN Arabidopsis full-length (RAFL) cDNAs.";
RL Submitted (MAR-2005) to the EMBL/GenBank/DDBJ databases.
RN [7]
RP FUNCTION, COMPONENT OF THE TELOMERASE COMPLEX, AND SUBCELLULAR LOCATION.
RX PubMed=17627276; DOI=10.1038/sj.emboj.7601792;
RA Surovtseva Y.V., Shakirov E.V., Vespa L., Osbun N., Song X., Shippen D.E.;
RT "Arabidopsis POT1 associates with the telomerase RNP and is required for
RT telomere maintenance.";
RL EMBO J. 26:3653-3661(2007).
RN [8]
RP INTERACTION WITH TERT.
RX PubMed=17911168; DOI=10.1242/jcs.004119;
RA Rossignol P., Collier S., Bush M., Shaw P., Doonan J.H.;
RT "Arabidopsis POT1A interacts with TERT-V(I8), an N-terminal splicing
RT variant of telomerase.";
RL J. Cell Sci. 120:3678-3687(2007).
RN [9]
RP INTERACTION WITH CBF5, AND COMPONENT OF THE TELOMERASE COMPLEX.
RX PubMed=18212040; DOI=10.1128/mcb.01490-07;
RA Kannan K., Nelson A.D., Shippen D.E.;
RT "Dyskerin is a component of the Arabidopsis telomerase RNP required for
RT telomere maintenance.";
RL Mol. Cell. Biol. 28:2332-2341(2008).
RN [10]
RP FUNCTION.
RX PubMed=19228335; DOI=10.1111/j.1365-313x.2009.03837.x;
RA Shakirov E.V., McKnight T.D., Shippen D.E.;
RT "POT1-independent single-strand telomeric DNA binding activities in
RT Brassicaceae.";
RL Plant J. 58:1004-1015(2009).
RN [11]
RP FUNCTION, RNA-BINDING, AND RETRACTED ARTICLE.
RX PubMed=21164032; DOI=10.1073/pnas.1013021107;
RA Cifuentes-Rojas C., Kannan K., Tseng L., Shippen D.E.;
RT "Two RNA subunits and POT1a are components of Arabidopsis telomerase.";
RL Proc. Natl. Acad. Sci. U.S.A. 108:73-78(2011).
RN [12]
RP RETRACTION NOTICE OF PUBMED:21164032, AND CAUTION.
RX PubMed=31754033; DOI=10.1073/pnas.1918863116;
RA Cifuentes-Rojas C., Kannan K., Tseng L., Shippen D.E.;
RT "Retraction for Cifuentes-Rojas et al., Two RNA subunits and POT1a are
RT components of Arabidopsis telomerase.";
RL Proc. Natl. Acad. Sci. U.S.A. 116:24908-24908(2019).
RN [13]
RP FUNCTION, AND INTERACTION WITH CTC1; STN1 AND TEN1.
RX PubMed=25329641; DOI=10.1371/journal.pgen.1004738;
RA Renfrew K.B., Song X., Lee J.R., Arora A., Shippen D.E.;
RT "POT1a and components of CST engage telomerase and regulate its activity in
RT Arabidopsis.";
RL PLoS Genet. 10:E1004738-E1004738(2014).
RN [14]
RP FUNCTION, INTERACTION WITH CTC1 AND STN1, AND MUTAGENESIS OF GLU-35;
RP PHE-65; LEU-132; SER-221; GLU-297 AND 458-TYR--HIS-467.
RX PubMed=25697340; DOI=10.1093/molbev/msv025;
RA Beilstein M.A., Renfrew K.B., Song X., Shakirov E.V., Zanis M.J.,
RA Shippen D.E.;
RT "Evolution of the telomere-associated protein POT1a in Arabidopsis thaliana
RT is characterized by positive selection to reinforce protein-protein
RT interaction.";
RL Mol. Biol. Evol. 32:1329-1341(2015).
RN [15]
RP FUNCTION, AND MUTAGENESIS OF PHE-65.
RX PubMed=27651456; DOI=10.1093/nar/gkw807;
RA Arora A., Beilstein M.A., Shippen D.E.;
RT "Evolution of Arabidopsis protection of telomeres 1 alters nucleic acid
RT recognition and telomerase regulation.";
RL Nucleic Acids Res. 44:9821-9830(2016).
RN [16]
RP COMPONENT OF THE TELOMERASE COMPLEX.
RX PubMed=31392988; DOI=10.1093/nar/gkz695;
RA Fajkus P., Peska V., Zavodnik M., Fojtova M., Fulneckova J., Dobias S.,
RA Kilar A., Dvorackova M., Zachova D., Necasova I., Sims J., Sykorova E.,
RA Fajkus J.;
RT "Telomerase RNAs in land plants.";
RL Nucleic Acids Res. 47:9842-9856(2019).
RN [17]
RP INTERACTION WITH CBF5, AND SUBCELLULAR LOCATION.
RX PubMed=30834599; DOI=10.1111/tpj.14306;
RA Schorova S., Fajkus J., Zaveska Drabkova L., Honys D., Schrumpfova P.P.;
RT "The plant Pontin and Reptin homologues, RuvBL1 and RuvBL2a, colocalize
RT with TERT and TRB proteins in vivo, and participate in telomerase
RT biogenesis.";
RL Plant J. 98:195-212(2019).
RN [18]
RP COMPONENT OF THE TELOMERASE COMPLEX.
RX PubMed=31754031; DOI=10.1073/pnas.1915312116;
RA Song J., Logeswaran D., Castillo-Gonzalez C., Li Y., Bose S., Aklilu B.B.,
RA Ma Z., Polkhovskiy A., Chen J.J., Shippen D.E.;
RT "The conserved structure of plant telomerase RNA provides the missing link
RT for an evolutionary pathway from ciliates to humans.";
RL Proc. Natl. Acad. Sci. U.S.A. 116:24542-24550(2019).
CC -!- FUNCTION: Component of the telomerase ribonucleoprotein (RNP) complex
CC that is essential for the positive regulation of telomere length
CC (PubMed:16107718, PubMed:17627276, PubMed:25697340). Binds RNA non-
CC specifically (PubMed:27651456). Binds specifically single-stranded
CC telomeric DNA (PubMed:16107718, PubMed:27651456). Not required to
CC recruit telomerase to telomeres, but stimulates TER1 RNP repeat
CC addition processivity (PubMed:25329641). {ECO:0000269|PubMed:16107718,
CC ECO:0000269|PubMed:17627276, ECO:0000269|PubMed:19228335,
CC ECO:0000269|PubMed:25329641, ECO:0000269|PubMed:25697340,
CC ECO:0000269|PubMed:27651456}.
CC -!- SUBUNIT: Component of the telomerase holoenzyme complex at least
CC composed of TERT, CBF5 and POT1a (PubMed:18212040) (Probable). The RNA
CC molecule associated to the telomerase complex, and providing a template
CC for telomeric DNA synthesis, is most likely TR and not TER1 as
CC described previously (PubMed:31754033, PubMed:31392988,
CC PubMed:31754031). Interacts with the N-terminal part of TERT
CC (PubMed:17911168). Interacts with CBF5 (PubMed:18212040,
CC PubMed:30834599). Interacts with CTC1 and STN1 (PubMed:25329641,
CC PubMed:25697340). Does not interact with TEN1 (PubMed:25329641).
CC {ECO:0000269|PubMed:17911168, ECO:0000269|PubMed:18212040,
CC ECO:0000269|PubMed:25329641, ECO:0000269|PubMed:25697340,
CC ECO:0000269|PubMed:30834599, ECO:0000269|PubMed:31392988,
CC ECO:0000269|PubMed:31754031, ECO:0000269|PubMed:31754033,
CC ECO:0000305|PubMed:31392988}.
CC -!- INTERACTION:
CC Q56Y52; Q9SPU7: TERT; NbExp=4; IntAct=EBI-1606062, EBI-1606133;
CC -!- SUBCELLULAR LOCATION: Nucleus {ECO:0000305|PubMed:17627276}.
CC Chromosome, telomere {ECO:0000269|PubMed:17627276}. Nucleus, nucleolus
CC {ECO:0000269|PubMed:30834599}. Cytoplasm {ECO:0000269|PubMed:30834599}.
CC Note=Localizes to telomeres in S-phase (PubMed:17627276). Localizes to
CC cytoplasmic foci (PubMed:30834599). {ECO:0000269|PubMed:17627276,
CC ECO:0000269|PubMed:30834599}.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=3;
CC Name=1;
CC IsoId=Q56Y52-1; Sequence=Displayed;
CC Name=2;
CC IsoId=Q56Y52-2; Sequence=VSP_043057, VSP_043059;
CC Name=3;
CC IsoId=Q56Y52-3; Sequence=VSP_043058, VSP_043059;
CC -!- TISSUE SPECIFICITY: Expressed in roots, rosette leaves, cauline leaves,
CC stems and flowers. {ECO:0000269|PubMed:16107718}.
CC -!- SIMILARITY: Belongs to the telombin family. {ECO:0000305}.
CC -!- CAUTION: Was originally thought to associate with TER1, the RNA
CC molecule of the telomerase complex that provides a template for
CC telomeric DNA synthesis (PubMed:21164032). The authentic RNA subunit of
CC the telomerase that associates with POT1A has been recently shown to be
CC TR and not TER1 (PubMed:31392988, PubMed:31754031). The original
CC publication has been retracted. {ECO:0000269|PubMed:21164032,
CC ECO:0000269|PubMed:31392988, ECO:0000269|PubMed:31754031,
CC ECO:0000305|PubMed:31754033}.
CC -!- SEQUENCE CAUTION:
CC Sequence=AAD29059.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};
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DR EMBL; AY553323; AAS59561.1; -; mRNA.
DR EMBL; AB195819; BAD99146.1; -; Genomic_DNA.
DR EMBL; AB195819; BAD99147.1; -; Genomic_DNA.
DR EMBL; AB195819; BAD99148.1; -; Genomic_DNA.
DR EMBL; AY884593; AAX78213.2; -; mRNA.
DR EMBL; AC007018; AAD29059.1; ALT_SEQ; Genomic_DNA.
DR EMBL; CP002685; AEC05904.1; -; Genomic_DNA.
DR EMBL; CP002685; AEC05905.1; -; Genomic_DNA.
DR EMBL; CP002685; AEC05906.1; -; Genomic_DNA.
DR EMBL; AK221471; BAD94597.1; -; mRNA.
DR PIR; A84466; A84466.
DR RefSeq; NP_001118270.1; NM_001124798.2. [Q56Y52-1]
DR RefSeq; NP_001118271.1; NM_001124799.2. [Q56Y52-1]
DR RefSeq; NP_178592.3; NM_126547.5. [Q56Y52-1]
DR AlphaFoldDB; Q56Y52; -.
DR SMR; Q56Y52; -.
DR BioGRID; 469; 40.
DR IntAct; Q56Y52; 4.
DR STRING; 3702.AT2G05210.2; -.
DR PaxDb; Q56Y52; -.
DR PRIDE; Q56Y52; -.
DR ProMEX; Q56Y52; -.
DR EnsemblPlants; AT2G05210.1; AT2G05210.1; AT2G05210. [Q56Y52-1]
DR EnsemblPlants; AT2G05210.2; AT2G05210.2; AT2G05210. [Q56Y52-1]
DR EnsemblPlants; AT2G05210.3; AT2G05210.3; AT2G05210. [Q56Y52-1]
DR GeneID; 815069; -.
DR Gramene; AT2G05210.1; AT2G05210.1; AT2G05210. [Q56Y52-1]
DR Gramene; AT2G05210.2; AT2G05210.2; AT2G05210. [Q56Y52-1]
DR Gramene; AT2G05210.3; AT2G05210.3; AT2G05210. [Q56Y52-1]
DR KEGG; ath:AT2G05210; -.
DR Araport; AT2G05210; -.
DR TAIR; locus:2051214; AT2G05210.
DR eggNOG; KOG4757; Eukaryota.
DR HOGENOM; CLU_020958_0_1_1; -.
DR InParanoid; Q56Y52; -.
DR OMA; FRCEERY; -.
DR OrthoDB; 940962at2759; -.
DR PhylomeDB; Q56Y52; -.
DR PRO; PR:Q56Y52; -.
DR Proteomes; UP000006548; Chromosome 2.
DR ExpressionAtlas; Q56Y52; baseline and differential.
DR Genevisible; Q56Y52; AT.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0000783; C:nuclear telomere cap complex; IBA:GO_Central.
DR GO; GO:0005730; C:nucleolus; IEA:UniProtKB-SubCell.
DR GO; GO:0098505; F:G-rich strand telomeric DNA binding; IBA:GO_Central.
DR GO; GO:0003723; F:RNA binding; IDA:TAIR.
DR GO; GO:0043047; F:single-stranded telomeric DNA binding; TAS:UniProtKB.
DR GO; GO:0010521; F:telomerase inhibitor activity; IBA:GO_Central.
DR GO; GO:0042162; F:telomeric DNA binding; IDA:TAIR.
DR GO; GO:0051974; P:negative regulation of telomerase activity; IBA:GO_Central.
DR GO; GO:0032206; P:positive regulation of telomere maintenance; IMP:UniProtKB.
DR GO; GO:0032212; P:positive regulation of telomere maintenance via telomerase; IMP:UniProtKB.
DR GO; GO:0032210; P:regulation of telomere maintenance via telomerase; IBA:GO_Central.
DR GO; GO:0016233; P:telomere capping; IBA:GO_Central.
DR GO; GO:0000723; P:telomere maintenance; IMP:TAIR.
DR Gene3D; 2.40.50.140; -; 1.
DR InterPro; IPR012340; NA-bd_OB-fold.
DR InterPro; IPR028389; POT1.
DR InterPro; IPR011564; Telomer_end-bd_POT1/Cdc13.
DR PANTHER; PTHR14513; PTHR14513; 1.
DR Pfam; PF02765; POT1; 1.
DR SMART; SM00976; Telo_bind; 1.
DR SUPFAM; SSF50249; SSF50249; 2.
PE 1: Evidence at protein level;
KW Alternative splicing; Chromosome; Cytoplasm; DNA-binding; Nucleus;
KW Reference proteome; RNA-binding; Telomere.
FT CHAIN 1..467
FT /note="Protection of telomeres protein 1a"
FT /id="PRO_0000416957"
FT VAR_SEQ 186..199
FT /note="ILHADEDTSAVFVW -> VICSILSINYSPCR (in isoform 2)"
FT /evidence="ECO:0000305"
FT /id="VSP_043057"
FT VAR_SEQ 186..199
FT /note="ILHADEDTSAVFVW -> VICSILSINCEKAF (in isoform 3)"
FT /evidence="ECO:0000305"
FT /id="VSP_043058"
FT VAR_SEQ 200..467
FT /note="Missing (in isoform 2 and isoform 3)"
FT /evidence="ECO:0000305"
FT /id="VSP_043059"
FT MUTAGEN 35
FT /note="E->F: Reduces POT1A function in positive regulation
FT of telomere length; reduces binding affinity for CTC1; has
FT no effect on binding affinity for STN1."
FT /evidence="ECO:0000269|PubMed:25697340"
FT MUTAGEN 65
FT /note="F->A: Almost abolishes POT1A function in positive
FT regulation of telomere length; abolishes telomeric DNA
FT binding."
FT /evidence="ECO:0000269|PubMed:25697340,
FT ECO:0000269|PubMed:27651456"
FT MUTAGEN 132
FT /note="L->D: Has no effect on POT1A function in positive
FT regulation of telomere length; has no effect on binding
FT affinity for CTC1."
FT /evidence="ECO:0000269|PubMed:25697340"
FT MUTAGEN 221
FT /note="S->A: Reduces POT1A function in positive regulation
FT of telomere length; reduces binding affinity for CTC1; has
FT no effect on binding affinity for STN1."
FT /evidence="ECO:0000269|PubMed:25697340"
FT MUTAGEN 297
FT /note="E->F: Has minor effect on POT1A function in positive
FT regulation of telomere length, reduces binding affinity for
FT CTC1; has no effect on binding affinity for STN1."
FT /evidence="ECO:0000269|PubMed:25697340"
FT MUTAGEN 458..467
FT /note="Missing: Abolishes POT1A function in positive
FT regulation of telomere length."
FT /evidence="ECO:0000269|PubMed:25697340"
FT CONFLICT 292
FT /note="D -> G (in Ref. 1; AAS59561)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 467 AA; 53923 MW; 47DBF3508E48EC67 CRC64;
MAKKRESPKL IKIKDAIKLI NQQVSLIGIV LEQREPKQCR NNDWICTLRI IDDTYPSPGL
TVNVFSKTLE QLPQIKNHDD MILFTRIKMQ TFDSGERVNA ACSRWVSSFA LFEGVDFVCY
QCSTNFHEEE ALYKSAMDDL RKVFAGCSQV IKAMQSISYR TKPCSEVFSF LREIKIGKRF
DLVCRILHAD EDTSAVFVWD GTDAPPASIL AKRSEEDKAF SSLSVHTLLS RDVLLSFPTV
GTILRVHLSS HLFYRVKPGD WVKLYHLLCE VDRGSWVIKV TSSTKVHHLA QDDRLVEKIM
RIYDKRLSSK LGHISFWCFP SPPGLTETDD NCAPFVTLMD IITFPKVTCK YRCIVRVVAA
YPWQVEDFCS DENRRHHQVL LTLEDSTATL EAFLCNKDAE YFWGLGFQDT ETLRKKRNWL
LGIRESSNFV APRNPPWIEC CILSYYTNKA DPWNTRLYRI FGTRLLH
