ID   POT1B_ARATH             Reviewed;         454 AA.
AC   Q6NKX5; Q4W6W7; Q9FNH7;
DT   18-APR-2012, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   03-AUG-2022, entry version 134.
DE   RecName: Full=Protection of telomeres protein 1b {ECO:0000303|PubMed:23109676};
DE            Short=AtPOT1b {ECO:0000303|PubMed:23109676};
DE   AltName: Full=Protection of telomeres protein 2 {ECO:0000303|PubMed:16107718};
DE            Short=AtPot2 {ECO:0000303|PubMed:16107718};
GN   Name=POT1B {ECO:0000303|PubMed:23109676};
GN   Synonyms=POT2 {ECO:0000303|PubMed:16107718}; OrderedLocusNames=At5g06310;
GN   ORFNames=MHF15;
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 [GENOMIC DNA], AND ALTERNATIVE SPLICING (ISOFORMS 1 AND
RP   2).
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   [2]
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   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=9405937; DOI=10.1093/dnares/4.4.291;
RA   Kotani H., Nakamura Y., Sato S., Kaneko T., Asamizu E., Miyajima N.,
RA   Tabata S.;
RT   "Structural analysis of Arabidopsis thaliana chromosome 5. II. Sequence
RT   features of the regions of 1,044,062 bp covered by thirteen physically
RT   assigned P1 clones.";
RL   DNA Res. 4:291-300(1997).
RN   [4]
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   [5]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
RC   STRAIN=cv. Columbia;
RA   Shinn P., Chen H., Cheuk R., Kim C.J., Carninci P., Hayashizaki Y.,
RA   Ishida J., Kamiya A., Kawai J., Narusaka M., Sakurai T., Satou M., Seki M.,
RA   Shinozaki K., Ecker J.R.;
RT   "Arabidopsis ORF clones.";
RL   Submitted (APR-2004) to the EMBL/GenBank/DDBJ databases.
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   INTERACTION WITH TRB1.
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   [8]
RP   INTERACTION WITH TRB1; TRB2 AND TRB3.
RX   PubMed=18387366; DOI=10.1016/j.febslet.2008.03.034;
RA   Schrumpfova P.P., Kuchar M., Palecek J., Fajkus J.;
RT   "Mapping of interaction domains of putative telomere-binding proteins
RT   AtTRB1 and AtPOT1b from Arabidopsis thaliana.";
RL   FEBS Lett. 582:1400-1406(2008).
RN   [9]
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   [10]
RP   FUNCTION.
RX   PubMed=23109676; DOI=10.1101/gad.202960.112;
RA   Cifuentes-Rojas C., Nelson A.D., Boltz K.A., Kannan K., She X.,
RA   Shippen D.E.;
RT   "An alternative telomerase RNA in Arabidopsis modulates enzyme activity in
RT   response to DNA damage.";
RL   Genes Dev. 26:2512-2523(2012).
RN   [11]
RP   FUNCTION, AND MUTAGENESIS OF VAL-63.
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).
CC   -!- FUNCTION: Negatively regulates telomerase activity and participates in
CC       chromosome end protection (PubMed:16107718, PubMed:23109676). Binds RNA
CC       non-specifically (PubMed:27651456). Associates with a regulatory Pol
CC       III-dependent lncRNA, which represses telomerase activity in response
CC       to DNA damage (PubMed:23109676). Binds single-stranded telomeric DNA
CC       with weak affinity (PubMed:16107718, PubMed:27651456).
CC       {ECO:0000269|PubMed:16107718, ECO:0000269|PubMed:23109676,
CC       ECO:0000269|PubMed:27651456}.
CC   -!- SUBUNIT: Interacts with TRB1, TRB2 and TRB3.
CC       {ECO:0000269|PubMed:15589838, ECO:0000269|PubMed:18387366}.
CC   -!- INTERACTION:
CC       Q6NKX5; Q8VWK4: TRB1; NbExp=4; IntAct=EBI-476223, EBI-476101;
CC   -!- SUBCELLULAR LOCATION: Nucleus {ECO:0000250}. Chromosome, telomere
CC       {ECO:0000250}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=2;
CC       Name=1;
CC         IsoId=Q6NKX5-1; Sequence=Displayed;
CC       Name=2;
CC         IsoId=Q6NKX5-2; Sequence=VSP_043060, VSP_043061;
CC   -!- TISSUE SPECIFICITY: Expressed at low levels in roots, rosette leaves,
CC       cauline leaves, stems and flowers. {ECO:0000269|PubMed:16107718}.
CC   -!- SIMILARITY: Belongs to the telombin family. {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=BAB08953.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};
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DR   EMBL; AB195820; BAD99149.1; -; Genomic_DNA.
DR   EMBL; AB195820; BAD99150.1; -; Genomic_DNA.
DR   EMBL; AY884594; AAX78214.1; -; mRNA.
DR   EMBL; AB006700; BAB08953.1; ALT_SEQ; Genomic_DNA.
DR   EMBL; CP002688; AED91001.1; -; Genomic_DNA.
DR   EMBL; BT012568; AAS99712.1; -; mRNA.
DR   EMBL; AK221379; BAD94288.1; -; mRNA.
DR   RefSeq; NP_196249.2; NM_120714.4. [Q6NKX5-1]
DR   AlphaFoldDB; Q6NKX5; -.
DR   SMR; Q6NKX5; -.
DR   IntAct; Q6NKX5; 3.
DR   MINT; Q6NKX5; -.
DR   STRING; 3702.AT5G06310.1; -.
DR   PaxDb; Q6NKX5; -.
DR   PRIDE; Q6NKX5; -.
DR   ProteomicsDB; 249396; -. [Q6NKX5-1]
DR   EnsemblPlants; AT5G06310.1; AT5G06310.1; AT5G06310. [Q6NKX5-1]
DR   GeneID; 830519; -.
DR   Gramene; AT5G06310.1; AT5G06310.1; AT5G06310. [Q6NKX5-1]
DR   KEGG; ath:AT5G06310; -.
DR   Araport; AT5G06310; -.
DR   TAIR; locus:2164295; AT5G06310.
DR   eggNOG; KOG4757; Eukaryota.
DR   HOGENOM; CLU_020958_0_1_1; -.
DR   InParanoid; Q6NKX5; -.
DR   OMA; WNPIARC; -.
DR   PhylomeDB; Q6NKX5; -.
DR   PRO; PR:Q6NKX5; -.
DR   Proteomes; UP000006548; Chromosome 5.
DR   ExpressionAtlas; Q6NKX5; baseline and differential.
DR   GO; GO:0000783; C:nuclear telomere cap complex; IBA:GO_Central.
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:0051974; P:negative regulation of telomerase activity; IBA:GO_Central.
DR   GO; GO:0032210; P:regulation of telomere maintenance via telomerase; IBA:GO_Central.
DR   GO; GO:0016233; P:telomere capping; IMP:UniProtKB.
DR   GO; GO:0000723; P:telomere maintenance; IMP:UniProtKB.
DR   Gene3D; 2.40.50.140; -; 2.
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; DNA-binding; Nucleus; Reference proteome;
KW   RNA-binding; Telomere.
FT   CHAIN           1..454
FT                   /note="Protection of telomeres protein 1b"
FT                   /id="PRO_0000416958"
FT   VAR_SEQ         152..179
FT                   /note="SCCFTSLKDIKEGECSNLSCQIVHISKV -> NYDAISFLMNSTYSLKSLYA
FT                   NVCFVLYL (in isoform 2)"
FT                   /evidence="ECO:0000305"
FT                   /id="VSP_043060"
FT   VAR_SEQ         180..454
FT                   /note="Missing (in isoform 2)"
FT                   /evidence="ECO:0000305"
FT                   /id="VSP_043061"
FT   MUTAGEN         63
FT                   /note="V->A: Binds specifically single-stranded telomeric
FT                   DNA."
FT                   /evidence="ECO:0000269|PubMed:27651456"
SQ   SEQUENCE   454 AA;  52572 MW;  5D44880EAD60E400 CRC64;
     MEEERRDDYK FLRIQDAFKA LHLHVNLIGV IVELGFSNGS DCSCTLKIVD PWYSGSGLPV
     KFVARTIRDL PRVESIGDII LLSRVKIVLI NRKITALCNE TTSSSFALFN GKHSVDSIPY
     QSSPKFLMRE QDKNFLSNLR EWMITYKFED GSCCFTSLKD IKEGECSNLS CQIVHISKVY
     KDRWYLFVWD GTEMPPCNIL VKSERLPLCV EPEMLPTYML RKFPTFGSVL RIIVDRVSEK
     QAIHCLQPGQ HVKLLNLFFQ VNMGLWNATF TPSTKMQYTM SREMEAFSPQ RMCGEKFSPR
     WNPIARCISR SHSEITGVAH DDAPFVSLMD ILTYHNVTAK FRCVVRFIQV YPRDVRKLRD
     INGNIKLVAI LEDATARIHA SLYADEGEKF FGCDESDEEA LVKKLNRLLG GEEMEKVPRN
     PPWVQCCLFS FYKHKMDQWE SRRFRIFDTW INAS