Gene Symbol: EST1
Description: Est1p
Alias: Est1p
Species: Saccharomyces cerevisiae S288c

Top Publications

  1. Lendvay T, Morris D, Sah J, Balasubramanian B, Lundblad V. Senescence mutants of Saccharomyces cerevisiae with a defect in telomere replication identify three additional EST genes. Genetics. 1996;144:1399-412 pubmed
    ..However, a yeast strain defective for the EST1 gene exhibits the same phenotypes (progressively shorter telomeres and a senescence phenotype) as a strain deleted ..
  2. Wu Y, Zakian V. The telomeric Cdc13 protein interacts directly with the telomerase subunit Est1 to bring it to telomeric DNA ends in vitro. Proc Natl Acad Sci U S A. 2011;108:20362-9 pubmed publisher
    In Saccharomyces cerevisiae, a Cdc13-Est1 interaction is proposed to mediate recruitment of telomerase to DNA ends...
  3. Tuzon C, Wu Y, Chan A, Zakian V. The Saccharomyces cerevisiae telomerase subunit Est3 binds telomeres in a cell cycle- and Est1-dependent manner and interacts directly with Est1 in vitro. PLoS Genet. 2011;7:e1002060 pubmed publisher
    ..telomerase consists of TLC1 (the RNA template), Est2 (the catalytic subunit), and two accessory proteins, Est1 and Est3, that are essential in vivo for telomerase activity but are dispensable for catalysis in vitro...
  4. Yu E, Steinberg Neifach O, Dandjinou A, Kang F, Morrison A, Shen X, et al. Regulation of telomere structure and functions by subunits of the INO80 chromatin remodeling complex. Mol Cell Biol. 2007;27:5639-49 pubmed
    ..chromatin remodeling complex interacts with a conserved tetratricopeptide repeat domain of the telomerase protein Est1p. Deletion of IES3 and some other subunits of the complex induced telomere elongation and altered telomere position ..
  5. Osterhage J, Talley J, Friedman K. Proteasome-dependent degradation of Est1p regulates the cell cycle-restricted assembly of telomerase in Saccharomyces cerevisiae. Nat Struct Mol Biol. 2006;13:720-8 pubmed
    ..telomerase contains an RNA template (TLC1), a reverse transcriptase (Est2p) and at least two regulatory proteins (Est1p and Est3p)...
  6. Chan A, Boulé J, Zakian V. Two pathways recruit telomerase to Saccharomyces cerevisiae telomeres. PLoS Genet. 2008;4:e1000236 pubmed publisher
    ..subunit of yeast telomerase, Est2p, is a telomere associated throughout most of the cell cycle, while the Est1p subunit binds only in late S/G2 phase, the time of telomerase action...
  7. Tong X, Li Q, Duan Y, Liu N, Zhang M, Zhou J. Est1 protects telomeres and inhibits subtelomeric y'-element recombination. Mol Cell Biol. 2011;31:1263-74 pubmed publisher
    ..In this study, we employed both the CDC13-EST1 fusion gene and the separation-of-function allele est1-D514A to elucidate that Est1 provided a telomere protection ..
  8. Lundblad V, Szostak J. A mutant with a defect in telomere elongation leads to senescence in yeast. Cell. 1989;57:633-43 pubmed
    ..This mutation defines a new gene, designated EST1 (for ever shorter telomeres)...
  9. Sabourin M, Tuzon C, Zakian V. Telomerase and Tel1p preferentially associate with short telomeres in S. cerevisiae. Mol Cell. 2007;27:550-61 pubmed
    ..Two telomerase holoenzyme components, Est1p and Est2p, were preferentially enriched at short telomeres in late S/G2 phase, the time of telomerase action...

More Information


  1. Hughes T, Evans S, Weilbaecher R, Lundblad V. The Est3 protein is a subunit of yeast telomerase. Curr Biol. 2000;10:809-12 pubmed
    ..b>Est1p and Cdc13p, as components of telomerase and telomeric chromatin, respectively, cooperate to recruit telomerase to ..
  2. Seto A, Livengood A, Tzfati Y, Blackburn E, Cech T. A bulged stem tethers Est1p to telomerase RNA in budding yeast. Genes Dev. 2002;16:2800-12 pubmed
    ..Suppression of bulged-stem mutant phenotypes by overexpression of Est1p and loss of co-immunoprecipitation of the mutant RNAs with Est1p indicated that this bulged stem is necessary for ..
  3. Fisher T, Taggart A, Zakian V. Cell cycle-dependent regulation of yeast telomerase by Ku. Nat Struct Mol Biol. 2004;11:1198-205 pubmed
    ..The telomere association of Est1p, a telomerase component that binds telomeres only in late S phase, was also reduced in the absence of Ku...
  4. Lubin J, Tucey T, Lundblad V. The interaction between the yeast telomerase RNA and the Est1 protein requires three structural elements. RNA. 2012;18:1597-604 pubmed publisher
    ..3-kb TLC1 RNA that forms a complex with Est2 (the catalytic subunit) and two regulatory proteins, Est1 and Est3...
  5. Gallardo F, Olivier C, Dandjinou A, Wellinger R, Chartrand P. TLC1 RNA nucleo-cytoplasmic trafficking links telomerase biogenesis to its recruitment to telomeres. EMBO J. 2008;27:748-57 pubmed publisher
    ..which adds telomeric repeats at the chromosome ends, is composed of the TLC1 RNA and the associated proteins Est1, Est2 and Est3...
  6. Li S, Makovets S, Matsuguchi T, Blethrow J, Shokat K, Blackburn E. Cdk1-dependent phosphorylation of Cdc13 coordinates telomere elongation during cell-cycle progression. Cell. 2009;136:50-61 pubmed publisher
    ..for efficient recruitment of the yeast telomerase complex to telomeres by favoring the interaction of Cdc13 with Est1 rather than the competing Stn1-Ten1 complex...
  7. Evans S, Lundblad V. The Est1 subunit of Saccharomyces cerevisiae telomerase makes multiple contributions to telomere length maintenance. Genetics. 2002;162:1101-15 pubmed
    The telomerase-associated Est1 protein of Saccharomyces cerevisiae mediates enzyme access by bridging the interaction between the catalytic core of telomerase and the telomere-binding protein Cdc13...
  8. Luciano P, Coulon S, Faure V, Corda Y, Bos J, Brill S, et al. RPA facilitates telomerase activity at chromosome ends in budding and fission yeasts. EMBO J. 2012;31:2034-46 pubmed publisher
    ..The interaction of RPA with telomerase appears to be mediated by both yKu and the telomerase subunit Est1. Moreover, a mutation in Rfa1 that affects both the interaction with yKu and telomerase reduces the dramatic ..
  9. Teo S, Jackson S. Telomerase subunit overexpression suppresses telomere-specific checkpoint activation in the yeast yku80 mutant. EMBO Rep. 2001;2:197-202 pubmed
    ..This is suppressed by overexpression of several components of telomerase (EST1, EST2 and TLC1)...
  10. Virta Pearlman V, Morris D, Lundblad V. Est1 has the properties of a single-stranded telomere end-binding protein. Genes Dev. 1996;10:3094-104 pubmed
    In Saccharomyces cerevisiae, deletion of the EST1 gene results in phenotypes identical to those displayed by a deletion of a known component of telomerase (the yeast telomerase RNA), arguing that EST1 is also critical for telomerase ..
  11. Zhang M, Tong X, Fu X, Zhou B, Wang J, Liao X, et al. Yeast telomerase subunit Est1p has guanine quadruplex-promoting activity that is required for telomere elongation. Nat Struct Mol Biol. 2010;17:202-9 pubmed publisher
    ..Here we show that the yeast telomerase subunit Est1p, known to be involved in telomerase recruitment to telomeres, can convert single-stranded telomeric G-rich DNA ..
  12. Qi H, Zakian V. The Saccharomyces telomere-binding protein Cdc13p interacts with both the catalytic subunit of DNA polymerase alpha and the telomerase-associated est1 protein. Genes Dev. 2000;14:1777-88 pubmed
    ..with both the catalytic subunit of DNA polymerase alpha, Pol1p, and the telomerase RNA-associated protein, Est1p. The association of these proteins was confirmed by biochemical analysis using full-length or nearly full-length ..
  13. Lowell J, Roughton A, Lundblad V, Pillus L. Telomerase-independent proliferation is influenced by cell type in Saccharomyces cerevisiae. Genetics. 2003;164:909-21 pubmed
    ..We propose that cell-type-specific regulation of recombination at human telomeres may similarly contribute to the tissue-specific patterns of disease found in telomerase-deficient tumors. ..
  14. Lemieux B, Laterreur N, Perederina A, Noël J, Dubois M, Krasilnikov A, et al. Active Yeast Telomerase Shares Subunits with Ribonucleoproteins RNase P and RNase MRP. Cell. 2016;165:1171-1181 pubmed publisher
    ..The results also show that Pop1/Pop6/Pop7 function to maintain the essential components Est1 and Est2 on the RNA in vivo...
  15. Chen Y, Lu C, Lin Y, Yu T, Chang C, Li J, et al. Modulation of yeast telomerase activity by Cdc13 and Est1 in vitro. Sci Rep. 2016;6:34104 pubmed publisher
    ..The findings also showed that the inhibitory effect can be relieved by telomerase-associated protein Est1, consistent with the role of Cdc13 and Est1 in regulating telomere extension in vivo...
  16. Williams J, Ouenzar F, Lemon L, Chartrand P, Bertuch A. The principal role of Ku in telomere length maintenance is promotion of Est1 association with telomeres. Genetics. 2014;197:1123-36 pubmed publisher
    ..In contrast, forced recruitment of Est1, which has roles in telomerase recruitment and activation, to telomeres promotes efficient and progressive telomere ..
  17. Gao H, Toro T, Paschini M, Braunstein Ballew B, Cervantes R, Lundblad V. Telomerase recruitment in Saccharomyces cerevisiae is not dependent on Tel1-mediated phosphorylation of Cdc13. Genetics. 2010;186:1147-59 pubmed publisher
    In Saccharomyces cerevisiae, association between the Est1 telomerase subunit and the telomere-binding protein Cdc13 is essential for telomerase to be recruited to its site of action...
  18. Meier B, Driller L, Jaklin S, Feldmann H. New function of CDC13 in positive telomere length regulation. Mol Cell Biol. 2001;21:4233-45 pubmed
    ..Therefore we discuss a key role of CDC13 not only in telomerase recruitment but also in regulating telomerase access, which might be modulated by protein-protein interactions acting as inhibitors or activators of telomerase activity. ..
  19. Hang L, Liu X, Cheung I, Yang Y, Zhao X. SUMOylation regulates telomere length homeostasis by targeting Cdc13. Nat Struct Mol Biol. 2011;18:920-6 pubmed publisher
    ..cdc13-snm's effect on telomere length is epistatic with stn1, but not with yku70, tel1 or est1 alleles, and is suppressed by Stn1 overexpression...
  20. Tucey T, Lundblad V. Regulated assembly and disassembly of the yeast telomerase quaternary complex. Genes Dev. 2014;28:2077-89 pubmed publisher
    ..In budding yeast, telomerase consists of the catalytic Est2 protein and two regulatory subunits (Est1 and Est3) in association with the TLC1 RNA, with each of the four subunits essential for in vivo telomerase ..
  21. Li Q, Tong X, Duan Y, Zhou J. Characterization of the intramolecular G-quadruplex promoting activity of Est1. FEBS Lett. 2013;587:659-65 pubmed publisher
    ..Our previous studies revealed that the telomerase regulatory subunit Est1 promotes telomeric single-stranded DNA to form intermolecular G-quadruplex in vitro, and this activity is required ..
  22. Tucey T, Lundblad V. A yeast telomerase complex containing the Est1 recruitment protein is assembled early in the cell cycle. Biochemistry. 2013;52:1131-3 pubmed publisher
    In budding yeast, association of the Est1 regulatory protein with telomerase is thought to be limited to the late S phase, when telomere elongation occurs...
  23. Laterreur N, Eschbach S, Lafontaine D, Wellinger R. A new telomerase RNA element that is critical for telomere elongation. Nucleic Acids Res. 2013;41:7713-24 pubmed publisher
    ..Indeed, the distal portion of stem-loop IVc stimulates telomerase activity in vitro in a way that is independent of Est1 binding on more proximal portions of this stem-loop...
  24. Antoniacci L, Kenna M, Skibbens R. The nuclear envelope and spindle pole body-associated Mps3 protein bind telomere regulators and function in telomere clustering. Cell Cycle. 2007;6:75-9 pubmed
    ..pull-downs and in vivo coprecipitations also show that Mps3p associates with the telomerase-assembly component Est1p. Moreover, pair-wise combinations of mps3, est1 or ctf7 alleles all produce conditional lethality...
  25. Hawkins C, Friedman K. Normal telomere length maintenance in Saccharomyces cerevisiae requires nuclear import of the ever shorter telomeres 1 (Est1) protein via the importin alpha pathway. Eukaryot Cell. 2014;13:1036-50 pubmed publisher
    ..Here we identify three nuclear localization sequences (NLSs) in Est1p. Mutation of the most N-terminal NLS in the context of full-length Est1p reduces Est1p nuclear localization and ..
  26. Lai X, Beilharz T, Au W, Hammet A, Preiss T, Basrai M, et al. Yeast hEST1A/B (SMG5/6)-like proteins contribute to environment-sensing adaptive gene expression responses. G3 (Bethesda). 2013;3:1649-59 pubmed publisher
    ..Overall, these results suggest that Esl1 and Esl2 contribute to the regulation of adaptive gene expression responses of environmental sensing pathways. ..
  27. Evans S, Sistrunk M, Nugent C, Lundblad V. Telomerase, Ku, and telomeric silencing in Saccharomyces cerevisiae. Chromosoma. 1998;107:352-8 pubmed genes involved in the telomerase pathway also exhibit TPE defects and find that deletion or overexpression of EST1 or EST2 does not significantly affect telomeric silencing...
  28. Shen Z, Hsu P, Su Y, Yang C, Kao L, Tseng S, et al. PP2A and Aurora differentially modify Cdc13 to promote telomerase release from telomeres at G2/M phase. Nat Commun. 2014;5:5312 pubmed publisher
    ..Cdc13 recruits telomerase to telomeres through its interaction with Est1, a component of telomerase. However, how cells terminate the function of telomerase at G2/M is still elusive...
  29. Ponnusamy S, Alderson N, Hama H, Bielawski J, Jiang J, Bhandari R, et al. Regulation of telomere length by fatty acid elongase 3 in yeast. Involvement of inositol phosphate metabolism and Ku70/80 function. J Biol Chem. 2008;283:27514-24 pubmed publisher
  30. Gipson C, Xin Z, Danzy S, Parslow T, Ly H. Functional characterization of yeast telomerase RNA dimerization. J Biol Chem. 2007;282:18857-63 pubmed
    ..This study, therefore, highlights dimerization as a functionally conserved feature of the RNA templates utilized by reverse transcriptases of both viral and cellular origins. ..
  31. Wu H, Becker D, Krebber H. Telomerase RNA TLC1 shuttling to the cytoplasm requires mRNA export factors and is important for telomere maintenance. Cell Rep. 2014;8:1630-1638 pubmed publisher
  32. Sealey D, Kostic A, Lebel C, Pryde F, Harrington L. The TPR-containing domain within Est1 homologs exhibits species-specific roles in telomerase interaction and telomere length homeostasis. BMC Mol Biol. 2011;12:45 pubmed publisher
    The first telomerase-associated protein (Est1) was isolated in yeast due to its essential role in telomere maintenance...
  33. Teixeira M, Forstemann K, Gasser S, Lingner J. Intracellular trafficking of yeast telomerase components. EMBO Rep. 2002;3:652-9 pubmed
    ..telomerase reverse transcriptase subunit Est2p, the telomerase RNA moiety TLC1, the telomerase associated proteins Est1p and Est3p, and Sm proteins...
  34. Enomoto S, Glowczewski L, Lew Smith J, Berman J. Telomere cap components influence the rate of senescence in telomerase-deficient yeast cells. Mol Cell Biol. 2004;24:837-45 pubmed
    ..the telomerase holoenzyme components Est2p and TLC1 RNA, as well as in cells lacking the telomerase regulators Est1p and Est3p. The delay of senescence in upfDelta cells is not due to an increased rate of survivor formation...