Telomerase: Structure and Function

Nathaniel J Hansen, University of Alabama at Birmingham, Birmingham, Alabama, USA
Joseph C Poole, Medical College of Georgia, Augusta, Georgia, USA
Lucy G Andrews, University of Alabama at Birmingham, Birmingham, Alabama, USA
Trygve O Tollefsbol, University of Alabama at Birmingham, Birmingham, Alabama, USA

Published online: January 2006

DOI: 10.1038/npg.els.0006167

Telomerase, the enzyme that completes DNA replication at the termini of eukaryotic chromosomes, is an important factor in chromosomal stability, cellular senescence and tumorigenesis.

Keywords: telomerase; ribonucleoprotein; senescence; immortality; cancer

Figure 1. Simplified model of telomeric addition. After recruitment of the telomerase holoenzyme to telomeric DNA, the template domain of the telomerase RNA (hTER) allows complementary base-pairing to existing hexameric repeats (a). Reverse transcription by the telomerase reverse transcriptase (hTERT) continues until the RNA template sequence is fully replicated, at which time the enzyme complex must translocate to continue synthesis of the next repeat (b). In the ciliate Tetrahymena, this translocation is accompanied by a pause in polymerization, and telomerase can maintain processive synthesis for an average of roughly 520 nt before dissociating from the DNA substrate (Greider, 1991). Here, an oligomer of several RNA subunits is shown to illustrate how the enzyme might extend telomeric DNA using multiple active sites. (Modified with permission from Greider 1991)
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 References
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 Further Reading
    Bodnar AG, Ouellette EH, Frolkis M, et al. (1998) Extension of life-span by introduction of telomerase into normal human cells. Science 279: 349–352.
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    Peterson SE, Stellwagen AE, Diede SJ, et al. (2001) The function of a stem-loop in telomerase RNA is linked to the DNA repair protein Ku. Nature Genetics 27: 64–67.
    Xu D, Popov N, Hou M, et al. (2001) Switch from Myc/Max to Mad1/Max binding and decrease in histone acetylation at the telomerase reverse transcriptase promoter during differentiation of HL60 cells. Proceedings of the National Academy of Sciences of the United States of America 98: 3826–3831.
 Web Links
    ePath Telomerase-associated protein 1 (TEP1); LocusID: 7011. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=7011
    ePath Telomerase RNA component (TERC); LocusID: 7012. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=7012
    ePath Telomerase reverse transcriptase (TERT); LocusID: 7015. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=7015
    ePath Telomerase-associated protein 1 (TEP1); MIM number: 601686. OMIM: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?601686
    ePath Telomerase RNA component (TERC); MIM number: 602322. OMIM: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?602322
    ePath Telomerase reverse transcriptase (TERT); MIM number: 187270. OMIM: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?187270

Related Sub-Topics:

Nucleic Acid Structure | Chromosomes and Chromatin Modifications | DNA Structure and Function | Proteins: Structure, Function, Metabolism | Enzymes: Structure and Action Mechanism | Nucleic Acids: Structure, Function, Metabolism
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Article Title: Telomerase: Structure and Function
 
How to Cite close
Hansen, Nathaniel J, Poole, Joseph C, Andrews, Lucy G, and Tollefsbol, Trygve O(Jan 2006) Telomerase: Structure and Function. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0006167]