Telomeres: Protection and Maintenance

Titia de Lange, The Rockefeller University, New York, USA

Published online: September 2005

DOI: 10.1038/npg.els.0005281

Eukaryotic chromosomes terminate in telomeres, nucleoprotein complexes thought to mask chromosome ends from the machinery that detects and repairs damaged deoxyribonucleic acid (DNA). The maintenance of this protective telomeric cap requires a specialized mode of DNA synthesis, because chromosome duplication results in incomplete replication of DNA ends. Proteins associated with the telomeric DNA sequence at chromosome ends execute and regulate the maintenance and protection functions of telomeres.

Keywords: telomere; telomerase; cancer; chromosome; genome instability

Figure 1. Proteins associated with human telomeres. Additional components (not shown) are Ku, DNA-PKcs and the RECQ helicases BLM and WRN (see text for details).
Figure 2. Dynamics of human telomeres.
Figure 3. Model of telomere length regulation by TRF1.
Figure 4. T-loop model of telomere protection and length regulation.
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 References
    Baumann P and Cech TR (2001) Pot1, the putative telomere end-binding protein in fission yeast and humans. Science 292: 1171–1175.
    Morin GB (1989) The human telomere terminal transferase enzyme is a ribonucleoprotein that synthesizes TTAGGG repeats. Cell 59: 521–529.
    Nakamura TM, Morin GB, Chapman KB, et al. (1997) Telomerase catalytic subunit homologs from fission yeast and human. Science 277: 955–959.
 Further Reading
    book Blackburn EH and Greider CW (eds.) (1995) Telomeres Cold Spring Harbor, NY: Cold Spring Harbor Press.
    Collins K (2000) Mammalian telomeres and telomerase. Current Opinion in Cell Biology 12(3): 378–383.
    de Lange T (2001) Telomere capping – one strand fits all. Science 292: 1075–1076.
    de Lange T and Jacks T (1999) For better or worse? Telomerase inhibition and cancer. Cell 98: 273–275.
    McEachern MJ, Krauskopf A and Blackburn EH (2000) Telomeres and their control. Annual Review of Genetics 34: 331–358.
    Nugent CI and Lundblad V (1998) The telomerase reverse transcriptase: components and regulation. Genes and Development 12: 1073–1085.
    Oulton R and Harrington L (2000) Telomeres, telomerase, and cancer: life on the edge of genomic stability. Current Opinion in Oncology 12: 74–81.
    Sherr CJ and DePinho RA (2000) Cellular senescence: mitotic clock or culture shock? Cell 102: 407–410.
 Web Links
    ePath TERF2(telomeric repeat binding factor 2); LocusID: 7014. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=7014
    ePath TERT(telomerase reverse transcriptase); LocusID: 7015. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=7015
    ePath TERF2(telomeric repeat binding factor 2); MIM number: 602027. OMIM: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?602027
    ePath TERT(telomerase reverse transcriptase); MIM number: 187270. OMIM: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?187270

Related Sub-Topics:

Protein Structure | Nucleic Acid Structure | Replication and Recombination | Cancer Genetics | Gene and Genome Structure and Organisation | Chromosomal Disorders | Proteomic Studies of Genetic Disease | Chromosomes and Chromatin Modifications | DNA Structure and Function | DNA Damage and Repair | Mechanisms of Cell Death, Senescence and Metabolism
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Article Title: Telomeres: Protection and Maintenance
 
How to Cite close
de Lange, Titia(Sep 2005) Telomeres: Protection and Maintenance. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0005281]