How telomeres solve the end-protection problem.
The ends of eukaryotic chromosomes have the potential to be mistaken for damaged or broken DNA and must therefore be protected from cellular DNA damage response pathways. Otherwise, cells might permanently arrest in the cell cycle, and attempts to "repair" the chromosome ends would have devastating consequences for genome integrity. This end-protection problem is solved by protein-DNA complexes called telomeres. Studies of mammalian cells have recently uncovered the mechanism by which telomeres disguise the chromosome ends. Comparison to unicellular eukaryotes reveals key differences in the DNA damage response systems that inadvertently threaten chromosome ends. Telomeres appear to be tailored to these variations, explaining their variable structure and composition.
de Lange
Titia
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Laboratory of Cell Biology and Genetics, Rockefeller University, New York, NY 10021, USA. delange@mail.rockefeller.edu
D000818:Animals; D002875:Chromosomes / Q000502:physiology; D033481:Chromosomes, Mammalian / Q000502:physiology* / Q000648:ultrastructure; D016798:Ciliophora / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis / Q000378:metabolism*; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D012091:Repetitive Sequences, Nucleic Acid; D000089804:Shelterin Complex; D015398:Signal Transduction; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000502:physiology* / Q000648:ultrastructure; D034501:Telomere-Binding Proteins / Q000378:metabolism*; D035341:Telomeric Repeat Binding Protein 2 / Q000378:metabolism; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; C440849:POT1 protein, human; C507326:POT1 protein, mouse; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; D035341:Telomeric Repeat Binding Protein 2; D004247:DNA; D019098:Telomerase