Telomeres, telomerase, and the cell cycle.
Telomeres protect the ends of chromosomes from degradation and fusion. In most eukaryotes telomeres are replicated by a specialised polymerase, telomerase. Telomerase synthesises one strand of the telomere; while conventional DNA polymerases synthesise the complementary strand. Additional processing of telomeres occurs in ciliates and yeast during each cell cycle. Telomerase activity and RNA levels change as cells enter and exit the cell cycle. Gradual telomere shortening in the absence of telomerase does not immediately affect cell cycling; however, "critically" short telomeres are hypothesised to play a role in senescence and the triggering of DNA damage checkpoints.
Buchkovich
K J
KJ
University of Illinois at Chicago, Department of Pharmacology, Chicago 60612, USA.
D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division; D016922:Cellular Senescence; D004249:DNA Damage; D004261:DNA Replication; D006801:Humans; D008954:Models, Biological; D019098:Telomerase / Q000502:physiology*; D016615:Telomere / Q000502:physiology*
D019098:Telomerase