Nurturing Life Sciences
#Id: 6445
#Id: 666
#Unit 3. Fundamental Processes
Short repeating sequence from the human telomere forms three stacked G quartets.
#Id: 667
Telomerase, a reverse transcriptase that contains an RNA template, repeatedly adds TTAGGG repeats
#Id: 668
Embryonic cells, germ-line cells, and stem cells produce telomerase, but most human somatic cells produce only a small amount of telomerase as they enter S phase.
#Id: 669
As a result of their modest telomerase activity, their telomeres shorten with each cell cycle.
#Id: 670
Extensive shortening of telomeres is recognized by the cell as a double-strand break and consequently triggers cell cycle arrest and apoptosis.
#Id: 671
In mammals, six telomeric proteins (TRF1, TRF2, Rap1, TIN2, TPP1, and POT1) comprise a complex called shelterin