Telomere Capping

Cancer Terms -> Biological Process -> Subcellular Process -> Biochemical Process -> DNA Maintenance Process -> DNA Maintenance -> Telomere Maintenance -> Telomere Capping

Telomere Capping Definition

Telomere capping protects chromosome ends from cellular DNA-damage responses, such as cell cycle arrest or apoptosis. Telomere capping involves multiple molecular pathways and at least four distinct structural components contribute to telomere capping: (1) the higher order telomeric DNA-protein complex, whose overall length (i.e., the number of telomeric repeats) dictates whether telomerase or nuclease can access telomeric DNA; (2) the protein complex found on the terminal few repeats; (3) the DNA-protein complex on the single stranded G-rich DNA extension of the telomere, which is most likely important for preventing DNA damage response and regulating the cell cycle dependent structure of the telomere; and (4) telomerase itself. Telomere capping is influenced by multiple, mutually reinforcing factors including telomere length, although telomere length is only one of several determinants of telomere functionality. (from PMID 11850780 and NCI)