Search results
Results from the WOW.Com Content Network
(A) Telomere-bound proteins involved in preventing the activation of the DNA damage response checkpoint and of DSB repair mechanisms in S. cerevisiae (top) and in humans (bottom). (B) Overview of the normal function of telomere-shelterin complexes and the pathways activated by telomere shortening. [5]
Telomeres at the end of a chromosome. The relationship between telomeres and longevity and changing the length of telomeres is one of the new fields of research on increasing human lifespan and even human immortality. [1] [2] Telomeres are sequences at the ends of chromosomes that shorten with each cell division and determine the lifespan of ...
While the exact transcription start site is still a matter of debate, it is widely held that TERRA transcription begins in the subtelomeric region at the end of chromosomes, just before the tandem repeats of the telomere begin. In humans, at least 20 of 23 chromosome ends have been shown to contain CpG islands, which are generally found at or ...
Critically short telomeres trigger a DNA damage response and cellular senescence. [32] Mice have much longer telomeres, but a greatly accelerated telomere shortening-rate and greatly reduced lifespan compared to humans and elephants. [33] Telomere shortening is associated with aging, mortality, and aging-related diseases in experimental animals.
However, other studies have shown that under certain conditions TERRA can recruit telomerase to telomeres. [2] TERRAs are essential for telomere length and maintenance. [3] [2] At least four factors contribute to telomere maintenance: telomerase, shelterin, TERRA and the CST Complex. [4]
Shelterin (also called telosome) is a protein complex known to protect telomeres in many eukaryotes from DNA repair mechanisms, as well as to regulate telomerase activity. In mammals and other vertebrates, telomeric DNA consists of repeating double-stranded 5'-TTAGGG-3' (G-strand) sequences (2-15 kilobases in humans) along with the 3'-AATCCC-5' (C-strand) complement, ending with a 50-400 ...
In human liver, cholangiocytes and hepatocytes show no age-related telomere shortening. [38] Another study found little evidence that, in humans, telomere length is a significant biomarker of normal aging with respect to important cognitive and physical abilities. [39]
Telomerase is a ribonucleoprotein polymerase that maintains telomere ends by addition of the telomere repeat TTAGGG. The enzyme consists of a protein component with reverse transcriptase activity, encoded by this gene, and an RNA component that serves as a template for the telomere repeat.