POT1: Component of the telomerase ribonucleoprotein (RNP) complex that is essential for the replication of chromosome termini. Is a component of the double-stranded telomeric DNA- binding TRF1 complex which is involved in the regulation of telomere length by cis-inhibition of telomerase. Also acts as a single-stranded telomeric DNA-binding protein and thus may act as a downstream effector of the TRF1 complex and may transduce information about telomere maintenance and/or length to the telomere terminus. Component of the shelterin complex (telosome) that is involved in the regulation of telomere length and protection. Shelterin associates with arrays of double-stranded TTAGGG repeats added by telomerase and protects chromosome ends; without its protective activity, telomeres are no longer hidden from the DNA damage surveillance and chromosome ends are inappropriately processed by DNA repair pathways. Binds to two or more telomeric single-stranded 5'-TTAGGG-3' repeats (G-strand) and with high specificity to a minimal telomeric single-stranded 5'- TAGGGTTAG-3' sequence. Binds telomeric single-stranded sequences internally or at proximity of a 3'-end. Its activity is TERT dependent but it does not increase TERT activity by itself. In contrast, the ACD-POT1 heterodimer enhances telomere elongation by increasing telomerase processivity. Belongs to the telombin family. 2 isoforms of the human protein are produced by alternative splicing.
Protein type: DNA-binding
Chromosomal Location of Human Ortholog: 7q31.33
Cellular Component: nucleoplasm; chromosome, telomeric region; nuclear telomere cap complex; cytoplasm; nucleus
Molecular Function: protein binding; single-stranded telomeric DNA binding; DEAD/H-box RNA helicase binding
Biological Process: positive regulation of helicase activity; negative regulation of telomerase activity; telomere assembly; telomere capping; telomere maintenance via telomerase; positive regulation of telomerase activity; negative regulation of telomere maintenance via telomerase; telomere maintenance; DNA duplex unwinding; positive regulation of telomere maintenance via telomerase
Disease: Melanoma, Cutaneous Malignant, Susceptibility To, 10
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