Distinct functions of POT1 proteins contribute to the regulation of telomerase recruitment to telomeres.
Nat Commun
; 12(1): 5514, 2021 09 17.
Article
en En
| MEDLINE
| ID: mdl-34535663
ABSTRACT
Human shelterin components POT1 and TPP1 form a stable heterodimer that protects telomere ends from ATR-dependent DNA damage responses and regulates telomerase-dependent telomere extension. Mice possess two functionally distinct POT1 proteins. POT1a represses ATR/CHK1 DNA damage responses and the alternative non-homologous end-joining DNA repair pathway while POT1b regulates C-strand resection and recruits the CTC1-STN1-TEN1 (CST) complex to telomeres to mediate C-strand fill-in synthesis. Whether POT1a and POT1b are involved in regulating the length of the telomeric G-strand is unclear. Here we demonstrate that POT1b, independent of its CST function, enhances recruitment of telomerase to telomeres through three amino acids in its TPP1 interacting C-terminus. POT1b thus coordinates the synthesis of both telomeric G- and C-strands. In contrast, POT1a negatively regulates telomere length by inhibiting telomerase recruitment to telomeres. The identification of unique amino acids between POT1a and POT1b helps us understand mechanistically how human POT1 switches between end protective functions and promoting telomerase recruitment.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Telómero
/
Telomerasa
/
Proteínas de Unión a Telómeros
/
Proteínas de Unión al ADN
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Nat Commun
Asunto de la revista:
BIOLOGIA
/
CIENCIA
Año:
2021
Tipo del documento:
Article
País de afiliación:
Estados Unidos