A telomerase-associated RecQ protein-like helicase resolves telomeric G-quadruplex structures during replication.
Gene
; 497(2): 147-54, 2012 Apr 15.
Article
en En
| MEDLINE
| ID: mdl-22327026
ABSTRACT
It is well established that G-quadruplex DNA structures form at ciliate telomeres and their formation throughout the cell-cycle by telomere-end-binding proteins (TEBPs) has been analyzed. During replication telomeric G-quadruplex structure has to be resolved to allow telomere replication by telomerase. It was shown that both phosphorylation of TEBPß and binding of telomerase are prerequisites for this process, but probably not sufficient to unfold G-quadruplex structure in timely manner to allow replication to proceed. Here we describe a RecQ-like helicase required for unfolding of G-quadruplex structures in vivo. This helicase is highly reminiscent of human RecQ protein-like 4 helicase as well as other RecQ-like helicase found in various eukaryotes and E. coli. In situ analyses combined with specific silencing of either the telomerase or the helicase by RNAi and co-immunoprecipitation experiments demonstrate that this helicase is associated with telomerase during replication and becomes recruited to telomeres by this enzyme. In vitro assays showed that a nuclear extract prepared from cells in S-phase containing both the telomerase as well as the helicase resolves telomeric G-quadruplex structure. This finding can be incorporated into a mechanistic model about the replication of telomeric G-quadruplex structures during the cell cycle.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Telómero
/
ADN Helicasas
/
Telomerasa
/
Replicación del ADN
/
RecQ Helicasas
/
G-Cuádruplex
Tipo de estudio:
Risk_factors_studies
Idioma:
En
Revista:
Gene
Año:
2012
Tipo del documento:
Article
País de afiliación:
Alemania