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A telomerase-associated RecQ protein-like helicase resolves telomeric G-quadruplex structures during replication
- Source :
- Gene
- Publication Year :
- 2012
- Publisher :
- Elsevier BV, 2012.
-
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 TEBPβ 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.<br />Highlights ► Stylonychia StyRecQL is a helicase reminiscent of human RecQ protein-like 4. ► StyRecQL is enriched in replication band of the macronucleus during S-phase. ► StyRecQL colocalizes and is associated with Tert during telomere replication.
- Subjects :
- DNA Replication
Telomerase
TSP, telomere-suppression PCR
TEBP, telomere-binding-protein
Sporadotrichina
RecQ helicase
Molecular Sequence Data
Telomere-Binding Proteins
PAGE, polyacrylamide-gel electrophoresis
Article
S Phase
Telomerase RNA component
DNA, deoxyribonucleic acid
Control of chromosome duplication
Stylonychia lemnae
Macronucleus
ssDNA, single-stranded DNA
Genetics
Immunoprecipitation
heterocyclic compounds
Amino Acid Sequence
Replication band
SDS, sodium dodecyl sulphate
dnaB helicase
Genome
TR, telomerase RNA subunit
Ciliates
RecQ Helicases
biology
Tert
E. coli, Escherichia coli
DNA Helicases
Helicase
General Medicine
Telomere
RNA Helicase A
Molecular biology
TERT, telomerase reverse transcriptase
Cell biology
G-Quadruplexes
UTR, untranslated region
RNAi, ribonucleic acid interference
RNA, ribonucleic acid
biology.protein
dsRNA, double-stranded RNA
Subjects
Details
- ISSN :
- 03781119
- Volume :
- 497
- Database :
- OpenAIRE
- Journal :
- Gene
- Accession number :
- edsair.doi.dedup.....9e453bc723eff53b385bc483ab3bfdde
- Full Text :
- https://doi.org/10.1016/j.gene.2012.01.068