Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Control of telomerase recruitment and end protection by independent shelterin components

ABSTRACT: Telomeres are proposed to alternate between “closed” states, in which chromosome ends are protected from DNA damage signaling and inaccessible to telomerase, and “open” states, where they become accessible for telomerase mediated elongation but less protected. Whether these states reflect distinct molecular mechanisms or mutually exclusive structural conformations remains unclear. Here, we develop a single-cell assay to monitor telomerase activity in mouse embryonic stem cells. Using this approach, we demonstrate that the shelterin component TPP1 is essential for telomerase recruitment via its interaction with TIN2, independently of POT1. In contrast, POT1 is dispensable for telomerase function but required for telomere end protection, acting independently of TPP1. These findings challenge the classical open-closed telomere model and reveal that telomerase recruitment and end protection are mediated by genetically and molecularly separable mechanisms.

ORGANISM(S): Mus musculus

PROVIDER: GSE304164 | GEO | 2026/02/25

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

PROTECTION OF TELOMERES 1b safeguards the Arabidopsis genome by regulating ROS homeostasis

Project description:Telomeres safeguard the genome, acting as sentinels of oxidative stress and preventing chromosome ends from eliciting a DNA damage response. PROTECTION OF TELOMERES 1 (POT1) is a highly conserved telomere protein, essential for chromosome integrity and telomeric DNA replication. Arabidopsis thaliana encodes two divergent POT1 paralogs: AtPOT1a stimulates telomerase activity, but AtPOT1b function is unknown. Here we show that AtPOT1b modulates reactive oxygen species (ROS) homeostasis. Oxidative stress induces AtPOT1b expression and telomeric accumulation, while AtPOT1b inactivation elevates ROS, increases telomeric and genome-wide oxidation, and causes stochastic telomere length changes. To address how AtPOT1b controls ROS, we report its localization in nuclei and peroxisomes, and association with catalases and peroxidases that enhance ROS scavenging. Impairing AtPOT1b-CAT2 interaction increases ROS accumulation and telomeric oxidation. Moss or human POT1 rescues ROS overaccumulation in Arabidopsis pot1b mutants, but not telomere deficiency in pot1a pot1b mutants, supporting a conserved role for POT1 in modulating ROS homeostasis and genome stability, distinct from canonical telomeric functions.

2026-03-04 | GSE297308 | GEO

POT1 mutations identify inferior outcomes in chronic lymphocytic leukemia and disrupted telomere biology function

Project description:Telomere protection 1 (POT1) is an important subunit in the shelterin complex, considered the telomere protector. POT1 dysfunction may lead to telomere length dysregulation and genomic instability. Both germline and somatic POT1 mutations have been identified in CLL patients, suggesting the development of the disease. This study aimedto evaluate the occurrence of POT1 mutations throughout CLL's progression and determine their prognostic significance.

2025-03-14 | GSE261569 | GEO

PhastID reveals STRBP/ILF3L as a central hub connecting S-phase telomerase recruitment with nuclear GEM bodies

Project description:Telomere maintenance is essential for genome stability, and its regulation during the cell cycle remains a critical area of research. Screening for telomerase-interacting proteins is crucial for understanding the biological processes of telomerase maturation, processing, and recruitment. Using PhastID screening with TERT during S-phase, we identify STRBP, a GEMs-associated protein, as a novel regulator of telomerase activity and telomere length. Our data demonstrate that STRBP mediates interaction with telomerase through TERRA, this interaction negatively regulates telomerase activity, thereby limiting telomere elongation. Notably, TERRA levels decrease during S-phase, potentially facilitating the recruitment of telomerase to telomeres and enabling telomere extension.

2025-10-09 | PXD069238 |

ZNF524 directly binds telomeres and supports their integrity via TRF2/RAP1

Project description:Telomeres are nucleoprotein structures at the ends of linear chromosomes. In humans, they consist of TTAGGG repeats, which are bound by dedicated proteins such as the shelterin complex. This complex consists of six proteins (TRF1, TRF2, RAP1, POT1, TPP1 and TIN2) and blocks unwanted DNA damage repair at telomeres, e.g. by suppressing non-homologous end joining (NHEJ) through its subunit TRF2. While shelterin does not work autonomously, additional direct telomere binding proteins have been described to function in a supplementary role. We here describe ZNF524, a zinc finger protein that directly binds to telomeric repeats with nanomolar affinity and reveal the base-specific sequence recognition by co-crystallization with telomeric DNA. ZNF524 localizes to telomeres and specifically maintains the presence of the TRF2/RAP1 subcomplex at telomeres without affecting the other shelterin members. Loss of ZNF524 concomitantly results in an increase in DNA damage signaling and recombination events. Overall, we identified ZNF524 as a direct telomere binding protein and propose that ZNF524 is involved in the maintenance of telomere integrity by promoting TRF2/RAP1 subcomplex binding.

2023-10-21 | PXD024630 | Pride

ZNF524 directly binds telomeres and supports their integrity via TRF2/RAP1

2023-10-22 | PXD031416 | Pride

Human POT1 Prevents Severe Telomere Damage Instability Induced by Homology Directed DNA Repair

Project description:The evolutionarily conserved POT1 protein binds the single stranded G-rich telomeric DNA and has been implicated in telomeric DNA maintenance and the suppression of DNA damage checkpoint signaling. Here, we explore human POT1 function through genetics and proteomics discovering that the complete absence of POT1 leads to severe telomere maintenance defects that had not been anticipated from previous depletion studies. We determine the telomeric proteome upon POT1-loss by implementing an improved telomeric chromatin isolation protocol. Using quantitative proteomics by tandem mass tags (TMT) we identified a large set of proteins involved in nucleic acid metabolism that engage with telomeres upon loss of POT1. Inactivation of the homology directed repair machinery suppresses POT1-loss mediated telomeric DNA defects. Our results unravel as major function of human POT1 the suppression of telomere instability induced by homology directed repair.

2020-10-21 | PXD016826 | Pride

A genetic interaction between RAP1 and telomerase reveals an unanticipated role for RAP1 in telomere protection

Project description:RAP1 is one of the components of mammalian shelterin, the capping complex at chromosome ends or telomeres, although its role in telomere protection has remained elusive. RAP1 binds along chromosome arms, where it regulates gene expression and has been shown to function in metabolism control. Telomerase is the enzyme that elongates telomeres and its deficiency causes a premature aging in mice. We describe an unanticipated genetic interaction between RAP1 and telomerase. While RAP1 deficiency alone does not impact in mouse survival, mice lacking both RAP1 and telomerase show a progressive decreased survival with increasing mouse generation as compared to telomerase single mutants. Telomere shortening was more pronounced in Rap1-/- Terc-/- than in Terc-/- counterparts, leading to an earlier onset of DNA damage and its consequent DNA damage response as well as accelerated degenerative pathologies in the intestines. In its turn, telomerase deficiency abolishes RAP1-mediated obesity and liver pathologies. Mouse embryonic fibroblasts with shorten telomeres present less amount of telomere-bound RAP1 but in contrast show higher numbers of RAP1 bound extratelomeric sites genomewide. Absence of RAP1 leads to deregulation of several metabolic pathways, and these changes were more pronounce in cells with short telomeres suggesting that RAP1 release from telomere foci could constitute a coordinated genomic response to telomere shortening. Our findings also demonstrate that although RAP1 is not a key factor in telomere capping under normal conditios, under stress situation such as critical telomere shortening RAP1 exerts an important function for telomere protection and justify its evolutionary conservation as a shelterin component in mammalian cells.

2016-11-16 | GSE79996 | GEO

Drug sensitivity, gene dependency and proteogenomic correlates of the spectrum of telomere maintenance mechanisms in cancer cells

Project description:Replicative immortality is a hallmark of cancer, driven by activation of telomere maintenance mechanisms (TMM), that is yet to be therapeutically exploited. To expedite discoveries that will enable development of TMM-targeted therapeutics, we have generated a resource of telomere biology metrics for a pan-cancer panel of 976 cell lines. We have also produced new proteomic data from data-independent mass spectrometry for most of these cell lines. These data link to pre-existing multi-omic data, drug sensitivity and molecular dependency data from CRISPR/Cas9 knock-out screens for most cell lines. The TMM data illustrate a previously unappreciated range and heterogeneity in telomere biology measures, including telomere biology states that diverge from the binary model of TMM activation involving either telomerase or Alternative Lengthening of Telomeres (ALT). The multi-omic data were applied in conjunction with the TMM data to derive proteomic and transcriptomic predictors of ALT and telomerase activity levels. Our investigations also revealed molecular vulnerabilities of ALT cancer cells and identified an investigational drug, Pevonedistat, with activity that strongly correlates with telomerase activity levels. These discoveries illustrate the potential for leveraging this new resource of telomere biology metrics to realise the potential for TMM-directed cancer therapeutics and companion diagnostics.

2025-10-17 | PXD058664 | Pride

Peroxiredoxin 1 protects telomeres from oxidative damage preserving chromosome ends for extension by telomerase

Project description:With the increase of atmospheric oxygen 2.3 billion years ago, mechanisms evolved to mitigate the toxic effects of oxygen radicals. Telomeres appear particularly susceptible to oxidative damage, which leads to cellular and organismal aging, cancer, cardiac failure and other diseases. Specific mechanisms of telomere protection from oxidative damage and the molecular consequences of the damage have not been described. Here, we identify the antioxidant enzyme peroxiredoxin 1 (PRDX1) enriched in telomeric chromatin in S and G2 phases of the cell cycle during which telomeres become replicated. PRDX1 depletion leads to oxidative damage of telomeric DNA without affecting the bulk of genomic DNA. The oxidized nucleotide 8-oxo-2’deoxyguanosine-5’-triphosphate (8oxodGTP) can be incorporated by telomerase into telomeric repeats but it mediates premature chain termination when incorporated as first G in the telomeric 5’-TTAGGG-3’ sequence. In dependency of the alignment position within the telomerase RNA template, terminus 8oxoG containing DNA substrates also completely block extension by telomerase. We propose two major mechanisms by which PRDX1 counteracts telomere damage and aging. In safeguarding telomeres from oxygen radicals, PRDX1 prevents DNA damage, telomere replication defects and mutations that will perturb recognition of telomeric DNA by shelterin components. In preventing modification of the telomeric DNA substrate and the dNTP pool, PRDX1 preserves telomeres for elongation by telomerase.

2016-12-07 | PXD002626 | Pride

Disruption of ZC3H15 Compromises Telomere Length Maintenance by Sequestering Telomerase within Cajal bodies

Project description:Telomere homeostasis, crucial for various biological processes, relies on telomerase activity. We identified ZC3H15 as a novel telomerase-interacting protein. Its deletion unexpectedly increased telomerase activity but led to shortened telomeres and cellular senescence. ZC3H15 interacts with telomerase and itself, regulating telomerase activity in an RNA-dependent manner. Proximity labeling showed ZC3H15's interaction with proteins involved in organelle assembly and RNA processes. Loss of ZC3H15 sequestered TERC in the Cajal body, reducing telomerase recruitment to telomeres during S phase. These findings unveil ZC3H15's role in telomere dynamics and cellular senescence, suggesting its potential as a target for cancer therapy or anti-aging interventions.

2024-05-06 | PXD052036 |

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data