regulation of telomere capping

Definition

Target type: biologicalprocess

Any process that modulates the frequency, rate or extent of telomere capping. [GO_REF:0000058, GOC:BHF, GOC:BHF_telomere, GOC:nc, GOC:TermGenie, PMID:23959892]

Telomere capping is a critical process that protects the ends of chromosomes from degradation and fusion, preventing genomic instability and cellular senescence. Telomeres, repetitive DNA sequences at chromosome ends, are bound by a specialized protein complex known as the shelterin complex. This complex plays a crucial role in regulating telomere capping and protecting the chromosome ends from degradation.

The shelterin complex consists of six core proteins: TRF1, TRF2, RAP1, TIN2, TPP1, and POT1. Each protein has a specific function in telomere capping:

- **TRF1 and TRF2**: These proteins bind directly to the double-stranded telomeric DNA and regulate telomere length. TRF1 inhibits telomerase activity, preventing excessive telomere elongation, while TRF2 promotes telomere protection by recruiting other shelterin components.
- **RAP1**: This protein binds to the double-stranded telomeric DNA and interacts with TRF2, contributing to telomere length regulation.
- **TIN2**: This protein acts as a scaffold, linking TRF1 and TRF2 to other shelterin components, including TPP1 and POT1.
- **TPP1**: This protein interacts with POT1 and facilitates its recruitment to the telomere.
- **POT1**: This protein binds to the single-stranded overhang of telomeric DNA, protecting it from degradation and preventing inappropriate DNA repair mechanisms.

The shelterin complex, through its interaction with the telomeric DNA and other cellular components, performs several key functions in telomere capping:

- **Protection from degradation**: The shelterin complex prevents the recognition of telomeres as damaged DNA, preventing their degradation by exonucleases.
- **Prevention of end-to-end fusions**: The shelterin complex protects the telomeric ends from inappropriate recombination and fusion with other chromosomes, maintaining genomic stability.
- **Regulation of telomere length**: The shelterin complex, through its interaction with telomerase, controls the length of telomeres, preventing their excessive elongation or shortening.

In addition to the shelterin complex, other factors are involved in telomere capping:

- **Telomerase**: This enzyme adds repetitive DNA sequences to the ends of chromosomes, counteracting the loss of telomeric DNA during replication.
- **DNA repair pathways**: These pathways, particularly the non-homologous end joining (NHEJ) pathway, play a role in repairing DNA damage at telomeres.

The regulation of telomere capping is a complex and tightly controlled process that is essential for maintaining genomic integrity. Dysregulation of telomere capping can lead to various diseases, including cancer and premature aging. Understanding the molecular mechanisms of telomere capping is crucial for developing new therapeutic strategies targeting telomere dysfunction.'
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Proteins (1)

Compounds (6)