T-loop dynamics: telomere structure shapes cell fate decisions - PubMed
4 hours ago
- #cell fate
- #telomere
- #mitosis
- Telomeres are nucleoprotein elements protected by shelterin, preventing DNA damage signaling and inappropriate repair.
- The telomere loop (t-loop) is a lariat structure formed by 3' overhang invasion into duplex telomeric DNA, shielding chromosome ends from damage recognition.
- T-loop stability is disrupted by the loss of the shelterin component TRF2 and progressive telomere shortening during aging.
- An active, shelterin-directed mechanism unwinds t-loops during mitotic arrest, promoting mitotic death.
- This process requires Aurora B kinase-dependent shelterin phosphorylation and the BTR complex, and is opposed by WRN.
- Dynamic t-loop architecture integrates telomere signaling with cell fate decisions.