Telomere structure shapes cell fate decisions
Telomere loops (t-loops) are dynamic DNA structures, remodelled during the cell cycle and stress, rather than static protective caps.
The three-state model defines closed, intermediate, and uncapped telomeres, linking intermediate telomeres to programmed, fusion-resistant deprotection, which activates checkpoints without genome instability.
Mitotic arrest-dependent telomere deprotection is an active pathway in which Aurora B kinase drives t-loop unwinding without telomere shortening.
Aurora B kinase phosphorylation reprograms shelterin components (TRF1 and TRF2), enabling BTR-mediated t-loop dissolution and paradoxically converting protective factors into facilitators of deprotection.
T-loop dynamics reframe telomeres as responsive signalling hubs that couple chromosome architecture to genome surveillance and cell fate control.
https://www.cell.com/trends/cell-biology/fulltext/S0962-8924(26)00001-2
