Fig. 6
From: Telomerase subunit Est2 marks internal sites that are prone to accumulate DNA damage
Parking model of Est2 at NTBS regions in cell cycle and DNA damaging condition. Est2 is parked at multiple internal regions, termed as NTBS (denoted by “parking” sign) within the genome in G1 and G2 phases. In S-phase, Est2 forms an active telomerase unit with Est1, Est3, and Tlc1 template along with recruitment factors Cdc13 and Ku70. Pif1, a helicase, can negatively regulate the telomerase activity. Under conditions of DNA damage, this parking is disrupted and telomerase subunit Est2, misrecognizes the breaks at NTBS regions as ends of chromosomes, and adds telomeric repeats to these regions, causing genome instability