posted on 2023-06-15, 14:44authored byMansi Garg, Resham L Gurung, Sahar Mansoubi, Jubed O Ahmed, Anoushka Dave, Felicity Watts, Alessandro BianchiAlessandro Bianchi
Elongation of the telomeric overhang by telomerase is counteracted by synthesis of the complementary strand by the CST complex, CTC1(Cdc13)/Stn1/Ten1. Interaction of budding yeast Stn1 with overhang-binding Cdc13 is increased by Cdc13 SUMOylation. Human and fission yeast CST instead interact with overhang-binding TPP1/POT1. We show that the fission yeast TPP1 ortholog, Tpz1, is SUMOylated. Tpz1 SUMOylation restricts telomere elongation and promotes Stn1/Ten1 telomere association,and a SUMO-Tpz1 fusion protein has increased affinity for Stn1. Our data suggest that SUMO inhibits telomerase through stimulation of Stn1/Ten1 action by Tpz1, highlighting the evolutionary conservation of the regulation of CST function by SUMOylation.
Funding
Analysis of regulation telomerase action & telomore capping function by the telomeric complex (Fellow: Bianchi); G0129; MRC-MEDICAL RESEARCH COUNCIL; G0701428