The Saccharomyces cerevisiae telomerase subunit Est3 binds telomeres in a cell cycle- and Est1-dependent manner and interacts directly with Est1 in vitro.

ABSTRACT: Telomerase is a telomere dedicated reverse transcriptase that replicates the very ends of eukaryotic chromosomes. Saccharomyces cerevisiae telomerase consists of TLC1 (the RNA template), Est2 (the catalytic subunit), and two accessory proteins, Est1 and Est3, that are essential in vivo for telomerase activity but are dispensable for catalysis in vitro. Est1 functions in both recruitment and activation of telomerase. The association of Est3 with telomeres occurred largely in late S/G2 phase, the time when telomerase acts and Est1 telomere binding occurs. Est3 telomere binding was Est1-dependent. This dependence is likely due to a direct interaction between the two proteins, as purified recombinant Est1 and Est3 interacted in vitro. Est3 abundance was neither cell cycle-regulated nor Est1-de

SUBMITTER: Tuzon CT 

PROVIDER: S-EPMC3088721 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature