Telomere extension occurs at most chromosome ends and is uncoupled from fill-in in human cancer cells.

ABSTRACT: Telomeres are thought to be maintained by the preferential recruitment of telomerase to the shortest telomeres. The extension of the G-rich telomeric strand by telomerase is also believed to be coordinated with the complementary synthesis of the C strand by the conventional replication machinery. However, we show that under telomere length-maintenance conditions in cancer cells, human telomerase extends most chromosome ends during each S phase and is not preferentially recruited to the shortest telomeres. Telomerase rapidly extends the G-rich strand following telomere replication but fill-in of the C strand is delayed into late S phase. This late C-strand fill-in is not executed by conventional Okazaki fragment synthesis but by a mechanism using a series of small incremental steps. These f

SUBMITTER: Zhao Y 

PROVIDER: S-EPMC2726829 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature