Telomerase shuttling

Telomerase is a ribonucleoprotein-associated reverse transcriptase involved in the maintenance of chromosome integrity and the control of cell proliferation, but how telomerase is regulated in human cells has been unclear. In August 27 Nature Cell Biology, Judy Wong and colleagues at the University of California, Berkeley, California, show that catalytically active human telomerase has a regulated intranuclear localization that is dependent on cell cycle stage, transformation and DNA damage (Nat Cell Biol 2002, DOI: 10.1038/ncb846).

Wong et al. used primary dermal fibroblasts cells and a GFP-hTERT fusion protein marker. They observed that telomerase is released into the nucleoplasm from nucleolar sites, coincident with the initiation of telomere replication. But in tumor and transformed cells, they observed an almost complete dissociation of telomerase from nucleoli at all stages of the cell cycle.

In addition, they showed that transfection of the simian virus 40 genome into the primary cell line is sufficient ...