Protection of internal (TTAGGG)n repeats in Chinese hamster cells by telomeric protein TRF1.

Chinese hamster cells have large interstitial (TTAGGG) bands (ITs) which are unstable and should be protected by an unknown mechanism. Here, we expressed in Chinese hamster V79 cells green fluorescent protein (GFP)-tagged human TRF1, and found that a major fraction of GFP-TRF1 bound to ITs is diffusionally mobile. This fraction strongly decreases after treatment of cells with wortmannin, a protein kinase inhibitor, and this drug also increases the frequency of chromosome aberrations.