FIG. 3.
Recombinant hTR incorporation into an active telomerase RNP. (A) Northern blot analysis of total RNA prepared from cells transiently transfected with WT and AT versions of the sequence-tagged SE construct (arrowheads). The blot was probed with αTag oligonucleotide. Lane i contains in vitro-transcribed hTR standards E and N. (B) TRAP activity assay of extracts prepared from WT and AT transiently transfected 293 cells. Oligonucleotides amplifying WT (C3TA2) or AT (A2C4, C4A2, C2A2C2) telomerase extension products were used as indicated. For lanes 9 to 12 and 21 to 24, extracts were incubated with RNase A prior to the telomerase extension reaction. Each pair of lanes corresponds to 20- and 100-fold dilutions of whole-cell extracts.