FIG. 2.

Analysis of the N-terminal domain and RT domain in immortalization and telomere maintenance. (A) Schematic diagram of TERT delineating the three major domains: N terminus, RT domain, and the C terminus (C-term). Functional regions I, II, III, T, N-DAT, and C-DAT are indicated in dark gray. Conserved RT motifs 1, 2, A, B′, C, D, and E are designated by white lines. C1 and C2 regions that are defined in this paper are shown in light gray. (B) TRAP analysis and (C) serial passage of BJT cells that were transduced with retroviruses expressing HMM, MHH, HMH, MHM, hTERT, mTERT, or vector alone (IC, internal control). (D) Telomeres shorten in HMM-BJT cells. TRF analysis of HMM-BJT cells over multiple population doublings (vector-BJT and hTERT-BJT are shown for comparison). (E and F) Telomeres shorten, but then stabilize in HMH-expressing cells. TRF analysis of HMH-BJT and empty vector-BJT over multiple population doublings by TRF Southern blot analysis (hTERT, hTERT-BJT sample for comparison) is shown.