FIG. 6.

Proximity to TSS silences the poly(A) signal in human cells. (A) Schematics of Adh-ΔLuc (truncated Luc) reporters in pCDNA 3.1 plasmid (Invitrogen). The constructs are flanked by the CMV promoter and a BGH poly(A) signal. The SV40 poly(A) signal was inserted at P1, P2, or P3 in Adh. Distances from the TSS to AAUAAA are indicated below each diagram. (B) Northern blots of total RNA from 293T cells transfected with the reporters shown in panel A. Probes are those described for Fig. 2. The mRNAs generated at each position are indicated.