To address the question of intracellular reduction of the reovirus s1
RNA by S1–553-Rz, primers were designed to amplify the full-length s1
RNA and the control hGAPDH RNA fragment (509 bases) from the same cell
lysates by RT-PCR. Two terminal primers (1 and 2, A)
were used to amplify the full-length s1 (1.4 kb) RNA. They had the
following sequence: forward, 5′-GATCCTCGCCTACGTG and reverse,
5′-CAACGATAGATCTCCACC. Total cellular RNA was isolated from Cos-1 cells
that were first transfected with 1 or 4 μg of plasmid encoding Rz-553
and then challenged with reovirus at 1 plaque-forming unit/cell.
Serial dilutions of the target gene and number of cycles for PCR were
optimized initially to determine the linear range. (B)
Lane 1 depicts the size of standard DNAs as shown on the left. As
expected the plain cells showed no evidence of the presence of s1 RNA
(lane 2). The same was true if the enzyme RT was omitted from the
reaction (lane 3). Reovirus infected cells, as expected, showed a
prominent signal for s1 RNA (lane 4). The intensity of the signal
diminished when either 1 μg (lane 5) or 4 μg (lane 6) of Rz-553 was
used. Mutant-S1–553-Rz at a concentration of 4 μg failed to decrease
the levels of s1 RNA (lane 7). This decrease was specific for the
reovirus s1 RNA as the levels of the control RNA (hGAPDH) in all four
corresponding lysates remained unchanged (C, shown by
arrows).