Figure 5.

The efficiency of reverse transcription on the 3′-UTR template RNA is increased in the presence of RHA. Synthesis of the (−)cDNA was carried out using a 5′-Cy3–labeled DNA as the primer annealed to the 3′-UTR template (333 nm), and reactions were collected and analyzed at the indicated time points. The RNA size marker is labeled with M on the top of the gels. A, diagram of the 5′-Cy3–labeled DNA primer annealed to the RNA template. Guanosines (bold letters) in the sequence 8995–9023 are predicted to form G-quadruplexes. B, the 3′-UTR RNA template was preincubated in the presence of K⁺ to promote G-quadruplex formation. Comparison of the primer extension products, synthesized in the absence and presence of RHA (1 μm), and separated by 8% urea–PAGE. Representative gels are shown. C, primer extension assay carried out with the 3′-UTR template (333 nm) preincubated in Li⁺ buffer that diminishes G-quadruplex formation. The strong RT pause bands caused by the putative G-quadruplex in B were not observed.