Polyadenylation is required for PANΔENE RNA decay.

<p>(<b>A</b>) Western blot analysis of cells transfected with either a control siRNA or siRNA pools targeting PAPα, PAPγ, or both. Specific proteins were detected using antibodies against PAPα, PAPγ, or β-actin (loading control). (<b>B</b> and <b>C</b>) Representative transcription pulse assay and decay curves of PANΔENE from cells transfected with the indicated siRNAs <i>(n≥4)</i>. (<b>D</b>) Length analysis of PANΔENE from cells transfected with the indicated siRNAs. RNA was harvested following a two-hour transcription pulse (T = 0). The samples in lanes 7–12 were treated with RNase H and oligo(dT) prior to northern blot analysis. (<b>E</b>) Schematic showing the domain structure of PABPN1 as well as the mutations made to generate the dominant negative construct, LALA. (<b>F</b>) Results from a transcription pulse from cells transfected with the dominant negative allele LALA. (<b>G</b>) Decay curves from a transcription pulse as shown in (<b>F</b>)<i>(n≥3)</i>. (<b>H</b> and <b>I</b>) Representative transcription pulse assay and decay curves of PANΔENE performed in the presence or absence of cordycepin <i>(n = 3)</i>. Cordycepin was added either during (T = −2) or after (T = 0) the transcriptional pulse.