Condition- and isoform-dependent UPF1 activity

HEK-293 cells transfected with non-targeting control siRNA or UPF1LL-specific siRNA were treated with vehicle control, puromycin, or thapsigargin as indicated and used for total RNA-seq. Paired-end high-throughput RNA sequencing of total RNA from triplicate biological replicate treatments of HEK-293 cells. Cells were reverse-transfected with the indicated siRNAs and re-plated 48-hours post-transfection. The next day, cells at 70-75% confluency were treated with vehicle control, 25, 50, or 100 µg/mL puromycin (Sigma) for 4 hours, or 1 µM thapsigargin for 6 hours.