Effects of GPS491 on HIV-1 RNA accumulation and processing. HeLa rtTA HIV∆mls cells were treated with DMSO or varying concentrations of GPS491 +/− doxycycline (Dox) for 24 h. Cells were then harvested, total RNA was extracted, and cDNA was generated. Samples were subsequently analyzed (a) by RT-qPCR to measure levels of HIV-1 US, SS, and MS RNA levels or (b) by RT-PCR to measure levels of different MS RNA isoforms. Shown is a representative gel and summary quantitation of results from n > 3 independent assays. Data are indicated as mean ± SD, * p ≤ 0.05, ** p ≤ 0.01, ns—not significant.