RNA-Seq of SMG1 inhibition via SMG1i in human foreskin fibroblast (HFF) and human umbilical vein endothelial cells (HUVEC)

UPF1 is a multi-domain RNA helicase that constantly monitors the transcriptome by non-specifically binding to mRNAs, dissociating from non-target transcripts, and initiating degradation on selected target RNAs via multiple proposed pathways such as nonsense-mediated decay (NMD). NMD is a translation-coupled mechanism that targets mRNAs harboring a premature stop codon (PTC) for degradation, thereby serving as a quality control and gene regulatory pathway ensuring transcriptome integrity. The execution of NMD requires the phosphorylation of N- and C-terminal tails of the key NMD factor UPF1, which thereby serve as binding platforms for the degradation factors SMG5, SMG6 and SMG7. UPF1 phosphorylation is mediated by the kinase SMG1, which catalytic activity can be inhibited with the SMG1 inhibitor SMG1i, a small molecule that functions as an ATP-competitive inhibitor and binds to the active site of SMG1. We wanted to assess the transcriptome-wide expression changes upon inhibition of SMG1. To this end, we treated human foreskin fibroblast (HFF) and human umbilical vein endothelial cells (HUVEC) with 1 µM SMG1i inhibitor for 24h. As controls, cells were treated with DMSO for 24h.