Differential nonsense-mediated decay (NMD) of TRPC1 transcripts. (a, b) In paired experiments, cells were pretreated with vehicle control (dimethylsulphoxide) or 25 μg/ml cycloheximide (CHX) for 6 hr prior to isolation of RNA and reverse transcription. PCR primer pairs spanned from exon 6 to 10 and data are shown with (+) and without (-) reverse transcriptase (RT) reaction. (a) HEK 293 cell data. The lower panel shows analysis of β-actin mRNA expression in the same samples. (b) Human saphenous vein VSMC data. (c) PCR with primers spanning exons 6 to 10. (a, c) Messenger RNA was analysed with (+) or without (-) reverse transcription (RT). (a-c) Experiments were repeated independently 4 times and yielded similar results.