Promoter directionality is controlled by U1 snRNP and polyadenylation signals

Asymmetric sequence determinants flanking gene transcription start sites are shown to control directionality of transcription elongation in mammalian cells by regulating promoter-proximal cleavage and polyadenylation. RNA polymerase II (RNAPII) initiates transcription divergently from most active gene promoters, but an unknown mechanism limits productive elongation to the sense, coding direction. Here, Albert Almada et al. show that asymmetric...