Transcription rate strongly affects splicing fidelity and co-transcriptionality in budding yeast
Aslanzadeh, V., Huang, Y., Sanguinetti, G., Beggs, J.D.
In this work, we show that slow RNA polymerase II elongation increases both co-transcriptional splicing and splicing efficiency and faster elongation reduces co-transcriptional splicing and splicing efficiency in budding yeast, suggesting that splicing is more efficient when co-transcriptional. We demonstrate that altering RNA polymerase II elongation rate in either direction compromises splicing fidelity. Moreover, we reveal that the highly expressed ribosomal protein coding (RP) transcripts are spliced with much higher fidelity (lower Splicing Error Frequency (SEF; see figure) than are other (non-RP) transcripts. We propose that transcription by RNA polymerase II is tuned to optimise the efficiency and accuracy of ribosomal protein gene expression, while allowing flexibility in splice site choice with the non-ribosomal protein transcripts.