Our new noise paper just got published. In this work we explore the effects of two types of promoter elements on transcription: transcription factor binding sites and nucleosome disfavouring sequences. We show that both can change the mean expression of a gene, across a population of cells, however in different ways. Gene expression occurs in bursts, and we predict that changes in binding affinity change the number of transcripts produced per burst, while changes in the nucleosome occupancy change the frequency of bursts. The former should increase the noise with expression, the latter should decrease the noise. Both time-lapse microscopy and flow-cytometry measurements confirm this prediction.
Two DNA-encoded strategies for increasing expression with opposing effects on promoter dynamics and transcriptional noise
M Dadiani, D van Dijk, B Segal, Y Field, G Ben-Artzi, T Raveh-Sadka, M Levo, I Kaplow, A Weinberger and E Segal