Stochastic modeling of dwell-time distributions during transcriptional pausing and initiation

The process of transcription has been intensively studied for several decades, however there is still much to learn about the underlying biochemical processes. Recent advances in single-molecule techniques have provided new experimental data that highlights the role of transcriptional pausing in the regulation of gene expression. In some cases, it has been shown that transcriptional pauses are rate-limiting stochastic processes, thus a quantitative understanding requires stochastic modeling of the underlying processes. We propose a coarse-grained stochastic model to analyze the dwell-time distribution for transcriptional pausing. The proposed kinetic scheme can also be used to model transcriptional initiation and to analyze the corresponding noise in gene expression. We obtain analytical solutions which can provide useful insights into current and future experiments focusing on time-resolved single-molecule studies of transcriptional pausing and noise in gene expression.