Attenuation of transcriptional bursting in mRNA transport

TL;DR

This paper develops analytical methods to show how mRNA transport mechanisms, especially saturation effects, can significantly reduce transcriptional noise caused by bursting, impacting gene expression variability.

Contribution

The study introduces new analytic approaches to quantify how different mRNA transport dynamics attenuate transcriptional bursting noise.

Findings

Transport rate influences noise smoothing

Saturation of transport mediators reduces fluctuations

Transport mechanisms impact gene expression variability

Abstract

Due to the stochastic nature of biochemical processes, the copy number of any given type of molecule inside a living cell often exhibits large temporal fluctuations. Here, we develop analytic methods to investigate how the noise arising from a bursting input is reshaped by a transport reaction which is either linear or of the Michaelis-Menten type. A slow transport rate smoothes out fluctuations at the output end and minimizes the impact of bursting on the downstream cellular activities. In the context of gene expression in eukaryotic cells, our results indicate that transcriptional bursting can be substantially attenuated by the transport of mRNA from nucleus to cytoplasm. Saturation of the transport mediators or nuclear pores contributes further to the noise reduction. We suggest that the mRNA transport should be taken into account in the interpretation of relevant experimental data on transcriptional bursting.