  The intrinsic stochasticity of gene expression can lead to large variability
of protein levels across a population of cells. Variability (or noise) in
protein distributions can be modulated by cellular mechanisms of gene
regulation; in particular, there is considerable interest in understanding the
role of post-transcriptional regulation. To address this issue, we propose and
analyze a stochastic model for post-transcriptional regulation of gene
expression. The analytical solution of the model provides insight into the
effects of different mechanisms of post-transcriptional regulation on the noise
in protein distributions. The results obtained also demonstrate how different
sources of intrinsic noise in gene expression can be discriminated based on
observations of regulated protein distributions.
