Time delay and protein modulation analysis in a model of RNA si

RNA silencing is a recently discovered mechanism for posttranscriptional regulation of gene expression. Precisely, in RNA interference, RNAi, endogenous expressed or exogenously induced small RNAs promote and modulate the cleavage of complementary messenger RNA involved in the synthesis of targeted proteins. In this paper we investigated the role of time delay and protein regulation in the posttranslational protein regulation through RNA interference. Towards this end, we used and modified a simple model accounting for RNAi and used qualitative bifurcation analysis, sensitivity analysis and predictive simulations to analyze it. Our results suggest that some processes in the system, like Dicer­mediated mRNA degradation or non specific mRNA degradation, play an important role in the modulation of RNA silencing, whereas silencing seems virtually independent of modulation in other processes.