Kinetic models of the interference of gene transcription to ncRNA and mRNA

Artikel i vetenskaplig tidskrift, 2011

The experiments indicate that the transcription of genes into ncRNA can positively or negatively interfere with transcription into mRNA. We propose two kinetic models describing this effect. The first model is focused on the ncRNA-induced chromatin modification facilitating the transcription of the downstream gene into mRNA. The second model includes the competition between the transcription into ncRNA and the binding of activator to a regulatory site of the downstream gene transcribed into mRNA. Our analysis based on the mean-field kinetic equations and Monte Carlo simulations shows the likely dependences of the transcription rate on RNA polymerase concentration in situations with different rate-limiting steps. Our models can also be used to scrutinize the dependence of the transcription rate on other kinetic parameters. Our kinetic Monte Carlo simulations show that the first model predicts stochastic bursts in the mRNA formation provided that the transcription into ncRNA is slow, while the second model predicts in addition anti-phase stochastic bursts in the mRNA and ncRNA formation provided that that the protein attachment to and detachment from a regulatory site is slow.