Análisis determinístico de la red de regulación génica involucrada en la expresión y función del factor de transcripción σ^32 en E. coli.

Motivation: The expression of σ 32 factor is a response of E. coli under thermal shock conditions. The mechanism of induction of chaperone proteins and thermal shock proteases has been well studied, but much of the regulation network of the σ32 factor is not fully understood. For this reason, inthis work a deterministic model of the network is proposed, which was solved by means of the tools present in Matlab® and then evaluated the influence of the transcription, translation and degradation speed on all concentrations of the species involved in the network, in order to determine which of these factors is the one that the cell possibly employs to regulate the expression of the factor σ32. Results: In the resolution of the ordinary equation system using the ode45 algorithm, it was corroborated that the mean life time of sigma 32 is 1 minute for the concentration in steady state. In addition, variations in rpoH transcription constants and o32 mRNA degradation in the network (k1, k2) were found to be non-significant in σ32 factor production, nor in the production of thermal shock proteins. On the other hand, from sensitivity analysis it was inferred that the k3 translation constant of σ32 RNA is the most critical speed for regulating the expression of the σ32 factor in thenetwork. Finally, with respect to k12 it is concluded that it is an important term in the stabilization of the σ32 factor. Availability and Implementation: The analysis was conducted at MatLab_R 2011a and the source code is found in the Supplemental Material