title: Stochastic single-gene autoregulation.
abstract: A detailed stochastic model of single-gene autoregulation is established and its solutions are explored when mRNA dynamics is fast compared with protein dynamics and in the opposite regime. The model includes all the sources of randomness that are intrinsic to the autoregulation process and it considers both transcriptional and post-transcriptional regulation. The time-scale separation allows the derivation of analytic expressions for the equilibrium distributions of protein and mRNA. These distributions are generally well described in the continuous approximation, which is used to discuss the qualitative features of the protein equilibrium distributions as a function of the biological parameters in the fast mRNA regime. The performance of the time-scale approximation is assessed by comparison with simulations of the full stochastic system, and a good quantitative agreement is found for a wide range of parameter values. We show that either unimodal or bimodal equilibrium protein distributions can arise, and we discuss the autoregulation mechanisms associated with bimodality.
authors.affiliation: Centro de Física da Matéria Condensada and Departamento de Física, Faculdade de Ciências da Universidade de Lisboa, P-1649-003 Lisboa, Portugal.
authors.forename: Tomás
authors.initials: T
authors.lastname: Aquino
authors.forename: Elsa
authors.initials: E
authors.lastname: Abranches
authors.forename: Ana
authors.initials: A
authors.lastname: Nunes
mesh_terms: D003198:Computer Simulation; D005786:Gene Expression Regulation / Q000235:genetics*; D008957:Models, Genetic; D015233:Models, Statistical; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D013269:Stochastic Processes; D015533:Transcriptional Activation / Q000235:genetics*
chemical_list: D011506:Proteins; D012333:RNA, Messenger