title: When activators repress and repressors activate: a qualitative analysis of the Shea-Ackers model.
abstract: The concept of activation in transcriptional regulation is based on the assumption that product mRNA increases monotonically as a function of regulator concentration. We analyze the Shea-Ackers model of transcription and find this assumption to be correct only for the simplest of promoters. We define a new regulatory constant that is a nonlinear combination of association and transcription initiation constants characterizing activation and repression for more complicated promoters. Our results can guide the synthesis of new promoters and lead to a deeper understanding of the constraints guiding the natural promoters evolution.
authors.affiliation: Department of Mathematics, Montana State University, Bozeman, MT 59715, USA.
authors.forename: Tomás
authors.initials: T
authors.lastname: Gedeon
authors.forename: Konstantin
authors.initials: K
authors.lastname: Mischaikow
authors.forename: Kate
authors.initials: K
authors.lastname: Patterson
authors.forename: Eliane
authors.initials: E
authors.lastname: Traldi
mesh_terms: D000465:Algorithms; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005786:Gene Expression Regulation; D015964:Gene Expression Regulation, Bacterial; D015967:Gene Expression Regulation, Viral; D008954:Models, Biological; D008957:Models, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics; D012097:Repressor Proteins / Q000502:physiology*; D015534:Trans-Activators / Q000502:physiology*; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D012097:Repressor Proteins; D015534:Trans-Activators; D012321:DNA-Directed RNA Polymerases