Bistability and Nonmonotonic Induction of the lac Operon in the Natural Lactose Uptake System.

ABSTRACT: The Escherichia coli lac operon is regulated by a positive feedback loop whose potential to generate an all-or-none response in single cells has been a paradigm for bistable gene expression. However, so far bistable lac induction has only been observed using gratuitous inducers, raising the question about the biological relevance of bistable lac induction in the natural setting with lactose as the inducer. In fact, the existing experimental evidence points to a graded rather than an all-or-none response in the natural lactose uptake system. In contrast, predictions based on computational models of the lactose uptake pathway remain controversial. Although some argue in favor of bistability, others argue against it. Here, we reinvestigate lac operon expression in single cells using a combine

SUBMITTER: Zander D 

PROVIDER: S-EPMC5425413 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature