Reciprocal regulation as a source of ultrasensitivity in two-component systems with a bifunctional sensor kinase.

ABSTRACT: Two-component signal transduction systems, where the phosphorylation state of a regulator protein is modulated by a sensor kinase, are common in bacteria and other microbes. In many of these systems, the sensor kinase is bifunctional catalyzing both, the phosphorylation and the dephosphorylation of the regulator protein in response to input signals. Previous studies have shown that systems with a bifunctional enzyme can adjust the phosphorylation level of the regulator protein independently of the total protein concentrations--a property known as concentration robustness. Here, I argue that two-component systems with a bifunctional enzyme may also exhibit ultrasensitivity if the input signal reciprocally affects multiple activities of the sensor kinase. To this end, I consider the case whe

SUBMITTER: Straube R 

PROVIDER: S-EPMC4014401 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature