Signal discrimination by differential regulation of protein stability in quorum sensing.
Journal Article (Journal Article)
Quorum sensing (QS) is a communication mechanism exploited by a large variety of bacteria to coordinate gene expression at the population level. In Gram-negative bacteria, QS occurs via synthesis and detection of small chemical signals, most of which belong to the acyl-homoserine lactone class. In such a system, binding of an acyl-homoserine lactone signal to its cognate transcriptional regulator (R-protein) often induces stabilization and subsequent dimerization of the R-protein, which results in the regulation of downstream gene expression. Existence of diverse QS systems within and among species of bacteria indicates that each bacterium needs to distinguish among a myriad of structurally similar chemical signals. We show, using a mathematical model, that fast degradation of an R-protein monomer can facilitate discrimination of signals that differentially stabilize it. Furthermore, our results suggest an inverse correlation between the stability of an R-protein and the achievable limits of fidelity in signal discrimination. In particular, an unstable R-protein tends to be more specific to its cognate signal, whereas a stable R-protein tends to be more promiscuous. These predictions are consistent with experimental data on well-studied natural and engineered R-proteins and thus have implications for understanding the functional design of QS systems.
Full Text
Duke Authors
Cited Authors
- Smith, C; Song, H; You, L
Published Date
- October 2008
Published In
Volume / Issue
- 382 / 5
Start / End Page
- 1290 - 1297
PubMed ID
- 18721812
Pubmed Central ID
- PMC2573026
Electronic International Standard Serial Number (EISSN)
- 1089-8638
International Standard Serial Number (ISSN)
- 0022-2836
Digital Object Identifier (DOI)
- 10.1016/j.jmb.2008.08.009
Language
- eng