Relative binding affinities of OmpR and OmpR-phosphate at the ompF and ompC regulatory sites 1 1Edited by R. Ebright

Head, Charlotte; Tardy, Adrienne; Kenney, Linda J.

doi:10.1006/jmbi.1998.1985

Cited by 136 publications

(190 citation statements)

References 55 publications

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“…6 that incorporates these findings. We propose that unphosphorylated OmpR does not play a role in the osmoregulation of porin genes, because it interacts with the promoter regions with low affinity (10). At low osmo- larity, OmpR-P exists in a conformation that activates expression of ompF but binds only at the high affinity C1 site and as such fails to activate transcription from the ompC promoter (Fig.…”

Section: Discussionmentioning

confidence: 97%

The Linker Region Plays an Important Role in the Interdomain Communication of the Response Regulator OmpR

Mattison¹,

Oropeza²,

Kenney

2002

Journal of Biological Chemistry

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OmpR is the response regulator of a two-component regulatory system that controls the expression of the porin genes ompF and ompC in Escherichia coli. This regulator consists of two domains joined by a flexible linker region. The amino-terminal domain is phosphorylated by the sensor kinase EnvZ, and the carboxylterminal domain binds DNA via a winged helix-turn-helix motif. In vitro studies have shown that amino-terminal phosphorylation enhances the DNA binding affinity of OmpR and, conversely, that DNA binding by the carboxyl terminus increases OmpR phosphorylation. In the present work, we demonstrate that the linker region contributes to this communication between the two domains of OmpR. Changing the specific amino acid composition of the linker alters OmpR function, as does increasing or decreasing its length. Three linker mutants give rise to an OmpF ؉ OmpC ؊ phenotype, but the defects are not due to a shared molecular mechanism. Currently, functional homology between response regulators is predicted based on similarities in the amino and carboxylterminal domains. The results presented here indicate that linker length and composition should also be considered. Furthermore, classification of response regulators in the same subfamily does not necessarily imply that they share a common response mechanism.

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Section: Discussionmentioning

confidence: 97%

The Linker Region Plays an Important Role in the Interdomain Communication of the Response Regulator OmpR

Mattison¹,

Oropeza²,

Kenney

2002

Journal of Biological Chemistry

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show abstract

“…23,25) In Synechocystis sp. strain PCC 6803, acetyl phosphate and the NblS homolog Hik33 might co-phosphorylate an unknown cognate response regulator and thus cause degradation of PBS in response to nitrogen starvation.…”

Section: Discussionmentioning

confidence: 99%

NblR Is a Novel One-Component Response Regulator in the CyanobacteriumSynechococcus elongatusPCC 7942

Katô

Chibazakura

Yoshikawa

2008

Bioscience, Biotechnology, and Biochemistry

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“…OmpR is a transcription factor that regulates the transcription of the outer-membrane porin genes ompF and ompC (6)(7)(8)(9)(10)(11)(12)(13)(14)(15). Phosphorylation of OmpR changes its affinity for promoters of outer membrane porin genes, resulting in altered porin expression (16).…”

Section: Introductionmentioning

confidence: 99%

Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays

Ghosh

Wang

Ramesh

et al. 2017

Biophysical Journal

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Membrane-anchored receptors are essential cellular signaling elements for stimulus sensing, propagation, and transmission inside cells. However, the contributions of lipid interactions to the function and dynamics of embedded receptor kinases have not been described in detail. In this study, we used amide hydrogen/deuterium exchange mass spectrometry, a sensitive biophysical approach, to probe the dynamics of a membrane-embedded receptor kinase, EnvZ, together with functional assays to describe the role of lipids in receptor kinase function. Our results reveal that lipids play an important role in regulating receptor function through interactions with transmembrane segments, as well as through peripheral interactions with nonembedded domains. Specifically, the lipid membrane allosterically modulates the activity of the embedded kinase by altering the dynamics of a glycine-rich motif that is critical for phosphotransfer from ATP. This allostery in EnvZ is independent of membrane composition and involves direct interactions with transmembrane and periplasmic segments, as well as peripheral interactions with nonembedded domains of the protein. In the absence of the membrane-spanning regions, lipid allostery is propagated entirely through peripheral interactions. Whereas lipid allostery impacts the phosphotransferase function of the kinase, extracellular stimulus recognition is mediated via a four-helix bundle subdomain located in the cytoplasm, which functions as the osmosensing core through osmolality-dependent helical stabilization. Our findings emphasize the functional modularity in a membrane-embedded kinase, separated into membrane association, phosphotransferase function, and stimulus recognition. These components are integrated through long-range communication relays, with lipids playing an essential role in regulation.

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Relative binding affinities of OmpR and OmpR-phosphate at the ompF and ompC regulatory sites 1 1Edited by R. Ebright

Cited by 136 publications

References 55 publications

The Linker Region Plays an Important Role in the Interdomain Communication of the Response Regulator OmpR

The Linker Region Plays an Important Role in the Interdomain Communication of the Response Regulator OmpR

NblR Is a Novel One-Component Response Regulator in the CyanobacteriumSynechococcus elongatusPCC 7942

Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays

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