TorI, a response regulator inhibitor of phage origin in Escherichia coli.

Proc Natl Acad Sci U S A

Laboratoire de Chimie Bactérienne, Institut de Biologie Structurale et Microbiologie, Centre National de la Recherche Scientifique, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.

Published: June 2004

The torI gene has been identified by using a genetic multicopy approach as a negative regulator of the torCAD operon that encodes the trimethylamine N-oxide reductase respiratory system in Escherichia coli. The negative effect was due to a previously unidentified small ORF (66 aa) of phage origin that we called torI for Tor inhibition. Overexpression of torI led to an 8-fold decrease of the torCAD operon transcription. This operon is positively regulated, in the presence of trimethylamine N-oxide, by a four-step phosphorelay involving the TorS sensor and the TorR response regulator. Epistatic experiments showed that TorI acts downstream of TorS and needs the presence of TorR. In vitro experiments showed that it is neither a TorR phosphatase nor a histidine kinase inhibitor and that it binds to the effector domain of TorR. Unexpectedly, TorI did not impede TorR DNA binding, and we propose that it may prevent RNA polymerase recruitment to the torC promoter. This study thus reveals a previously uncharacterized class of response regulator inhibitors.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC438992PMC
http://dx.doi.org/10.1073/pnas.0401927101DOI Listing

Publication Analysis

Top Keywords

response regulator
12
phage origin
8
escherichia coli
8
torcad operon
8
trimethylamine n-oxide
8
tori
6
torr
5
tori response
4
regulator
4
regulator inhibitor
4

Similar Publications

Study on the Synergistic Effect of Klotho and KRAS on Reducing Ferroptosis After Myocardial Infarction by Regulating RAP1/ERK Signaling Pathway.

Appl Biochem Biotechnol

January 2025

Department of Internal Medicine-Cardiovascular, Guangzhou Twelfth People's Hospital, No.1, Tianqiang Road, Tianhe District, Guangzhou City, Guangdong Province, 510620, China.

Myocardial infarction (MI) is a coronary artery-related disease that seriously threatens human life and is the leading cause of sudden death worldwide, where a lack of nutrients and oxygen leads to an inflammatory response and death of cardiomyocytes. Ferroptosis is a form of non-apoptotic cell death associated with metabolic dysfunction, resulting in abnormal breakdown of glutamine and iron-dependent accumulation of reactive oxygen species (ROS) during metabolism. However, the molecular mechanism of ferroptosis in the pathogenesis of MI and the function of Klotho and KRAS on ferroptosis during MI remain unclear.

View Article and Find Full Text PDF

Purpose Of Review: The purpose of this review is to summarize the current understanding of cell-autonomous innate immune pathways that contribute to bone homeostasis and disease.

Recent Findings: Germ-line encoded pattern recognition receptors (PRRs) are the first line of defense against danger and infections. In the bone microenvironment, PRRs and downstream signaling pathways, that mount immune defense, interface intimately with the core cellular processes in bone cells to alter bone formation and resorption.

View Article and Find Full Text PDF

Rationale: Rapid adaptation to stressful events is essential for survival and requires acute stress response and stress-coping strategy. However, the molecular mechanisms that govern this coping strategy have yet to be fully discovered.

Objectives: This study aims to investigate the effects of poly ADP-ribosylation (PARylation) on stress-coping strategies following acute stress and to identify the target genes influenced by Parp1-induced histone PARylation.

View Article and Find Full Text PDF

MircoRNAs predict and modulate responses to chemotherapy in leukemic patients.

Naunyn Schmiedebergs Arch Pharmacol

January 2025

Oral Biology Department, Faculty of Dentistry, Galala Plateau, Galala University, 15888), Attaka, Suez Governorate, Egypt.

Leukemia covers a broad category of cancer malignancies that specifically affect bone marrow and blood cells. While different kinds of leukemia have been identified, effective treatments are still lacking for most forms, and even those treatments considered effective can lead to relapses. MicroRNAs, or miRNAs, are short endogenous non-coding single-stranded RNAs that help control the epigenetics of gene expression.

View Article and Find Full Text PDF

Bone Marrow Adipocytes as Novel Regulators of Metabolic Homeostasis: Clinical Consequences of Bone Marrow Adiposity.

Curr Obes Rep

January 2025

Maine Medical Center Research Institute, Maine Medical Center, 81 Research Drive, Scarborough, ME, 04074, USA.

Purpose Of Review: Bone marrow adipose tissue is a distinctive fat depot located within the skeleton, with the potential to influence both local and systemic metabolic processes. Although significant strides have been made in understanding bone marrow adipose tissue over the past decade, many questions remain regarding their precise lineage and functional roles.

Recent Findings: Recent studies have highlighted bone marrow adipose tissue's involvement in continuous cross-talk with other organs and systems, exerting both endocrine and paracrine functions that play a crucial role in metabolic homeostasis, skeletal remodeling, hematopoiesis, and the progression of bone metastases.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!