The EvgS/EvgA two-component signal transduction system in is activated under mildly acidic pH conditions. Upon activation, this system induces the expression of a number of genes that confer acid resistance. The EvgS histidine kinase sensor has a large periplasmic domain that is required for perceiving acidic signals. In addition, we have previously proposed that the cytoplasmic linker region of EvgS is also involved in the activation of this sensor. The cytoplasmic linker region resembles a Per-ARNT-Sim (PAS) domain, which is known to act as a molecular sensor that is responsive to chemical and physical stimuli and regulates the activity of diverse effector domains. Our EvgS/EvgA reporter assays revealed that under EvgS-activating mildly acidic pH conditions, EvgS was activated only during aerobic growth conditions, and not during anaerobic growth. Studies using EvgS mutants revealed that C671A and C683A mutations in the cytoplasmic PAS domain activated EvgS even under anaerobic conditions. Furthermore, among the electron carriers of the electron transport chain, ubiquinone was required for EvgS activation. The present study proposes a model of EvgS activation by oxidation and suggests that the cytoplasmic PAS domain serves as an intermediate redox switch for this sensor.
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http://dx.doi.org/10.3389/fmicb.2021.652546 | DOI Listing |
J Physiol
January 2025
College of Medicine, Department of Pharmacology, University of Arizona, Tucson, AZ, USA.
The endocannabinoid system's significance in maintaining blood-brain barrier (BBB) integrity under physiological and pathological conditions is suggested by several reports, but the underlying molecular mechanisms are not well understood. In this paper, we investigated the effects of depletion of 2-arachidonoylglycerol (2-AG), one of the main endocannabinoids in the central nervous system, on BBB integrity using pharmacological tools. Female Sprague-Dawley rats were injected with the diacylglycerol lipase α (DAGLα) inhibitor LEI-106 (40 mg/kg, i.
View Article and Find Full Text PDFCell Mol Life Sci
January 2025
Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Hypoxia, or a state of low tissue oxygenation, has been characterized as an important feature of solid tumors that is related to aggressive phenotypes. The cellular response to hypoxia is controlled by Hypoxia-inducible factors (HIFs), a family of transcription factors. HIFs promote the transcription of gene products that play a role in tumor progression including proliferation, angiogenesis, metastasis, and drug resistance.
View Article and Find Full Text PDFBiochem Pharmacol
January 2025
Department of Cell Biology, Faculty of Medicine, Complutense University of Madrid, Spain; Institute of Medical Research at the San Carlos Clinic Hospital (IdISSC), Madrid, Spain.
PAS domain-containing serine/threonine-protein kinase (PASK) is a nutrient and energy sensor regulated by fasting/refeeding conditions in hypothalamic areas involved in controlling energy balance. In this sense, PASK plays a role in coordinating the activation/inactivation of AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin (mTOR) in response to fasting. PASK deficiency protects against the development of diet-induced obesity.
View Article and Find Full Text PDFGenes Cells
January 2025
Department of Urology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
Tumor development often requires cellular adaptation to a unique, high metabolic state; however, the molecular mechanisms that drive such metabolic changes in TFE3-rearranged renal cell carcinoma (TFE3-RCC) remain poorly understood. TFE3-RCC, a rare subtype of RCC, is defined by the formation of chimeric proteins involving the transcription factor TFE3. In this study, we analyzed cell lines and genetically engineered mice, demonstrating that the expression of the chimeric protein PRCC-TFE3 induced a hypoxia-related signature by transcriptionally upregulating HIF1α and HIF2α.
View Article and Find Full Text PDFJMIR Public Health Surveill
January 2025
Faculty of Human-Environment Studies, Kyushu University, Fukuoka, Japan.
Background: The effects of physical activity (PA) across different domains and intensities on depressive symptoms remain inconclusive. Incorporating the community-built environment (CBE) into longitudinal analyses of PA's impact on depressive symptoms is crucial.
Objective: This study aims to examine the effects of PA at different intensities-low-intensity PA (eg, walking activities) and moderate-to-vigorous-intensity PA (eg, activities requiring substantial effort and causing faster breathing or shortness of breath)-across leisure-time and occupational domains on depressive symptom trajectories among middle-aged and older adults.
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