mTORC1 is an important regulator of muscle mass but how it is modulated by oxygen and nutrients is not completely understood. We show that loss of the prolyl hydroxylase domain isoform 1 oxygen sensor in mice (PHD1) reduces muscle mass. PHD1 muscles show impaired mTORC1 activation in response to leucine whereas mTORC1 activation by growth factors or eccentric contractions was preserved. The ability of PHD1 to promote mTORC1 activity is independent of its hydroxylation activity but is caused by decreased protein content of the leucyl tRNA synthetase (LRS) leucine sensor. Mechanistically, PHD1 interacts with and stabilizes LRS. This interaction is promoted during oxygen and amino acid depletion and protects LRS from degradation. Finally, elderly subjects have lower PHD1 levels and LRS activity in muscle from aged versus young human subjects. In conclusion, PHD1 ensures an optimal mTORC1 response to leucine after episodes of metabolic scarcity.
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http://dx.doi.org/10.1038/s41467-019-13889-6 | DOI Listing |
J Antimicrob Chemother
December 2024
Division of Mycobacterial and Respiratory Infections, Department of Medicine, National Jewish Health, Denver, CO, USA.
Background: Mycobacterium abscessus is a highly drug-resistant non-tuberculous mycobacterium (NTM) for which treatment is limited by the lack of active oral antimycobacterials and frequent adverse reactions. Epetraborole is a novel oral, boron-containing antimicrobial that inhibits bacterial leucyl-tRNA synthetase, an essential enzyme in protein synthesis, and has been shown to have anti-M. abscessus activity in preclinical studies.
View Article and Find Full Text PDFSite-specific incorporation of noncanonical amino acids (ncAAs) into proteins in eukaryotes has predominantly relied on the pyrrolysyl-tRNA synthetase/tRNA pair. However, access to additional easily engineered pairs is crucial for expanding the structural diversity of the ncAA toolbox in eukaryotes. The -derived leucyl-tRNA synthetase (EcLeuRS)/tRNA pair presents a particularly promising alternative.
View Article and Find Full Text PDFJ Immunother Cancer
November 2024
Department of Gastrointestinal Cancer Biology, Tianjin Medical University Cancer Institute & Hospital, Tianjin, China
Background: Tumor-infiltrating regulatory T cells (TI-Tregs) are well-adapted to thrive in the challenging tumor microenvironment (TME) by undergoing metabolic reprogramming, notably shifting from glycolysis to mitochondrial oxidative phosphorylation (OXPHOS) for energy production. The extracellular matrix is an important component of the TME, contributing to the regulation of both tumor and immune cell metabolism patterns by activating mechanosensors such as YAP. Whether YAP plays a part in regulating TI-Treg mitochondrial function and the underlying mechanisms are yet to be elucidated.
View Article and Find Full Text PDFJ Mol Recognit
October 2024
Department of Protein Synthesis Enzymology, Institute of Molecular Biology and Genetics, the NAS of Ukraine, Kyiv, Ukraine.
Leucyl-tRNA synthetase (LeuRS) is clinically validated molecular target for antibiotic development. Recently, we have reported several classes of small-molecular inhibitors targeting aminoacyl-adenylate binding site of Mycobacterium tuberculosis LeuRS with antibacterial activity. In this work, we performed in silico site-directed mutagenesis of M.
View Article and Find Full Text PDFPLoS One
September 2024
Molecular Bacteriology Laboratory, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil.
Acinetobacter baumannii is a worldwide Gram-negative bacterium with a high resistance rate, responsible for a broad spectrum of hospital-acquired infections. A computational chemogenomics framework was applied to investigate the repurposing of approved drugs to target A. baumannii.
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