Mammals detect and discriminate numerous odors via a large family of G protein-coupled odorant receptors (ORs). However, little is known about the molecular and structural basis underlying OR response properties. Using site-directed mutagenesis and computational modeling, we studied ORs sharing high sequence homology but with different response properties. When tested in heterologous cells by diverse odorants, MOR256-3 responded broadly to many odorants, whereas MOR256-8 responded weakly to a few odorants. Out of 36 mutant MOR256-3 ORs, the majority altered the responses to different odorants in a similar manner and the overall response of an OR was positively correlated with its basal activity, an indication of ligand-independent receptor activation. Strikingly, a single mutation in MOR256-8 was sufficient to confer both high basal activity and broad responsiveness to this receptor. These results suggest that broad responsiveness of an OR is at least partially attributed to its activation likelihood.
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http://dx.doi.org/10.1073/pnas.1517510112 | DOI Listing |
Int J Mol Sci
December 2024
Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea.
Odorant receptors (ORs), which constitute approximately 50% of all human G protein-coupled receptors, are increasingly recognized for their diverse roles beyond odor perception, including functions in various pathological conditions like brain diseases and cancers. However, the roles of ORs in glioblastoma (GBM), the most aggressive primary brain tumor with a median survival of only 15 months, remain largely unexplored. Here, we performed an integrated transcriptomic analysis combining The Cancer Genome Atlas RNA-seq and single-cell RNA sequencing data from GBM patients to uncover cell-type-specific roles of ORs within the tumor and its microenvironment.
View Article and Find Full Text PDFJ Clin Med
December 2024
Department of Cardiothoracic Surgery, University General Hospital, Democritus University of Thrace, 68100 Alexandroupolis, Greece.
Aortic aneurysm, the pathological dilatation of the aorta at distinct locations, can be attributed to many different genetic and environmental factors. The resulting pathobiological disturbances generate a complex interplay of processes affecting cells and extracellular molecules of the tunica interna, media and externa. In short, aortic aneurysm can affect processes involving the extracellular matrix, lipid trafficking/atherosclerosis, vascular smooth muscle cells, inflammation, platelets and intraluminal thrombus formation, as well as various endothelial functions.
View Article and Find Full Text PDFFront Neurosci
December 2024
Jeffrey Cheah School of Medicine & Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia.
G protein-coupled receptor 139 (GPR139), a highly conserved orphan receptor, is predominantly expressed in the habenula of vertebrate species. Habenula is an ancient epithalamic structure, which is critical to comprehending adaptive behaviors in vertebrates. We have previously demonstrated the role of GPR139 agonists in fear-associated decision-making processes in zebrafish.
View Article and Find Full Text PDFFoods
December 2024
College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Odorant receptors (ORs) have long been thought to serve as chemosensors located on the cilia of olfactory sensory neurons (OSNs) in the olfactory epithelium, where they recognize odorant molecules and comprise the largest family of seven transmembrane-domain G protein-coupled receptors (GPCRs). Over the last three decades, accumulating evidence has suggested that ORs are distributed in a variety of peripheral tissues beyond their supposed typical tissue expression in the olfactory epithelium. These ectopic ORs play a role in regulating various cellular, physiological, and pathophysiological phenomena in the body, such as regulation of hypertension, hepatic glucose production, cancer development, and chronic skin disease.
View Article and Find Full Text PDFFood Res Int
November 2024
School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai 201418, China; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; Agricultural Products Processing Center, Henan Academy of Agricultural Sciences, Zhengzhou, China. Electronic address:
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