Determining membrane protein quaternary structure is extremely challenging, especially in live cell membranes. We measured the oligomerization of opsin, a prototypical G protein-coupled receptor with pulsed-interleaved excitation fluorescence cross-correlation spectroscopy (PIE-FCCS). Individual cell measurements revealed that opsin is predominantly organized into dimeric clusters. At low concentrations, we observed that the population of oligomers increased linearly with the square of the individual monomer populations. This finding supports a monomer-dimer equilibrium and provides an experimental measurement of the equilibrium constant.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4063175PMC
http://dx.doi.org/10.1021/ja501948wDOI Listing

Publication Analysis

Top Keywords

protein-coupled receptor
8
live cell
8
cell membranes
8
time-resolved fluorescence
4
fluorescence spectroscopy
4
spectroscopy measures
4
measures clustering
4
clustering mobility
4
mobility protein-coupled
4
receptor opsin
4

Similar Publications

Understanding the dynamics of membrane protein-ligand interactions within a native lipid bilayer is a major goal for drug discovery. Typically, cell-based assays are used, however, they are often blind to the effects of protein modifications. In this study, using the archetypal G protein-coupled receptor rhodopsin, we found that the receptor and its effectors can be released directly from retina rod disc membranes using infrared irradiation in a mass spectrometer.

View Article and Find Full Text PDF

The expression of CD38 by cancer cells may mediate an immune-suppressive effect by producing Extracellular Adenosine (ADO) acting through G-protein-coupled cell surface receptors on cellular components and tumor cells. This can increase PD-1 expression and interaction with PD-L1, suppressing CD8 + cytotoxic T cells. This study examines the impact of heightened CD38 expression and extracellular ADO on various hematological and clinical parameters in patients with mature B-cell lymphoma, alongside their correlation with the soluble counterparts of the PD-1/PD-L1 axis.

View Article and Find Full Text PDF

Dysregulated autoantibodies targeting AGTR1 are associated with the accumulation of COVID-19 symptoms.

NPJ Syst Biol Appl

January 2025

BIH Center for Regenerative Therapies (BCRT), Julius Wolff Institute (JWI), and Berlin Institute of Health (BIH); all Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), 10117, Berlin, Germany.

Coronavirus disease 2019 (COVID-19) presents a wide spectrum of symptoms, the causes of which remain poorly understood. This study explored the associations between autoantibodies (AABs), particularly those targeting G protein-coupled receptors (GPCRs) and renin‒angiotensin system (RAS) molecules, and the clinical manifestations of COVID-19. Using a cross-sectional analysis of 244 individuals, we applied multivariate analysis of variance, principal component analysis, and multinomial regression to examine the relationships between AAB levels and key symptoms.

View Article and Find Full Text PDF

The metabotropic glutamate receptors (mGlus) are class C G protein-coupled receptors (GPCR) that form obligate dimers activated by the major excitatory neurotransmitter L-glutamate. The architecture of mGlu receptor comprises an extracellular Venus-Fly Trap domain (VFT) connected to the transmembrane domain (7TM) through a Cysteine-Rich Domain (CRD). The binding of L-glutamate in the VFTs and subsequent conformational change results in the signal being transmitted to the 7TM inducing G protein binding and activation.

View Article and Find Full Text PDF

[Mechanism of inflammatory microecological response to TAS2R14/SIgA/TSLP in regulating epithelial cell barrier in cold asthma rats through lung-gut axis by using Shegan Mahuang Decoction and bitter and purging Chinese herbs].

Zhongguo Zhong Yao Za Zhi

December 2024

Anhui University of Chinese Medicine Hefei 230012, China Anhui Province Key Laboratory of Application and Transformation of Traditional Chinese Medicine in Prevention and Treatment of Major Pulmonary Diseases Hefei 230031, China Key Laboratory of Xin'an Medicine, Ministry of Education Hefei 230038, China.

This study aimed to investigate the mechanism by which Shegan Mahuang Decoction(SGMH) and its bitter Chinese herbs(BCHs) regulated the lung-gut axis through the bitter taste receptor 14(TAS2R14)/secretory immunoglobulin A(SIgA)/thymic stromal lymphopoietin(TSLP) to intervene in the epithelial cell barrier of cold asthma rats. Fifty SD rats were randomly divided into the following five groups: normal group, model group, dexamethasone group, SGMH group, and BCHs group. A 10% ovalbumin(OVA) solution was used to sensitize the rats via subcutaneous injection on both sides of the abdomen and groin, combined with 2% OVA atomization and cold(2-4 ℃) stimulation to induce a cold asthma model in rats.

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!