scholarly journals EFR3s are palmitoylated plasma membrane proteins that control responsiveness to G-protein-coupled receptors

2014 ◽  
Vol 128 (1) ◽  
pp. 118-128 ◽  
Author(s):  
N. Bojjireddy ◽  
M. L. Guzman-Hernandez ◽  
N. R. Reinhard ◽  
M. Jovic ◽  
T. Balla
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
Plasma Membrane Proteins ◽  
G Protein Coupled

scholarly journals Transport of vesicular stomatitis virus G protein to the cell surface is signal mediated in polarized and nonpolarized cells.

1996 ◽  
Vol 133 (3) ◽  
pp. 543-558 ◽  
Author(s):  
A Müsch ◽  
H Xu ◽  
D Shields ◽  
E Rodriguez-Boulan
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Mdck Cells ◽  
Current Model ◽  
Gh3 Cells ◽  
Plasma Membrane Proteins ◽  
Vesicular Release ◽  
Vesicular Stomatitis

Current model propose that in nonpolarized cells, transport of plasma membrane proteins to the surface occurs by default. In contrast, compelling evidence indicates that in polarized epithelial cells, plasma membrane proteins are sorted in the TGN into at least two vectorial routes to apical and basolateral surface domains. Since both apical and basolateral proteins are also normally expressed by both polarized and nonpolarized cells, we explored here whether recently described basolateral sorting signals in the cytoplasmic domain of basolateral proteins are recognized and used for post TGN transport by nonpolarized cells. To this end, we compared the inhibitory effect of basolateral signal peptides on the cytosol-stimulated release of two basolateral and one apical marker in semi-intact fibroblasts (3T3), pituitary (GH3), and epithelial (MDCK) cells. A basolateral signal peptide (VSVGp) corresponding to the 29-amino acid cytoplasmic tail of vesicular stomatitis virus G protein (VSVG) inhibited with identical potency the vesicular release of VSVG from the TGN of all three cell lines. On the other hand, the VSVG peptide did not inhibit the vesicular release of HA in MDCK cells not of two polypeptide hormones (growth hormone and prolactin) in GH3 cells, whereas in 3T3 cells (influenza) hemagglutinin was inhibited, albeit with a 3x lower potency than VSVG. The results support the existence of a basolateral-like, signal-mediated constitutive pathway from TGN to plasma membrane in all three cell types, and suggest that an apical-like pathway may be present in fibroblast. The data support cargo protein involvement, not bulk flow, in the formation of post-TGN vesicles and predict the involvement of distinct cytosolic factors in the assembly of apical and basolateral transport vesicles.

scholarly journals Misfolded G Protein-Coupled Receptors and Endocrine Disease. Molecular Mechanisms and Therapeutic Prospects

2021 ◽  
Vol 22 (22) ◽  
pp. 12329
Author(s):  
Alfredo Ulloa-Aguirre ◽  
Teresa Zariñán ◽  
Eduardo Jardón-Valadez
Keyword(s):  
Plasma Membrane ◽  
G Protein ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
G Protein Coupled Receptors ◽  
Membrane Receptors ◽  
Therapeutic Interventions ◽  
Endocrine Function ◽  
Receptor Protein ◽  
G Protein Coupled

Misfolding of G protein-coupled receptors (GPCRs) caused by mutations frequently leads to disease due to intracellular trapping of the conformationally abnormal receptor. Several endocrine diseases due to inactivating mutations in GPCRs have been described, including X-linked nephrogenic diabetes insipidus, thyroid disorders, familial hypocalciuric hypercalcemia, obesity, familial glucocorticoid deficiency [melanocortin-2 receptor, MC2R (also known as adrenocorticotropin receptor, ACTHR), and reproductive disorders. In these mutant receptors, misfolding leads to endoplasmic reticulum retention, increased intracellular degradation, and deficient trafficking of the abnormal receptor to the cell surface plasma membrane, causing inability of the receptor to interact with agonists and trigger intracellular signaling. In this review, we discuss the mechanisms whereby mutations in GPCRs involved in endocrine function in humans lead to misfolding, decreased plasma membrane expression of the receptor protein, and loss-of-function diseases, and also describe several experimental approaches employed to rescue trafficking and function of the misfolded receptors. Special attention is given to misfolded GPCRs that regulate reproductive function, given the key role played by these particular membrane receptors in sexual development and fertility, and recent reports on promising therapeutic interventions targeting trafficking of these defective proteins to rescue completely or partially their normal function.

scholarly journals Stabilization of Membrane Proteins: the Case of G‐Protein‐Coupled Receptors

2008 ◽  
Vol 8 (3) ◽  
pp. 207-217 ◽  
Author(s):  
A. Reyes‐Alcaraz ◽  
T. Tzanov ◽  
P. Garriga
Keyword(s):  
Membrane Proteins ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
G Protein Coupled

scholarly journals Selectivity Landscape of 100 Therapeutically Relevant GPCR Profiled by an Effector Translocation-Based BRET Platform

2020 ◽  
Author(s):  
Charlotte Avet ◽  
Arturo Mancini ◽  
Billy Breton ◽  
Christian Le Gouill ◽  
Alexander S. Hauser ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Drug Discovery ◽  
Signaling Pathways ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
Systems Pharmacology ◽  
New Knowledge ◽  
Translocation Assay ◽  
Multiple Signaling ◽  
G Protein Coupled

SUMMARYThe ability of individual G protein-coupled receptors (GPCR) to engage multiple signaling pathways opens opportunities for the development of better drugs. This requires new knowledge and tools to determine the G protein subtypes and βarrestins engaged by a given receptor. Here, we used a new BRET-based effector membrane translocation assay (EMTA) that monitors activation of each Gα protein through the recruitment of selective G protein effectors and βarrestins to the plasma membrane. Profiling of 100 therapeutically relevant GPCR revealed a great diversity of coupling profiles with some receptors displaying exquisite selectivity, whereas others promiscuitely engage all four G protein families. Comparison with existing datasets points to commonalities but also to critical differences between studies. Combining a biosensor subset allowed detecting activity of nearly all GPCR thus providing a new tool for safety screens and systems pharmacology. Overall, this work describes unique resources for studying GPCR function and drug discovery.

scholarly journals Machine Learning for Prioritization of Thermostabilizing Mutations for G-protein Coupled Receptors

2019 ◽  
Author(s):  
S. Muk ◽  
S. Ghosh ◽  
S. Achuthan ◽  
X. Chen ◽  
X. Yao ◽  
...  
Keyword(s):  
Machine Learning ◽  
Membrane Proteins ◽  
G Protein ◽  
Three Dimensional ◽  
G Protein Coupled Receptors ◽  
Complement Factor ◽  
Computational Framework ◽  
Alanine Scanning ◽  
Structure And Dynamics ◽  
G Protein Coupled

AbstractAlthough the three-dimensional structures of G-protein-coupled receptors (GPCRs), the largest superfamily of drug targets, have enabled structure-based drug design, there are no structures available for 87% of GPCRs. This is due to the stiff challenge in purifying the inherently flexible GPCRs. Identifying thermostabilized mutant GPCRs via systematic alanine scanning mutations has been a successful strategy in stabilizing GPCRs, but it remains a daunting task for each GPCR. We developed a computational method that combines sequence, structure and dynamics based molecular properties of GPCRs that recapitulate GPCR stability, with four different machine learning methods to predict thermostable mutations ahead of experiments. This method has been trained on thermostability data for 1231 mutants, the largest publicly available dataset. A blind prediction for thermostable mutations of the Complement factor C5a Receptor retrieved 36% of the thermostable mutants in the top 50 prioritized mutants compared to 3% in the first 50 attempts using systematic alanine scanning.Statement Of SignifiganceG-protein-coupled receptors (GPCRs), the largest superfamily of membrane proteins play a vital role in cellular physiology and are targets to blockbuster drugs. Hence it is imperative to solve the three dimensional structures of GPCRs in various conformational states with different types of ligands bound. To reduce the experimental burden in identifying thermostable GPCR mutants, we report a computational framework using machine learning algorithms trained on thermostability data for 1231 mutants and features calculated from analysis of GPCR sequences, structure and dynamics to predict thermostable mutations ahead of experiments. This work represents a significant advancement in the development, validation and testing of a computational framework that can be extended to other class A GPCRs and helical membrane proteins.

scholarly journals Development of OPLS-AA/M Parameters for Simulations of G Protein-Coupled Receptors and Other Membrane Proteins

2022 ◽  
Author(s):  
Michael J. Robertson ◽  
Georgios Skiniotis
Keyword(s):  
Membrane Proteins ◽  
Force Field ◽  
G Protein ◽  
Drug Targets ◽  
G Protein Coupled Receptors ◽  
Dynamic Nature ◽  
Post Translational Modifications ◽  
Dynamics Simulations ◽  
High Level ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) and other membrane proteins are valuable drug targets, and their dynamic nature makes them attractive systems for study with molecular dynamics simulations and free energy approaches. Here, we report the development, implementation, and validation of OPLS-AA/M force field parameters to enable simulations of these systems. These efforts include the introduction of post-translational modifications including lipidations and phosphorylation. We also modify previously reported parameters for lipids to be more consistent with the OPLS-AA force field standard and extend their coverage. These new parameters are validated on a variety of test systems, with the results compared to high-level quantum mechanics calculations, experimental data, and simulations with CHARMM36m where relevant. The results demonstrate that the new parameters reliably reproduce the behavior of membrane protein systems.

scholarly journals Lipid nanoparticle technologies for the study of G protein-coupled receptors in lipid environments

2020 ◽  
Vol 12 (6) ◽  
pp. 1287-1302 ◽  
Author(s):  
Steven Lavington ◽  
Anthony Watts
Keyword(s):  
Membrane Proteins ◽  
G Protein ◽  
Drug Targets ◽  
Large Family ◽  
G Protein Coupled Receptors ◽  
Integral Membrane Proteins ◽  
Lipid Nanoparticle ◽  
Wide Range ◽  
Biophysical Studies ◽  
G Protein Coupled

AbstractG protein-coupled receptors (GPCRs) are a large family of integral membrane proteins which conduct a wide range of biological roles and represent significant drug targets. Most biophysical and structural studies of GPCRs have been conducted on detergent-solubilised receptors, and it is clear that detergents can have detrimental effects on GPCR function. Simultaneously, there is increasing appreciation of roles for specific lipids in modulation of GPCR function. Lipid nanoparticles such as nanodiscs and styrene maleic acid lipid particles (SMALPs) offer opportunities to study integral membrane proteins in lipid environments, in a form that is soluble and amenable to structural and biophysical experiments. Here, we review the application of lipid nanoparticle technologies to the study of GPCRs, assessing the relative merits and limitations of each system. We highlight how these technologies can provide superior platforms to detergents for structural and biophysical studies of GPCRs and inform on roles for protein-lipid interactions in GPCR function.

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