scholarly journals Conformational dynamics of a G protein–coupled receptor helix 8 in lipid membranes

2020 ◽  
Vol 6 (33) ◽  
pp. eaav8207 ◽  
Author(s):  
Patricia M. Dijkman ◽  
Juan C. Muñoz-García ◽  
Steven R. Lavington ◽  
Patricia Suemy Kumagai ◽  
Rosana I. dos Reis ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
Lipid Membranes ◽  
Transmembrane Helix ◽  
Conformational Dynamics ◽  
Paramagnetic Resonance ◽  
Lipid Protein Interactions ◽  
Dynamics Simulations ◽  
Neurotensin Receptor 1 ◽  
G Protein Coupled

G protein–coupled receptors (GPCRs) are the largest and pharmaceutically most important class of membrane proteins encoded in the human genome, characterized by a seven-transmembrane helix architecture and a C-terminal amphipathic helix 8 (H8). In a minority of GPCR structures solved to date, H8 either is absent or adopts an unusual conformation. The controversial existence of H8 of the class A GPCR neurotensin receptor 1 (NTS1) has been examined here for the nonthermostabilized receptor in a functionally supporting membrane environment using electron paramagnetic resonance, molecular dynamics simulations, and circular dichroism. Lipid-protein interactions with phosphatidylserine and phosphatidylethanolamine lipids, in particular, stabilize the residues 374 to 390 of NTS1 into forming a helix. Furthermore, introduction of a helix-breaking proline residue in H8 elicited an increase in ß-arrestin–NTS1 interactions observed in pull-down assays, suggesting that the structure and/or dynamics of H8 might play an important role in GPCR signaling.

scholarly journals Lipid Protein Interactions Of G Protein Coupled Receptors

2016 ◽  
Vol 110 (3) ◽  
pp. 423a
Author(s):  
Besian Sejdiu ◽  
Christine DeGagne ◽  
Valentina Corradi ◽  
Peter Tieleman
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
G Protein Coupled Receptors ◽  
Lipid Protein Interactions ◽  
G Protein Coupled

scholarly journals Insights from Molecular Dynamics Simulations for GPCR Drug Discovery

2019 ◽  
Author(s):  
Ye Zou ◽  
John Ewalt ◽  
Ho-Leung Ng
Keyword(s):  
Molecular Dynamics ◽  
Drug Discovery ◽  
G Protein ◽  
Drug Targets ◽  
Conformational Dynamics ◽  
Md Simulations ◽  
Protein Activation ◽  
Downstream Signaling ◽  
Dynamics Simulations ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) are critical drug targets. GPCRs convey signals from the extracellular to the intracellular environment through G proteins. There is evidence that some ligands that bind to the GPCRs activate different downstream signaling pathways. G protein activation or -arrestin biased signaling involves ligands binding to receptors and stabilizing conformations that trigger a specific pathway. Molecular dynamics (MD) simulations are especially valuable for obtaining detailed mechanistic information, including identification of allosteric sites and understanding modulators' interactions between receptors and ligands. Here, we highlight recent simulation studies and methods used to study biased G protein-coupled receptor signaling and their conformational dynamics. We also highlight applications of MD simulations to drug discovery.

scholarly journals A molecular sensor for cholesterol in the human serotonin1A receptor

2021 ◽  
Vol 7 (30) ◽  
pp. eabh2922
Author(s):  
G. Aditya Kumar ◽  
Parijat Sarkar ◽  
Tomasz Maciej Stepniewski ◽  
Md. Jafurulla ◽  
Shishu Pal Singh ◽  
...  
Keyword(s):  
Transmembrane Helix ◽  
Conformational Dynamics ◽  
Structural Features ◽  
Receptor Interaction ◽  
Specific Sequence ◽  
Cholesterol Levels ◽  
Extracellular Loops ◽  
Dynamics Simulations ◽  
Key Residues ◽  
G Protein Coupled

The function of several G protein–coupled receptors (GPCRs) exhibits cholesterol sensitivity. Cholesterol sensitivity of GPCRs could be attributed to specific sequence and structural features, such as the cholesterol recognition/interaction amino acid consensus (CRAC) motif, that facilitate their cholesterol-receptor interaction. In this work, we explored the molecular basis of cholesterol sensitivity exhibited by the serotonin1A receptor, the most studied GPCR in the context of cholesterol sensitivity, by generating mutants of key residues in CRAC motifs in transmembrane helix 2 (TM2) and TM5 of the receptor. Our results show that a lysine residue (K101) in one of the CRAC motifs is crucial for sensing altered membrane cholesterol levels. Insights from all-atom molecular dynamics simulations showed that cholesterol-sensitive functional states of the serotonin1A receptor are associated with reduced conformational dynamics of extracellular loops of the receptor. These results constitute one of the first reports on the molecular mechanism underlying cholesterol sensitivity of GPCRs.

scholarly journals A complex structure of arrestin-2 bound to a G protein-coupled receptor

2019 ◽  
Author(s):  
Wanchao Yin ◽  
Zhihai Li ◽  
Mingliang Jin ◽  
Yu-Ling Yin ◽  
Parker W. de Waal ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
G Protein ◽  
Complex Structure ◽  
Transmembrane Helix ◽  
G Protein Coupled Receptors ◽  
Dynamics Simulation ◽  
Intracellular Loop ◽  
Neurotensin Receptor 1 ◽  
G Protein Coupled

AbstractArrestins comprise a family of signal regulators of G-protein-coupled receptors (GPCRs), which include arrestins 1 to 4. While arrestins 1 and 4 are visual arrestins dedicated to rhodopsin, arrestins 2 and 3 (Arr2 and Arr3) are β-arrestins known to regulate many nonvisual GPCRs. The dynamic and promiscuous coupling of Arr2 to nonvisual GPCRs has posed technical challenges to tackle the basis of arrestin binding to GPCRs. Here we report the structure of Arr2 in complex with neurotensin receptor 1 (NTSR1), which reveals an overall assembly that is strikingly different from the visual arrestin-rhodopsin complex by a 90° rotation of Arr2 relative to the receptor. In this new configuration, intracellular loop 3 (ICL3) and transmembrane helix 6 (TM6) of the receptor are oriented toward the N-terminal domain of the arrestin, making it possible for GPCRs that lack the C-terminal tail to couple Arr2 through their ICL3. Molecular dynamics simulation and crosslinking data further support the assembly of the Arr2–NTSR1 complex. Sequence analysis and homology modeling suggest that the Arr2–NTSR1 complex structure may provide an alternative template for modeling arrestin-GPCR interactions.

scholarly journals Structural Characterization of Receptor–Receptor Interactions in the Allosteric Modulation of G Protein-Coupled Receptor (GPCR) Dimers

2021 ◽  
Vol 22 (6) ◽  
pp. 3241
Author(s):  
Raudah Lazim ◽  
Donghyuk Suh ◽  
Jai Woo Lee ◽  
Thi Ngoc Lan Vu ◽  
Sanghee Yoon ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
Metabotropic Glutamate Receptor ◽  
Three Dimensional ◽  
Allosteric Modulation ◽  
Experimental Investigations ◽  
G Protein Coupled Receptor ◽  
Metabotropic Glutamate ◽  
Gpcr Activation ◽  
G Protein Coupled

G protein-coupled receptor (GPCR) oligomerization, while contentious, continues to attract the attention of researchers. Numerous experimental investigations have validated the presence of GPCR dimers, and the relevance of dimerization in the effectuation of physiological functions intensifies the attractiveness of this concept as a potential therapeutic target. GPCRs, as a single entity, have been the main source of scrutiny for drug design objectives for multiple diseases such as cancer, inflammation, cardiac, and respiratory diseases. The existence of dimers broadens the research scope of GPCR functions, revealing new signaling pathways that can be targeted for disease pathogenesis that have not previously been reported when GPCRs were only viewed in their monomeric form. This review will highlight several aspects of GPCR dimerization, which include a summary of the structural elucidation of the allosteric modulation of class C GPCR activation offered through recent solutions to the three-dimensional, full-length structures of metabotropic glutamate receptor and γ-aminobutyric acid B receptor as well as the role of dimerization in the modification of GPCR function and allostery. With the growing influence of computational methods in the study of GPCRs, we will also be reviewing recent computational tools that have been utilized to map protein–protein interactions (PPI).

scholarly journals Every Detail Matters. That Is, How the Interaction between Gα Proteins and Membrane Affects Their Function

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 222
Author(s):  
Agnieszka Polit ◽  
Paweł Mystek ◽  
Ewa Błasiak
Keyword(s):  
Signal Transduction ◽  
G Protein ◽  
G Proteins ◽  
Lipid Membranes ◽  
Signaling Proteins ◽  
Heterotrimeric G Proteins ◽  
Membrane Attachment ◽  
The Individual ◽  
Multicellular Organisms ◽  
G Protein Coupled

In highly organized multicellular organisms such as humans, the functions of an individual cell are dependent on signal transduction through G protein-coupled receptors (GPCRs) and subsequently heterotrimeric G proteins. As most of the elements belonging to the signal transduction system are bound to lipid membranes, researchers are showing increasing interest in studying the accompanying protein–lipid interactions, which have been demonstrated to not only provide the environment but also regulate proper and efficient signal transduction. The mode of interaction between the cell membrane and G proteins is well known. Despite this, the recognition mechanisms at the molecular level and how the individual G protein-membrane attachment signals are interrelated in the process of the complex control of membrane targeting of G proteins remain unelucidated. This review focuses on the mechanisms by which mammalian Gα subunits of G proteins interact with lipids and the factors responsible for the specificity of membrane association. We summarize recent data on how these signaling proteins are precisely targeted to a specific site in the membrane region by introducing well-defined modifications as well as through the presence of polybasic regions within these proteins and interactions with other components of the heterocomplex.

Interprotein interactions are responsible for the confined diffusion of a G-protein-coupled receptor at the cell surface

2003 ◽  
Vol 31 (5) ◽  
pp. 1001-1005 ◽  
Author(s):  
F. Daumas ◽  
N. Destainville ◽  
C. Millot ◽  
A. Lopez ◽  
D. Dean ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
Domain Size ◽  
Single Particle Tracking ◽  
G Protein Coupled Receptor ◽  
Short Term ◽  
Detailed Statistical Analysis ◽  
G Protein Coupled ◽  
Dynamic Organization

The monitoring of the movements of membrane proteins (or lipids) by single-particle tracking enables one to obtain reliable insights into the complex dynamic organization of the plasma membrane constituents. Using this technique, we investigated the diffusional behaviour of a G-protein-coupled receptor. The trajectories of the receptors revealed a diffusion mode combining a short-term rapid confined diffusion with a long-term slow diffusion. A detailed statistical analysis shows that the receptors have a diffusion confined to a domain which itself diffuses, the confinement being due to long-range attractive inter-protein interactions. The existing models of the dynamic organization of the cell membrane cannot explain our results. We propose a theoretical Brownian model of interacting proteins that is consistent with the experimental observations and accounts for the variations found as a function of the domain size of the short-term and long-term diffusion coefficients.

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