Faculty Opinions recommendation of Asymmetric conformational changes in a GPCR dimer controlled by G-proteins.

2006 ◽  
Author(s):  
Ralf Jockers
Keyword(s):  
G Proteins ◽  
Conformational Changes ◽  
Gpcr Dimer

scholarly journals Asymmetric conformational changes in a GPCR dimer controlled by G-proteins

2006 ◽  
Vol 25 (24) ◽  
pp. 5693-5702 ◽  
Author(s):  
Marjorie Damian ◽  
Aimée Martin ◽  
Danielle Mesnier ◽  
Jean-Philippe Pin ◽  
Jean-Louis Banères
Keyword(s):  
G Proteins ◽  
Conformational Changes ◽  
Gpcr Dimer

scholarly journals Characterisation of Antibody Interactions with the G Protein of Vesicular Stomatitis Virus Indiana Strain and Other Vesiculovirus G Proteins

2018 ◽  
Author(s):  
Altar M Munis ◽  
Maha Tijani ◽  
Mark Hassall ◽  
Giada Mattiuzzo ◽  
Mary K Collins ◽  
...  
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Vesicular Stomatitis Virus ◽  
Conformational Changes ◽  
Lentiviral Vectors ◽  
Medicinal Products ◽  
Vaccine Vectors ◽  
Receptor Binding Site ◽  
Advanced Therapy ◽  
Vesicular Stomatitis

ABSTRACTVesicular stomatitis virus Indiana strain G protein (VSVind.G) is the most commonly used envelope glycoprotein to pseudotype lentiviral vectors (LV) for experimental and clinical applications. Recently, G proteins derived from other vesiculoviruses (VesG), for example Cocal virus, have been proposed as alternative LV envelopes with possible advantages compared to VSVind.G. Well-characterised antibodies that recognise VesG will be useful for vesiculovirus research, development of G protein-containing advanced therapy medicinal products (ATMPs), and deployment of VSVind-based vaccine vectors. Here we show that one commercially available monoclonal antibody, 8G5F11, binds to and neutralises G proteins from three strains of VSV as well as Cocal, and Maraba viruses, whereas the other commercially available monoclonal anti-VSVind.G antibody, IE9F9, binds to and neutralises only VSVind.G. Using a combination of G protein chimeras and site-directed mutations, we mapped the binding epitopes of IE9F9 and 8G5F11 on VSVind.G. IE9F9 binds close to the receptor binding site and competes with soluble low-density lipoprotein receptor (LDLR) for binding to VSVind.G, explaining its mechanism of neutralisation. In contrast, 8G5F11 binds close to a region known to undergo conformational changes when the G protein moves to its post-fusion structure, and we propose that 8G5F11 cross-neutralises VesGs by inhibiting this.IMPORTANCEVSVind.G is currently regarded as the gold-standard envelope to pseudotype lentiviral vectors. However, recently other G proteins derived from vesiculoviruses have been proposed as alternative envelopes. Here, we investigated two anti-VSVind.G monoclonal antibodies for their ability to cross-react with other vesiculovirus G proteins, and identified the epitopes they recognise, and explored the mechanisms behind their neutralisation activity. Understanding how cross-neutralising antibodies interact with other G proteins may be of interest in the context of host-pathogen interaction and co-evolution as well as providing the opportunity to modify the G proteins and improve G protein-containing medicinal products and vaccine vectors.

scholarly journals Class Frizzled GPCRs (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Elisa Arthofer ◽  
Jacomijn Dijksterhuis ◽  
Belma Hot ◽  
Paweł Kozielewicz ◽  
Matthias Lauth ◽  
...  
Keyword(s):  
G Proteins ◽  
Conformational Changes ◽  
Hedgehog Signaling ◽  
Cell Signalling ◽  
Resonance Energy Transfer ◽  
Rho Kinase ◽  
Density Lipoprotein ◽  
Resonance Energy ◽  
Scaffolding Protein ◽  
Heterotrimeric G Proteins

Receptors of the Class Frizzled (FZD, nomenclature as agreed by the NC-IUPHAR subcommittee on the Class Frizzled GPCRs [156]), are GPCRs originally identified in Drosophila [17], which are highly conserved across species. While SMO shows structural resemblance to the 10 FZDs, it is functionally separated as it mediates effects in the Hedgehog signaling pathway [156]. FZDs are activated by WNTs, which are cysteine-rich lipoglycoproteins with fundamental functions in ontogeny and tissue homeostasis. FZD signalling was initially divided into two pathways, being either dependent on the accumulation of the transcription regulator β-catenin or being β-catenin-independent (often referred to as canonical vs. non-canonical WNT/FZD signalling, respectively). WNT stimulation of FZDs can, in cooperation with the low density lipoprotein receptors LRP5 (O75197) and LRP6 (O75581), lead to the inhibition of a constitutively active destruction complex, which results in the accumulation of β-catenin and subsequently its translocation to the nucleus. β-Catenin, in turn, modifies gene transcription by interacting with TCF/LEF transcription factors. β-Catenin-independent FZD signalling is far more complex with regard to the diversity of the activated pathways. WNT/FZD signalling can lead to the activation of heterotrimeric G proteins [28, 159, 135], the elevation of intracellular calcium [164], activation of cGMP-specific PDE6 [2] and elevation of cAMP as well as RAC-1, JNK, Rho and Rho kinase signalling [48]. Novel resonance energy transfer-based tools have allowed the study of the GPCR-like nature of FZDs in greater detail. Upon ligand stimulation, FZDs undergo conformational changes and signal via heterotrimeric G proteins [213, 214]. Furthermore, the phosphoprotein Dishevelled constitutes a key player in WNT/FZD signalling. Importantly, FZDs exist in at least two distinct conformational states that regulate the pathway selection [214]. As with other GPCRs, members of the Frizzled family are functionally dependent on the arrestin scaffolding protein for internalization [19], as well as for β-catenin-dependent [12] and -independent [80, 13] signalling. The pattern of cell signalling is complicated by the presence of additional ligands, which can enhance or inhibit FZD signalling (secreted Frizzled-related proteins (sFRP), Wnt-inhibitory factor (WIF), sclerostin or Dickkopf (DKK)), as well as modulatory (co)-receptors with Ryk, ROR1, ROR2 and Kremen, which may also function as independent signalling proteins.

scholarly journals Roco Proteins and the Parkinson’s Disease-Associated LRRK2

2018 ◽  
Vol 19 (12) ◽  
pp. 4074 ◽  
Author(s):  
Jingling Liao ◽  
Quyen Hoang
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
G Proteins ◽  
Conformational Changes ◽  
Effector Proteins ◽  
Cellular Processes ◽  
Current State ◽  
Specific Effector ◽  
Unique Domain ◽  
Small G Proteins

Small G-proteins are structurally-conserved modules that function as molecular on-off switches. They function in many different cellular processes with differential specificity determined by the unique effector-binding surfaces, which undergo conformational changes during the switching action. These switches are typically standalone monomeric modules that form transient heterodimers with specific effector proteins in the ‘on’ state, and cycle to back to the monomeric conformation in the ‘off’ state. A new class of small G-proteins called “Roco” was discovered about a decade ago; this class is distinct from the typical G-proteins in several intriguing ways. Their switch module resides within a polypeptide chain of a large multi-domain protein, always adjacent to a unique domain called COR, and its effector kinase often resides within the same polypeptide. As such, the mechanisms of action of the Roco G-proteins are likely to differ from those of the typical G-proteins. Understanding these mechanisms is important because aberrant activity in the human Roco protein LRRK2 is associated with the pathogenesis of Parkinson’s disease. This review provides an update on the current state of our understanding of the Roco G-proteins and the prospects of targeting them for therapeutic purposes.

Overcoming autoinhibition

2020 ◽  
Vol 13 (632) ◽  
pp. eabc8254
Author(s):  
John F. Foley
Keyword(s):  
G Proteins ◽  
Conformational Changes ◽  
Terminal Region

Conformational changes in the C-terminal region of PLC-β2 caused by G proteins release autoinhibition.

scholarly journals Allosteric control of an asymmetric transduction in a G protein-coupled receptor heterodimer

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Junke Liu ◽  
Zongyong Zhang ◽  
David Moreno-Delgado ◽  
James AR Dalton ◽  
Xavier Rovira ◽  
...  
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Cell Communication ◽  
Allosteric Modulators ◽  
Protein Activation ◽  
Metabotropic Glutamate ◽  
Allosteric Control ◽  
G Protein Activation ◽  
Gpcr Dimer ◽  
G Protein Coupled

GPCRs play critical roles in cell communication. Although GPCRs can form heteromers, their role in signaling remains elusive. Here we used rat metabotropic glutamate (mGlu) receptors as prototypical dimers to study the functional interaction between each subunit. mGluRs can form both constitutive homo- and heterodimers. Whereas both mGlu2 and mGlu4 couple to G proteins, G protein activation is mediated by mGlu4 heptahelical domain (HD) exclusively in mGlu2-4 heterodimers. Such asymmetric transduction results from the action of both the dimeric extracellular domain, and an allosteric activation by the partially-activated non-functional mGlu2 HD. G proteins activation by mGlu2 HD occurs if either the mGlu2 HD is occupied by a positive allosteric modulator or if mGlu4 HD is inhibited by a negative modulator. These data revealed an oriented asymmetry in mGlu heterodimers that can be controlled with allosteric modulators. They provide new insight on the allosteric interaction between subunits in a GPCR dimer.

scholarly journals Comprehensive analysis of heterotrimeric G-protein complex diversity and their interactions with GPCRs in solution

2015 ◽  
Vol 112 (11) ◽  
pp. E1181-E1190 ◽  
Author(s):  
Matthias Hillenbrand ◽  
Christian Schori ◽  
Jendrik Schöppe ◽  
Andreas Plückthun
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Conformational Changes ◽  
Protein Complex ◽  
Protein Complexes ◽  
Heterotrimeric G Proteins ◽  
Agonist Binding ◽  
Transient Nature ◽  
The Stability ◽  
Neurotensin Receptor 1

Agonist binding to G-protein–coupled receptors (GPCRs) triggers signal transduction cascades involving heterotrimeric G proteins as key players. A major obstacle for drug design is the limited knowledge of conformational changes upon agonist binding, the details of interaction with the different G proteins, and the transmission to movements within the G protein. Although a variety of different GPCR/G protein complex structures would be needed, the transient nature of this complex and the intrinsic instability against dissociation make this endeavor very challenging. We have previously evolved GPCR mutants that display higher stability and retain their interaction with G proteins. We aimed at finding all G-protein combinations that preferentially interact with neurotensin receptor 1 (NTR1) and our stabilized mutants. We first systematically analyzed by coimmunoprecipitation the capability of 120 different G-protein combinations consisting of αi1or αsLand all possible βγ-dimers to form a heterotrimeric complex. This analysis revealed a surprisingly unrestricted ability of the G-protein subunits to form heterotrimeric complexes, including βγ-dimers previously thought to be nonexistent, except for combinations containing β5. A second screen on coupling preference of all G-protein heterotrimers to NTR1 wild type and a stabilized mutant indicated a preference for those Gαi1βγ combinations containing γ1and γ11. Heterotrimeric G proteins, including combinations believed to be nonexistent, were purified, and complexes with the GPCR were prepared. Our results shed new light on the combinatorial diversity of G proteins and their coupling to GPCRs and open new approaches to improve the stability of GPCR/G-protein complexes.

Analysis of GTP-Binding Protein–Coupled Receptor Assemblies by Flow Cytometry

2005 ◽  
Author(s):  
Peter Simons ◽  
Charlotte M. Vines
Keyword(s):  
G Proteins ◽  
Conformational Changes ◽  
Prescription Drugs ◽  
Binding Protein ◽  
Receptor Internalization ◽  
Traditional Role ◽  
Gtp Binding Protein ◽  
Alpha Helices ◽  
Gtp Binding ◽  
Associated Proteins

GTP-binding protein–coupled receptors (GPCRs) represent the largest family of integral membrane signal-transducing molecules in the human genome, with estimates of at least 600 members. As such, they represent the targets of approximately 30%–50% of the prescription drugs on the market. They are involved in virtually every physiological process in the human body, with ligands including light, odorants, amines, peptides, proteins, lipids, and nucleotides. Binding of these ligands on the extracellular surface of the receptor leads to conformational changes within the receptor, resulting in a multitude of cellular responses. GPCRs, as their name implies, function through the actions of heterotrimeric GTP-binding proteins (G proteins). These G proteins then couple to a diverse array of effector molecules at the cell surface and inside the cell. GPCRs contain a common structural motif, with seven transmembrane alpha helices. With the recent description of the three-dimensional crystal structure of rhodopsin in its inactive state, a greater, though still incomplete, understanding of the functions of this receptor family has been achieved. In addition to the activation of G proteins, GPCRs undergo extensive regulation mediated primarily by a variety of kinases, including second messenger kinases and the family of G protein–coupled receptor kinases (GRKs). Following receptor phosphorylation by GRKs, additional proteins named arrestins associate with GPCRs. The traditional role of these molecules has been to serve as desensitizing agents, preventing further association of the receptor with G proteins. However, recent studies have demonstrated that arrestins can serve as adapters in the process of receptor internalization as well as scaffolds in the activation of numerous kinase pathways. Interactions between GPCRs and cellular proteins such as adaptins, rab GTPases, phosphatases, and ion channels have also been described. Thus, it has become apparent that understanding the interactions between GPCRs and their associated proteins is critical for any detailed understanding of receptor function. An overview of the activation and regulation of GPCRs is shown in figure 17.1 to provide a context for the approaches to be described in the remainder of this chapter.

A genetically encoded small-size fluorescent pair reveals allosteric conformational changes of G proteins upon its interaction with GPCRs by fluorescence lifetime based FRET

2020 ◽  
Vol 56 (51) ◽  
pp. 6941-6944
Author(s):  
Pan Shi ◽  
Yanan Zhang ◽  
Pei Lv ◽  
Wei Fang ◽  
Shenglong Ling ◽  
...  
Keyword(s):  
G Proteins ◽  
Conformational Changes ◽  
Fluorescence Lifetime

A genetically encoded small-size fluorescent pair to reveal the conformational changes of G proteins upon binding GPCRs by fluorescence lifetime based FRET.

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