Non-classical amine recognition evolved in a large clade of olfactory receptors

Biogenic amines are important signaling molecules, and the structural basis for their recognition by G Protein-Coupled Receptors (GPCRs) is well understood. Amines are also potent odors, with some activating olfactory trace amine-associated receptors (TAARs). Here, we report that teleost TAARs evolved a new way to recognize amines in a non-classical orientation. Chemical screens de-orphaned eleven zebrafish TAARs, with agonists including serotonin, histamine, tryptamine, 2-phenylethylamine, putrescine, and agmatine. Receptors from different clades contact ligands through aspartates on transmembrane α-helices III (canonical Asp3.32) or V (non-canonical Asp5.42), and diamine receptors contain both aspartates. Non-classical monoamine recognition evolved in two steps: an ancestral TAAR acquired Asp5.42, gaining diamine sensitivity, and subsequently lost Asp3.32. Through this transformation, the fish olfactory system dramatically expanded its capacity to detect amines, ecologically significant aquatic odors. The evolution of a second, alternative solution for amine detection by olfactory receptors highlights the tremendous structural versatility intrinsic to GPCRs.

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Yeast-Based Directed-Evolution For High-Throughput Structural Stabilization of G Protein-Coupled Receptors (GPCRs)

10.21203/rs.3.rs-1066896/v1 ◽

2021 ◽

Author(s):

May Meltzer ◽

Zvagelsky Tatiana ◽

Niv Papo ◽

Stanislav Engel

Keyword(s):

G Protein ◽

Resistant Cell ◽

Single Step ◽

G Protein Coupled Receptors ◽

Structural Basis ◽

Diffusion Method ◽

Structural Stabilization ◽

C Terminus ◽

Screening Platform ◽

G Protein Coupled

Abstract The immense potential of G protein-coupled receptors (GPCRs) as targets for drug discovery is not fully realized due to the enormous difficulties associated with structure elucidation of these profoundly unstable membrane proteins. The existing methods of GPCR stability-engineering are cumbersome and low-throughput; in addition, the scope of GPCRs that could benefit from these techniques is limited. Here, we presented a yeast-based screening platform for a single-step isolation of GRCR variants stable in the presence of short-chain detergents, a feature essential for their successful crystallization using vapor diffusion method. The detergent-resistant cell wall of yeast provides a unique compartmentalization opportunity to physically link the receptor phenotype to its encoding DNA, and thus enable discovery of stable GPCR variants with unprecedent efficiency. The scope of mutations identified by the method offers important insights into the structural basis of GPCR stability, questioning the inherent instability of the GPCR scaffold, and revealing the potential role of the C-terminus in receptor stabilization.

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Structural Basis for Allosteric Modulation of Class B G Protein–Coupled Receptors

The Annual Review of Pharmacology and Toxicology ◽

10.1146/annurev-pharmtox-010919-023301 ◽

2020 ◽

Vol 60 (1) ◽

pp. 89-107 ◽

Cited By ~ 7

Author(s):

Denise Wootten ◽

Laurence J. Miller

Keyword(s):

G Protein ◽

Allosteric Modulation ◽

G Protein Coupled Receptors ◽

Structural Basis ◽

Allosteric Modulators ◽

Class B ◽

Endogenous Proteins ◽

And Function ◽

Agonist Ligands ◽

G Protein Coupled

Recent advances in our understanding of the structure and function of class B G protein–coupled receptors (GPCRs) provide multiple opportunities for targeted development of allosteric modulators. Given the pleiotropic signaling patterns emanating from these receptors in response to a variety of natural agonist ligands, modulators have the potential to sculpt the responses to meet distinct needs of different groups of patients. In this review, we provide insights into how this family of GPCRs differs from the rest of the superfamily, how orthosteric agonists bind and activate these receptors, the potential for allosteric modulators to interact with various regions of these targets, and the allosteric influence of endogenous proteins on the pharmacology of these receptors, all of which are important considerations when developing new therapies.

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Functional Role of the C-Terminal Amphipathic Helix 8 of Olfactory Receptors and Other G Protein-Coupled Receptors

International Journal of Molecular Sciences ◽

10.3390/ijms17111930 ◽

2016 ◽

Vol 17 (11) ◽

pp. 1930 ◽

Cited By ~ 18

Author(s):

Takaaki Sato ◽

Takashi Kawasaki ◽

Shouhei Mine ◽

Hiroyoshi Matsumura

Keyword(s):

G Protein ◽

Functional Role ◽

Olfactory Receptors ◽

G Protein Coupled Receptors ◽

Amphipathic Helix ◽

G Protein Coupled

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Structural Basis for Activation of G-Protein-Coupled Receptors

Pharmacology & Toxicology ◽

10.1034/j.1600-0773.2002.910607.x ◽

2002 ◽

Vol 91 (6) ◽

pp. 304-312 ◽

Cited By ~ 67

Author(s):

Ulrik Gether ◽

Fazila Asmar ◽

Anne Kristine Meinild ◽

Søren G. F. Rasmussen

Keyword(s):

G Protein ◽

G Protein Coupled Receptors ◽

Structural Basis ◽

G Protein Coupled

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Structural Basis of Arrestin Selectivity for Active Phosphorylated G Protein-Coupled Receptors

International Journal of Molecular Sciences ◽

10.3390/ijms222212481 ◽

2021 ◽

Vol 22 (22) ◽

pp. 12481

Author(s):

Preethi C. Karnam ◽

Sergey A. Vishnivetskiy ◽

Vsevolod V. Gurevich

Keyword(s):

G Protein ◽

Receptor Binding ◽

G Protein Coupled Receptors ◽

Structural Basis ◽

Preferential Binding ◽

High Affinity Receptor ◽

Functional Forms ◽

Affinity Receptor ◽

G Protein Coupled ◽

Receptor Conformation

Arrestins are a small family of proteins that bind G protein-coupled receptors (GPCRs). Arrestin binds to active phosphorylated GPCRs with higher affinity than to all other functional forms of the receptor, including inactive phosphorylated and active unphosphorylated. The selectivity of arrestins suggests that they must have two sensors, which detect receptor-attached phosphates and the active receptor conformation independently. Simultaneous engagement of both sensors enables arrestin transition into a high-affinity receptor-binding state. This transition involves a global conformational rearrangement that brings additional elements of the arrestin molecule, including the middle loop, in contact with a GPCR, thereby stabilizing the complex. Here, we review structural and mutagenesis data that identify these two sensors and additional receptor-binding elements within the arrestin molecule. While most data were obtained with the arrestin-1-rhodopsin pair, the evidence suggests that all arrestins use similar mechanisms to achieve preferential binding to active phosphorylated GPCRs.

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Seeing cells smell: Dynamic optical measurements of Ca2+ and cAMP signaling from Olfactory Receptors transiently expressed in HEK293TN cells

10.1101/771261 ◽

2019 ◽

Author(s):

A Pietraszewska-Bogiel ◽

L van Weeren ◽

J Goedhart

Keyword(s):

G Protein ◽

Therapeutic Potential ◽

Olfactory Receptors ◽

Functional Expression ◽

G Protein Coupled Receptors ◽

Optical Measurements ◽

Camp Signaling ◽

Kinetic Measurements ◽

Fluorescent Biosensors ◽

G Protein Coupled

ABSTRACTOlfactory receptors (ORs) constitute the largest family of G-protein coupled receptors. They are responsible for the perception of odor (olfaction) and also play important roles in other biological processes, including regulation of cell proliferation. Their increasing diagnostic and therapeutic potential, especially for cancer research, requests the ongoing development of methodologies that would allow their robust functional expression in non-olfactory cells, and dynamic analysis of their signaling pathways. To enable realtime detection of OR activity, we use single cell imaging with genetically encoded fluorescent biosensors, Yellow Cameleon or EPAC, which are routinely used for kinetic measurements of Ca2+ or cAMP signaling downstream of various G-protein coupled receptors. We demonstrate that the co-expression of Lucy-Rho tagged variants of ORs together with an accessory protein, RTP1s, in HEK293TN cells is sufficient to detect the activity of a panel of ORs. Using this methodology, we were able to detect both Ca2+ and cAMP signaling downstream of twelve ORs within 2 minutes from the application of odorant.

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