scholarly journals MicroED structure of the human adenosine receptor determined from a single nanocrystal in LCP

2020 ◽  
Author(s):  
Michael W. Martynowycz ◽  
Anna Shiriaeva ◽  
Xuanrui Ge ◽  
Johan Hattne ◽  
Brent L. Nannenga ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
G Protein Coupled Receptors ◽  
Cubic Phase ◽  
Transmembrane Receptors ◽  
X Ray ◽  
X Ray Crystallography ◽  
Physiological Processes ◽  
Sponge Phase ◽  
Traditional Approaches ◽  
G Protein Coupled

AbstractG Protein-Coupled Receptors (GPCRs), or 7-transmembrane receptors, are a superfamily of membrane proteins that are critically important to physiological processes in the human body. Determining high-resolution structures of GPCRs without signaling partners bound requires crystallization in lipidic cubic phase (LCP). GPCR crystals grown in LCP are often too small for traditional X-ray crystallography. These microcrystals are ideal for investigation by microcrystal electron diffraction (MicroED), but the gel-like nature of LCP makes traditional approaches to MicroED sample preparation insurmountable. Here we show that the structure of a human A2A adenosine receptor can be determined by MicroED after converting the LCP into the sponge phase followed by cryoFIB milling. We determined the structure of the A2A receptor to 2.8 Å resolution and resolved an antagonist in its orthosteric ligand-binding site as well as 4 cholesterol molecules bound to the receptor. This study lays the groundwork for future GPCR structural studies using single microcrystals that would otherwise be impossible by other crystallographic methods.One sentence summaryFIB milled LCP-GPCR structure determined by MicroED

scholarly journals MicroED structure of the human adenosine receptor determined from a single nanocrystal in LCP

2021 ◽  
Vol 118 (36) ◽  
pp. e2106041118
Author(s):  
Michael W. Martynowycz ◽  
Anna Shiriaeva ◽  
Xuanrui Ge ◽  
Johan Hattne ◽  
Brent L. Nannenga ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
G Protein ◽  
Adenosine Receptor ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cubic Phase ◽  
Transmembrane Receptors ◽  
X Ray Crystallography ◽  
Physiological Processes ◽  
Traditional Approaches

G protein–coupled receptors (GPCRs), or seven-transmembrane receptors, are a superfamily of membrane proteins that are critically important to physiological processes in the human body. Determining high-resolution structures of GPCRs without bound cognate signaling partners, such as a G protein, requires crystallization in lipidic cubic phase (LCP). GPCR crystals grown in LCP are often too small for traditional X-ray crystallography. These microcrystals are ideal for investigation by microcrystal electron diffraction (MicroED), but the gel-like nature of LCP makes traditional approaches to MicroED sample preparation insurmountable. Here, we show that the structure of a human A2A adenosine receptor can be determined by MicroED after converting the LCP into the sponge phase followed by focused ion-beam milling. We determined the structure of the A2A adenosine receptor to 2.8-Å resolution and resolved an antagonist in its orthosteric ligand-binding site, as well as four cholesterol molecules bound around the receptor. This study lays the groundwork for future structural studies of lipid-embedded membrane proteins by MicroED using single microcrystals that would be impossible with other crystallographic methods.

scholarly journals Rastering strategy for screening and centring of microcrystal samples of human membrane proteins with a sub-10 µm size X-ray synchrotron beam

2009 ◽  
Vol 6 (suppl_5) ◽  
Author(s):  
Vadim Cherezov ◽  
Michael A. Hanson ◽  
Mark T. Griffith ◽  
Mark C. Hilgart ◽  
Ruslan Sanishvili ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
G Protein Coupled Receptors ◽  
Cubic Phase ◽  
High Quality ◽  
Crystal Sample ◽  
X Ray ◽  
Synchrotron Beam ◽  
Lipidic Cubic Phase ◽  
Diffraction Patterns ◽  
G Protein Coupled

Crystallization of human membrane proteins in lipidic cubic phase often results in very small but highly ordered crystals. Advent of the sub-10 µm minibeam at the APS GM/CA CAT has enabled the collection of high quality diffraction data from such microcrystals. Herein we describe the challenges and solutions related to growing, manipulating and collecting data from optically invisible microcrystals embedded in an opaque frozen in meso material. Of critical importance is the use of the intense and small synchrotron beam to raster through and locate the crystal sample in an efficient and reliable manner. The resulting diffraction patterns have a significant reduction in background, with strong intensity and improvement in diffraction resolution compared with larger beam sizes. Three high-resolution structures of human G protein-coupled receptors serve as evidence of the utility of these techniques that will likely be useful for future structural determination efforts. We anticipate that further innovations of the technologies applied to microcrystallography will enable the solving of structures of ever more challenging targets.

scholarly journals Serial Femtosecond Crystallography of G Protein–Coupled Receptors

2018 ◽  
Vol 47 (1) ◽  
pp. 377-397 ◽  
Author(s):  
Benjamin Stauch ◽  
Vadim Cherezov
Keyword(s):  
G Protein ◽  
G Protein Coupled Receptors ◽  
Structural Studies ◽  
Body Structure ◽  
X Ray ◽  
Physiological Processes ◽  
Recent Emergence ◽  
Mediate Cell ◽  
G Protein Coupled ◽  
Serial Femtosecond Crystallography

G protein–coupled receptors (GPCRs) represent a large superfamily of membrane proteins that mediate cell signaling and regulate a variety of physiological processes in the human body. Structure-function studies of this superfamily were enabled a decade ago by multiple breakthroughs in technology that included receptor stabilization, crystallization in a membrane environment, and microcrystallography. The recent emergence of X-ray free-electron lasers (XFELs) has further accelerated structural studies of GPCRs and other challenging proteins by overcoming radiation damage and providing access to high-resolution structures and dynamics using micrometer-sized crystals. Here, we summarize key technology advancements and major milestones of GPCR research using XFELs and provide a brief outlook on future developments in the field.

scholarly journals ‘Hit and run’ serial femtosecond crystallography of a membrane kinase in the lipid cubic phase

2014 ◽  
Vol 369 (1647) ◽  
pp. 20130621 ◽  
Author(s):  
Martin Caffrey ◽  
Dianfan Li ◽  
Nicole Howe ◽  
Syed T. A. Shah
Keyword(s):  
Membrane Proteins ◽  
Long Range ◽  
Range Order ◽  
Cubic Phase ◽  
Long Range Order ◽  
It Use ◽  
X Ray ◽  
X Ray Crystallography ◽  
Sponge Phase ◽  
Serial Femtosecond Crystallography

The lipid-based bicontinuous cubic mesophase is a nanoporous membrane mimetic with applications in areas that include medicine, personal care products, foods and the basic sciences. An application of particular note concerns it use as a medium in which to grow crystals of membrane proteins for structure determination by X-ray crystallography. At least two variations of the mesophase exist. One is the highly viscous cubic phase, which has well developed long-range order. The other so-called sponge phase is considerably more fluid and lacks long-range order. The sponge phase has recently been shown to be a convenient vehicle for delivering microcrystals of membrane proteins to an X-ray free-electron laser beam for serial femtosecond crystallography (SFX). Unfortunately, the sponge phase approach calls for large amounts of protein that are not always available in the case of membrane proteins. The cubic phase offers the advantage of requiring significantly less protein for SFX but comes with its own challenges. Here, we describe the physico-chemical bases for these challenges, solutions to them and prospects for future uses of lipidic mesophases in the SFX arena.

A study of membrane lipids from dehydration-acclimated Brassica napus root cells: formation of a cubic phase under physiological conditions

1990 ◽  
Vol 68 (1) ◽  
pp. 102-105 ◽  
Author(s):  
P. Norberg ◽  
K. Larsson ◽  
C. Liljenberg
Keyword(s):  
Water Deficit ◽  
Membrane Lipids ◽  
Phase Behaviour ◽  
Water Deficit Stress ◽  
Cubic Phase ◽  
Polarization Microscopy ◽  
Root Cells ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microsomal Membranes

Rape seedlings were acclimated to evaporative dehydration by exposure to repeated moderate water-deficit stress. The stress program started after 19 days of growth and consisted of three, 24-h stress periods interspersed with 24-h rewatering periods. After the third stress period the roots were harvested and microsomal membranes were isolated. Control plants were grown under equivalent conditions without stress (nonacclimated cells). Total lipids were extracted from the membranes and investigated with X-ray crystallography and polarization microscopy at different degrees of hydration and temperatures. In excess water, the membrane lipids from both acclimated and nonacclimated cells exhibited a cubic phase. The lipids from the nonacclimated cells formed a hexagonal (HII) phase on dehydration. The lipids from the acclimated cells behaved in a different way during dehydration, where the cubic phase was transformed to an L2 phase via an intermediate HII phase. At increasing temperatures, the hydrated cubic phase started to form an L2 phase at 30 °C and was fully converted to the liquid-type state at 42 °C. The mesomorphic phase behaviour is discussed in relation to membrane activity.Key words: water-deficit stress, microsomal membranes, X-ray crystallography, polarization microscopy.

Compartmentalization of GPCR signalling controls unique cellular responses

2016 ◽  
Vol 44 (2) ◽  
pp. 562-567 ◽  
Author(s):  
Andrew M. Ellisdon ◽  
Michelle L. Halls
Keyword(s):  
Drug Discovery ◽  
Drug Targets ◽  
Cell Types ◽  
G Protein Coupled Receptors ◽  
Attrition Rates ◽  
Physiological Processes ◽  
Simple Chain ◽  
G Protein Coupled ◽  
Major Drug ◽  
Very High

With >800 members, G protein-coupled receptors (GPCRs) are the largest class of cell-surface signalling proteins, and their activation mediates diverse physiological processes. GPCRs are ubiquitously distributed across all cell types, involved in many diseases and are major drug targets. However, GPCR drug discovery is still characterized by very high attrition rates. New avenues for GPCR drug discovery may be provided by a recent shift away from the traditional view of signal transduction as a simple chain of events initiated from the plasma membrane. It is now apparent that GPCR signalling is restricted to highly organized compartments within the cell, and that GPCRs activate distinct signalling pathways once internalized. A high-resolution understanding of how compartmentalized signalling is controlled will probably provide unique opportunities to selectively and therapeutically target GPCRs.

scholarly journals The Role of Prokineticin 2 in Oxidative Stress and in Neuropathological Processes

2021 ◽  
Vol 12 ◽  
Author(s):  
Roberta Lattanzi ◽  
Cinzia Severini ◽  
Daniela Maftei ◽  
Luciano Saso ◽  
Aldo Badiani
Keyword(s):  
Pain Perception ◽  
G Protein Coupled Receptors ◽  
Cellular Processes ◽  
Prokineticin 2 ◽  
Physiological Processes ◽  
Pathological Conditions ◽  
Double Function ◽  
The Central Nervous System ◽  
G Protein Coupled

The prokineticin (PK) family, prokineticin 1 and Bv8/prokineticin 2 (PROK2), initially discovered as regulators of gastrointestinal motility, interacts with two G protein-coupled receptors, PKR1 and PKR2, regulating important biological functions such as circadian rhythms, metabolism, angiogenesis, neurogenesis, muscle contractility, hematopoiesis, immune response, reproduction and pain perception. PROK2 and PK receptors, in particular PKR2, are widespread distributed in the central nervous system, in both neurons and glial cells. The PROK2 expression levels can be increased by a series of pathological insults, such as hypoxia, reactive oxygen species, beta amyloid and excitotoxic glutamate. This suggests that the PK system, participating in different cellular processes that cause neuronal death, can be a key mediator in neurological/neurodegenerative diseases. While many PROK2/PKRs effects in physiological processes have been documented, their role in neuropathological conditions is not fully clarified, since PROK2 can have a double function in the mechanisms underlying to neurodegeneration or neuroprotection. Here, we briefly outline the latest findings on the modulation of PROK2 and its cognate receptors following different pathological insults, providing information about their opposite neurotoxic and neuroprotective role in different pathological conditions.

Identification Methods of G Protein-Coupled Receptors

2011 ◽  
Vol 2 (4) ◽  
pp. 35-52
Author(s):  
Meriem Zekri ◽  
Karima Alem ◽  
Labiba Souici-Meslati
Keyword(s):  
Immune Responses ◽  
G Protein ◽  
Pharmaceutical Research ◽  
G Protein Coupled Receptors ◽  
Machine Learning Algorithms ◽  
Signaling Networks ◽  
Identification Methods ◽  
Physiological Processes ◽  
Cell Signaling Networks ◽  
G Protein Coupled

The G protein-coupled receptors (GPCRs) include one of the largest and most important families of multifunctional proteins known to molecular biology. They play a key role in cell signaling networks that regulate many physiological processes, such as vision, smell, taste, neurotransmission, secretion, immune responses, metabolism, and cell growth. These proteins are thus very important for understanding human physiology and they are involved in several diseases. Therefore, many efforts in pharmaceutical research are to understand their structures and functions, which is not an easy task, because although thousands GPCR sequences are known, many of them remain orphans. To remedy this, many methods have been developed using methods such as statistics, machine learning algorithms, and bio-inspired approaches. In this article, the authors review the approaches used to develop algorithms for classification GPCRs by trying to highlight the strengths and weaknesses of these different approaches and providing a comparison of their performances.

scholarly journals Characterization and Expression Profiling of Neuropeptides and G-Protein-Coupled Receptors (GPCRs) for Neuropeptides in the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Psyllidae)

2018 ◽  
Vol 19 (12) ◽  
pp. 3912 ◽  
Author(s):  
Zhengbing Wang ◽  
Wenwu Zhou ◽  
Muhammad Hameed ◽  
Jiali Liu ◽  
Xinnian Zeng
Keyword(s):  
G Protein ◽  
Developmental Stages ◽  
G Protein Coupled Receptors ◽  
Nerve Tissue ◽  
Asian Citrus Psyllid ◽  
Diaphorina Citri ◽  
Physiological Processes ◽  
Neuropeptide Receptors ◽  
G Protein Coupled ◽  
Active Substances

Neuropeptides are endogenous active substances that widely exist in multicellular biological nerve tissue and participate in the function of the nervous system, and most of them act on neuropeptide receptors. In insects, neuropeptides and their receptors play important roles in controlling a multitude of physiological processes. In this project, we sequenced the transcriptome from twelve tissues of the Asian citrus psyllid, Diaphorina citri Kuwayama. A total of 40 candidate neuropeptide genes and 42 neuropeptide receptor genes were identified. Among the neuropeptide receptor genes, 35 of them belong to the A-family (or rhodopsin-like), four of them belong to the B-family (or secretin-like), and three of them are leucine-rich repeat-containing G-protein-coupled receptors. The expression profile of the 82 genes across developmental stages was determined by qRT-PCR. Our study provides the first investigation on the genes of neuropeptides and their receptors in D. citri, which may play key roles in regulating the physiology and behaviors of D. citri.

G-Protein-Coupled Receptors in Drug Discovery: Nanosizing Using Cell-Free Technologies and Molecular Biology Approaches

2005 ◽  
Vol 10 (8) ◽  
pp. 765-779 ◽  
Author(s):  
Wayne R. Leifert ◽  
Amanda L. Aloia ◽  
Olgatina Bucco ◽  
Richard V. Glatz ◽  
Edward J. McMurchie
Keyword(s):  
Signal Transduction ◽  
G Protein ◽  
Drug Targets ◽  
G Protein Coupled Receptors ◽  
Orphan Receptors ◽  
Molecular Switching ◽  
Physiological Processes ◽  
Current Cell ◽  
G Protein Coupled ◽  
Signaling Components

Signal transduction by G-protein-coupled receptors (GPCRs) underpins a multitude of physiological processes. Ligand recognition by the receptor leads to activation of a genericmolecular switch involving heterotrimeric G-proteins and guanine nucleotides. Signal transduction has been studied extensively with both cell-based systems and assays comprising isolated signaling components. Interest and commercial investment in GPCRs in areas such as drug targets, orphan receptors, highthroughput screening, biosensors, and so on will focus greater attention on assay development to allow for miniaturization, ultra-high throughput and, eventually, microarray/biochip assay formats. Although cell-based assays are adequate for many GPCRs, it is likely that these formatswill limit the development of higher density GPCRassay platforms mandatory for other applications. Stable, robust, cell-free signaling assemblies comprising receptor and appropriate molecular switching components will form the basis of future GPCR assay platforms adaptable for such applications as microarrays. The authors review current cell-free GPCR assay technologies and molecular biological approaches for construction of novel, functional GPCR assays.

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