Tyrosine phosphorylation of S1PR1 leads to chaperone BiP-mediated import to the endoplasmic reticulum

Cell surface G protein–coupled receptors (GPCRs), upon agonist binding, undergo serine–threonine phosphorylation, leading to either receptor recycling or degradation. Here, we show a new fate of GPCRs, exemplified by ER retention of sphingosine-1-phosphate receptor 1 (S1PR1). We show that S1P phosphorylates S1PR1 on tyrosine residue Y143, which is associated with recruitment of activated BiP from the ER into the cytosol. BiP then interacts with endocytosed Y143-S1PR1 and delivers it into the ER. In contrast to WT-S1PR1, which is recycled and stabilizes the endothelial barrier, phosphomimicking S1PR1 (Y143D-S1PR1) is retained by BiP in the ER and increases cytosolic Ca2+ and disrupts barrier function. Intriguingly, a proinflammatory, but non-GPCR agonist, TNF-α, also triggered barrier-disruptive signaling by promoting S1PR1 phosphorylation on Y143 and its import into ER via BiP. BiP depletion restored Y143D-S1PR1 expression on the endothelial cell surface and rescued canonical receptor functions. Findings identify Y143-phosphorylated S1PR1 as a potential target for prevention of endothelial barrier breakdown under inflammatory conditions.

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Understudied G Protein-Coupled Receptors in the Kidney

Nephron ◽

10.1159/000517355 ◽

2021 ◽

pp. 1-4

Author(s):

Nathan A. Zaidman ◽

Jennifer L. Pluznick

Keyword(s):

Renal Function ◽

Cell Surface ◽

Gene Family ◽

G Protein ◽

External Environment ◽

G Protein Coupled Receptors ◽

Surface Proteins ◽

Cell Surface Proteins ◽

Large Subset ◽

G Protein Coupled

G protein-coupled receptors (GPCRs) are cell surface proteins which play a key role in allowing cells, tissues, and organs to respond to changes in the external environment in order to maintain homeostasis. Despite the fact that GPCRs are known to play key roles in a variety of tissues, there are a large subset of GPCRs that remain poorly studied. In this minireview, we will summarize what is known regarding the “understudied” GPCRs with respect to renal function, and in so doing will highlight the promise represented by studying this gene family.

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Integrating High-Content Analysis into a Multiplexed Screening Approach to Identify and Characterize GPCR Agonists

CrossRef Listing of Deleted DOIs ◽

10.1177/1087057114533146 ◽

2014 ◽

Vol 19 (7) ◽

pp. 1079-1089 ◽

Cited By ~ 6

Author(s):

Yingjie Zhu ◽

John Watson ◽

Mengjie Chen ◽

Ding Ren Shen ◽

Melissa Yarde ◽

...

Keyword(s):

Drug Discovery ◽

G Protein Coupled Receptors ◽

High Content Imaging ◽

Biased Agonism ◽

Receptor Oligomerization ◽

Sphingosine 1 Phosphate ◽

High Content Analysis ◽

Screening Assays ◽

Hit Identification ◽

G Protein Coupled

G protein–coupled receptors (GPCRs) are one of the most popular and proven target classes for therapeutic intervention. The increased appreciation for allosteric modulation, receptor oligomerization, and biased agonism has led to the development of new assay platforms that seek to capitalize on these aspects of GPCR biology. High-content screening is particularly well suited for GPCR drug discovery given the ability to image and quantify changes in multiple cellular parameters, to resolve subcellular structures, and to monitor events within a physiologically relevant environment. Focusing on the sphingosine-1-phosphate (S1P1) receptor, we evaluated the utility of high-content approaches in hit identification efforts by developing and applying assays to monitor β-arrestin translocation, GPCR internalization, and GPCR recycling kinetics. Using these approaches in combination with more traditional GPCR screening assays, we identified compounds whose unique pharmacological profiles would have gone unnoticed if using a single platform. In addition, we identified a compound that induces an atypical pattern of β-arrestin translocation and GPCR recycling kinetics. Our results highlight the value of high-content imaging in GPCR drug discovery efforts and emphasize the value of a multiassay approach to study pharmacological properties of compounds of interest.

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Signaling of sphingosine-1-phosphate via the S1P/EDG-family of G-protein-coupled receptors

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids ◽

10.1016/s1388-1981(02)00139-7 ◽

2002 ◽

Vol 1582 (1-3) ◽

pp. 72-80 ◽

Cited By ~ 227

Author(s):

M Kluk

Keyword(s):

G Protein ◽

G Protein Coupled Receptors ◽

Sphingosine 1 Phosphate ◽

G Protein Coupled

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Sphingosine 1-phosphate signalling through the G-protein-coupled receptor Edg-1

Biochemical Journal ◽

10.1042/bj3300605 ◽

1998 ◽

Vol 330 (2) ◽

pp. 605-609 ◽

Cited By ~ 181

Author(s):

C. M. Gerben ZONDAG ◽

R. Friso POSTMA ◽

Ingrid VAN ETTEN ◽

Ingrid VERLAAN ◽

H. Wouter MOOLENAAR

Keyword(s):

Adenylate Cyclase ◽

Map Kinase ◽

G Protein ◽

G Protein Coupled Receptors ◽

Lpa Receptor ◽

Kinase Activation ◽

Protein Map ◽

Mitogen Activated Protein ◽

Sphingosine 1 Phosphate ◽

G Protein Coupled

Sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) are structurally related lipid mediators that act on distinct G-protein-coupled receptors to evoke similar responses, including Ca2+ mobilization, adenylate cyclase inhibition, and mitogen-activated protein (MAP) kinase activation. However, little is still known about the respective receptors. A recently cloned putative LPA receptor (Vzg-1/Edg-2) is similar to an orphan Gi-coupled receptor termed Edg-1. Here we show that expression of Edg-1 in Sf9 and COS-7 cells results in inhibition of adenylate cyclase and activation of MAP kinase (Gi-mediated), but not Ca2+ mobilization, in response to S1P. These responses are specific in that (i) S1P action is not mimicked by LPA, and (ii) Vzg-1/Edg-2 cannot substitute for Edg-1. Thus the Edg-1 receptor is capable of mediating a subset of the cellular responses to S1P.

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ADP-Ribosylation Factors Modulate the Cell Surface Transport of G Protein-Coupled Receptors

Journal of Pharmacology and Experimental Therapeutics ◽

10.1124/jpet.109.161489 ◽

2010 ◽

Vol 333 (1) ◽

pp. 174-183 ◽

Cited By ~ 32

Author(s):

Chunmin Dong ◽

Xiaoping Zhang ◽

Fuguo Zhou ◽

Huijuan Dou ◽

Matthew T. Duvernay ◽

...

Keyword(s):

Cell Surface ◽

G Protein ◽

G Protein Coupled Receptors ◽

Surface Transport ◽

Adp Ribosylation ◽

G Protein Coupled

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S1P/S1P Receptor Signaling in Neuromuscolar Disorders

International Journal of Molecular Sciences ◽

10.3390/ijms20246364 ◽

2019 ◽

Vol 20 (24) ◽

pp. 6364 ◽

Cited By ~ 2

Author(s):

Elisabetta Meacci ◽

Mercedes Garcia-Gil

Keyword(s):

Neuromuscular Diseases ◽

Clinical Applications ◽

G Protein Coupled Receptors ◽

Receptor Signaling ◽

Charcot Marie Tooth Disease ◽

System Degeneration ◽

Sphingosine 1 Phosphate ◽

S1p Receptor ◽

G Protein Coupled ◽

Tooth Disease

The bioactive sphingolipid metabolite, sphingosine 1-phosphate (S1P), and the signaling pathways triggered by its binding to specific G protein-coupled receptors play a critical regulatory role in many pathophysiological processes, including skeletal muscle and nervous system degeneration. The signaling transduced by S1P binding appears to be much more complex than previously thought, with important implications for clinical applications and for personalized medicine. In particular, the understanding of S1P/S1P receptor signaling functions in specific compartmentalized locations of the cell is worthy of being better investigated, because in various circumstances it might be crucial for the development or/and the progression of neuromuscular diseases, such as Charcot–Marie–Tooth disease, myasthenia gravis, and Duchenne muscular dystrophy.

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Sphingosine 1-Phosphate (S1P) Induces Migration and ERK/MAP-Kinase-Dependent Proliferation in Chronic Lymphocytic Leukemia (B-CLL) Due to Expression of the G Protein-Coupled Receptors S1P1/4.

Blood ◽

10.1182/blood.v106.11.4996.4996 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4996-4996

Author(s):

Gabriele Seitz ◽

Sedat Yildirim ◽

Andreas M. Boehmler ◽

Lothar Kanz ◽

Robert Möhle

Keyword(s):

Chronic Lymphocytic Leukemia ◽

G Protein ◽

Cell Lines ◽

Peripheral Blood ◽

G Protein Coupled Receptors ◽

Lymphocytic Leukemia ◽

S1p Receptors ◽

Sphingosine 1 Phosphate ◽

G Protein Coupled

Abstract Egress of lymphocytes from lymphoid organs into the circulation has been shown to depend on the presence of the lipid mediator sphingosine 1-phosphate (S1P) in the peripheral blood, and expression of corresponding S1P receptors (i.e., S1P1), that belong to the family of 7-transmembrane G protein-coupled receptors (GPCR). As circulating lymphocytic lymphoma cells are a hallmark of chronic lymphocytic leukemia, we analyzed expression of different S1P receptors and the effects of S1P on B-CLL cells. By qualitative and quantitative (TaqMan) RT-PCR, significant mRNA expression of S1P1 and S1P4 was found in CLL cell lines (EHEB, MEC-1) and in most samples (S1P1 in 88%, S1P4 in 100%) of primary CD19+ cells isolated from the peripheral blood of untreated B-CLL patients. mRNA of other S1P receptors (S1P2, S1P3, S1P5) was less consistently detected. Normal, nonmalignant B cells were strongly positive for S1P1, while other S1P receptors were weakly expressed or negative. S1P induced typical effects of chemotactic GPCR, such as actin polymerization (analyzed by flow cytometry) and chemotaxis (measured in a modified Boyden chamber assay) in CLL cell lines and primary B-CLL cells. After serum deprivation in vitro, S1P induced phosphorylation of ERK/MAP-kinase as analyzed by Western blot, demonstrating that S1P receptors expressed in CLL were able to activate signaling pathways of GPCR not only related to cell migration and chemotaxis, but also to cell proliferation. Of note, the S1P1 ligand FTY720, which induces receptor internalization after prolonged exposure and acts as an antagonist, resulted in apoptosis in CLL cell lines and primary CLL cells in vitro, as measured by MTT-test and staining with Annexin-FITC, respectively. We conclude that sphingosine 1-phosphate, which is present in the peripheral blood in considerable amounts, contributes to the trafficking of B-CLL cells expressing the GPCRs S1P1/4, and to their prolonged survival.

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Sphingosine-1-Phosphate Signaling via the EDG-1 Family of G-Protein-Coupled Receptors

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.2000.tb06534.x ◽

2006 ◽

Vol 905 (1) ◽

pp. 16-24 ◽

Cited By ~ 36

Author(s):

TIMOTHY HLA ◽

MENQ-JER LEE ◽

NICOLAS ANCELLIN ◽

SHOBHA THANGADA ◽

CATHERINE H. LIU ◽

...

Keyword(s):

G Protein ◽

G Protein Coupled Receptors ◽

Sphingosine 1 Phosphate ◽

G Protein Coupled

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Sphingosine-1-Phosphate Via Activation of a G-Protein-Coupled Receptor(s) Enhances the Excitability of Rat Sensory Neurons

Journal of Neurophysiology ◽

10.1152/jn.00120.2006 ◽

2006 ◽

Vol 96 (3) ◽

pp. 1042-1052 ◽

Cited By ~ 58

Author(s):

Y. H. Zhang ◽

J. C. Fehrenbacher ◽

M. R. Vasko ◽

G. D. Nicol

Keyword(s):

G Protein ◽

Sensory Neurons ◽

Small Diameter ◽

G Protein Coupled Receptors ◽

External Application ◽

Nociceptive Neurons ◽

Firing Threshold ◽

Current Ramp ◽

Sphingosine 1 Phosphate ◽

G Protein Coupled

Sphingosine-1-phosphate (S1P) is released by immune cells and is thought to play a key role in chemotaxis and the onset of the inflammatory response. The question remains whether this lipid mediator also contributes to the enhanced sensitivity of nociceptive neurons that is associated with inflammation. Therefore we examined whether S1P alters the excitability of small diameter, capsaicin-sensitive sensory neurons by measuring action potential (AP) firing and two of the membrane currents critical in regulating the properties of the AP. External application of S1P augments the number of APs evoked by a depolarizing current ramp. The enhanced firing is associated with a decrease in the rheobase and an increase in the resistance at firing threshold although neither the firing threshold nor the resting membrane potential are changed. Treatment with S1P enhanced the tetrodotoxin-resistant sodium current and decreased the total outward potassium current ( IK). When sensory neurons were internally perfused with GDP-β-S, a blocker of G protein activation, the S1P-induced increase in APs was completely blocked and suggests the excitatory actions of S1P are mediated through G-protein-coupled receptors called endothelial differentiation gene or S1PR. In contrast, internal perfusion with GDP-β-S and S1P increased the number of APs evoked by the current ramp. These results and our finding that the mRNAs for S1PRs are expressed in both the intact dorsal root ganglion and cultures of adult sensory neurons supports the notion that S1P acts on S1PRs linked to G proteins. Together these findings demonstrate that S1P can regulate the excitability of small diameter sensory neurons by acting as an external paracrine-type ligand through activation of G-protein-coupled receptors and thus may contribute to the hypersensitivity during inflammation.

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