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Peña KA, Savransky S, Lewis B. Endosomal signaling via cAMP in parathyroid hormone (PTH) type 1 receptor biology. Mol Cell Endocrinol 2024; 581:112107. [PMID: 37981188 DOI: 10.1016/j.mce.2023.112107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/25/2023] [Accepted: 11/06/2023] [Indexed: 11/21/2023]
Abstract
Compartmentalization of GPCR signaling is an emerging topic that highlights the physiological relevance of spatial bias in signaling. The parathyroid hormone (PTH) type 1 receptor (PTH1R) was the first GPCR described to signal via heterotrimeric G-protein and cAMP from endosomes after β-arrestin mediated internalization, challenging the canonical GPCR signaling model which established that signaling is terminated by receptor internalization. More than a decade later, many other GPCRs have been shown to signal from endosomes via cAMP, and recent studies have proposed that location of cAMP generation impacts physiological outcomes of GPCR signaling. Here, we review the extensive literature regarding PTH1R endosomal signaling via cAMP, the mechanisms that regulate endosomal generation of cAMP, and the implications of spatial bias in PTH1R physiological functions.
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Affiliation(s)
- Karina A Peña
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Sofya Savransky
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Breanna Lewis
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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2
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Peña KA. Endosomal parathyroid hormone receptor signaling. Am J Physiol Cell Physiol 2022; 323:C783-C790. [PMID: 35912987 PMCID: PMC9467467 DOI: 10.1152/ajpcell.00452.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/22/2022]
Abstract
The canonical model for G protein-coupled receptors (GPCRs) activation assumes that stimulation of heterotrimeric G protein signaling upon ligand binding occurs solely at the cell surface and that duration of the stimulation is transient to prevent overstimulation. In this model, GPCR signaling is turned-off by receptor phosphorylation via GPCR kinases (GRKs) and subsequent recruitment of β-arrestins, resulting in receptor internalization into endosomes. Internalized receptors can then recycle back to the cell surface or be trafficked to lysosomes for degradation. However, over the last decade, this model has been extended by discovering that some internalized GPCRs continue to signal via G proteins from endosomes. This is the case for the parathyroid hormone (PTH) type 1 receptor (PTHR), which engages on sustained cAMP signaling from endosomes upon PTH stimulation. Accumulative evidence shows that the location of signaling has an impact on the physiological effects of GPCR signaling. This mini-review discusses recent insights into the mechanisms of PTHR endosomal signaling and its physiological impact.
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Affiliation(s)
- Karina A Peña
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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3
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Wang FI, Ding G, Ng GS, Dixon SJ, Chidiac P. Luciferase-based GloSensor™ cAMP assay: Temperature optimization and application to cell-based kinetic studies. Methods 2021; 203:249-258. [PMID: 34737032 DOI: 10.1016/j.ymeth.2021.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/13/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are an important receptor superfamily and common therapeutic targets. The second messenger cyclic adenosine monophosphate (cAMP) is a key mediator in many GPCR signaling pathways. Monitoring intracellular cAMP levels can help identify orthosteric agonists and antagonists, as well as allosteric modulators. In this regard, luminescence-based biosensors have revolutionized our ability to monitor GPCR signaling kinetics. The GloSensor™ cAMP assay enables real-time monitoring of signaling downstream of many GPCRs. However, it is crucial to optimize assay conditions such as temperature. As well, it has not been reported whether the effects of temperature on biosensor activity are reversible. Here, we describe the temperature sensitivity and reversibility of the GloSensor™ cAMP assay, and which GloSensor™ version is optimal for measuring cytosolic cAMP. We also present a detailed protocol for monitoring cAMP levels in live cells expressing endogenous or exogenous GPCRs. Temperature optimization studies were carried out using HEK293H cells transiently transfected with the adenosine receptor A2a and the GloSensor™ plasmid (pGloSensor-20F or -22F). We found that preincubation and luminescence reading at room temperature were optimal as compared to higher temperatures. As well, the GloSensor-22F biosensor had a superior signal-to-background ratio and the effect of temperature on biosensor activity was reversible. However, thermal instability of the biosensor may pose a problem for in vivo studies. Nevertheless, the GloSensor™ cAMP assay can be applied to analyze signaling by a wide range of GPCRs for drug discovery purposes.
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Affiliation(s)
- Fang I Wang
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - Gucci Ding
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - Garmen S Ng
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - S Jeffrey Dixon
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - Peter Chidiac
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada.
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Extracellular purines and bone homeostasis. Biochem Pharmacol 2021; 187:114425. [PMID: 33482152 DOI: 10.1016/j.bcp.2021.114425] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/12/2022]
Abstract
Maintenance of a healthy skeleton is highly dependent on an intricate regulation of bone metabolism, as changes in the balance between bone formation and bone resorption leads to bone loss, bone fragility and ultimately bone fractures. During the last three decades it has become increasingly evident that physiological release of purines in the extracellular space is imperative for bone homeostasis and is orchestrated via the network of purinoceptors. Adenosine derivatives are released locally in the skeleton either by the bone forming osteoblasts or the bone degrading osteoclasts actioned directly by processes like mechanical loading and indirectly by systemic hormones. Adenosine derivatives directly affect the bone cells by their action on the membranal receptors or have co-stimulatory actions with bone active hormones such as parathyroid hormone or the gut hormones. Any deviations leading to increased levels of extracellular adenosine derivatives in the bone tissue such as in pathologic situations, trigger complex pathways with opposing effects on tissue health as presented by studies involving a range of model organisms. Pathological conditions where skeletal purinergic signaling is affected are following tissue injury like microdamage and macroscopic fractures; and during inflammatory processes where nucleotides and nucleosides play an important part in the pathophysiological skeletal response. Moreover, adenosine derivatives also play an important role in the interaction between malignant cells and bone cells in several types of cancers involving the skeleton, such as but not limited to multiple myeloma and bone osteolysis. Much knowledge has been gained over the last decades. The net- resulting phenotype of adenosine derivatives in bone (including the ratio of ATP to Adenosine) is highly dependent on CD39 and CD73 enzymes together with the expression and activity of the specific receptors. Thus, each component is important in the physiological and pathophysiological processes in bone. Promising perspectives await in the future in treating skeletal disorders with medications targeting the individual components of the purinergic signaling pathway.
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Ren T, Zhang Z, Fu R, Yang Y, Li W, Liang J, Mo G, Luo W, Zhang X. A 51 bp indel polymorphism within the PTH1R gene is significantly associated with chicken growth and carcass traits. Anim Genet 2020; 51:568-578. [PMID: 32400914 DOI: 10.1111/age.12942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2020] [Indexed: 01/04/2023]
Abstract
Parathyroid hormone (PTH) is a crucial regulator of calcium homeostasis and bone remodeling, and the parathyroid hormone 1 receptor (PTH1R) belongs to a class II G-protein-coupled receptor. PTH activates PTH1R, which mediates catabolic and anabolic processes in the skeleton. However, the functional mechanism of PTH1R has not been thoroughly elucidated in organisms. This study identified a 51 bp indel mutation in the first intron of the PTH1R gene and elucidated the effect of this gene mutation on the growth and carcass traits in chickens. The results indicated that the 51 bp indel was significantly associated with subcutaneous fat thickness, abdominal fat weight, body weight and daily gain over 4-8 weeks. Furthermore, we found that PTH1R gene expression was highest in the kidney and liver tissues, and it showed a trend of decreasing in leg and breast muscle tissues at different embryonic stages. In addition, we examined the expression of the three genotypes of the PTH1R gene in the liver, breast muscle and abdominal fat and found that the II genotype was significantly higher than the DD and ID genotypes. In summary, these findings suggest that the PTH1R gene can serve as a potential molecular marker for chicken breeding.
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Affiliation(s)
- T Ren
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
| | - Z Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
| | - R Fu
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
| | - Y Yang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China
| | - W Li
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
| | - J Liang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
| | - G Mo
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
| | - W Luo
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
| | - X Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, Guangdong, China
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Matthus E, Sun J, Wang L, Bhat MG, Mohammad-Sidik AB, Wilkins KA, Leblanc-Fournier N, Legué V, Moulia B, Stacey G, Davies JM. DORN1/P2K1 and purino-calcium signalling in plants: making waves with extracellular ATP. ANNALS OF BOTANY 2020; 124:1227-1242. [PMID: 31904093 PMCID: PMC6943698 DOI: 10.1093/aob/mcz135] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND AND AIMS Extracellular ATP governs a range of plant functions, including cell viability, adaptation and cross-kingdom interactions. Key functions of extracellular ATP in leaves and roots may involve an increase in cytosolic free calcium as a second messenger ('calcium signature'). The main aim here was to determine to what extent leaf and root calcium responses require the DORN1/P2K1 extracellular ATP receptor in Arabidopsis thaliana. The second aim was to test whether extracellular ATP can generate a calcium wave in the root. METHODS Leaf and root responses to extracellular ATP were reviewed for their possible links to calcium signalling and DORN1/P2K1. Leaves and roots of wild type and dorn1 plants were tested for cytosolic calcium increase in response to ATP, using aequorin. The spatial abundance of DORN1/P2K1 in the root was estimated using green fluorescent protein. Wild type roots expressing GCaMP3 were used to determine the spatial variation of cytosolic calcium increase in response to extracellular ATP. KEY RESULTS Leaf and root ATP-induced calcium signatures differed markedly. The leaf signature was only partially dependent on DORN1/P2K1, while the root signature was fully dependent. The distribution of DORN1/P2K1 in the root supports a key role in the generation of the apical calcium signature. Root apical and sub-apical calcium signatures may operate independently of each other but an apical calcium increase can drive a sub-apical increase, consistent with a calcium wave. CONCLUSION DORN1 could underpin several calcium-related responses but it may not be the only receptor for extracellular ATP in Arabidopsis. The root has the capacity for a calcium wave, triggered by extracellular ATP at the apex.
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Affiliation(s)
- Elsa Matthus
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Jian Sun
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
- Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou, China
| | - Limin Wang
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Madhura G Bhat
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | | | - Katie A Wilkins
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | | | - Valérie Legué
- Université Clermont Auvergne, INRA, PIAF, Clermont-Ferrand, France
| | - Bruno Moulia
- Université Clermont Auvergne, INRA, PIAF, Clermont-Ferrand, France
| | - Gary Stacey
- Divisions of Plant Science and Biochemistry, University of Missouri, Columbia, MO, USA
| | - Julia M Davies
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
- For correspondence. E-mail
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Sutkeviciute I, Clark LJ, White AD, Gardella TJ, Vilardaga JP. PTH/PTHrP Receptor Signaling, Allostery, and Structures. Trends Endocrinol Metab 2019; 30:860-874. [PMID: 31699241 PMCID: PMC6857722 DOI: 10.1016/j.tem.2019.07.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/09/2019] [Accepted: 07/12/2019] [Indexed: 02/08/2023]
Abstract
The parathyroid hormone (PTH) type 1 receptor (PTHR) is the canonical G protein-coupled receptor (GPCR) for PTH and PTH-related protein (PTHrP) and the key regulator of calcium homeostasis and bone turnover. PTHR function is critical for human health to maintain homeostatic control of ionized serum Ca2+ levels and has several unusual signaling features, such as endosomal cAMP signaling, that are well-studied but not structurally understood. In this review, we discuss how recently solved high resolution near-atomic structures of hormone-bound PTHR in its inactive and active signaling states and discovery of extracellular Ca2+ allosterism shed light on the structural basis for PTHR signaling and function.
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Affiliation(s)
- Ieva Sutkeviciute
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Lisa J Clark
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Graduate Program in Molecular Biophysics and Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Alex D White
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
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Kim BH, Wang FI, Pereverzev A, Chidiac P, Dixon SJ. Toward Defining the Pharmacophore for Positive Allosteric Modulation of PTH1 Receptor Signaling by Extracellular Nucleotides. ACS Pharmacol Transl Sci 2019; 2:155-167. [PMID: 32259054 DOI: 10.1021/acsptsci.8b00053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Indexed: 12/17/2022]
Abstract
The parathyroid hormone 1 receptor (PTH1R) is a Class B G-protein-coupled receptor that is a target for osteoporosis therapeutics. Activated PTH1R couples through Gs to the stimulation of adenylyl cyclase. As well, β-arrestin is recruited to PTH1R leading to receptor internalization and MAPK/ERK signaling. Previously, we reported that the agonist potency of PTH1R is increased in the presence of extracellular ATP, which acts as a positive allosteric modulator of PTH signaling. Another nucleotide, cytidine 5'-monophosphate (CMP), also enhances PTH1R signaling, suggesting that ATP and CMP share a moiety responsible for positive allostery, possibly ribose-5-phosphate. Therefore, we examined the effect of extracellular sugar phosphates on PTH1R signaling. cAMP levels and β-arrestin recruitment were monitored using luminescence-based assays. Alone, ribose-5-phosphate had no detectable effect on adenylyl cyclase activity in UMR-106 rat osteoblastic cells, which endogenously express PTH1R. However, ribose-5-phosphate markedly enhanced the activation of adenylyl cyclase induced by PTH. Other sugar phosphates, including glucose-1-phosphate, glucose-6-phosphate, fructose-6-phosphate, and fructose-1,6-bisphosphate, also potentiated PTH-induced adenylyl cyclase activation. As well, some sugar phosphates enhanced PTH-induced β-arrestin recruitment to human PTH1R heterologously expressed in HEK293H cells. Interestingly, the effects of glucose-1-phosphate were greater than those of its isomer glucose-6-phosphate. Our results suggest that phosphorylated monosaccharides such as ribose-5-phosphate contain the pharmacophore for positive allosteric modulation of PTH1R. At least in some cases, the extent of modulation depends on the position of the phosphate group. Knowledge of the pharmacophore may permit future development of positive allosteric modulators to increase the therapeutic efficacy of PTH1R agonists.
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Affiliation(s)
- Brandon H Kim
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry; and Bone and Joint Institute; The University of Western Ontario, London, Canada
| | - Fang I Wang
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry; and Bone and Joint Institute; The University of Western Ontario, London, Canada
| | - Alexey Pereverzev
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry; and Bone and Joint Institute; The University of Western Ontario, London, Canada
| | - Peter Chidiac
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry; and Bone and Joint Institute; The University of Western Ontario, London, Canada
| | - S Jeffrey Dixon
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry; and Bone and Joint Institute; The University of Western Ontario, London, Canada
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