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Geng S, Xu T, Sun Y. Genome-wide identification and analysis of chemokine receptor superfamily in miiuy croaker, Miichthys miiuy. FISH & SHELLFISH IMMUNOLOGY 2021; 118:343-353. [PMID: 34555531 DOI: 10.1016/j.fsi.2021.09.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
The chemokine receptor (ChemR) superfamily, which is divided into 4 subfamilies (CXCR, CCR, XCR, and CX3CR), is the main receptors of chemokines in innate immune responses. In the current study, we have identified 27 ChemRs in miiuy croaker: 13 CCR genes, 11 CXCR genes, and 3 XCR genes. Multiple characteristics of these genes, including phylogeny, gene structures, conserved motifs, chromosome locations, evolutionary mechanism, and expression levels upon the bacterial challenge were analyzed. Gene structure and location analysis showed that all ChemR genes contain fewer introns (≤4) and they are unevenly distributed on the 12 chromosomes. And the XCR subfamily of miiuy croaker don't have the DRY motif of ChemR. Phylogenetic and synteny analysis showed that these genes experienced tandem and segmental duplication event in several species, and tandem duplication might be the main expansion way in miiuy croaker. The major ChemRs of each orthologous group in vertebrates were selected for molecular evolution analysis, the results of which indicated that compared with vertebrates, ChemRs of teleost fishes may have a relatively high evolutionary dynamic. In addition, a total of 21 positively selected codons were detected in vertebrate ChemRs under Model 8. RNA-Seq analysis and qRT-PCR verification demonstrated that CXCR3.2, CXCR5, and XCR1 genes were up-regulated significantly upon the Vibrio harveyi infection. These results provide valuable information for investigating the evolutionary relationships of chemokine receptor superfamily in miiuy croaker and laid the basis for further functional analysis.
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Affiliation(s)
- Shang Geng
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Tianjun Xu
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, China
| | - Yuena Sun
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, China.
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2
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Singh SP, Foley JF, Zhang HH, Hurt DE, Richards JL, Smith CS, Liao F, Farber JM. Selectivity in the Use of Gi/o Proteins Is Determined by the DRF Motif in CXCR6 and Is Cell-Type Specific. Mol Pharmacol 2015; 88:894-910. [PMID: 26316539 DOI: 10.1124/mol.115.099960] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 08/21/2015] [Indexed: 01/02/2023] Open
Abstract
CXCR6, the receptor for CXCL16, is expressed on multiple cell types and can be a coreceptor for human immunodeficiency virus 1. Except for CXCR6, all human chemokine receptors contain the D(3.49)R(3.50)Y(3.51) sequence, and all but two contain A(3.53) at the cytoplasmic terminus of the third transmembrane helix (H3C), a region within class A G protein-coupled receptors that contacts G proteins. In CXCR6, H3C contains D(3.49)R(3.50)F(3.51)I(3.52)V(3.53) at positions 126-130. We investigated the importance and interdependence of the canonical D126 and the noncanonical F128 and V130 in CXCR6 by mutating D126 to Y, F128 to Y, and V130 to A singly and in combination. For comparison, we mutated the analogous positions D142, Y144, and A146 to Y, F, and V, respectively, in CCR6, a related receptor containing the canonical sequences. Mutants were analyzed in both human embryonic kidney 293T and Jurkat E6-1 cells. Our data show that for CXCR6 and/or CCR6, mutations in H3C can affect both receptor signaling and chemokine binding; noncanonical H3C sequences are functionally linked, with dual changes mitigating the effects of single mutations; mutations in H3C that compromise receptor activity show selective defects in the use of individual Gi/o proteins; and the effects of mutations in H3C on receptor function and selectivity in Gi/o protein use can be cell-type specific. Our findings indicate that the ability of CXCR6 to make promiscuous use of the available Gi/o proteins is exquisitely dependent on sequences within the H3C and suggest that the native sequence allows for preservation of this function across different cellular environments.
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Affiliation(s)
- Satya P Singh
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
| | - John F Foley
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
| | - Hongwei H Zhang
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
| | - Darrell E Hurt
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
| | - Jennifer L Richards
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
| | - Craig S Smith
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
| | - Fang Liao
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
| | - Joshua M Farber
- Laboratory of Molecular Immunology (S.P.S., J.F.F., H.H.Z., J.L.R., C.S.S., F.L., J.M.F.) and Bioinformatics and Scientific IT Program, Office of Technology Information Systems, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland (D.E.H.); and Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, Maryland (C.S.S.)
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3
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Characterization of G protein coupling mediated by the conserved D134(3.49) of DRY motif, M241(6.34), and F251(6.44) residues on human CXCR1. FEBS Open Bio 2015; 5:182-90. [PMID: 25834784 PMCID: PMC4372616 DOI: 10.1016/j.fob.2015.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 01/01/2023] Open
Abstract
Mutations in the DRY motif of CXCR1 abolish ligand binding and receptor activation. Point mutations between TM6 and i3 loop result in constitutive activity of CXCR1. Constitutive activity of mutant CXCR1 occurs via Gα15 signaling activation. The highly conserved DRY motifs have distinct roles in CXCR1 and CXCR2.
CXCR1, a receptor for interleukin-8 (IL-8), plays an important role in defending against pathogen invasion during neutrophil-mediated innate immune response. Human CXCR1 is a G protein-coupled receptor (GPCR) with its characteristic seven transmembrane domains (TMs). Functional and structural analyses of several GPCRs have revealed that conserved residues on TM3 (including the highly conserved Asp-Arg-Tyr (DRY) motif) and TM6 near intracellular loops contain domains critical for G protein coupling as well as GPCR activation. The objective of this study was to elucidate the role of critical amino acid residues on TM3 near intracellular loop 2 (i2) and TM6 near intracellular loop 3 (i3), including S1323.47 (Baldwin location), D1343.49, M2416.34, and F2516.44, in G protein coupling and CXCR1 activation. The results demonstrate that mutations of D1343.49 at DRY motif of CXCR1 (D134N and D134V) completely abolished the ligand binding and functional response of the receptor. Additionally, point mutations at positions 241 and 251 between TM6 and i3 loop generated mutant receptors with modest constitutive activity via Gα15 signaling activation. Our results show that D1343.49 on the highly conserved DRY motif has a distinct role for CXCR1 compared to its homologues (CXCR2 and KSHV-GPCR) in G protein coupling and receptor activation. In addition, M2416.34 and F2516.44 along with our previously identified V2476.40 on TM6 are spatially located in a “hot spot” likely essential for CXCR1 activation. Identification of these amino acid residues may be useful for elucidating mechanism of CXCR1 activation and designing specific antagonists for the treatment of CXCR1-mediated diseases.
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Key Words
- CXCR1
- CXCR1, CXC receptor 1
- Chemokine receptor
- Constitutive activity
- DRY motif, Asp-Arg-Tyr motif
- G protein coupled receptor
- GPCR, G protein-coupled receptor
- Gα15
- Gαi
- IL-8, interleukin 8
- IP, inositol phosphate
- Kd, affinity constants
- PLC, phospholipase C
- PTX, pertussis toxin
- TMs, transmembrane domain
- WT, wild type
- i2, intracellular loop 2
- i3, intracellular loop 3
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Chen X, Bai B, Tian Y, Du H, Chen J. Identification of serine 348 on the apelin receptor as a novel regulatory phosphorylation site in apelin-13-induced G protein-independent biased signaling. J Biol Chem 2014; 289:31173-87. [PMID: 25271156 DOI: 10.1074/jbc.m114.574020] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Phosphorylation plays vital roles in the regulation of G protein-coupled receptor (GPCR) functions. The apelin and apelin receptor (APJ) system is involved in the regulation of cardiovascular function and central control of body homeostasis. Here, using tandem mass spectrometry, we first identified phosphorylated serine residues in the C terminus of APJ. To determine the role of phosphorylation sites in APJ-mediated G protein-dependent and -independent signaling and function, we induced a mutation in the C-terminal serine residues and examined their effects on the interaction between APJ with G protein or GRK/β-arrestin and their downstream signaling. Mutation of serine 348 led to an elimination of both GRK and β-arrestin recruitment to APJ induced by apelin-13. Moreover, APJ internalization and G protein-independent ERK signaling were also abolished by point mutation at serine 348. In contrast, this mutant at serine residues had no demonstrable impact on apelin-13-induced G protein activation and its intracellular signaling. These findings suggest that mutation of serine 348 resulted in inactive GRK/β-arrestin. However, there was no change in the active G protein thus, APJ conformation was biased. These results provide important information on the molecular interplay and impact of the APJ function, which may be extrapolated to design novel drugs for cardiac hypertrophy based on this biased signal pathway.
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Affiliation(s)
- Xiaoyu Chen
- From the Department of Physiology, Shandong University School of Medicine, Jinan, Shandong 250012, People's Republic of China, the Department of physiology, Taishan Medical College, Taian, Shandong 271000, People's Republic of China
| | - Bo Bai
- the Neurobiology Institute, Jining Medical University, Jining, Shandong 272067, People's Republic of China,
| | - Yanjun Tian
- the Neurobiology Institute, Jining Medical University, Jining, Shandong 272067, People's Republic of China
| | - Hui Du
- the Department of physiology, Taishan Medical College, Taian, Shandong 271000, People's Republic of China
| | - Jing Chen
- the Neurobiology Institute, Jining Medical University, Jining, Shandong 272067, People's Republic of China, the Division of Translational and Systems Medicine, Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom, and
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5
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Desai AJ, Harikumar KG, Miller LJ. A type 1 cholecystokinin receptor mutant that mimics the dysfunction observed for wild type receptor in a high cholesterol environment. J Biol Chem 2014; 289:18314-26. [PMID: 24825903 DOI: 10.1074/jbc.m114.570200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cholecystokinin (CCK) stimulates the type 1 CCK receptor (CCK1R) to elicit satiety after a meal. Agonists with this activity, although potentially useful for treatment of obesity, can also have side effects and toxicities of concern, making the development of an intrinsically inactive positive allosteric modulator quite attractive. Positive allosteric modulators also have the potential to correct the defective receptor-G protein coupling observed in the high membrane cholesterol environment described in metabolic syndrome. Current model systems to study CCK1R in such an environment are unstable and expensive to maintain. We now report that the Y140A mutation within a cholesterol-binding motif and the conserved, class A G protein-coupled receptor-specific (E/D)RY signature sequence results in ligand binding and activity characteristics similar to wild type CCK1R in a high cholesterol environment. This is true for natural CCK, as well as ligands with distinct chemistries and activity profiles. Additionally, the Y140A construct also behaved like CCK1R in high cholesterol in regard to its internalization, sensitivity to a nonhydrolyzable GTP analog, and anisotropy of a bound fluorescent CCK analog. Chimeric CCK1R/CCK2R constructs that systematically changed the residues in the allosteric ligand-binding pocket were studied in the presence of Y140A. This established increased importance of unique residues within TM3 and reduced the importance of TM2 for binding in the presence of this mutation, with the agonist trigger likely pulled away from its Leu(356) target on TM7. The distinct conformation of this intramembranous pocket within Y140A CCK1R provides an opportunity to normalize this by using a small molecule allosteric ligand, thereby providing safe and effective correction of the coupling defect in metabolic syndrome.
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Affiliation(s)
- Aditya J Desai
- From the Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259
| | - Kaleeckal G Harikumar
- From the Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259
| | - Laurence J Miller
- From the Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259
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6
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Matos-Cruz V, Blasic J, Nickle B, Robinson PR, Hattar S, Halpern ME. Unexpected diversity and photoperiod dependence of the zebrafish melanopsin system. PLoS One 2011; 6:e25111. [PMID: 21966429 PMCID: PMC3178608 DOI: 10.1371/journal.pone.0025111] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 08/24/2011] [Indexed: 12/02/2022] Open
Abstract
Animals have evolved specialized photoreceptors in the retina and in extraocular tissues that allow them to measure light changes in their environment. In mammals, the retina is the only structure that detects light and relays this information to the brain. The classical photoreceptors, rods and cones, are responsible for vision through activation of rhodopsin and cone opsins. Melanopsin, another photopigment first discovered in Xenopus melanophores (Opn4x), is expressed in a small subset of retinal ganglion cells (RGCs) in the mammalian retina, where it mediates non-image forming functions such as circadian photoentrainment and sleep. While mammals have a single melanopsin gene (opn4), zebrafish show remarkable diversity with two opn4x-related and three opn4-related genes expressed in distinct patterns in multiple neuronal cell types of the developing retina, including bipolar interneurons. The intronless opn4.1 gene is transcribed in photoreceptors as well as in horizontal cells and produces functional photopigment. Four genes are also expressed in the zebrafish embryonic brain, but not in the photoreceptive pineal gland. We discovered that photoperiod length influences expression of two of the opn4-related genes in retinal layers involved in signaling light information to RGCs. Moreover, both genes are expressed in a robust diurnal rhythm but with different phases in relation to the light-dark cycle. The results suggest that melanopsin has an expanded role in modulating the retinal circuitry of fish.
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Affiliation(s)
- Vanessa Matos-Cruz
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland, United States of America
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Joseph Blasic
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, United States of America
| | - Benjamin Nickle
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, United States of America
| | - Phyllis R. Robinson
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, United States of America
| | - Samer Hattar
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail: (MEH); (SH)
| | - Marnie E. Halpern
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland, United States of America
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail: (MEH); (SH)
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Conner AC, Barwell J, Poyner DR, Wheatley M. The use of site-directed mutagenesis to study GPCRs. Methods Mol Biol 2011; 746:85-98. [PMID: 21607853 DOI: 10.1007/978-1-61779-126-0_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
G protein coupled receptors (GPCRs) are highly flexible and dynamic proteins, which are able to interact with diverse ligands, effectors, and regulatory proteins. Site-directed mutagenesis (SDM) is a powerful tool for providing insight into how these proteins actually work, both in its own right and when used in conjunction with information provided by other techniques such as crystallography or molecular modelling. Mutagenesis has been used to identify and characterise a myriad of functionally important residues, motifs and domains within the GPCR architecture, and to identify aspects of similarity and differences between the major families of GPCRs. This chapter presents the necessary information for undertaking informative SDM of these proteins. Whilst this is relevant to protein structure/function studies in -general, specific pitfalls and protocols suited to investigating GPCRs in particular will be highlighted.
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Affiliation(s)
- Alex C Conner
- Warwick Medical School, University of Warwick, Coventry, UK.
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Highly conserved tyrosine stabilizes the active state of rhodopsin. Proc Natl Acad Sci U S A 2010; 107:19861-6. [PMID: 21041664 DOI: 10.1073/pnas.1009405107] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Light-induced isomerization of the 11-cis-retinal chromophore in the visual pigment rhodopsin triggers displacement of the second extracellular loop (EL2) and motion of transmembrane helices H5, H6, and H7 leading to the active intermediate metarhodopsin II (Meta II). We describe solid-state NMR measurements of rhodopsin and Meta II that target the molecular contacts in the region of the ionic lock involving these three helices. We show that a contact between Arg135(3.50) and Met257(6.40) forms in Meta II, consistent with the outward rotation of H6 and breaking of the dark-state Glu134(3.49)-Arg135(3.50)-Glu247(6.30) ionic lock. We also show that Tyr223(5.58) and Tyr306(7.53) form molecular contacts with Met257(6.40). Together these results reveal that the crystal structure of opsin in the region of the ionic lock reflects the active state of the receptor. We further demonstrate that Tyr223(5.58) and Ala132(3.47) in Meta II stabilize helix H5 in an active orientation. Mutation of Tyr223(5.58) to phenylalanine or mutation of Ala132(3.47) to leucine decreases the lifetime of the Meta II intermediate. Furthermore, the Y223F mutation is coupled to structural changes in EL2. In contrast, mutation of Tyr306(7.53) to phenylalanine shows only a moderate influence on the Meta II lifetime and is not coupled to EL2.
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9
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Kosugi T, Sower SA. A role of Histidine151 in the lamprey gonadotropin-releasing hormone receptor-1 (lGnRHR-1): Functional insight of diverse amino acid residues in the position of Tyr of the DRY motif in GnRHR from an ancestral type II receptor. Gen Comp Endocrinol 2010; 166:498-503. [PMID: 20005226 PMCID: PMC2856804 DOI: 10.1016/j.ygcen.2009.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 12/04/2009] [Indexed: 10/20/2022]
Abstract
The highly conserved DRY motif located at the end of the third transmembrane of G-protein-coupled receptors has been described as a key motif for several aspects of GPCR functions. However, in the case of the vertebrate gonadotropin-releasing hormone receptor (GnRHR), the amino acid in the third position in the DRY motif is variable. In the lamprey, a most basal vertebrate, the third amino acid of the "DRY" in lamprey (lGnRHR-1) is His, while it is most often His/Gln in the type II GnRHR. To investigate the functional significance of the substitution of DRY to DRH in the GnRHR-1, second messenger signaling, ligand binding and internalization of the wild-type and mutant lGnRH receptors were characterized with site-directed mutagenesis. Treatment of the DRE(151) and DRS(151) mutant receptors with lamprey GnRH-I significantly reduced inositol phosphate compared to wild-type (DRH(151)) and DRY(151) receptors. The LogIC(50) of wild-type receptor (-9.554+/-0.049) was similar to the LogIC(50) of DRE(151), DRS(151) and DRX(151) mutants, yet these same mutants were shown to significantly reduce cell-surface expression. However, the DRY(151) mutant compared to the wild-type receptor increased cell-surface expression, suggesting that the reduction of IP production was due to the level of the cell-surface expression of the mutant receptors. The rate of internalization of DRX(151) (35.60%) was reduced compared to wild-type and other mutant receptors. These results suggest that His(151) of the lamprey GnRH receptor-1 may play a critical role in the retention of a certain level of cell-surface expression for subsequent cellular second messenger events.
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Affiliation(s)
| | - Stacia A. Sower
- Corresponding author: Dr. Stacia A. Sower. Center for Molecular and Comparative Endocrinology, University of New Hampshire, 46 College Road Durham NH 3824 USA.
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10
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Aizaki Y, Maruyama K, Nakano-Tetsuka M, Saito Y. Distinct roles of the DRY motif in rat melanin-concentrating hormone receptor 1 in signaling control. Peptides 2009; 30:974-81. [PMID: 19428776 DOI: 10.1016/j.peptides.2009.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2008] [Revised: 01/17/2009] [Accepted: 01/21/2009] [Indexed: 10/21/2022]
Abstract
Rhodopsin family (class A) G protein-coupled receptors possess common key residues or motifs that appear to be important for receptor function. To clarify the roles of the highly conserved amino acid triplet Asp(3.49)-Arg(3.50)-Tyr(3.51) (DRY motif), we examined how single-substitution mutations of the amino acids in the motif influenced specific features of rat melanin-concentrating hormone receptor 1 (MCH1R) activity. Substitution of either Asp140(3.49) or Tyr142(3.51) to Ala resulted in nonfunctional receptors, despite the retention of apparent potencies for agonist binding. These loss-of-function phenotypes may be caused by the lack of stimulation for GDP-GTP exchange observed in GTPgammaS-binding assays. On the other hand, substitution of Arg141(3.50) to Ala caused a 4-fold reduction in the agonist binding affinity and, concomitantly, a rightward shift of the dose-dependency curve for calcium mobilization and inhibition of cyclic AMP production. Although many experimental studies have suggested that the DRY motif is involved in maintaining the receptor in its ground state, none of the DRY motif substitutions to Ala in MCH1R led to constitutive activation, in terms of the basal signaling level for ERK1/2 activation or GTPgammaS binding. These data suggest that the major contribution of the DRY motif in MCH1R is to govern receptor conformation and G protein coupling/recognition.
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Affiliation(s)
- Yoshimi Aizaki
- Department of Pharmacology, Saitama Medical School of Medicine, Iruma-gun, Saitama, Japan
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11
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Proulx CD, Holleran BJ, Boucard AA, Escher E, Guillemette G, Leduc R. Mutational analysis of the conserved Asp2.50 and ERY motif reveals signaling bias of the urotensin II receptor. Mol Pharmacol 2008; 74:552-61. [PMID: 18509066 DOI: 10.1124/mol.108.045054] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Class A (rhodopsin-like) G protein-coupled receptors possess conserved residues and motifs that are important for their specific activity. In the present study, we examined the role of residue Asp97(2.50) as well as residues Glu147(3.49), Arg148(3.50), and Tyr149(3.51) of the ERY motif on the functionality of the urotensin II receptor (UT). Mutations D97(2.50)A, R148(3.50)A, and R148(3.50)H abolished the ability of UT to activate phospholipase C, whereas mutations E147(3.49)A and Y149(3.51)A reduced the ability to activate PLC by 50%. None of the mutants exhibited constitutive activity. However, R148(3.50)A and R148(3.50)H promoted ERK1/2 activation, which was abolished by 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG1478), an inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase activity. Both these mutants were capable of directly activating EGFR, which confirmed that they activated the mitogen-activated protein kinase (MAPK) pathway by a Galpha(q/11)-independent transactivation of EGFR. The D97(2.50)A, R148(3.50)A, and R148(3.50)H mutants did not readily internalize and did not promote translocation or colocalize with beta-arrestin2-GFP. Finally, the agonist-induced internalization of the E147(3.49)A mutant receptor was significantly increased compared with wild-type receptor. This study highlights the major contribution of the conserved Asp(2.50) residue to the functionality of the UT receptor. The Arg residue in the ERY motif of UT is an important structural element in signaling crossroads that determine whether Galpha(q/11)-dependent and -independent events can occur.
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Affiliation(s)
- Christophe D Proulx
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, J1H5N4 ON, Canada
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12
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Affiliation(s)
- David E Nichols
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47906-2091, USA.
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Fink S, Excoffier L, Heckel G. High variability and non-neutral evolution of the mammalian avpr1a gene. BMC Evol Biol 2007; 7:176. [PMID: 17900345 PMCID: PMC2121647 DOI: 10.1186/1471-2148-7-176] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 09/27/2007] [Indexed: 11/21/2022] Open
Abstract
Background The arginine-vasopressin 1a receptor has been identified as a key determinant for social behaviour in Microtus voles, humans and other mammals. Nevertheless, the genetic bases of complex phenotypic traits like differences in social and mating behaviour among species and individuals remain largely unknown. Contrary to previous studies focusing on differences in the promotor region of the gene, we investigate here the level of functional variation in the coding region (exon 1) of this locus. Results We detected high sequence diversity between higher mammalian taxa as well as between species of the genus Microtus. This includes length variation and radical amino acid changes, as well as the presence of distinct protein variants within individuals. Additionally, negative selection prevails on most parts of the first exon of the arginine-vasopressin receptor 1a (avpr1a) gene but it contains regions with higher rates of change that harbour positively selected sites. Synonymous and non-synonymous substitution rates in the avpr1a gene are not exceptional compared to other genes, but they exceed those found in related hormone receptors with similar functions. Discussion These results stress the importance of considering variation in the coding sequence of avpr1a in regards to associations with life history traits (e.g. social behaviour, mating system, habitat requirements) of voles, other mammals and humans in particular.
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Affiliation(s)
- Sabine Fink
- Computational and Molecular Population Genetics (CMPG), Zoological Institute, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
| | - Laurent Excoffier
- Computational and Molecular Population Genetics (CMPG), Zoological Institute, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
| | - Gerald Heckel
- Computational and Molecular Population Genetics (CMPG), Zoological Institute, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
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Rovati GE, Capra V, Neubig RR. The highly conserved DRY motif of class A G protein-coupled receptors: beyond the ground state. Mol Pharmacol 2006; 71:959-64. [PMID: 17192495 DOI: 10.1124/mol.106.029470] [Citation(s) in RCA: 278] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Despite extensive study of heptahelical G protein-coupled receptors (GPCRs), the precise mechanism of G protein activation is unknown. The role of one highly conserved stretch of residues, the amino acids glutamic acid/aspartic acid-arginine-tyrosine (i.e., the E/DRY motif), has received considerable attention with respect to regulating GPCR conformational states. In the consensus view, glutamic acid/aspartic acid maintains the receptor in its ground state, because mutations frequently induce constitutive activity (CA). This hypothesis has been confirmed by the rhodopsin ground-state crystal structure and by computational modeling approaches. However, some class A GPCRs are resistant to CA, suggesting alternative roles for the glutamic acid/aspartic acid residue and the E/DRY motif. Here, we propose two different subgroups of receptors within class A GPCRs that make different use of the E/DRY motif, independent of the G protein type (G(s), G(i), or G(q)) to which the receptor couples. In phenotype 1 receptors, nonconservative mutations of the glutamic acid/aspartic acid-arginine residues, besides inducing CA, increase affinity for agonist binding, retain G protein coupling, and retain an agonist-induced response. In contrast, in second phenotype receptors, the E/DRY motif is more directly involved in governing receptor conformation and G protein coupling/recognition. Hence, mutations of the glutamic acid/aspartic acid residues do not induce CA. Conversely, nonconservative mutations of the arginine of the E/DRY motif always impair agonist-induced receptor responses and, generally, reduce agonist binding affinity. Thus, it is essential to look beyond the rhodopsin ground-state model of conformational activation to clarify the role of this highly conserved triplet in GPCR activation and function.
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Affiliation(s)
- G Enrico Rovati
- Laboratory of Molecular Pharmacology, Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy.
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Römpler H, Yu HT, Arnold A, Orth A, Schöneberg T. Functional consequences of naturally occurring DRY motif variants in the mammalian chemoattractant receptor GPR33. Genomics 2006; 87:724-32. [PMID: 16595170 DOI: 10.1016/j.ygeno.2006.02.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 01/30/2006] [Accepted: 02/14/2006] [Indexed: 11/24/2022]
Abstract
Most members of the large family of rhodopsin-like G-protein-coupled receptors possess an evolutionarily conserved Asp-Arg-Tyr (DRY) motif in the C-terminal region of the third transmembrane domain. Mutations of residues within this motif usually abolish receptor function and, when they occur naturally, can even cause human diseases. By analyzing over 100 mammalian orthologs of the chemoattractant receptor GPR33 we identified several polymorphic and fixed sequence variations within the DRY motif. Unexpectedly, the naturally occurring mutation of Arg(3.50) to His in mouse GPR33 showed no difference from the wild-type receptor in several functional tests. Sequence analysis of GPR33 from Asian house mice revealed the polymorphic existence of Arg(3.50) and His(3.50) alleles in wild-trapped populations, further supporting the functional equivalence of both allelic variants. In contrast, the Arg(3.50) to Gly mutation found in hamster GPR33 inactivates the receptor and may have contributed to pseudogenization of this gene in this species. Functional data with GPR33 variants indicate different receptor- and context-specific consequences of DRY mutations. Our study also reveals GPR33 as a new example illustrating missense mutations as a first step in the pseudogenization process.
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Affiliation(s)
- Holger Römpler
- Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, University of Leipzig, Johannisallee 30, 04103 Leipzig, Germany
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Hawtin SR. Pharmacological Chaperone Activity of SR49059 to Functionally Recover Misfolded Mutations of the Vasopressin V1a Receptor. J Biol Chem 2006; 281:14604-14. [PMID: 16565083 DOI: 10.1074/jbc.m511610200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pharmacological chaperones represent a new class of ligand with the potential to facilitate the delivery of misfolded, but still active, G-protein-coupled receptors to the cell surface. Using transfected HEK 293T cells, treatment with a nonpeptide antagonist, SR49059, dramatically increased ( approximately 60-fold) the surface expression of a misfolded, nonfunctional and intracellularly localized vasopressin V(1a) receptor (V(1a)R) mutant (D148A). This rescue of surface expression (111 +/- 7%) was almost identical to wild type assessed by confocal microscopy and quantitative enzyme-linked immunosorbent assay-based techniques. Recovery was not specific to D148A, since other surface-impaired mutations, D148N and D148E, and wild type were also increased following SR49059 exposure. However, surface delivery was specific to SR49059, since V(1a)R-selective peptide ligands or unrelated ligands were unable to mimic this action, suggesting that SR49059 acts intracellularly. SR49059-mediated surface rescue was time-, mutant-, and concentration-dependent but not directly related to its binding affinity. Maximal recovery was achieved following 12 h of treatment and did not involve de novo receptor synthesis or a consequence of preventing endogenous constitutive activity and/or internalization. Once at the surface, all mutants displayed enhanced signaling ability, and D148A was able to undergo agonist-mediated internalization. SR49059 was not effectively removed from the receptor, since signaling (EC(50)) of both wild type and D148A was reduced approximately 40-fold. This is the first report of a pharmacological chaperone ligand to act on misfolded mutant V(1a) Rs. This work provides an excellent model to understand the mechanistic action of an important new class of drug that may have potential in the treatment of diseases caused by inherited mutations.
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Affiliation(s)
- Stuart R Hawtin
- Institute of Cell Signalling, School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, United Kingdom.
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Slusarz MJ, Slusarz R, Ciarkowski J. Investigation of mechanism of desmopressin binding in vasopressin V2 receptor versus vasopressin V1a and oxytocin receptors: Molecular dynamics simulation of the agonist-bound state in the membrane–aqueous system. Biopolymers 2006; 81:321-38. [PMID: 16333859 DOI: 10.1002/bip.20420] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The vasopressin V2 receptor (V2R) belongs to the Class A G protein-coupled receptors (GPCRs). V2R is expressed in the renal collecting duct (CD), where it mediates the antidiuretic action of the neurohypophyseal hormone arginine vasopressin (CYFQNCPRG-NH2, AVP). Desmopressin ([1-deamino, 8-D]AVP, dDAVP) is strong selective V2R agonist with negligible pressor and uterotonic activity. In this paper, the interactions responsible for binding of dDAVP to vasopressin V2 receptor versus vasopressin V1a and oxytocin receptors has been examined. Three-dimensional activated models of the receptors were constructed using the multiple sequence alignment and the complex of activated rhodopsin with Gt(alpha) C-terminal peptide of transducin MII-Gt(alpha) (338-350) prototype (Slusarz, R.; Ciarkowski, J. Acta Biochim Pol 2004 51, 129-136) as a template. The 1-ns unconstrained molecular dynamics (MD) of receptor-dDAVP complexes immersed in the fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) membrane model was conducted in an Amber 7.0 force field. Highly conserved transmembrane residues have been proposed as being responsible for V2R activation and G protein coupling. Molecular mechanism of the dDAVP binding has been suggested. The internal water molecules involved in an intricate network of the hydrogen bonds inside the receptor cavity have been identified and their role in the stabilization of the agonist-bound state proposed.
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Affiliation(s)
- Magdalena J Slusarz
- Faculty of Chemistry, University of Gdańsk, Sobieskiego 18,80-952 Gdańsk,Poland.
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