Browsing by Subject "PROTEIN-COUPLED RECEPTORS"

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  • Escala-Garcia, M.; Abraham, J.; Andrulis, I.L.; Anton-Culver, H.; Arndt, V.; Ashworth, A.; Auer, P.L.; Auvinen, P.; Beckmann, M.W.; Beesley, J.; Behrens, S.; Benitez, J.; Bermisheva, M.; Blomqvist, C.; Blot, W.; Bogdanova, N.V.; Bojesen, S.E.; Bolla, M.K.; Børresen-Dale, A.-L.; Brauch, H.; Brenner, H.; Brucker, S.Y.; Burwinkel, B.; Caldas, C.; Canzian, F.; Chang-Claude, J.; Chanock, S.J.; Chin, S.-F.; Clarke, C.L.; Couch, F.J.; Cox, A.; Cross, S.S.; Czene, K.; Daly, M.B.; Dennis, J.; Devilee, P.; Dunn, J.A.; Dunning, A.M.; Dwek, M.; Earl, H.M.; Eccles, D.M.; Eliassen, A.H.; Ellberg, C.; Evans, D.G.; Fasching, P.A.; Figueroa, J.; Flyger, H.; Gago-Dominguez, M.; Gapstur, S.M.; García-Closas, M.; García-Sáenz, J.A.; Gaudet, M.M.; George, A.; Giles, G.G.; Goldgar, D.E.; González-Neira, A.; Grip, M.; Guénel, P.; Guo, Q.; Haiman, C.A.; Håkansson, N.; Hamann, U.; Harrington, P.A.; Hiller, L.; Hooning, M.J.; Hopper, J.L.; Howell, A.; Huang, C.-S.; Huang, G.; Hunter, D.J.; Jakubowska, A.; John, E.M.; Kaaks, R.; Kapoor, P.M.; Keeman, R.; Kitahara, C.M.; Koppert, L.B.; Kraft, P.; Kristensen, V.N.; Lambrechts, D.; Le Marchand, L.; Lejbkowicz, F.; Lindblom, A.; Lubiński, J.; Mannermaa, A.; Manoochehri, M.; Manoukian, S.; Margolin, S.; Martinez, M.E.; Maurer, T.; Mavroudis, D.; Meindl, A.; Milne, R.L.; Mulligan, A.M.; Neuhausen, S.L.; Nevanlinna, H.; Newman, W.G.; Olshan, A.F.; Olson, J.E.; Olsson, H.; Orr, N.; Peterlongo, P.; Petridis, C.; Prentice, R.L.; Presneau, N.; Punie, K.; Ramachandran, D.; Rennert, G.; Romero, A.; Sachchithananthan, M.; Saloustros, E.; Sawyer, E.J.; Schmutzler, R.K.; Schwentner, L.; Scott, C.; Simard, J.; Sohn, C.; Southey, M.C.; Swerdlow, A.J.; Tamimi, R.M.; Tapper, W.J.; Teixeira, M.R.; Terry, M.B.; Thorne, H.; Tollenaar, R.A.E.M.; Tomlinson, I.; Troester, M.A.; Truong, T.; Turnbull, C.; Vachon, C.M.; van der Kolk, L.E.; Wang, Q.; Winqvist, R.; Wolk, A.; Yang, X.R.; Ziogas, A.; Pharoah, P.D.P.; Hall, P.; Wessels, L.F.A.; Chenevix-Trench, G.; Bader, G.D.; Dörk, T.; Easton, D.F.; Canisius, S.; Schmidt, M.K. (2020)
    Identifying the underlying genetic drivers of the heritability of breast cancer prognosis remains elusive. We adapt a network-based approach to handle underpowered complex datasets to provide new insights into the potential function of germline variants in breast cancer prognosis. This network-based analysis studies similar to 7.3 million variants in 84,457 breast cancer patients in relation to breast cancer survival and confirms the results on 12,381 independent patients. Aggregating the prognostic effects of genetic variants across multiple genes, we identify four gene modules associated with survival in estrogen receptor (ER)-negative and one in ER-positive disease. The modules show biological enrichment for cancer-related processes such as G-alpha signaling, circadian clock, angiogenesis, and Rho-GTPases in apoptosis.
  • Riederer, Monika; Ojala, Pauli J.; Hrzenjak, Andelko; Tritscher, Michaela; Hermansson, Martin; Watzer, Bernhard; Schweer, Horst; Desoye, Gernot; Heinemann, Akos; Frank, Sasa (2010)
  • Leino, Teppo O.; Turku, Ainoleena; Yli-Kauhaluoma, Jari Tapani; Kukkonen, Jyrki P.; Xhaard, Henri; Wallén, Erik A. A. (2018)
    A library of 70 000 synthetically accessible azulene-based compounds was virtually screened at the OX2 receptor. Based on the results, a series of azulene derivatives was synthesized and the binding to and activation of both orexin receptor subtypes were assessed. Two most promising binders were determined to have inhibition constants in the 3-9 mu M range and two other compounds showed weak OX2 receptor agonism. Furthermore, three compounds exhibited a concentration-dependent potentiation of the response to orexin-A at the OX1 but not the OX2 receptors. Altogether this data opens new approaches for further development of antagonists, agonists, and potentiators of orexin response based on the azulene scaffold. (C) 2018 Elsevier Masson SAS. All rights reserved.
  • Gorvin, C.M.; Hannan, F.M.; Cranston, T.; Valta, Helena; Mäkitie, Outi; Schalin-Jäntti, Camilla; Thakker, R.V. (2018)
    G-protein subunit -11 (G(11)) couples the calcium-sensing receptor (CaSR) to phospholipase C (PLC)-mediated intracellular calcium (Ca-i(2+)) and mitogen-activated protein kinase (MAPK) signaling, which in the parathyroid glands and kidneys regulates parathyroid hormone release and urinary calcium excretion, respectively. Heterozygous germline loss-of-function G(11) mutations cause familial hypocalciuric hypercalcemia type 2 (FHH2), for which effective therapies are currently not available. Here, we report a novel heterozygous G(11) germline mutation, Phe220Ser, which was associated with hypercalcemia in a family with FHH2. Homology modeling showed the wild-type (WT) Phe220 nonpolar residue to form part of a cluster of hydrophobic residues within a highly conserved cleft region of G(11), which binds to and activates PLC; and predicted that substitution of Phe220 with the mutant Ser220 polar hydrophilic residue would disrupt PLC-mediated signaling. In vitro studies involving transient transfection of WT and mutant G(11) proteins into HEK293 cells, which express the CaSR, showed the mutant Ser220 G(11) protein to impair CaSR-mediated Ca-i(2+) and extracellular signal-regulated kinase 1/2 (ERK) MAPK signaling, consistent with diminished activation of PLC. Furthermore, engineered mutagenesis studies demonstrated that loss of hydrophobicity within the G(11) cleft region also impaired signaling by PLC. The loss-of-function associated with the Ser220 G(11) mutant was rectified by treatment of cells with cinacalcet, which is a CaSR-positive allosteric modulator. Furthermore, in vivo administration of cinacalcet to the proband harboring the Phe220Ser G(11) mutation, normalized serum ionized calcium concentrations. Thus, our studies, which report a novel G(11) germline mutation (Phe220Ser) in a family with FHH2, reveal the importance of the G(11) hydrophobic cleft region for CaSR-mediated activation of PLC, and show that allosteric CaSR modulation can rectify the loss-of-function Phe220Ser mutation and ameliorate the hypercalcemia associated with FHH2. (c) 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.
  • Zueva, Ksenia J.; Lumme, Jaakko; Veselov, Alexey E.; Kent, Matthew P.; Primmer, Craig R. (2018)
    Abstract Understanding the genomic basis of host-parasite adaptation is important for predicting the long-term viability of species and developing successful management practices. However, in wild populations, identifying specific signatures of parasite-driven selection often presents a challenge, as it is difficult to unravel the molecular signatures of selection driven by different, but correlated, environmental factors. Furthermore, separating parasite-mediated selection from similar signatures due to genetic drift and population history can also be difficult. Populations of Atlantic salmon (Salmo salar L.) from northern Europe have pronounced differences in their reactions to the parasitic flatworm Gyrodactylus salaris Malmberg 1957 and are therefore a good model to search for specific genomic regions underlying inter-population differences in pathogen response. We used a dense Atlantic salmon SNP array, along with extensive sampling of 43 salmon populations representing the two G. salaris response extremes (extreme susceptibility vs resistant), to screen the salmon genome for signatures of directional selection while attempting to separate the parasite effect from other factors. After combining the results from two independent genome scan analyses, 57 candidate genes potentially under positive selection were identified, out of which 50 were functionally annotated. This candidate gene set was shown to be functionally enriched for lymph node development, focal adhesion genes and anti-viral response, which suggests that the regulation of both innate and acquired immunity might be an important mechanism for salmon response to G. salaris. Overall, our results offer insights into the apparently complex genetic basis of pathogen susceptibility in salmon and highlight methodological challenges for separating the effects of various environmental factors.
  • Karhu, Lasse; Turku, Ainoleena; Xhaard, Henri (2015)
    Background: Interactions between the orexin peptides and their cognate OX1 and OX2 receptors remain poorly characterized. Site-directed mutagenesis studies on orexin peptides and receptors have indicated amino acids important for ligand binding and receptor activation. However, a better understanding of specific pairwise interactions would benefit small molecule discovery. Results: We constructed a set of three-dimensional models of the orexin 1 receptor based on the 3D-structures of the orexin 2 receptor (released while this manuscript was under review), neurotensin receptor 1 and chemokine receptor CXCR4, conducted an exhaustive docking of orexin-A(16-33) peptide fragment with ZDOCK and RDOCK, and analyzed a total of 4301 complexes through multidimensional scaling and clustering. The best docking poses reveal two alternative binding modes, where the C-terminus of the peptide lies deep in the binding pocket, on average about 5-6 angstrom above Tyr(6.48) and close to Gln(3.32). The binding modes differ in the about 100 degrees rotation of the peptide; the peptide His26 faces either the receptor's fifth transmembrane helix or the seventh helix. Both binding modes are well in line with previous mutation studies and partake in hydrogen bonding similar to suvorexant. Conclusions: We present two binding modes for orexin-A into orexin 1 receptor, which help rationalize previous results from site-directed mutagenesis studies. The binding modes should serve small molecule discovery, and offer insights into the mechanism of receptor activation.
  • Thompson, Miles D.; Xhaard, Henri; Sakurai, Takeshi; Rainero, Innocenzo; Kukkonen, Jyrki P. (2014)
    Orexin/hypocretin peptide mutations are rare in humans. Even though human narcolepsy is associated with orexin deficiency, this is only extremely rarely due to mutations in the gene coding prepro-orexin, the precursor for both orexin peptides. In contrast, coding and non-coding variants of the OX1 and OX2 orexin receptors have been identified in many human populations; sometimes, these have been associated with disease phenotype, although most confer a relatively low risk. In most cases, these studies have been based on a candidate gene hypothesis that predicts the involvement of orexins in the relevant pathophysiological processes. In the current review, the known human OX1/HCRTR1 and OX2/HCRTR2 genetic variants/polymorphisms as well as studies concerning their involvement in disorders such as narcolepsy, excessive daytime sleepiness, cluster headache, polydipsia-hyponatremia in schizophrenia, and affective disorders are discussed. In most cases, the functional cellular or pharmacological correlates of orexin variants have not been investigated-with the exception of the possible impact of an amino acid 10 Pro/Ser variant of OX2 on orexin potency-leaving conclusions on the nature of the receptor variant effects speculative. Nevertheless, we present perspectives that could shape the basis for further studies. The pharmacology and other properties of the orexin receptor variants are discussed in the context of GPCR signaling. Since orexinergic therapeutics are emerging, the impact of receptor variants on the affinity or potency of ligands deserves consideration. This perspective (pharmacogenetics) is also discussed in the review.
  • Louhivuori, Lauri M.; Turunen, Pauli M.; Louhivuori, Verna; Yellapragada, Venkatram; Nordstrom, Tommy; Uhlen, Per; Akerman, Karl E. (2018)
    Radial glial cells play an essential role through their function as guides for neuronal migration during development. Disruption of metabotropic glutamate receptor 5 (mGluR5) function retards the growth of radial glial processes in vitro. Neuregulins (NRG) are activated by proteolytic cleavage and regulate (radial) glial maintenance via ErbB3/ErbB4 receptors. We show here that blocking ErbB4 disrupts radial process extension. Soluble NRG acting on ErbB4 receptors is able to promote radial process extension in particular where process elongation has been impeded by blockade of mGluR5, the nonselective cation channel canonical transient receptor potential 3 (TRPC3), or matrix metalloproteases (MMP). NRG does not restore retarded process growth caused by ErbB4 blockade. Stimulation of muscarinic receptors restores process elongation due to mGluR5 blockade but not that caused by TRPC3, MMP or ErbB4 blockade suggesting that muscarinic receptors can replace mGluR5 with respect to radial process extension. Additionally, NRG/ErbB4 causes Ca2+ mobilization in a population of cells through cooperation with ErbB1 receptors. Our results indicate that mGluR5 promotes radial process growth via NRG activation by a mechanism involving TRPC3 channels and MMPs. Thus neurotransmitters acting on G-protein coupled receptors could play a central role in the maintenance of the radial glial scaffold through activation of NRG/ErbB4 signaling.