Elsevier

Neuroscience Letters

Volume 405, Issues 1–2, 11 September 2006, Pages 94-99
Neuroscience Letters

New kappa opioid receptor from zebrafish Danio rerio

https://doi.org/10.1016/j.neulet.2006.06.028Get rights and content

Abstract

A cDNA that encodes a kappa opioid receptor like from zebrafish (ZFOR3) has been cloned and characterized. The encoded protein is 377 residues long and presents 70% identity with the mammalian kappa receptors, although less homology is found in the amino- and carboxyl-terminus as well as in the extracellular loops. In situ hybridization studies have revealed that ZFOR3 mRNA is highly expressed in particular brain areas that coincide with the expression of the kappa opioid receptor in other species. When ZFOR3 is stably expressed in HEK293 cells, [3H]-diprenorphine binds with high affinity (KD = 1.05 ± 0.26 nM), being this value on the same range as those reported for mammalian kappa opioid receptors. On the other hand, the selective agonist for mammalian kappa receptors U69,593 does not bind to ZFOR3. [3H]-diprenorphine binding is readily displaced by the peptidic ligand dynorphin A and by the non-endogenous compounds bremazocine, naloxone and morphine, although with different affinities. Our results demonstrate that ZFOR3 is a unique model to study the kappa opioid receptor functionality.

Section snippets

Acknowledgments

This study was supported by grants from Ministerio de Educación y Ciencia (SAF2004-05144) and Junta de Castilla y León (SA080A05).

References (31)

  • J.C. Xue et al.

    Differential binding domains of peptide and non-peptide ligands in the cloned rat kappa opioid receptor

    J. Biol. Chem.

    (1994)
  • C.S. Bradford et al.

    Cloning, heterologous expression and pharmacological characterization of a kappa opioid receptor from the brain of the rough-skinned newt, Taricha granulosa

    J. Mol. Endocrinol.

    (2005)
  • A.B. Butler et al.

    Comparative vertebrate neuroanatomy: evolution and adaptation

    (1996)
  • S. Chakrabarti et al.

    Distinct differences between morphine- and [D-Ala2,N-MePhe4,Gly-ol5]-enkephalin-mu-opioid receptor complexes demonstrated by cyclic AMP-dependent protein kinase phosphorylation

    J. Neurochem.

    (1988)
  • Y. Chen et al.

    Molecular cloning of a rat kappa opioid receptor reveals sequence similarities to the mu and delta opioid receptors

    Biochem. J.

    (1993)
  • Cited by (44)

    • Unconventional anxiety pharmacology in zebrafish: Drugs beyond traditional anxiogenic and anxiolytic spectra

      2021, Pharmacology Biochemistry and Behavior
      Citation Excerpt :

      For instance, baseline plasma β-endorphin levels are 5-fold higher in some teleost fish (e.g., rainbow trout) (Pottinger et al., 1995) than in rats (Zalewska-Kaszubska et al., 2008), and are >100-fold higher than in humans (Nakao et al., 1978). Endogenous opioids and their receptors have been identified in zebrafish brain (Alvarez et al., 2006; Bao et al., 2019; Demin et al., 2018a; Gonzalez-Nunez and Rodríguez, 2009; Marron Fdez de Velasco et al., 2009; Schulman et al., 1981). However, some differences are observed between mammals and zebrafish, who display reduced affinity of receptors for highly selective opioid agents with proven activity in mammals, suggesting that their binding pockets are highly conserved throughout evolution, unlike the extracellular domains that confer ligand selectivity (Gonzalez-Nunez and Rodríguez, 2009; Gonzalez-Nuñez et al., 2007).

    • Analgesia, anesthesia, and euthanasia in zebrafish

      2021, Laboratory Fish in Biomedical Research: Biology, Husbandry and Research Applications for Zebrafish, Medaka, Killifish, Cavefish, Stickleback, Goldfish and Danionella Translucida
    • Opioid Neurobiology, Neurogenetics and Neuropharmacology in Zebrafish

      2019, Neuroscience
      Citation Excerpt :

      Given the additional affinity of NOP for opioid peptides (e.g., dynorphin A), the endogenous nociceptin system of zebrafish does not seem to have the molecular gap (unlike mammals) from the classical DOP/MOP/KOP opioid system (Gonzalez-Nunez et al., 2003b). The expression patterns of zebrafish opioid-related genes show that classical opioid receptors are strongly expressed in adult fish brain, with broad distribution in all subdivisions (telencephalon, diencephalon, mesencephalon, metencephalon and myelencephalon), but relatively low levels in the spinal cord (Barrallo et al., 1998a; Porteros et al., 1999; Alvarez et al., 2006; Pinal-Seoane et al., 2006; also see Gonzalez-Nunez and Rodriguez, 2009). However, striking variation of expression intensity exists between different CNS areas for these zebrafish genes, like in their mammalian counterparts, especially robust in regions related to sensory processing and pain (Gonzalez-Nunez and Rodriguez, 2009).

    View all citing articles on Scopus
    1

    These authors have equally contributed to this work.

    View full text