A full pharmacological analysis of the three turkey β-adrenoceptors and comparison with the human β-adrenoceptors

PLoS One. 2010 Nov 30;5(11):e15487. doi: 10.1371/journal.pone.0015487.


Background: There are three turkey β-adrenoceptors: the original turkey β-adrenoceptor from erythrocytes (tβtrunc, for which the X-ray crystal structure has recently been determined), tβ3C and tβ4C-receptors. This study examined the similarities and differences between these avian receptors and mammalian receptors with regards to binding characteristics and functional high and low affinity agonist conformations.

Methodology/principal findings: Stable cell lines were constructed with each of the turkey β-adrenoceptors and 3H-CGP12177 whole cell binding, CRE-SPAP production and (3)H-cAMP accumulation assays performed. It was confirmed that the three turkey β-adrenoceptors are distinct from each other in terms of amino acid sequence and binding characteristics. The greatest similarity of any of the turkey β-adrenoceptors to human β-adrenoceptors is between the turkey β3C-receptor and the human β2-adrenoceptor. There are pharmacologically distinct differences between the binding of ligands for the tβtrunc and tβ4C and the human β-adrenoceptors (e.g. with CGP20712A and ICI118551). The tβtrunc and tβ4C-adrenoceptors appear to exist in at least two different agonist conformations in a similar manner to that seen at both the human and rat β1-adrenoceptor and human β3-adrenoceptors. The tβ3C-receptor, similar to the human β2-adrenoceptor, does not, at least so far, appear to exist in more than one agonist conformation.

Conclusions/significance: There are several similarities, but also several important differences, between the recently crystallised turkey β-adrenoceptor and the human β-adrenoceptors. These findings are important for those the field of drug discovery using the recently structural information from crystallised receptors to aid drug design. Furthermore, comparison of the amino-acid sequence for the turkey and human adrenoceptors may therefore shed more light on the residues involved in the existence of the secondary β-adrenoceptor conformation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Agonists / metabolism*
  • Adrenergic beta-Agonists / pharmacology
  • Adrenergic beta-Antagonists / metabolism*
  • Adrenergic beta-Antagonists / pharmacology
  • Amino Acid Sequence
  • Animals
  • Binding, Competitive / drug effects
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Cyclic AMP / metabolism
  • Dose-Response Relationship, Drug
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Propanolamines / metabolism
  • Propanolamines / pharmacology
  • Propranolol / metabolism
  • Propranolol / pharmacology
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Radioligand Assay
  • Receptors, Adrenergic, beta / genetics
  • Receptors, Adrenergic, beta / metabolism*
  • Sequence Homology, Amino Acid
  • Tritium
  • Turkey


  • Adrenergic beta-Agonists
  • Adrenergic beta-Antagonists
  • Propanolamines
  • Protein Isoforms
  • Receptors, Adrenergic, beta
  • Tritium
  • Propranolol
  • Cyclic AMP
  • CGP 12177