Ligand binding and subtype selectivity of the human A(2A) adenosine receptor: identification and characterization of essential amino acid residues

Jaakola, Veli-Pekka; Lane, J Robert; Lin, Judy Y; Katritch, Vsevolod; Ijzerman, Adriaan P; Stevens, Raymond C

Abstract

The crystal structure of the human A(2A) adenosine receptor bound to the A(2A) receptor-specific antagonist, ZM241385, was recently determined at 2.6-A resolution. Surprisingly, the antagonist binds in an extended conformation, perpendicular to the plane of the membrane, and indicates a number of interactions unidentified before in ZM241385 recognition. To further understand the selectivity of ZM241385 for the human A(2A) adenosine receptor, we examined the effect of mutating amino acid residues within the binding cavity likely to have key interactions and that have not been previously examined. Mutation of Phe-168 to Ala abolishes both agonist and antagonist binding as well as receptor activity, whereas mutation of this residue to Trp or Tyr had only moderate effects. The Met-177 --> Ala mutation impeded antagonist but not agonist binding. Finally, the Leu-249 --> Ala mutant showed neither agonist nor antagonist binding affinity. From our results and previously published mutagenesis data, we conclude that conserved residues Phe-168(5.29), Glu-169(5.30), Asn-253(6.55), and Leu-249(6.51) play a central role in coordinating the bicyclic core present in both agonists and antagonists. By combining the analysis of the mutagenesis data with a comparison of the sequences of different adenosine receptor subtypes from different species, we predict that the interactions that determine subtype selectivity reside in the more divergent "upper" region of the binding cavity while the "lower" part of the binding cavity is conserved across adenosine receptor subtypes.

Citation

Jaakola, V., Lane, J. R., Lin, J. Y., Katritch, V., Ijzerman, A. P., & Stevens, R. C. (2010). Ligand binding and subtype selectivity of the human A(2A) adenosine receptor: identification and characterization of essential amino acid residues. Journal of Biological Chemistry, 285(17), 13032-13044. https://doi.org/10.1074/jbc.M109.096974

• Journal Article Type: Article
• Online Publication Date: Feb 10, 2010
• Publication Date: Apr 23, 2010
• Deposit Date: Apr 22, 2020
• Journal: Journal of Biological Chemistry
• Print ISSN: 0021-9258
• Publisher: American Society for Biochemistry and Molecular Biology
• Peer Reviewed: Peer Reviewed
• Volume: 285
• Issue: 17
• Pages: 13032-13044
• DOI: https://doi.org/10.1074/jbc.M109.096974
• Public URL: http://www.jbc.org/cgi/doi/10.1074/jbc.M109.096974
• Publisher URL: https://www.jbc.org/content/285/17/13032