A2A and A2B adenosine receptors: The extracellular loop 2 determines high (A2A) or low affinity (A2B) for adenosine

Elisabetta De Filippo, Sonja Hinz, Veronica Pellizzari, Giuseppe Deganutti, Ali El-Tayeb, Gemma Navarro, Rafael Franco, Stefano Moro, Anke C. Schiedel, Christa E. Müller

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)

Abstract

A2A and A2B adenosine receptors (ARs) are closely related G protein-coupled receptor subtypes, which represent important (potential) drug targets. Despite their almost identical binding sites for adenosine, A2AARs are activated by low (nanomolar) adenosine concentrations, while A2BARs require micromolar concentrations. In the present study, we exchanged the extracellular loop 2 (ECL2) of the human A2AAR for that of the A2BAR. The resulting chimeric A2A(ECL2-A2B)AR was investigated in radioligand binding and cAMP accumulation assays in comparison to the wildtype A2AAR. While the ribose-modified adenosine analog N-ethylcarboxamidoadenosine (NECA) and its 2-substituted derivative CGS-21680 did not exhibit significant changes, adenosine showed dramatically reduced potency and affinity for the A2A(ECL2-A2B)AR mutant displaying similarly low potency as for the wt A2BAR. Supervised molecular dynamics simulation studies predicted a meta-binding site with high affinity for adenosine, but not for NECA, which may contribute to the observed effects.
Original languageEnglish
Article number113718
Number of pages14
JournalBiochemical Pharmacology
Volume172
Early online date18 Nov 2019
DOIs
Publication statusPublished - Feb 2020
Externally publishedYes

Funder

E.D.F., A.C.S., and C.E.M. were supported by the German Federal Ministery of Education and Research (BMBF project Bonn International Graduate School in Drug Sciences (BIGS DrugS)) and by the State of North-Rhine Westfalia (NRW International Research Graduate SchoolBIOTECH-PHARMA). [...] R.F. was supported by a grant from the Spanish Ministerio de Ciencia, Innovación y Universidades (# 2019_RTI2018-094204-B-I00; it may include EU FEDER funds). G.N. was supported by a grant from the Spanish Ministerio de Economía y Competitividad (MINECO #SAF2017-84117-R; it may include EU FEDER funds).

Funding

E.D.F., A.C.S., and C.E.M. were supported by the German Federal Ministery of Education and Research (BMBF project Bonn International Graduate School in Drug Sciences (BIGS DrugS)) and by the State of North-Rhine Westfalia (NRW International Research Graduate SchoolBIOTECH-PHARMA). [...] R.F. was supported by a grant from the Spanish Ministerio de Ciencia, Innovación y Universidades (# 2019_RTI2018-094204-B-I00; it may include EU FEDER funds). G.N. was supported by a grant from the Spanish Ministerio de Economía y Competitividad (MINECO #SAF2017-84117-R; it may include EU FEDER funds).

FundersFunder number
Federal Ministry of Education and Research
State of North-Rhine Westfalia
Ministry of Science, Innovation and Universities2019_RTI2018 -094204-B-I00
European Regional Development Fund
Ministerio de Economía y CompetitividadSAF2017-84117-R

    Keywords

    • Adenosine
    • Chimeric receptor
    • Extracellular loop
    • GPCR
    • Radioligand binding
    • cAMP

    ASJC Scopus subject areas

    • Biochemistry
    • Pharmacology

    Fingerprint

    Dive into the research topics of 'A2A and A2B adenosine receptors: The extracellular loop 2 determines high (A2A) or low affinity (A2B) for adenosine'. Together they form a unique fingerprint.

    Cite this