Please use this identifier to cite or link to this item:
Title: Molecular evidence of adenosine deaminase linking adenosine A2A receptor and CD26 proteins
Author: Moreno Guillén, Estefanía
Canet, Júlia
Gracia, Eduard
Lluís i Biset, Carme
Mallol Montero, Josefa
Canela Campos, Enric I.
Cortés Tejedor, Antonio
Casadó, Vicent
Keywords: Adenosina
Issue Date: 15-Feb-2018
Publisher: Frontiers Media
Abstract: Adenosine is an endogenous purine nucleoside that acts in all living systems as a homeostatic network regulator through many pathways, which are adenosine receptor (AR)-dependent and -independent. From a metabolic point of view, adenosine deaminase (ADA) is an essential protein in the regulation of the total intracellular and extracellular adenosine in a tissue. In addition to its cytosolic localization, ADA is also expressed as an ecto-enzyme on the surface of different cells. Dipeptidyl peptidase IV (CD26) and some ARs act as binding proteins for extracellular ADA in humans. Since CD26 and ARs interact with ADA at opposite sites, we have investigated if ADA can function as a cell-to-cell communication molecule by bridging the anchoring molecules CD26 and A2AR present on the surfaces of the interacting cells. By combining site-directed mutagenesis of ADA amino acids involved in binding to A2AR and a modification of the bioluminescence resonance energy transfer (BRET) technique that allows detection of interactions between two proteins expressed in different cell populations with low steric hindrance (NanoBRET), we show direct evidence of the specific formation of trimeric complexes CD26-ADA-A2AR involving two cells. By dynamic mass redistribution assays and ligand binding experiments, we also demonstrate that A2AR-NanoLuc fusion proteins are functional. The existence of this ternary complex is in good agreement with the hypothesis that ADA could bridge T-cells (expressing CD26) and dendritic cells (expressing A2AR). This is a new metabolic function for ecto-ADA that, being a single chain protein, it has been considered as an example of moonlighting protein, because it performs more than one functional role (as a catalyst, a costimulator, an allosteric modulator and a cell-to-cell connector) without partitioning these functions in different subunits.
Note: Reproducció del document publicat a:
It is part of: Frontiers in Pharmacology, 2018, vol. 9, p. 106
Related resource:
ISSN: 1663-9812
Appears in Collections:Articles publicats en revistes (Bioquímica i Biomedicina Molecular)

Files in This Item:
File Description SizeFormat 
676806.pdf1.62 MBAdobe PDFView/Open

This item is licensed under a Creative Commons License Creative Commons