title: Moonlighting adenosine deaminase: a target protein for drug development.
abstract: Interest in adenosine deaminase (ADA) in the context of medicine has mainly focused on its enzymatic activity. This is justified by the importance of the reaction catalyzed by ADA not only for the intracellular purine metabolism, but also for the extracellular purine metabolism as well, because of its capacity as a regulator of the concentration of extracellular adenosine that is able to activate adenosine receptors (ARs). In recent years, other important roles have been described for ADA. One of these, with special relevance in immunology, is the capacity of ADA to act as a costimulator, promoting T-cell proliferation and differentiation mainly by interacting with the differentiation cluster CD26. Another role is the ability of ADA to act as an allosteric modulator of ARs. These receptors have very general physiological implications, particularly in the neurological system where they play an important role. Thus, ADA, being a single chain protein, performs more than one function, consistent with the definition of a moonlighting protein. Although ADA has never been associated with moonlighting proteins, here we consider ADA as an example of this family of multifunctional proteins. In this review, we discuss the different roles of ADA and their pathological implications. We propose a mechanism by which some of their moonlighting functions can be coordinated. We also suggest that drugs modulating ADA properties may act as modulators of the moonlighting functions of ADA, giving them additional potential medical interest.
authors.affiliation: Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institute of Biomedicine of the University of Barcelona (IBUB), Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Cortés
authors.forename: Eduard
authors.initials: E
authors.lastname: Gracia
authors.forename: Estefania
authors.initials: E
authors.lastname: Moreno
authors.forename: Josefa
authors.initials: J
authors.lastname: Mallol
authors.forename: Carme
authors.initials: C
authors.lastname: Lluís
authors.forename: Enric I
authors.initials: EI
authors.lastname: Canela
authors.forename: Vicent
authors.initials: V
authors.lastname: Casadó
mesh_terms: D000243:Adenosine Deaminase / Q000187:drug effects*; D000818:Animals; D015195:Drug Design; D006801:Humans
chemical_list: D000243:Adenosine Deaminase
keywords: CD26; adenosine deaminase; adenosine receptors; allosteric modulator; moonlighting proteins