Catalyzes the hydrolytic deamination of adenosine and 2-deoxyadenosine (  ). Plays an important role in purine metabolism and in adenosine homeostasis. Modulates signaling by extracellular adenosine, and so contributes indirectly to cellular signaling events. Acts as a positive regulator of T-cell coactivation, by binding DPP4 . Its interaction with DPP4 regulates lymphocyte-epithelial cell adhesion . Enhances dendritic cell immunogenicity by affecting dendritic cell costimulatory molecule expression and cytokines and chemokines secretion (By similarity). Enhances CD4+ T-cell differentiation and proliferation . Acts as a positive modulator of adenosine receptors ADORA1 and ADORA2A, by enhancing their ligand affinity via conformational change . Stimulates plasminogen activation . Plays a role in male fertility (, ). Plays a protective role in early postimplantation embryonic development (By similarity).
Subcellular locations: Cell membrane, Cell junction, Cytoplasmic vesicle lumen, Cytoplasm, Lysosome
Colocalized with DPP4 at the cell surface.
Found in all tissues, occurs in large amounts in T-lymphocytes . Expressed at the time of weaning in gastrointestinal tissues.