N-Terminal EF-Hand Calcium Binding Protein 2 (NECAB2)

NECAB2, a neuronal calcium binding protein, was identified as a binding partner for the A2AR interacting with its C-terminal domain. Co-localization, co-immunoprecipitation and pull-down experiments showed a close and specific interaction between A2AR and NECAB2 in both transfected HEK-293 cells and also in rat striatum. Immunoelectron microscopy detection of NECAB2 and A2AR in the rat striatopallidal structures indicated that both proteins are co-distributed in the same glutamatergic nerve terminals. The interaction of NECAB2 with A2AR modulated the cell surface expression, the ligand-dependent internalization and the receptor-mediated activation of the MAPK pathway. A2AR interacts with NECAB2 in striatal neurones co-expressing the two proteins and that the interaction is relevant for A2AR function.