May act as a signaling scaffold protein that senses intracellular calcium. Can modulate ligand-induced internalization of ADORA2A and coupling efficiency of mGluR5/GRM5; for both receptors may regulate signaling activity such as promoting MAPK1/3 (ERK1/2) activation. Interacts (calcium-dependent) with ADORA2A and GRM5. Colocalizes with ADORA2A and/or mGluR5/GRM5 at the plasma membrane (PubMed:17689978, PubMed:19694902). Found in neuronal somata (PubMed:26843217). Detected in the cytoplasm of striatal neurons, at postsynaptic sites, filling dendritic shafts and spines, and at presynaptic sites, filling axon terminals (By similarity). Expressed in brain. Expressed in the spinal dorsal horn with especially strong expression in lamina IIi; found in excitory synaptic boutons and in ependymal cells (at protein level).