Neuronal calcium sensor, regulator of G protein-coupled receptor phosphorylation in a calcium dependent manner. Directly regulates GRK1 (RHOK), but not GRK2 to GRK5. Can substitute for calmodulin. Stimulates PI4KB kinase activity. Involved in long-term synaptic plasticity through its interaction with PICK1. May also play a role in neuron differentiation through inhibition of the activity of N- type voltage-gated calcium channel. Interacts with KCND2. Interacts in a calcium-independent manner with PI4KB. This binding competes with CALN2/CABP7 binding to PI4KB. Interacts with ARF1, ARF3, ARF5 and ARF6. Interacts in a calcium-dependent manner with PICK1 (via AH domain). Interacts with IL1RAPL1. Belongs to the recoverin family. Note: This description may include information from UniProtKB.