In neurons, modulates the degradation of NMDA receptor GRIN2B subunit. Plays a role in the regulation of neuronal excitability. Interacts with GRIN2B. Expressed throughout the brain with higher levels in the pyramidal cell layer of the hippocampal CA1 and CA3 regions. Also highly expressed within the hippocampal dentate gyrus region and cerebellum and in scattered neurons in the cerebral cortex.