NR2A (Glutamate [NMDA] receptor subunit epsilon-1 or NMDA NR2A) is a glutamate-gated ion channel with high calcium permeability and voltage-dependent sensitivity to magnesium. The NMDA channel is involved in long-term potentiation, an activity-dependent increase in synaptic transmission underlying memory and learning. NMDA NR2A is a heteromer composed of a zeta subunit (GRIN1), an epsilon subunit (GRIN2A, GRIN2Bovine, GRIN2C or GRIN2D) and a third subunit (GRIN3A or GRIN3B). NMDA NR2A activation requires binding of agonist to both types of subunits. Phosphorylation of tyrosine 1325 of the NR2A subunit has been shown to be increased in human brain tissue sections from HIV-infected individuals with encephalitis.