Several cDNA clones encoding the human N-methyl-D-aspartate receptor modulatory subunit hNR2A, were isolated from human hippocampus and fetal brain libraries. DNA sequence analysis revealed overlapping clones permitting the reconstruction of full-length hNR2A cDNA. The hNR2A cDNA demonstrated an 88-89% nucleotide (nt) identity with the corresponding rodent cDNAs. The nt sequence of hNR2A would encode a 1464-aa protein that has a 95.2% identity with the rodent NR2A subunits.