STABLE TRANSFECTION OF THE NR1 SUBUNIT IN CHINESE-HAMSTER OVARY CELLS FAILS TO PRODUCE A FUNCTIONAL N-METHYL-D-ASPARTATE RECEPTOR

The NR1 subunit of the N-methyl-D-aspartate (NMDA) receptor cDNA was stably transfected into Chinese hamster ovary (CHO) cells. Northern analysis revealed 3 clonal cell lines expressing high levels of NMDAR1 mRNA (BA1, BA2 and BA3). NMDAR1 protein was readily detected by Western analysis in only one of the clonal populations, BA1. Whole-cell patch clamp analysis revealed a lack of functional NMDA receptors in all of the cell lines, including BA1. NMDA-mediated responses were obtained only after a second subunit, NMDAR2A, was transiently expressed in BAI cells. Therefore, the NR1 subunit alone may not be sufficient to form functional NMDA receptors in CHO cells.