Expression of NMDA receptor subunits by megakaryocytes. RT-PCR amplified products for the NMDAR1 (A) and NMDAR2D (B) receptor subunit from rat bone marrow; NMDAR2A-C were identified in brain only (B). (C) RT-PCR confirmed expression of NMDAR1 (NR1) and NMDAR2D (NR2D) subunits by MEG-01 cells. (D) Northern blot analysis of total RNA (2 μg) from primary human megakaryocytes using an NMDAR1 probe, which identified a 4.4-kb mRNA species. (E) Western blot analysis of NMDAR1 protein in rat cerebellum, MEG-01 cells (cultured in the absence or presence of 10−7 mol/L PMA for 3 days) and N-deglycosylated rat cerebellum. CNS-type NMDAR1 was of expected size,17 116 kD, which was reduced to ∼100 kD following N-deglycosylation. Major MEG-01 NMDAR1 protein bands were detected at ∼100 kD, matching N-deglycosylated CNS-type NMDAR1 size.
