CLONING, EXPRESSION AND MODULATION OF A MOUSE NMDA RECEPTOR SUBUNIT

The primary structure and presence of two forms of the mouse N-methyl-D-aspartate (NMDA) receptor channel subunit zeta-1 have been disclosed by cloning and sequencing the cDNAs. The zeta-1 subunit shows approximately 20% amino acid sequence identities with the rodent alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)- or kainate-selective GluR subunits and has structural features common to neurotransmitter-gated ion channels. Functional homomeric zeta-1 channels expressed in Xenopus oocytes by injection of the subunit-specific mRNA exhibit current responses characteristic for the NMDA receptor channel such as activation by glycine, Ca2+ permeability, blocking by Mg2+ and activation by polyamine. It has been found that the zeta-1 channel activity is positively modulated by treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA).