Phosphorylation of the carboxyl-terminal domain of the zeta 1 subunit is not responsible for potentiation by TPA of the NMDA receptor channel.
The carboxyl-terminal domain of the zeta 1 subunit of the mouse NMDA receptor channel produced as a fusion protein with GST was phosphorylated in vitro by PKC. A mutant of the zeta 1 subunit without serine or threonine residues in the carboxyl-terminal domain (zeta 1-2-NST) was constructed and was expressed alone or together with the epsilon 2 subunit in Xenopus oocytes. Current responses of the zeta 1-2-NST homomeric and epsilon 2/zeta 1-2-NST heteromeric NMDA receptor channels were enhanced by treatment with TPA, a PKC activator, and the extents of potentiation were comparable with the corresponding wild-type channels. These results suggest that the phosphorylation of the carboxyl-terminal domain of the zeta 1 subunit is not responsible for potentiation of NMDA receptor channels by the TPA treatment.
Yamakura
T
T
Department of Neuropharmacology, Niigata University, Japan.
Mori
H
H
Shimoji
K
K
Mishina
M
M
D000595:Amino Acid Sequence; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D007473:Ion Channels / Q000096:biosynthesis / Q000187:drug effects / Q000502:physiology*; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009865:Oocytes / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000378:metabolism; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D011493:Protein Kinase C / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000096:biosynthesis / Q000187:drug effects / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014981:Xenopus
D007473:Ion Channels; D046911:Macromolecular Substances; D010446:Peptide Fragments; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; D011993:Recombinant Fusion Proteins; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate