Other interactions of NMDA receptors

The list of proteins that can interact with the cytoplasmic tail of NMDA receptor subunits is growing. Here we discuss a few examples that were not mentioned in earlier sections. S-SCAM, a protein with an N-terminal GK domain followed by two WW motifs and five PDZ domains, has been shown to bind to NR2 subunits with its fifth PDZ domain (Hirao et al., 1998). S-SCAM belongs to a family of proteins that includes AIPl and MAGI, which are distantly related to the MAGUK proteins. MALS, a mammalian homolog of LIN-7, can also bind to NR2 subunits via a PDZ-C-terminus interaction (Jo et al., 1999). The significance of these interactions for NMDA receptor function in vivo remains to be determined. 

In conclusion, it seems clear that NMDA receptors interact with a multitude of intracellular proteins, either directly or indirectly via scaffold proteins like PSD-95. Undoubtedly, there are many protein interactions involving NMDA receptors that remain to be uncovered. These interactions are likely to contribute to the cytoskeletal anchoring of NMDA receptors in the PSD, and to the coupling of NMDA receptors to intracellular signaling pathways. 

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