Table 1.
Summary of mechanisms involved in clustering ligand-gated ion channels
| Neurotransmitter receptor | Subunit composition | Clustering protein | Mode of interaction | Cytoskeletal attachment |
|---|---|---|---|---|
| AChR | α, β, γ/ɛ, and δ | Rapsyn | Coiled-coil region of rapsyn required for heterologous clustering of AChR | Actin via β-dystroglycan/utrophin? |
| GlyR | α and β | Gephyrin | Binding to gephyrin requires intracellular loop in β subunit of GlyR | Tubulin Microfilament? |
| GABAAR | α, β, and γ | Rapsyn? | ? | ? |
| Gephyrin? | ||||
| GluR-NMDA | NR1 and NR2 A–D | PSD-95 family members | PDZ domains of PSD-95 family members bind to C-terminal SXV sequences in NR2 subunits and induce clustering in heterologous cells | C0 cassette of NR1 binds α-actinin (37) C1 cassette binds neurofilament (38) and yotiao (39) |
| GluR-AMPA | GluR 1–4 | GRIP | PDZ domains in GRIP bind to C-terminal SKVI sequence in GluR subunits | ? |