Neuronal calcium channel α1 subunit interacts with AMPA receptor, increasing its cell surface localisation

Voltage-activated Ca2+ channels (Cav) play critical roles in excitable cells including neurons. Unlike the well-defined roles of Cav2 for pre-synaptic neurotransmission, the post-synaptic function of Cav2 is unclear. Based on our previous study demonstrating the postsynaptic association of the Cav2 with the AMPA receptor (AMPA-R), in this study we sought to further analyse the Cav2-AMPA-R association. We used a step-by-step dissociation of partially purified native Cav2-AMPA-R complexes and co-immunoprecipitation of the Cav2-AMPA-R complexes expressed in HEK293T cells to demonstrate that the main subunit of Cav, α1, formed a complex with the AMPA-R without the auxiliary subunits β, α2δ, γ2/3. The α1 subunit increased the cell-surface localisation of the AMPA-R, which could be a post-synaptic function of the Cav2.