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

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