Anti-beta 2 subunit antisense oligonucleotides modulate the surface expression of the alpha 1 subunit of N-type omega-CTX sensitive Ca2+ channels in IMR 32 human neuroblastoma cells.

High voltage activated Ca2+ channels are heteropolymeric complexes in which the alpha 1 subunit forms the channel, while the alpha 2-delta and beta subunits are important for the assembly and regulation of the biophysical properties of the channel. We have tested the role of the beta 2 subunit on the expression and electrophysiological properties of the omega-conotoxin GVIA-sensitive Ca2+ channel expressed in the IMR 32 human neuroblastoma cell line. Anti-beta 2 subunit antisense oligonucleotides supplied to the cells in culture induced a time-dependent increase in the number of [125I]-omega-conotoxin binding sites on the cell surface, which was not paralleled by an increase in current amplitude. We suggest that a reduction in the expression of beta 2 stimulates the transport to the plasma membrane of non-functioning Ca2+ channels and, in particular, of the alpha 1 omega-conotoxin binding subunit.