ANTI-BETA-2 SUBUNIT ANTISENSE OLIGONUCLEOTIDES MODULATE THE SURFACE EXPRESSION OF THE ALPHA-1 SUBUNIT OF N-TYPE OMEGA-CTX SENSITIVE CA2-32 HUMAN NEUROBLASTOMA-CELLS( CHANNELS IN IMR)

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 th e biophysical properties of the channel. We have tested the role of th e beta(2) subunit on the expression and electrophysiological propertie s of the omega-conotoxin GVIA-sensitive Ca2+ channel expressed in the IMR 32 human neuroblastoma cell line. Anti-beta(2) subunit antisense o ligonucleotides supplied to the cells in culture induced a time-depend ent increase in the number of [I-125]-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) st imulates the transport to the plasma membrane of non-functioning Ca2channels and, in particular, of the alpha(1) omega-conotoxin binding s ubunit. (C) 1994 Academic Press, Inc.