T-type Ca2+ current properties are not modified by Ca2+ channel beta subunit depletion in nodosus ganglion neurons.
At the molecular level, our knowledge of the low voltage-activated Ca2+ channel (T-type) has made little progress. Using an antisense strategy, we investigated the possibility that the T-type channels have a structure similar to high voltage-activated Ca2+ channels. It is assumed that high voltage-activated channels are made of at least three components: a pore forming alpha1 subunit combined with a cytoplasmic modulatory beta subunit and a primarily extracellular alpha2delta subunit. We have examined the effect of transfecting cranial primary sensory neurons with generic anti-beta antisense oligonucleotides. We show that in this cell type, blocking expression of all known beta gene products does not affect T-type current, although it greatly decreases the current amplitude of high voltage-activated channels and modifies their voltage dependence. This suggests that beta subunits are likely not constitutive of T-type Ca2+ channels in this cell type.
Lambert
R C
RC
Laboratoire de Neurobiologie Cellulaire, UPR 9009 Centre National de la Recherche Scientifique, 67084 Strasbourg, France.
Maulet
Y
Y
Mouton
J
J
Beattie
R
R
Volsen
S
S
De Waard
M
M
Feltz
A
A
D002118:Calcium / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000172:deficiency*; D002478:Cells, Cultured; D004553:Electric Conductivity; D007150:Immunohistochemistry; D007536:Isomerism; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D009620:Nodose Ganglion / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D016376:Oligonucleotides, Antisense; D002118:Calcium