title: Induction of calcium currents by the expression of the alpha 1-subunit of the dihydropyridine receptor from skeletal muscle.
abstract: The dihydropyridine (DHP) receptor purified from skeletal muscle comprises five protein subunits (alpha 1, alpha 2, beta, gamma and delta) and produces Ca2+ currents that are blocked by DHPs. Cloning of the alpha 1- and alpha 2-subunits, the former affinity-labelled by DHP, has shown that the alpha 1-subunit is expressed in skeletal muscle alone, whereas the alpha 2- and delta- subunits are also expressed in other tissues. Although the transient expression of the alpha 1-subunit in myoblasts from dysgenic mice (but not in oocytes) has been demonstrated, the use of these expression systems to determine the function of the alpha 1- subunit is complicated by the presence of endogenous Ca2+ currents, which may reflect the constitutive expression of proteins similar to the alpha 2-, beta-, gamma- and/or delta-subunits. We therefore selected a cell line which has no Ca2+ currents or alpha 2- subunit, and probably no delta-subunit for stable transformation with complementary DNA of the alpha 1- subunit. The transformed cells express DHP-sensitive, voltage-gated Ca2+ channels, indicating that the minimum structure of these channels is at most an alpha 1 beta gamma complex and possibly an alpha 1- subunit alone.
authors: Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.
authors: E
authors: E
authors: Perez-Reyes
authors: H S
authors: HS
authors: Kim
authors: A E
authors: AE
authors: Lacerda
authors: W
authors: W
authors: Horne
authors: X Y
authors: XY
authors: Wei
authors: D
authors: D
authors: Rampe
authors: K P
authors: KP
authors: Campbell
authors: A M
authors: AM
authors: Brown
authors: L
authors: L
authors: Birnbaumer
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000345:Affinity Labels; D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004095:Dihydropyridines / Q000494:pharmacology; D004553:Electric Conductivity; D005786:Gene Expression Regulation; D015151:Immunoblotting; D007739:L Cells; D046911:Macromolecular Substances; D051379:Mice; D008970:Molecular Weight; D009132:Muscles / Q000032:analysis; D011978:Receptors, Nicotinic / Q000235:genetics / Q000502:physiology*; D014162:Transfection; D014170:Transformation, Genetic
chemical_list: D000345:Affinity Labels; D015220:Calcium Channels; D004095:Dihydropyridines; D046911:Macromolecular Substances; D011978:Receptors, Nicotinic; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C038806:1,4-dihydropyridine; D004247:DNA