Abstract
The skeletal muscle dihydropyridine receptor/Ca2+ channel consists of five distinct subunits (alpha 1, alpha 2 delta, beta 1, and gamma). Homologous alpha 1, alpha 2 delta, and beta 2 subunits are expressed in heart and brain. The present study reports the cloning and expression of a third beta subunit, beta 3, which is expressed predominantly in brain. Its open reading frame encodes a protein with 484 amino acids with a predicted molecular mass of 54,571 Da. Coexpression of beta 3 with a cardiac alpha 1 in Xenopus oocytes induces similar changes in Ca2+ channel activity as beta 1 and beta 2, that is, it increases peak currents, modulates the voltage dependence of activation, and accelerates activation. In addition, beta 3 accelerates the rate of inactivation at positive test potentials.
Publication types
-
Comparative Study
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Amino Acid Sequence
-
Animals
-
Base Sequence
-
Blotting, Northern
-
Brain / physiology*
-
Calcium Channels / genetics*
-
Calcium Channels / physiology*
-
Casein Kinases
-
Cloning, Molecular
-
DNA / genetics
-
DNA / isolation & purification
-
Female
-
Gene Library
-
Heart / physiology*
-
Kinetics
-
Macromolecular Substances
-
Male
-
Molecular Sequence Data
-
Muscles / physiology*
-
Oligodeoxyribonucleotides
-
Oocytes / physiology*
-
Organ Specificity
-
Poly A / genetics
-
Poly A / isolation & purification
-
Polymerase Chain Reaction / methods
-
Protein Kinase C / genetics
-
Protein Kinases / genetics
-
RNA / genetics
-
RNA / isolation & purification
-
RNA, Messenger
-
Rats
-
Sequence Homology, Amino Acid
-
Xenopus
Substances
-
Calcium Channels
-
Macromolecular Substances
-
Oligodeoxyribonucleotides
-
RNA, Messenger
-
Poly A
-
RNA
-
DNA
-
Protein Kinases
-
Casein Kinases
-
Protein Kinase C