title: alpha1-beta interaction in voltage-gated cardiac L-type calcium channels.
abstract: The beta subunits of voltage-gated calcium channels normalize current amplitude, kinetics and voltage dependence of these channels by interacting with the channel's pore forming subunit alpha1. By screening an epitope expression library of alpha1Ca fusion proteins, a beta2a binding site of 22 amino acids was identified within the I-II cytoplasmic linker but not on other cytoplasmic sequences of alpha1Ca. This binding site overlaps by 14 amino acids with the conserved 18 amino acid peptide assumed to be essential for alpha1-beta interaction. The common 14 amino acid motif of alpha1Ca is sufficient to bind beta2a, and in addition beta1a, beta3 and beta4.
authors.affiliation: Institut für Pharmakologie, Universität Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Marquart
authors.forename: V
authors.initials: V
authors.lastname: Flockerzi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015220:Calcium Channels / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000939:Epitopes / Q000235:genetics / Q000378:metabolism; D015723:Gene Library; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012641:Selection, Genetic; D013329:Structure-Activity Relationship
chemical_list: D015220:Calcium Channels; D000939:Epitopes; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins