title: Solution structure of the N-terminal A domain of the human voltage-gated Ca2+channel beta4a subunit.
abstract: Ca2+ channel beta subunits regulate trafficking and gating (opening and closing) of voltage-dependent Ca2+ channel alpha1 subunits. Based on primary sequence comparisons, they are thought to be modular structures composed of five domains (A-E) that are related to the large family of membrane associated guanylate-kinase (MAGUK) proteins. The crystal structures of the beta subunit core, B-D, domains have recently been reported; however, very little is known about the structures of the A and E domains. The N-terminal A domain is a hypervariable region that differs among the four subtypes of Ca2+ channel beta subunits (beta1-beta4). Furthermore, this domain undergoes alternative splicing to create multiple N-terminal structures within a given gene class that have distinct effects on gating. We have solved the solution structure of the A domain of the human beta4a subunit, a splice variant that we have shown previously to have alpha1 subunit subtype-specific effects on Ca2+ channel trafficking and gating.
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80526, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Vendel
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Rithner
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Lyons
authors.forename: William A
authors.initials: WA
authors.lastname: Horne
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D012996:Solutions
chemical_list: C107598:CACNB4 protein, human; D015220:Calcium Channels; D011994:Recombinant Proteins; D012996:Solutions; D002118:Calcium