Reversibility of the Ca(2+) channel alpha(1)-beta subunit interaction.
The auxiliary beta subunit importantly regulates voltage-dependent Ca(2+) channel activity through an interaction with the AID domain, a binding site located in the cytoplasmic I-II linker of the ion-conducting alpha(1) subunit. In the present study, we used two synthetic peptides corresponding to partial sequences of the I-II linker of alpha(1A) (AID(A)-peptides) as tools to disrupt the alpha(1)-beta interaction. In vitro binding experiments confirmed that these peptides exhibit a reasonable affinity to the neuronal beta(3) subunit to serve this purpose, although they failed to prevent immunoprecipitation of native N- and P/Q-type channels by anti-beta(3) antibodies. Together, our results (i) provide evidence for the reversibility of channel subunit association suggesting that the disruption of the alpha(1)-beta interaction may be a possible mechanism for Ca(2+) channel regulation in vivo, and (ii) support a model whereby the alpha(1)-beta association is based on multiple interaction sites.
Bichet
D
D
Laboratoire de Neurobiologie des Canaux Ioniques, Laboratoire de Biochimie, CNRS UMR 6560, INSERM U464, Institut Fédératif Jean Roche, Boulevard Pierre Dramard, Marseille Cedex 20, 13916, France.
Lecomte
C
C
Sabatier
J M
JM
Felix
R
R
De Waard
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015220:Calcium Channels / Q000378:metabolism*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011817:Rabbits; D051381:Rats
D015220:Calcium Channels