Subunit stoichiometry of the CNG channel of rod photoreceptors.
Cyclic nucleotide-gated (CNG) channels play a central role in the conversion of sensory stimuli into electrical signals. CNG channels form heterooligomeric complexes built of A and B subunits. Here, we study the subunit stoichiometry of the native rod CNG channel by chemical crosslinking. The apparent molecular weight (M(w)) of each crosslink product was determined by SDS-PAGE, and its composition was analyzed by Western blotting using antibodies specific for the A1 or B1 subunit. The number of crosslink products and their M(w) as well as the immunological identification of A1 and B1 subunits in the crosslink products led us to conclude that the native rod CNG channel is a tetramer composed of three A1 and one B1 subunit. This is an example of violation of symmetry in tetrameric channels.
Weitz
Dietmar
D
Institut für Biologische Informationsverarbeitung, Forschungszentrum Jülich, Germany.
Ficek
Nicole
N
Kremmer
Elisabeth
E
Bauer
Paul J
PJ
Kaupp
U Benjamin
UB
D000818:Animals; D000906:Antibodies; D015153:Blotting, Western; D002138:Calibration; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry; D003432:Cross-Linking Reagents; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D054815:Cyclic Nucleotide-Gated Cation Channels; D005136:Eye Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D007473:Ion Channels / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D046911:Macromolecular Substances; D008958:Models, Molecular; D008970:Molecular Weight; D021122:Protein Subunits / Q000737:chemistry* / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D013388:Succinimides
D000906:Antibodies; D003432:Cross-Linking Reagents; D054815:Cyclic Nucleotide-Gated Cation Channels; D005136:Eye Proteins; D007473:Ion Channels; D046911:Macromolecular Substances; D021122:Protein Subunits; D013388:Succinimides; D000242:Cyclic AMP; C035760:bis(sulfosuccinimidyl)suberate; D006152:Cyclic GMP