Multiple conductance classes of mouse nicotinic acetylcholine receptors expressed in Xenopus oocytes.
Acetylcholine receptor (AcChoR) subunit mRNAs transcribed from mouse BC3H-1 cDNAs were injected into Xenopus oocytes and the expressed AcChoR channels were examined by single channel recording. Injection of alpha-, beta-, gamma-, and delta-subunit mRNAs produced two predominant channel classes with conductances of approximately 50 and approximately 12 pS, while infrequent openings of approximately 25-pS channels were also observed. Injection of alpha-, beta-, and gamma-subunit mRNAs produced a single class of approximately 12-pS AcChoR channels, which resembled the smallest conductance channels present in alpha beta gamma omega-injected oocytes. Assembly of delta-less channels may thus explain the lowest conductance AcChoR channels in alpha beta gamma delta-injected oocytes and might also account for similar channels that have been observed in vertebrate skeletal muscle.
Kullberg
R
R
Biology Department, University of Alaska, Anchorage 99508.
Owens
J L
JL
Camacho
P
P
Mandel
G
G
Brehm
P
P
D000595:Amino Acid Sequence; D000818:Animals; D004247:DNA / Q000235:genetics; D004553:Electric Conductivity; D005260:Female; D046911:Macromolecular Substances; D008564:Membrane Potentials; D051379:Mice; D008845:Microinjections; D008969:Molecular Sequence Data; D009865:Oocytes / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D011978:Receptors, Nicotinic / Q000235:genetics / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D046911:Macromolecular Substances; D012333:RNA, Messenger; D011978:Receptors, Nicotinic; D004247:DNA