Single-channel currents of rat neuronal nicotinic acetylcholine receptors expressed in Xenopus oocytes.
The neuronal nicotinic acetylcholine receptor subunits alpha 2, alpha 3, and alpha 4 form functional receptors with the beta 2 subunit. Each of these subunit combinations shows two distinct open states (referred to as primary and secondary). The primary open states of alpha 2 beta 2, alpha 3 beta 2, and alpha 4 beta 2 receptors were 33.6 +/- 1.8 pS, 15.4 +/- 0.8 pS, and 13.3 +/- 1.5 pS, respectively. The open times of the alpha 3 beta 2 primary open state were significantly longer than the open times of the other primary conductance states. The secondary open states of alpha 2 beta 2 and alpha 3 beta 2 were 15.5 +/- 1.3 pS and 5.1 +/- 0.4 pS, respectively. Secondary open states were seen infrequently with alpha 4 beta 2. Oocytes injected with alpha 2 RNA and a 9-fold excess of beta 2 RNA showed an enhanced expression of the secondary open state.
Papke
R L
RL
Molecular Neurobiology Laboratory, Salk Institute, San Diego, California 92138.
Boulter
J
J
Patrick
J
J
Heinemann
S
S
D000595:Amino Acid Sequence; D000818:Animals; D004553:Electric Conductivity; D004594:Electrophysiology; D007267:Injections; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism*; D010275:Parasympathetic Nervous System / Q000166:cytology / Q000502:physiology; D012313:RNA / Q000494:pharmacology; D051381:Rats; D011978:Receptors, Nicotinic / Q000235:genetics / Q000502:physiology*; D013997:Time Factors; D014981:Xenopus / Q000254:growth & development
D011978:Receptors, Nicotinic; D012313:RNA