Abstract
Each residue in and flanking the M2 membrane-spanning segment of the α subunit, from Glu-241 to Glu-262, was mutated to cysteine, and the mutant subunits were expressed together with wild-type β, γ, and δ subunits in Xenopus oocytes. Cysteines substituted for Glu-262, Leu-258, Val-255, Ser-252, Leu-251, Leu-250, Ser-248, Leu-245, Thr-244, and Glu-241 reacted with the positively charged, hydrophilic, sulfhydryl-specific reagent methanethiosulfonate ethylammonium (MTSEA), added extracellularly. These 10 residues, therefore, are exposed in the channel lumen. The pattern of exposure is compatible with an α helix, interrupted by an extended structure from Leu-250 to Ser-252. Acetylcholine caused subtle changes in the accessibilities of some of the engineered cysteines. Since all 10 residues are accessible to MTSEA in the closed state of the channel, the channel gate is at least as cytoplasmic as Glu-241, the most cytoplasmic of the residues tested.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 919-927 |
| Number of pages | 9 |
| Journal | Neuron |
| Volume | 13 |
| Issue number | 4 |
| DOIs | |
| State | Published - 1994 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Neuroscience(all)
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Identification of acetylcholine receptor channel-lining residues in the entire M2 segment of the α subunit. / Akabas, Myles; Kaufmann, Christine; Archdeacon, Patrick; Karlin, Arthur.
In: Neuron, Vol. 13, No. 4, 1994, p. 919-927.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Identification of acetylcholine receptor channel-lining residues in the entire M2 segment of the α subunit
AU - Akabas, Myles
AU - Kaufmann, Christine
AU - Archdeacon, Patrick
AU - Karlin, Arthur
PY - 1994
Y1 - 1994
N2 - Each residue in and flanking the M2 membrane-spanning segment of the α subunit, from Glu-241 to Glu-262, was mutated to cysteine, and the mutant subunits were expressed together with wild-type β, γ, and δ subunits in Xenopus oocytes. Cysteines substituted for Glu-262, Leu-258, Val-255, Ser-252, Leu-251, Leu-250, Ser-248, Leu-245, Thr-244, and Glu-241 reacted with the positively charged, hydrophilic, sulfhydryl-specific reagent methanethiosulfonate ethylammonium (MTSEA), added extracellularly. These 10 residues, therefore, are exposed in the channel lumen. The pattern of exposure is compatible with an α helix, interrupted by an extended structure from Leu-250 to Ser-252. Acetylcholine caused subtle changes in the accessibilities of some of the engineered cysteines. Since all 10 residues are accessible to MTSEA in the closed state of the channel, the channel gate is at least as cytoplasmic as Glu-241, the most cytoplasmic of the residues tested.
AB - Each residue in and flanking the M2 membrane-spanning segment of the α subunit, from Glu-241 to Glu-262, was mutated to cysteine, and the mutant subunits were expressed together with wild-type β, γ, and δ subunits in Xenopus oocytes. Cysteines substituted for Glu-262, Leu-258, Val-255, Ser-252, Leu-251, Leu-250, Ser-248, Leu-245, Thr-244, and Glu-241 reacted with the positively charged, hydrophilic, sulfhydryl-specific reagent methanethiosulfonate ethylammonium (MTSEA), added extracellularly. These 10 residues, therefore, are exposed in the channel lumen. The pattern of exposure is compatible with an α helix, interrupted by an extended structure from Leu-250 to Ser-252. Acetylcholine caused subtle changes in the accessibilities of some of the engineered cysteines. Since all 10 residues are accessible to MTSEA in the closed state of the channel, the channel gate is at least as cytoplasmic as Glu-241, the most cytoplasmic of the residues tested.
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UR - http://www.scopus.com/inward/citedby.url?scp=0027987062&partnerID=8YFLogxK
U2 - 10.1016/0896-6273(94)90257-7
DO - 10.1016/0896-6273(94)90257-7
M3 - Article
VL - 13
SP - 919
EP - 927
JO - Neuron
JF - Neuron
SN - 0896-6273
IS - 4
ER -