Cy3-RgIA-5727 Labels and Inhibits α9-Containing nAChRs of Cochlear Hair Cells.
Cy3-RgIA-5727 Labels and Inhibits α9-Containing nAChRs of Cochlear Hair Cells.
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DOI：
10.3389/fncel.2021.697560
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发表时间：
2021
影响因子：
5.3
通讯作者：
McIntosh JM
中科院分区：
文献类型：
--
作者：
Fisher F;Zhang Y;Vincent PFY;Gajewiak J;Gordon TJ;Glowatzki E;Fuchs PA;McIntosh JM
Efferent cholinergic neurons inhibit sensory hair cells of the vertebrate inner ear through the combined action of calcium-permeable α9α10-containing nicotinic acetylcholine receptors (nAChRs) and associated calcium-dependent potassium channels. The venom of cone snails is a rich repository of bioactive peptides, many with channel blocking activities. The conopeptide analog, RgIA-5474, is a specific and potent antagonist of α9α10-containing nAChRs. We added an alkyl functional group to the N-terminus of the RgIA-5474, to enable click chemistry addition of the fluorescent cyanine dye, Cy3. The resulting peptide, Cy3-RgIA-5727, potently blocked mouse α9α10 nAChRs expressed in Xenopus oocytes (IC50 23 pM), with 290-fold less activity on α7 nAChRs and 40,000-fold less activity on all other tested nAChR subtypes. The tight binding of Cy3-RgIA-5727 provided robust visualization of hair cell nAChRs juxtaposed to cholinergic efferent terminals in excised, unfixed cochlear tissue from mice. Presumptive postsynaptic sites on outer hair cells (OHCs) were labeled, but absent from inner hair cells (IHCs) and from OHCs in cochlear tissue from α9-null mice and in cochlear tissue pre-incubated with non-Cy3-conjugated RgIA-5474. In cochlear tissue from younger (postnatal day 10) mice, Cy3-RgIA-5727 also labeled IHCs, corresponding to transient efferent innervation at that age. Cy3 puncta in Kölliker’s organ remained in the α9-null tissue. Pre-exposure with non-Cy3-conjugated RgIA-5474 or bovine serum albumin reduced this non-specific labeling to variable extents in different preparations. Cy3-RgIA-5727 and RgIA-5474 blocked the native hair cell nAChRs, within the constraints of application to the excised cochlear tissue. Cy3-RgIA-5727 or RgIA-5474 block of efferent synaptic currents in young IHCs was not relieved after 50 min washing, so effectively irreversible.
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影响因子：
5.5
作者：
Goutman, JD;Fuchs, PA;Glowatzki, E
通讯作者：
Glowatzki, E
αO-芋螺毒素 GeXIVA 的克隆、合成和表征，一种有效的 α9α10 烟碱乙酰胆碱受体拮抗剂
DOI：
10.1073/pnas.1503617112
发表时间：
2015-07-28
影响因子：
11.1
作者：
Luo, Sulan;Zhangsuna, Dongting;McIntosh, Michael
通讯作者：
McIntosh, Michael
影响因子：
4.4
作者：
Hecker, Andreas;Kuellmar, Mira;Grau, Veronika
通讯作者：
Grau, Veronika
DOI：
10.1016/s0169-328x(97)00272-6
发表时间：
1998-01-01
期刊：
MOLECULAR BRAIN RESEARCH
影响因子：
--
作者：
Morley, BJ;Li, HS;Elgoyhen, AB
通讯作者：
Elgoyhen, AB
影响因子：
2.8
作者：
NADOL, JB;BURGESS, BJ
通讯作者：
BURGESS, BJ