TY - JOUR
T1 - TMIE Defines Pore and Gating Properties of the Mechanotransduction Channel of Mammalian Cochlear Hair Cells
AU - Cunningham, Christopher L.
AU - Qiu, Xufeng
AU - Wu, Zizhen
AU - Zhao, Bo
AU - Peng, Guihong
AU - Kim, Ye Hyun
AU - Lauer, Amanda
AU - Müller, Ulrich
N1 - Funding Information:
We thank members of the laboratory for comments and criticism and Angela Ballesteros for helpful suggestions. We are grateful to Michelle Monroe and Kaiping Zhang for assistance with mouse genotyping. We thank Chip Hawkins and the Johns Hopkins Transgenic Mouse Core for help with generating mouse mutants, Jodie Franklin and the Johns Hopkins University Synthesis and Sequencing Facility for DNA sequencing and peptide synthesis, and Michele Pucak and the Johns Hopkins Department of Neuroscience Multiphoton Imaging Core for assistance with Imaris. This work was supported by the NIH ( F32DC015724 to C.L.C.; K99DC016328 to Z.W.; and RO1DC005965 , RO1DC007704 , RO1DC014713 , and RO1DC016960 to U.M.) and the David M. Rubenstein Fund for Hearing Research . U.M. is a Bloomberg Distinguished Professor for Neuroscience and Biology.
Funding Information:
We thank members of the laboratory for comments and criticism and Angela Ballesteros for helpful suggestions. We are grateful to Michelle Monroe and Kaiping Zhang for assistance with mouse genotyping. We thank Chip Hawkins and the Johns Hopkins Transgenic Mouse Core for help with generating mouse mutants, Jodie Franklin and the Johns Hopkins University Synthesis and Sequencing Facility for DNA sequencing and peptide synthesis, and Michele Pucak and the Johns Hopkins Department of Neuroscience Multiphoton Imaging Core for assistance with Imaris. This work was supported by the NIH (F32DC015724 to C.L.C.; K99DC016328 to Z.W.; and RO1DC005965, RO1DC007704, RO1DC014713, and RO1DC016960 to U.M.) and the David M. Rubenstein Fund for Hearing Research. U.M. is a Bloomberg Distinguished Professor for Neuroscience and Biology. C.L.C. carried out genetic, immunohistological, and biochemical experiments and generated mutant mice. Z.W. contributed to the electrophysiological recordings, which were mostly carried out by X.Q. B.Z. contributed to the immunolocalization studies. G.P. assisted with molecular cloning. Y.-H.K. and A.L. carried out ABR recordings. C.L.C. X.Q. and U.M. designed the study. All authors contributed to data analysis. C.L.C. X.Q. and U.M. wrote the manuscript. Dr. M?ller is a co-founder of Decibel Therapeutics.
Publisher Copyright:
© 2020 Elsevier Inc.
PY - 2020/7/8
Y1 - 2020/7/8
N2 - TMC1 and TMC2 (TMC1/2) have been proposed to form the pore of the mechanotransduction channel of cochlear hair cells. Here, we show that TMC1/2 cannot form mechanotransduction channels in cochlear hair cells without TMIE. TMIE binds to TMC1/2, and a TMIE mutation that perturbs TMC1/2 binding abolishes mechanotransduction. N-terminal TMIE deletions affect the response of the mechanotransduction channel to mechanical force. Similar to mechanically gated TREK channels, the C-terminal cytoplasmic TMIE domain contains charged amino acids that mediate binding to phospholipids, including PIP2. TMIE point mutations in the C terminus that are linked to deafness disrupt phospholipid binding, sensitize the channel to PIP2 depletion from hair cells, and alter the channel's unitary conductance and ion selectivity. We conclude that TMIE is a subunit of the cochlear mechanotransduction channel and that channel function is regulated by a phospholipid-sensing domain in TMIE with similarity to those in other mechanically gated ion channels.
AB - TMC1 and TMC2 (TMC1/2) have been proposed to form the pore of the mechanotransduction channel of cochlear hair cells. Here, we show that TMC1/2 cannot form mechanotransduction channels in cochlear hair cells without TMIE. TMIE binds to TMC1/2, and a TMIE mutation that perturbs TMC1/2 binding abolishes mechanotransduction. N-terminal TMIE deletions affect the response of the mechanotransduction channel to mechanical force. Similar to mechanically gated TREK channels, the C-terminal cytoplasmic TMIE domain contains charged amino acids that mediate binding to phospholipids, including PIP2. TMIE point mutations in the C terminus that are linked to deafness disrupt phospholipid binding, sensitize the channel to PIP2 depletion from hair cells, and alter the channel's unitary conductance and ion selectivity. We conclude that TMIE is a subunit of the cochlear mechanotransduction channel and that channel function is regulated by a phospholipid-sensing domain in TMIE with similarity to those in other mechanically gated ion channels.
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U2 - 10.1016/j.neuron.2020.03.033
DO - 10.1016/j.neuron.2020.03.033
M3 - Article
C2 - 32343945
AN - SCOPUS:85087206613
SN - 0896-6273
VL - 107
SP - 126-143.e8
JO - Neuron
JF - Neuron
IS - 1
ER -