Related Experiment Video
Updated: Mar 28, 2026
09:54
Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea
Published on: May 10, 2019
12.8K
Evolutionary tuning of an auditory transduction channel
Nurunisa Akyuz1, Trey J Scott2, Corena Loeb3
1Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
Current Biology : CB
|March 26, 2026
Summary
Mechanosensory ion channels TMC1 and TMC2, crucial for hearing and balance, were studied to understand their mechanical force response. Researchers identified an extracellular loop as key to channel activation and adaptation, linking it to hereditary deafness.
Area of Science:
- Molecular Biology
- Neuroscience
- Genetics
Background:
- TMC1 and TMC2 are mechanosensory ion channels essential for hearing and balance in vertebrates.
- The precise mechanism by which these channels open in response to mechanical force is not fully understood.
Purpose of the Study:
- To investigate the structural and functional evolution of TMC1 and TMC2.
- To identify the molecular mechanisms underlying the mechanical gating of these ion channels.
Main Methods:
- Comparative genomic analysis of TMC proteins across eukaryotic species.
- Structural modeling of TMC1 and TMC2.
- Electrophysiological recordings in mouse cochlear hair cells.
Main Results:
- TMC1 and TMC2 evolved elaborate extracellular loops after gene duplication in vertebrates.
- A specific loop between transmembrane domains 1 and 2 was identified near the TMIE auxiliary protein.
- This loop in mammalian TMC1 shows signs of positive selection and contains deafness-associated mutations, influencing channel activation.
Conclusions:
- The extracellular loop of TMC1/TMC2 plays a critical role in channel gating and mechanical adaptation.
- Structural adaptations in this loop are linked to the specialized auditory function of TMC1 and hereditary deafness.
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