Researchers at the University of Iowa and Kansas State University say a deafness-causing gene defect in mice helped identify a new protein that protects sensory cells in the ear, according to findings in PLoS Genetics.
In humans, hereditary deafness is one of the most common birth defects, yet most genes involved in hearing are unidentified. Mice are used as research models because mouse and human auditory genetics are very similar.
Using a deaf mouse model generated at The Jackson Laboratory, the team identified the deafness-causing defect in the claudin-9 gene. The mutated gene fails to produce normal claudin-9 protein, which, the UI team showed, is needed to maintain the proper distribution of potassium in the inner ear.
"Genes in the claudin family number at least 24 and produce proteins that prevent ions, including potassium, from moving between cells," said senior author Botond Banfi. "Sensory cells in the hearing organ are bathed in a high potassium solution on one side and in a low potassium solution on the other side. We found that claudin-9 is very important in keeping the amount of potassium on the two sides separate. This separation protects sensory cells from potassium intoxication."
When claudin-9 is mutated, potassium floods the wrong part of the sensory cells, killing most and leaving the remaining ones functionally defective.
In follow-up efforts, Banfi and colleagues are screening people with hearing impairment to see if some of them have a mutation in claudin-9.
FINANCIAL DISCLOSURE: The study was funded in part by a grant from the National Institutes of Health and support from the UI Roy J. and Lucille A. Carver College of Medicine and the UI Gene Therapy Center. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
COMPETING INTERESTS: The authors have declared that no competing interests exist.
CITATION: Nakano Y, Kim SH, Kim H-M, Sanneman JD, Zhang Y, et al. (2009) A Claudin-9–Based Ion Permeability Barrier Is Essential for Hearing. PLoS Genet 5(8): e1000610. doi:10.1371/journal.pgen.1000610
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Is That A Real Patient Or A Junkie? Now There's An App For That
- How The Higgs Became The Target Of Run 2 At The Tevatron
- You Are Ready To Eat Insects If You Have These Characteristics
- Global 'Roadmap' Shows Where To Put Roads Without Costing The Earth
- How Neuroscience Is Being Used To Spread Quackery In Business And Education
- MOOCs: Learning About Online Learning, One Click At A Time
- Will We Meet ET Microbes On Mars? Why We Should Care Deeply About Them - Like Tigers
- "More precisely: you can say that you have a quantum of an EM wave *after* one combined creation/detection..."
- "What are you planning to do this Month? Here is the list of 200 free online courses that start..."
- "So in this representation every four vector is represented by a 4x4 matrix, but not every 4x4 matrix..."
- "If you look up a text on Quantum Electrodynamics you should find a Psi field for creating and destroying..."
- "You guessed alright, that is a page from the book...Cheers,T...."
- Geochronology and global context of the Charnian Supergroup
- Confirmation of a low pre-extensional geothermal gradient in the Grayback normal
- Scientists get set for simulated nuclear inspection
- Invisible blood in urine may indicate bladder cancer
- Sugar substance 'kills' good HDL cholesterol, new research finds