In silico modeling of the pore region of a KCNQ4 missense mutant from a patient with hearing loss

BMC Research Notes

Tatsuo Matsunaga¹  Sho Hashimoto³  Hiroki Kaneko²  Hideki Mutai¹  Kazunori Namba¹ 

[1] Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo, Japan;Department of Integrated Science in Physics and Biology, College of Humanities and Science, Nihon University, Tokyo, Japan;Department of Otolaryngology, National Sendai Medical Center, Miyagi, Japan

关键词: Structure;    Potassium;    Mutation;    Molecular Modeling;    Hearing loss;    Electrostatic;    Deafness;    Channel;   

Others  :  1166585
DOI  :  10.1186/1756-0500-5-145

 received in 2011-11-28, accepted in 2012-03-15,  发布年份 2012

【 摘 要 】

Background

Mutation of the voltage-gated potassium channel KCNQ4 causes DFNA2-type nonsyndromic autosomal dominant sensorineural hearing loss. KCNQ4 is expressed predominantly in the auditory sensory outer hair cells, which are critical for sound amplification.

Results

We sequenced KCNQ4 from Japanese patients with sensorineural hearing loss, and identified a novel missense mutation encoding a Tyr270His located at the N-terminus of the highly conserved pore helix sequence. As this patient was not accessible to us and information about them was limited, we used molecular modeling to investigate whether this novel mutation is hypothetically pathogenic. A careful examination of an in silico structural model of the KCNQ4 pore region revealed that the Tyr270His mutation caused an alteration in the electrostatic surface potential of the pore helix.

Conclusion

We propose two possible means by which the Tyr270His mutation causes hearing loss: a positively charged His270 side chain might enhance the helix dipole moment of the pore helix, thereby destabilizing the helix and/or the pore region, or it might disturb transport of K⁺ through the channel by electrostatic repulsion.

【 授权许可】

   
2012 Matsunaga et al; licensee BioMed Central Ltd.

【 图 表 】

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