Kazunori Namba

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BACKGROUND Genetic tests for hereditary hearing loss inform clinical management of patients and can provide the first step in the development of therapeutics. However, comprehensive genetic tests for deafness genes by Sanger sequencing is extremely expensive and time-consuming. Next-generation sequencing (NGS) technology is advantageous for genetic(More)
Adenosine and ATP/UTP are main components of the purinergic system that modulate cellular and tissue functions via specific adenosine and P2 receptors, respectively. Here, we explored the possibility that A(1) adenosine receptor (A(1)R) and P2Y(2) receptor (P2Y(2)R) form heterodimers with novel pharmacological properties. Coimmunoprecipitation showed these(More)
The access of bone morphogenetic protein (BMP) to the BMP receptors on the cell surface is regulated by its antagonist noggin, which binds to heparan-sulfate proteoglycans on the cell surface. Noggin is encoded by NOG and mutations in the gene are associated with aberrant skeletal formation, such as in the autosomal dominant disorders proximal symphalangism(More)
BACKGROUND Mutations in CDH23 are responsible for Usher syndrome 1D and recessive non-syndromic hearing loss. In this study, we revealed the prevalence of CDH23 mutations among patients with specific clinical characteristics. METHODS After excluding patients with GJB2 mutations and mitochondrial m.1555A > G and m.3243A > G mutations, subjects for CDH23(More)
Purines such as adenosine and ATP are now generally recognized as the regulators of many physiological functions, such as neurotransmission, pain, cardiac function, and immune responses. Purines exert their functions via purinergic receptors, which are divided into adenosine and P2 receptors. Recently, we demonstrated that the Gi/o-coupled adenosine A1(More)
Dimerization between G protein-coupled receptors (GPCRs) is a clearly established phenomenon. However, limited information is currently available on the interface essential for this process. Based on structural comparisons and sequence homology between rhodopsin and A(1) adenosine receptor (A(1)R), we initially hypothesized that four residues in(More)
OPA1 mutations are known to cause autosomal dominant optic atrophy (ADOA), and some types of OPA1 mutations also cause auditory neuropathy. In the present study, we evaluated the vestibular dysfunction that accompanied auditory neuropathy in a patient with an OPA1 mutation. A caloric test failed to elicit nystagmus or dizziness in either ear. Vestibular(More)
CONCLUSION PAX3 genetic analysis increased the diagnostic accuracy for Waardenburg syndrome type I (WS1). Analysis of the three-dimensional (3D) structure of PAX3 helped verify the pathogenicity of a missense mutation, and multiple ligation-dependent probe amplification (MLPA) analysis of PAX3 increased the sensitivity of genetic diagnosis in patients with(More)
It is well accepted that G protein-coupled receptors (GPCRs) arrange into dimers or higher-order oligomers that may modify various functions of GPCRs. GPCR-type purinergic receptors (i.e. adenosine and P2Y receptors) tend to form heterodimers with GPCRs not only of the different families but also of the same purinergic receptor families, leading to(More)
Genetic mutation is one of the causative factors for idiopathic progressive hearing loss. A patient with late-onset, moderate, and high-frequency hearing loss was found to have a novel, heterozygous KCNQ4 mutation, c.806_808delCCT, which led to a p.Ser260del located between S5 and the pore helix (PH). Molecular modeling analysis suggested that the(More)