Identification of CRYM as a candidate responsible for nonsyndromic deafness, through cDNA microarray analysis of human cochlear and vestibular tissues
Identification of CRYM as a candidate responsible for nonsyndromic deafness, through cDNA microarray analysis of human cochlear and vestibular tissues
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DOI：
10.1086/345398
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发表时间：
2003-01-01
影响因子：
9.8
通讯作者：
Nakamura, Y
中科院分区：
文献类型：
--
作者：
Abe, S;Katagiri, T;Nakamura, Y
通过对人类耳蜗和前庭基因表达的 cDNA 微阵列分析，我们仅在内耳组织中检测到 mu-晶状体蛋白（CRYM；也称为“NADP 调节的甲状腺激素结合蛋白”）的强表达。在随后对 CRYM 突变的研究中，我们在 192 名非综合征性耳聋患者中发现了 C 末端的两个突变；一种是父母未受影响的患者的从头突变（X315Y），另一种是错义突变（K314T），在先证者的家族中占主导地位。当突变蛋白在COS-7细胞中表达时，其亚细胞定位与正常蛋白不同：X315Y突变体在细胞质中呈空泡状分布，K314T突变体定位于核周区域，而正常蛋白在细胞质中均匀分布。突变蛋白的异常细胞内定位可能会导致 CRYM 产品功能障碍并导致听力障碍。使用小鼠组织进行的原位杂交分析表明其在螺旋韧带的外侧区域和螺旋缘的纤维细胞中表达，这意味着其可能参与钾离子回收系统。我们的结果强烈表明 CRYM 与正常听觉功能有关，并将其确定为导致非综合征性耳聋的基因之一。
Through cDNA microarray analysis of gene expression in human cochlea and vestibule, we detected strong expression of mu-crystallin (CRYM; also known as "NADP-regulated thyroid hormone-binding protein") only in these inner-ear tissues. In a subsequent search for mutations of CRYM, among 192 patients with nonsyndromic deafness, we identified two mutations at the C-terminus; one was a de novo change (X315Y) in a patient with unaffected parents, and the other was a missense mutation (K314T) that segregated dominantly in the proband's family. When the mutated proteins were expressed in COS-7 cells, their subcellular localizations were different from that of the normal protein: the X315Y mutant showed vacuolated distribution in the cytoplasm, and the K314T mutant localized in perinuclear areas, whereas normal protein was distributed homogeneously in the cytoplasm. Aberrant intracellular localization of the mutated proteins might cause dysfunction of the CRYM product and result in hearing impairment. In situ hybridization analysis using mouse tissues indicated its expression in the lateral region of the spiral ligament and the fibrocytes of the spiral limbus, implying its possible involvement in the potassium-ion recycling system. Our results strongly implicate CRYM in normal auditory function and identify it as one of the genes that can be responsible for nonsyndromic deafness.