IDENTIFICATION OF A 120 KD HAIR-BUNDLE MYOSIN LOCATED NEAR STEREOCILIARY TIPS
IDENTIFICATION OF A 120 KD HAIR-BUNDLE MYOSIN LOCATED NEAR STEREOCILIARY TIPS
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DOI：
10.1016/0896-6273(93)90071-x
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发表时间：
1993-10-01
期刊：
影响因子：
16.2
通讯作者：
HUDSPETH, AJ
中科院分区：
文献类型：
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作者：
GILLESPIE, PG;WAGNER, MC;HUDSPETH, AJ
通过适应持续的刺激，内耳的毛细胞对微小位移保持最佳的敏感性。生物物理实验表明，适应是由一个分子马达介导的，最有可能是肌球蛋白家族的成员。为了提供直接证据的存在下，肌球蛋白同工酶的毛束中，我们使用光亲和标记与钒酸捕获的尿苷和腺嘌呤核苷酸，以确定蛋白质的120，160，和230 kD的制备纯化的毛束从牛蛙的球囊。这些蛋白质的光亲和标记特性，特别是120 kd蛋白质，类似于其他良好的特点肌球蛋白。一个120 kd的毛束蛋白也被识别的单克隆抗体针对脊椎动物肌球蛋白I同工酶。免疫荧光显微镜定位这种蛋白质附近的毛束，机械电转导和适应的网站斜顶边缘。
By adapting to sustained stimuli, hair cells of the internal ear maintain their optimal sensitivity to minute displacements. Biophysical experiments have suggested that adaptation is mediated by a molecular motor, most likely a member of the myosin family. To provide direct evidence for the presence of myosin isozymes in hair bundles, we used photoaffinity labeling with vanadate-trapped uridine and adenine nucleotides to identify proteins of 120, 160, and 230 kd in a preparation of hair bundles purified from the bullfrog's sacculus. The photoaffinity labeling properties of these proteins, particularly the 120 kd protein, resembled those of other well-characterized myosins. A 120 kd hair-bundle protein was also recognized by a monoclonal antibody directed against a vertebrate myosin I isozyme. Immunofluorescence microscopy localized this protein near the beveled top edge of the hair bundle, the site of mechanoelectrical transduction and adaptation.