A critical role of CaBP4 in the cone synapse
A critical role of CaBP4 in the cone synapse
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DOI：
10.1167/iovs.05-0478
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发表时间：
2005-11-01
影响因子：
4.4
通讯作者：
Haeseleer, F
中科院分区：
文献类型：
--
作者：
Maeda, T;Lem, J;Haeseleer, F
目的。 CaBP4 是视杆细胞和视锥细胞的光感受器特异性蛋白，对于小鼠光感受器突触的发育和维持至关重要。在本研究中，产生并分析了缺乏杆介导的电生理反应成分的双CaBP4/杆α转导蛋白敲除小鼠(Cabp4(-/-)Gnat1(-/-))，以研究CaBP4在视锥细胞中的作用。方法。采用免疫细胞化学、电子显微镜、单次闪光和闪烁视网膜电图（ERG）分析2月龄Cbp4（-/-）Gnat1（-/-）小鼠的视网膜形态和生理功能。 Cbp4(-/-) Gnat1(-/-) 小鼠的外丛状层厚度和光感受器末端数量减少至与 Cbp4(-/-) 小鼠相似的水平。单次闪光和闪烁ERG显示，与野生型和Gnat1(-/-)小鼠相比，Cbp4(-/-) Gnat1(-/-)小鼠b波的幅度和敏感性严重减弱。结论。结果表明，Cbp4(-/-) Gnat1(-/-)小鼠的锥体突触功能严重受损，而Cbp4(-/-) Gnat1(-/-)小鼠的形态缺陷与单个Cbp4(-/-)敲除小鼠相似。这项研究和之前的一项研究表明，CaBP4 对于从视杆细胞和视锥细胞到二阶神经元的信号传输至关重要。
PURPOSE. CaBP4, a photoreceptor-specific protein of the rods and cones, is essential for the development and maintenance of the mouse photoreceptor synapse. In this study, double CaBP4/rod alpha-transducin knockout (Cabp4(-/-)Gnat1(-/-)) mice lacking the rod-mediated component of electrophysiologic responses were generated and analyzed to investigate the role of CaBP4 in cones.METHODS. The retinal morphology and physiologic function of 2-month-old Cabp4 (-/-) Gnat1(-/-) mice were analyzed using immunocytochemistry, electron microscopy, and single-flash and flicker electroretinography ( ERG).RESULTS. The thickness of the outer plexiform layer and the number of photoreceptor terminals in Cabp4(-/-) Gnat1(-/-) mice were reduced to levels similar to those of Cabp4(-/-) mice. Single-flash and flicker ERG showed that the amplitude and sensitivity of the b-wave in the Cabp4(-/-) Gnat1(-/-) mice were severely attenuated compared with those in wild-type and Gnat1(-/-) mice.CONCLUSIONS. Results indicate that the cone synaptic function in Cabp4(-/-) Gnat1(-/-) mice was severely disrupted, whereas the morphologic defects observed in Cabp4(-/-) Gnat1(-/-) mice were similar to those of single Cabp4(-/-) knockout mice. This and a previous study reveal that CaBP4 is critical for signal transmission from rods and cones to second-order neurons.