GCAP1 rescues rod photoreceptor response in GCAP1/GCAP2 knockout mice
GCAP1 rescues rod photoreceptor response in GCAP1/GCAP2 knockout mice
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DOI：
10.1093/emboj/21.7.1545
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发表时间：
2002-04-02
期刊：
影响因子：
11.4
通讯作者：
Baehr, W
中科院分区：
文献类型：
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作者：
Howes, KA;Pennesi, ME;Baehr, W
视网膜光感受器中的视觉转导通过Ca2+和cGMP这两个第二信使的动态相互作用来运作。Ca2+通过作用于鸟苷酸环化酶（GC）激活蛋白（GCAP）调节鸟苷酸环化酶（GC）的活性和cGMP的合成。虽然这种作用对于光反应的快速终止至关重要，但GCAP的作用尚未确定。为了测试GCAP1（小鼠棒中存在的两种gcap之一）是否支持正常闪光反应的产生，在内源性启动子的控制下产生了只表达GCAP1的转基因小鼠。配对闪光反应揭示了杆状体a波恢复程度与GCAP1表达水平之间的相关性。在单细胞记录中，大多数杆状体产生的闪光反应与野生型没有区别。这些结果表明，在GCAP2缺失的情况下，接近正常水平的GCAP1支持野生型闪光反应的产生。
Visual transduction in retinal photoreceptors operates through a dynamic interplay of two second messengers, Ca2+ and cGMP. Ca2+ regulates the activity of guanylate cyclase (GC) and the synthesis of cGMP by acting on a GC-activating protein (GCAP). While this action is critical for rapid termination of the light response, the GCAP responsible has not been identified. To test if GCAP1, one of two GCAPs present in mouse rods, supports the generation of normal flash responses, transgenic mice were generated that express only GCAP1 under the control of the endogenous promoter. Paired flash responses revealed a correlation between the degree of recovery of the rod a-wave and expression levels of GCAP1 In single cell recordings, the majority of the rods generated flash responses that were indistinguishable from wild type. These results demonstrate that GCAP1 at near normal levels supports the generation of wild-type flash responses in the absence of GCAP2.