Multiple phosphorylation of rhodopsin and the in vivo chemistry underlying rod photoreceptor dark adaptation
Multiple phosphorylation of rhodopsin and the in vivo chemistry underlying rod photoreceptor dark adaptation
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DOI：
10.1016/s0896-6273(01)00340-3
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发表时间：
2001-07-19
期刊：
影响因子：
16.2
通讯作者：
Hurley, JB
中科院分区：
文献类型：
--
作者：
Kennedy, MJ;Lee, KA;Hurley, JB
暗适应需要及时的光转导失活和视觉色素的有效再生。以前没有研究直接将暗适应的动力学与影响它的各种化学反应的速率进行比较。为了实现这一目标，我们开发了一种新的基于快速猝灭/质谱的方法来建立小鼠视网膜中光刺激视紫红质磷酸化的初始动力学和位点特异性。我们还在相同的体内条件下测量了磷酸化和去磷酸化，视紫红质的再生和全反式视网膜的减少。视网膜电图监测暗适应。我们发现视紫红质在暴露于光后被多次磷酸化，然后以有序的方式去磷酸化。最初在黑暗适应期间，转导活性随着多个磷酸盐的积累而减弱。此后，光敏性的完全恢复与视紫红质的再生和去磷酸化一致。
Dark adaptation requires timely deactivation of phototransduction and efficient regeneration of visual pigment. No previous study has directly compared the kinetics of dark adaptation with rates of the various chemical reactions that influence it. To accomplish this, we developed a novel rapid-quench/mass spectrometry-based method to establish the initial kinetics and site specificity of light-stimulated rhodopsin phosphorylation in mouse retinas. We also measured phosphorylation and dephosphorylation, regeneration of rhodopsin, and reduction of all-trans retinal all under identical in vivo conditions. Dark adaptation was monitored by electroretinography. We found that rhodopsin is multiply phosphorylated and then dephosphorylated in an ordered fashion following exposure to light. Initially during dark adaptation, transduction activity wanes as multiple phosphates accumulate. Thereafter, full recovery of photosensitivity coincides with regeneration and dephosphorylation of rhodopsin.