The expression of L-type voltage-gated calcium channels in retinal photoreceptors is under circadian control
The expression of L-type voltage-gated calcium channels in retinal photoreceptors is under circadian control
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DOI：
10.1111/j.1471-4159.2007.04816.x
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发表时间：
2007-10-01
影响因子：
4.7
通讯作者：
Ko, Gladys Y. -P.
中科院分区：
文献类型：
--
作者：
Ko, Michael L.;Liu, Yilin;Ko, Gladys Y. -P.
光感受器是非尖峰神经元，其突触在L型电压门控钙通道（VGCC）的控制下介导神经递质的持续释放。光感受器表达内源性昼夜节律振荡器，其在调节光感受器生理和功能中起重要作用。在这里，我们报告说，小鸡锥光感受器的L型VGCC的昼夜节律控制。在主观夜间测量时，L型VGCC电流比在主观白天测量时更大。使用针对VGCC α 1C和VGCC α 1D亚基的抗体，我们发现光感受器中VGCC α 1C和VGCC α 1D的免疫荧光强度在主观夜间较高。然而，VGCC α 1D的mRNA水平是有节律的，而VGCC α 1C的mRNA水平不是。夜间增加的L型VGCCs被manumycin A，PD 98059和KN 93阻断，这表明昼夜输出途径包括Ras，Erk和钙-钙调蛋白依赖性激酶II。总之，四条独立的证据表明，视锥细胞中的L-VGCC受昼夜节律控制。
Photoreceptors are non-spiking neurons, and their synapses mediate the continuous release of neurotransmitters under the control of L-type voltage-gated calcium channels (VGCCs). Photoreceptors express endogenous circadian oscillators that play important roles in regulating photoreceptor physiology and function. Here, we report that the L-type VGCCs in chick cone photoreceptors are under circadian control. The L-type VGCC currents are greater when measured during the subjective night than during the subjective day. Using antibodies against the VGCC alpha 1C and VGCC alpha 1D subunits, we found that the immunofluorescence intensities of both VGCC alpha 1C and VGCC alpha 1 D in photoreceptors are higher during the subjective night. However, the mRNA levels of VGCC alpha 1D, but not VGCC alpha 1C, are rhythmic. Nocturnal increases in L-type VGCCs are blocked by manumycin A, PD98059, and KN93, which suggest that the circadian output pathway includes Ras, Erk, and calcium-calmodulin dependent kinase II. In summary, four independent lines of evidence show that the L-VGCCs in cone photoreceptors are under circadian-control.