麩胺酸受器為哺乳動物中樞神經系統之中主要的興奮性神經傳導受器。依據藥理學與電生理學的特性，可將離子通道型麩胺酸受器次分為三大類：AMPA（α-amino-3-hydroxy -5-methyl-4-isoxazole propionate）受器、kainate受器及NMDA受器（N-methyl-D- aspartate）。其中kainate受器次單元有三個可能RNA editing位置：I/V site（GluR6），Y/C site（GluR6）和Q/R site（GluR5/6）。上述RNA editing sites中，Q/R site 位於TM2中，控制kainate受器的離子通道性質；I/V site和Y/C site位於TM1中，與Q/R site共同影響kainate受器的離子通道性質。RNA editing需由editing site鄰近序列和editing site complementary sequence（ECS）配對形成RNA二級結構（dsRNA），供adenosine deaminases that act on RNA（ADARs）為受質。我們想藉由dsRNA二級結構或ECS序列來推測pre-mRNA是否經RNA editing機制修飾editing site譯碼，且想知道mRNA中edited和unedited form比例。我們藉由mfold程式計算出dsRNA二級結構，且藉由dsRNA預測ECS序列，並經由DNA定序或primer extension方式，瞭解斑馬魚和河豚kainate受器次單元RNA editing site的edited和unedited form比例。經分析primer extension產物瞭解：河豚GluR5α Q/R site不經RNA editing，而河豚GluR6α I/V site及河豚GluR6α、河豚GluR6β和斑馬魚GluR5α Q/R site經RNA editing。將比例關係和dsRNA二級結構、ECS序列比對，我們知道可藉由ECS序列來預測pre-mRNA的RNA editing機制。

Glutamate receptors are the major excitatory neurotransmitter receptors in the mammalian CNS. Ionotropic glutamate receptors can be classified by their pharmacological properties and electrophysiological properties into three large families: AMPA receptors（α-amino-3-hydroxy-5-methyl-4-isoxazole propionate）, kainate receptors and NMDA receptors（N-methyl-D-aspartate）. Three sites of kainate receptor are edited. They are named the I/V, Y/C and Q/R sites. These RNA editing sites alter the Ca2+ permeability and kinetic aspects of channel gating. RNA editing requires a double-stranded RNA（dsRNA）structure formed by the exonic editing site and an editing site complementary sequence（ECS）. We used the dsRNA structures or ECS elements to predict if pre-mRNAs underwent RNA editing and analyzed the level of RNA editing by primer extension. We used the mfold program to calculate the dsRNA structures and predicted ECS elements from the dsRNA structures. We analyzed the level of RNA editing of kainate receptor pre-mRNA in zebrafish and pufferfish by DNA sequencing or primer extension. Our results show that pufferfish GluR5α is not edited at the Q/R site, whereas pufferfish GluR6α and GluR6β are edited at the Q/R site. In addition, pufferfish GluR6α is also edited at I/V site. We found that RNA editing is influenced predominantly by ECS elements. These results demonstrate that the presence of ECS elements in the intron can be a useful trait for prediction of putative RNA editing sites.

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