Biologie Cellulaire de la Synapse Normale et Pathologique, Institut National de la Santé et de la Recherche Médicale, Ecole Normale Supérieure Paris, France.
Front Neural Circuits. 2010 Mar 3;4:5. doi: 10.3389/neuro.04.005.2010. eCollection 2010.
Nova proteins are neuron-specific RNA binding proteins targeted by autoantibodies in a disorder manifest by failure of motor inhibition, and they regulate splicing and alternative 3' processing. Nova regulates splicing of RNAs encoding synaptic proteins, including the inhibitory glycine receptor alpha2 subunit (GlyRalpha2), and binds to others, including the GIRK2 channel. We found that Nova harbors functional NES and NLS elements, shuttles between the nucleus and cytoplasm, and that 50% of the protein localizes to the soma-dendritic compartment. Immunofluoresence and EM analysis of spinal cord motor neurons demonstrated that Nova co-localizes beneath synaptic contacts in dendrites with the same RNA, GlyRalpha2, whose splicing it regulates in the nucleus. HITS-CLIP identified intronic and 3' UTR sites where Nova binds to GlyRalpha2 and GIRK2 transcripts in the brain. This led directly to the identification of a 3' UTR localization element that mediates Nova-dependent localization of GIRK2 in primary neurons. These data demonstrate that HITS-CLIP can identify functional RNA localization elements, and they suggest new links between the regulation of nuclear RNA processing and mRNA localization.
Nova 蛋白是神经元特异性 RNA 结合蛋白，在一种以运动抑制失败为表现的疾病中，它们是自身抗体的靶标，它们调节剪接和选择性 3'加工。Nova 调节编码突触蛋白的 RNA 的剪接，包括抑制性甘氨酸受体 alpha2 亚基（GlyRalpha2），并与其他 RNA 结合，包括 GIRK2 通道。我们发现 Nova 具有功能性 NES 和 NLS 元件，在核和细胞质之间穿梭，并且有 50%的蛋白质定位于体树突区室。脊髓运动神经元的免疫荧光和 EM 分析表明，Nova 与 GlyRalpha2 共定位在树突的突触下，GlyRalpha2 的剪接在核中受其调节。HITS-CLIP 鉴定了 Nova 结合 GlyRalpha2 和 GIRK2 脑转录本的内含子和 3'UTR 位点。这直接导致鉴定出一个 3'UTR 定位元件，该元件介导 GIRK2 在原代神经元中的 Nova 依赖性定位。这些数据表明 HITS-CLIP 可以识别功能性 RNA 定位元件，并提示核 RNA 处理和 mRNA 定位之间的新联系。
