Nuclear Choline Acetyltransferase Activates Transcription of a High-affinity Choline Transporter
Nuclear Choline Acetyltransferase Activates Transcription of a High-affinity Choline Transporter
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DOI：
10.1074/jbc.m110.147611
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发表时间：
2011-02-18
影响因子：
4.8
通讯作者：
Kimura, Hiroshi
中科院分区：
文献类型：
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作者：
Matsuo, Akinori;Bellier, Jean-Pierre;Kimura, Hiroshi
胆碱乙酰转移酶（Choline acetyltransferase, ChAT）在胆碱能神经末端合成神经递质乙酰胆碱。ChAT含有核定位信号，也定位于神经细胞和非神经细胞的细胞核中。核ChAT可能具有尚未确定的功能，例如转录调节。在本研究中，我们研究了ChAT对候选基因转录的改变。我们选择高亲和胆碱转运蛋白（CHT1）和囊泡型乙酰胆碱转运蛋白（VACHT）作为候选基因，它们与ChAT一起作用于乙酰胆碱的产生。使用稳定表达野生型人ChAT的SH-SY5Y人神经母细胞瘤细胞，我们发现过表达ChAT可增强CHT1基因的转录，而不增强VACHT基因的转录。相反，核定位信号中断，催化失活突变体chat不能诱导CHT1表达。此外，ChAT没有改变非神经元HEK293细胞中CHT1的表达。我们的研究结果表明，ChAT激活了神经元细胞中选定的靶基因的转录。ChAT的转录增强需要酶活性和核易位。
Choline acetyltransferase (ChAT) synthesizes the neurotransmitter, acetylcholine, at cholinergic nerve terminals. ChAT contains nuclear localization signals and is also localized in the nuclei of neural and non-neuronal cells. Nuclear ChAT might have an as yet unidentified function, such as transcriptional regulation. In this study, we investigated the alteration of candidate gene transcription by ChAT. We chose high affinity choline transporter (CHT1) and vesicular acetylcholine transporter (VACHT) as candidate genes, which function together with ChAT in acetylcholine production. Using SH-SY5Y human neuroblastoma cells stably expressing wild-type human ChAT, we found that overexpressed ChAT enhanced transcription of the CHT1 gene but not the VACHT gene. In contrast, nuclear localization signal disrupted, and catalytically inactive mutant ChATs could not induce, CHT1 expression. Additionally, ChAT did not alter CHT1 expression in non-neuronal HEK293 cells. Our results suggest that ChAT activates the transcription of selected target genes in neuronal cells. Both enzymatic activity and nuclear translocation of ChAT are required for its transcriptional enhancement.