Regulation of α-synuclein expression by poly (ADP ribose) polymerase-1 (PARP-1) binding to the NACP-Rep1 polymorphic site upstream of the SNCA gene
Regulation of α-synuclein expression by poly (ADP ribose) polymerase-1 (PARP-1) binding to the NACP-Rep1 polymorphic site upstream of the SNCA gene
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DOI：
10.1086/428655
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发表时间：
2005-03-01
影响因子：
9.8
通讯作者：
Nussbaum, RL
中科院分区：
文献类型：
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作者：
Chiba-Falek, O;Kowalak, JA;Nussbaum, RL
在一些报道中，位于α-突触核蛋白基因(SNCA)上游10kb的多态微卫星重复序列NACP-Rep1的等位基因与散发性帕金森病(PD)的不同风险有关。我们以前发现NACP-Rep1作为SNCA转录的负调控因子，其作用在不同的NACP-Rep1等位基因之间差异三倍。鉴于SNCA的重复和三重与家族性帕金森病(PD)有关，即使α-突触核蛋白表达增加1.5-2倍，也可能在几十年内导致PD。因此，不同的NACP-Rep1等位基因与帕金森病的关联可能是SNCA转录调控的多态差异的结果。在这里，我们的目的是通过提取与NACP-Rep1结合的蛋白质并通过质谱分析来鉴定与NACP-Rep1结合并可能对SNCA转录调控做出贡献的因子(S)。这些蛋白质之一是多聚(ADP-核糖)转移酶/聚合酶-1(PARP-1)，它是一种DNA结合蛋白和转录调节因子。凝胶迁移率漂移和染色质免疫沉淀实验显示PARP-1与NACP-Rep1特异性结合。抑制PARP-1‘S催化结构域可增加培养的SH-SY5Y细胞内源性SNCA mRNA水平。此外，在荧光素酶报告分析中，PARP-1与NACP-Rep1结合特异性地降低了SNCA启动子/增强子的转录活性。PARP-1的这种下调作用依赖于NACP-Rep1的存在，并通过用3-氨基苯甲酰胺抑制PARP-1‘S的催化活性而被取消。不同的NACP-Rep1等位基因与PD的关联可能部分是通过PARP-1以及其他因素对SNCA表达的影响而介导的。
Alleles at NACP-Rep1, the polymorphic microsatellite repeat located similar to 10 kb upstream of the alpha-synuclein gene ( SNCA), are associated, in some reports, with differing risks of sporadic Parkinson disease (PD). We showed previously that NACP-Rep1 acts as a negative modulator of SNCA transcription, with an effect that varied threefold among different NACP-Rep1 alleles. Given that duplications and triplications of SNCA have been implicated in familial Parkinson disease (PD), even a 1.5 - 2-fold increase in alpha-synuclein expression may, over many decades, contribute to PD. Thus, the association of different NACP-Rep1 alleles with PD may be a consequence of polymorphic differences in transcriptional regulation of SNCA. Here we aimed to identify the factor(s) that bind to NACP-Rep1 and potentially contribute to SNCA transcriptional modulation, by pulling down proteins that bind to NACP- Rep1 and identifying them by mass spectrometry. One of these proteins was poly-(ADP-ribose) transferase/ polymerase-1 (PARP-1), a DNA-binding protein and transcriptional regulator. Electrophoresis mobility shift and chromatin immunoprecipitation assays showed specific binding of PARP-1 to NACP- Rep1. Inhibition of PARP-1's catalytic domain increased the endogenous SNCA mRNA levels in cultured SH-SY5Y cells. Furthermore, PARP-1 binding to NACP- Rep1 specifically reduced the transcriptional activity of the SNCA promoter/enhancer in luciferase reporter assays. This down-regulation effect of PARP-1 depended on NACP- Rep1 being present in the construct and was abrogated by inhibiting PARP-1's catalytic activity with 3-aminobenzamide. The association of different NACP- Rep1 alleles with PD may be mediated, in part, by the effect of PARP-1, as well as other factors, on SNCA expression.