Departamento de Bioquímica, Instituto de Investigaciones Biomédicas Alberto Sols, Universidad Autônoma de Madrid-Consejo Superior de Investigaciones Científicas, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Facultad de Medicina Universidad Autônoma de Madrid, Madrid, Spain.
PLoS One. 2013;8(2):e55999. doi: 10.1371/journal.pone.0055999. Epub 2013 Feb 7.
NURR1/NR4A2 is an orphan nuclear receptor that is critical for the development and maintenance of mesencephalic dopaminergic neurons and regulates transcription of genes involved in the function of dopaminergic neurons directly via specific NGFI-B response elements (NBRE).and substantial data support a possible role of Nurr1 in the pathogenesis of Parkinson's disease (PD). Here we show that Nurr1 is degraded by the ubiquitin-proteasome pathway and determined that N-terminal region (a.a 1-31) of Nurr1 is essential for an efficient targeting of Nurr1 to degradation in the cell. Nurr1 Δ1-31 has a much longer half-life, and as a consequence its steady-state protein levels were higher, than full-length Nurr1 in the cell. Nurr1 Δ1-31 was as potent as Nurr1 full length in transcriptional luciferase reporter assays after normalization with the corresponding steady-state protein expression levels, either in trans-activation of NBRE or trans-repression of iNOS (inducible NO synthase) reporters. These results suggest that Nurr1 Δ1-31, because of longer persistence in the cell, can be a good candidate for gene and cell therapies in the treatment of PD.
NURR1/NR4A2 是一种孤儿核受体,对于中脑多巴胺能神经元的发育和维持至关重要,并且通过特定的 NGFI-B 反应元件(NBRE)直接调节多巴胺能神经元功能相关基因的转录。大量数据支持 Nurr1 在帕金森病(PD)发病机制中的可能作用。在这里,我们表明 Nurr1 通过泛素蛋白酶体途径降解,并确定 Nurr1 的 N 端区域(a.a 1-31)对于 Nurr1 有效地靶向降解至关重要。Nurr1 Δ1-31 的半衰期明显更长,因此其在细胞中的稳定态蛋白水平高于全长 Nurr1。Nurr1 Δ1-31 在转录荧光素酶报告基因测定中与全长 Nurr1 一样有效,无论是在 NBRE 的反式激活还是 iNOS(诱导型一氧化氮合酶)报告基因的反式抑制中,均与相应的稳定态蛋白表达水平进行归一化。这些结果表明,由于在细胞中持续时间更长,Nurr1 Δ1-31 可能是治疗 PD 的基因和细胞治疗的良好候选物。