Prefoldin prevents aggregation of alpha-synuclein.
Prefoldin prevents aggregation of alpha-synuclein.
复制标题
前折叠蛋白可防止 α-突触核蛋白聚集。
DOI：
10.1016/j.brainres.2013.10.034
复制
发表时间：
2014
期刊：
影响因子：
2.9
通讯作者：
Ariga H.
中科院分区：
文献类型：
--
作者：
Takano M.;Tashiro E.;Kitamura A.;Maita H.;Iguchi-Ariga M.M.S.;Kinjo M.;Ariga H.
在包括帕金森病（PD）在内的各种神经变性疾病中观察到蛋白质聚集。α-突触核蛋白是家族性PD的致病基因产物，是PD中大聚集体（包涵体）的主要成分。前折叠蛋白（Prefoldin）是一种由PFD 1 ~6六个亚基组成的分子伴侣，它可以防止新生多肽的错误折叠，也可以防止蛋白质的聚集，如亨廷顿蛋白（Huntingtin），它是亨廷顿病的致病基因产物。在本研究中，我们首次发现在转染的Neuro-2a细胞中，TagRFP标记的野生型α-synuclein及其致病突变体发生聚集，而GFP标记的α-synuclein不发生聚集。GFP的荧光在pH 4.5-5.0的条件下减弱，TagRFP在酸性条件下是稳定的红色荧光蛋白。在此条件下，聚集的TagRFP-野生型α-突触核蛋白及其致病突变体在Neuro-2a细胞中被泛素化，并与溶酶体中的前折叠蛋白复合物共定位。此外，PFD 2和PFD 5的敲低破坏了表达α-突触核蛋白的细胞中前折叠蛋白的形成，导致野生型和致病性α-突触核蛋白聚集体的积累并诱导细胞死亡。致病性α-突触核蛋白转染细胞中的聚集和细胞死亡水平往往高于野生型α-突触核蛋白转染细胞中的聚集和细胞死亡水平。这些结果表明，prefoldin作为一个保护性因子在聚集的α-突触核蛋白诱导的细胞死亡。
Protein aggregation is observed in various neurodegeneration diseases, including Parkinson's disease (PD). Alpha-synuclein, a causative gene product of familial PD, is a major component of large aggregates (inclusion bodies) in PD. Prefoldin, a molecular chaperone comprised of six subunits, PFD1~6, prevents misfolding of newly synthesized nascent polypeptides and also prevents aggregation of protein such as a pathogenic form of Huntingtin, a causative gene product of Huntington disease. In this study, we first found that aggregation of TagRFP-tagged wild-type α-synuclein and its pathogenic mutants, but not that of GFP-tagged α-synuclein, occurred in transfected Neuro-2a cells. The fluorescence of GFP is weakened under the condition of pH 4.5–5.0, and TagRFP is a stable red fluorescence protein under an acidic condition. Aggregated TagRFP-wild-type α-synuclein and its pathogenic mutants in Neuro-2a cells were ubiquitinated and were colocalized with the prefoldin complex in the lysosome under this condition. Furthermore, knockdown of PFD2 and PFD5 disrupted prefoldin formation in α-synuclein-expressing cells, resulting in accumulation of aggregates of wild-type and pathogenic α-synuclein and in induction of cell death. The levels of aggregation and cell death in pathogenic α-synuclein-transfected cells tended to be higher than those in wild-type α-synuclein-transfected cells. These results suggest that prefoldin works as a protective factor in aggregated α-synuclein-induced cell death.