Neziri D, Ilhan A, Maj M, Majdic O, Baumgartner-Parzer S, Cohen G, Base W, Wagner L
Medical University of Vienna, Austria; Department of Internal Medicine III, Austria.
Biochim Biophys Acta. 2010 Apr;1800(4):430-8. doi: 10.1016/j.bbagen.2009.12.004. Epub 2009 Dec 29.
Characterization of gene products originating from undefined open reading frames and delineation of biological functions has become the task after the human genome has been decoded.
We cloned the human C20orf 116 and defined its transcript in liver, kidney and various brain regions by Northern analysis. Antibodies against recombinant protein used for immunofluorescence and immunoblots confirmed its expression in these tissues. With the focus on kidney, its tubular expression and presence in glomerula were shown.
A 28 aa long signal peptide predicted by in silico analysis is reflected by visualization of size variants of approximately 3kDa difference suggesting a signal peptidase cleavage of the proform. Cell compartment separation confirmed the presence of Dashurin in peroxisomes/mitochondria, microsomes, cytosol and nucleus. This is in line with green fluorescent protein (GFP)-Dashurin fusion protein shuttling between cytosol and nucleus. Luciferase reporter studies revealed a 2-3 fold increase of promoter activities upon over-expression. Bioinformatic analysis identified a PCI-domain at the C-terminus providing protein-protein interaction capabilities.
Our present findings suggest the involvement of Dashurin in gene transcription or mRNA translation.
Dashurin shares the PCI-domain with three multisubunit protein complexes (26S proteasome, COP9 signalosome and eIF3 translation initiation factor).
在人类基因组解码之后，对源自未定义开放阅读框的基因产物进行表征并描绘其生物学功能已成为一项任务。
我们克隆了人类C20orf116，并通过Northern分析确定了其在肝脏、肾脏和各个脑区的转录本。用于免疫荧光和免疫印迹的针对重组蛋白的抗体证实了其在这些组织中的表达。以肾脏为重点，显示了其在肾小管中的表达以及在肾小球中的存在。
通过计算机分析预测的一个28个氨基酸长的信号肽，在大小变体相差约3kDa的可视化结果中得到体现，这表明前体形式发生了信号肽酶切割。细胞区室分离证实了达舒林存在于过氧化物酶体/线粒体、微粒体、细胞质和细胞核中。这与绿色荧光蛋白（GFP）-达舒林融合蛋白在细胞质和细胞核之间穿梭一致。荧光素酶报告基因研究显示，过表达后启动子活性增加了2至3倍。生物信息学分析在C末端鉴定出一个PCI结构域，赋予蛋白质-蛋白质相互作用能力。
我们目前的研究结果表明达舒林参与基因转录或mRNA翻译。
达舒林与三种多亚基蛋白复合物（26S蛋白酶体、COP9信号体和eIF3翻译起始因子）共享PCI结构域。
