Nucleolar localization of the Werner syndrome protein in human cells
Nucleolar localization of the Werner syndrome protein in human cells
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DOI：
10.1073/pnas.95.12.6887
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发表时间：
1998-06-09
影响因子：
11.1
通讯作者：
Guarente, L
中科院分区：
文献类型：
--
作者：
Marciniak, RA;Lombard, DB;Guarente, L
沃纳综合征（WS）是一种具有许多早衰特征的人类遗传性疾病。WS （WRN）中有缺陷的基因已被克隆，并编码一种与多种解旋酶同源的蛋白质，包括大肠杆菌RecQ、人类Bloom综合征蛋白（BLM）和酿酒酵母Sgs1p。为了更好地定义WRN蛋白的功能，我们确定了它的亚细胞定位。使用多克隆抗人WRN的间接免疫荧光显示主要的核仁定位。对WRN突变细胞系的研究证实了抗体识别的特异性。在各种正常和转化的人细胞系（包括癌和肉瘤）中，WRN蛋白的亚细胞定位没有差异。人类WRN蛋白的核仁定位得到了以下发现的支持：在生化亚细胞分离中，WRN蛋白在富含核仁蛋白的亚核部分中以浓度增加的形式存在。我们还确定了小鼠WRN同源物（mWRN）的亚细胞定位。与人类的WRN蛋白不同，mWRN蛋白在细胞核中弥漫性存在。了解WRN在这些寿命差异巨大的生物体中的功能，可能会对寿命决定机制产生新的见解。
Werner Syndrome (WS) is a human genetic disorder with many features of premature aging. The gene defective in WS (WRN) has been cloned and encodes a protein homologous to several helicases, including Escherichia coli RecQ, the human Bloom syndrome protein (BLM), and Saccharomyces cerevisiae Sgs1p. To better define the function of WRN protein we have determined its subcellular localization. Indirect immunofluorescence using polyclonal anti-human WRN shows a predominant nucleolar localization. Studies of WRN mutant cells lines confirmed the specificity of antibody recognition. No difference was seen in the subcellular localization of the WRN protein in a variety of normal and transformed human cell lines, including both carcinomas and sarcomas, The nucleolar localization of human WRN protein was supported by the finding that upon biochemical subcellular fractionation, WRN protein is present in an increased concentration in a subnuclear fraction enriched for nucleolar proteins. We have also determined the subcellular localization of the mouse WRN homologue (mWRN). In contrast to human WRN protein, mWRN protein is present diffusely throughout the nucleus. Understanding the function of WRN in these organisms of vastly differing lifespan may yield new insights into the mechanisms of lifespan determination.