Distribution of emerin during the cell cycle
Distribution of emerin during the cell cycle
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DOI：
10.1016/s0171-9335(99)80043-0
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发表时间：
1999-10-01
影响因子：
6.6
通讯作者：
Müller, CR
中科院分区：
文献类型：
--
作者：
Dabauvalle, MC;Müller, E;Müller, CR
人Emerin是一种核膜蛋白，在Emery-Dreifuss肌营养不良症（EMD）患者中丢失或改变。虽然蛋白质在大多数分析的人体组织中表达，但在EMD患者的心脏和骨骼肌中，病理学占主导地位。我们的研究结果表明，emerin可以通过免疫细胞化学和免疫印迹法在从人到非洲爪蟾的所有脊椎动物的核膜中检测到。免疫定位和核膜提取实验证实，Emerin具有核膜完整膜蛋白的特征，一些核膜蛋白也定位于环状层（annulate laminae，AL），即被孔复合物穿透的细胞质扁平膜池。为了验证这些膜叠层中是否含有Emerin，我们通过暴露大鼠细胞来诱导AL的形成（系RV-SMC）对亚致死剂量的抗有丝分裂药物硫酸长春碱的作用，发现Emerin存在于核膜中，但不存在于AL中。与Emerin在间期细胞核膜中的均匀分布相反，该蛋白质在末期细胞的核膜中显示出局灶性积累。在此有丝分裂阶段核膜的早期重组期间，Emerin与核纤层蛋白A/C共定位，但不与核纤层蛋白B和LAP 2蛋白共定位。用Emerin和微管蛋白进行双标记实验后的激光扫描显微镜显示Emerin集中在有丝分裂纺锤体区域和有丝分裂细胞的中间体中，表明这些蛋白质的密切相互作用。我们的数据表明，emerin参与重组的核膜在有丝分裂结束。
Human emerin is a nuclear membrane protein that is lost or altered in patients with Emery-Dreifuss muscular dystrophy (EMD). While the protein is expressed in the majority of human tissues analyzed, the pathology predominates in cardiac and skeletal muscles of patients with EMD.Our results show that emerin can be detected by immunocytochemistry and immunoblotting in the nuclear envelope of all vertebrates studied from man to Xenopus. Immunolocalizations and nuclear envelope extraction experiments confirm that emerin possesses properties characteristic for integral membrane proteins of the inner nuclear membrane.Some nuclear envelope proteins are localized also in annulate lamellae (AL), i.e. cytoplasmic flattened membrane cisternae penetrated by pore complexes. To verify whether emerin is contained in these membrane stacks, we have induced the formation of AL by exposure of rat cells (line RV-SMC) to sublethal doses of the antimitotic drug vinblastine sulfate and found that emerin is present in the nuclear envelope, but is absent from AL.In contrast to the homogeneous distribution of emerin in the nuclear envelope of interphase cells, this protein shows a focal accumulation in the nuclear membranes of late telophase cells. During early reassembly of the nuclear envelope at this mitotic stage emerin colocalizes with lamin A/C but not with lamin B and LAP2 proteins, Confocal! laser scanning microscopy after double-labeling experiments with emerin and tubulin shows that emerin is concentrated in areas of the mitotic spindle and in the midbody of mitotic cells suggesting a close interaction of these proteins. Our data suggest that emerin participates in the reorganisation of the nuclear envelope at the end of mitosis.