Interphase nuclei of many mammalian cell types contain deep, dynamic, tubular membrane-bound invaginations of the nuclear envelope.
Interphase nuclei of many mammalian cell types contain deep, dynamic, tubular membrane-bound invaginations of the nuclear envelope.
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DOI：
10.1083/jcb.136.3.531
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发表时间：
1997-02-10
期刊：
影响因子：
--
通讯作者：
Vaux D
中科院分区：
文献类型：
--
作者：
Fricker M;Hollinshead M;White N;Vaux D
核膜由粗面内质网的双膜延伸组成。在这份报告中，我们描述了来源于核膜的长而动态的管状通道，它深入到核质中。这些通道显示细胞类型的特定形态，从单个短桩到多个复杂的分支结构。有些通道完全横穿细胞核，在核表面的两个不同点打开，而另一些通道终止于核仁或靠近核仁。这些通道有别于核膜的其他拓扑特征，如叶或折叠。通道壁由与核膜相连的两层膜组成，其间点缀着与核孔复合体难以区分的特征，并用薄层装饰在核质表面。封闭的核心与细胞质是连续的，膜之间的管腔空间含有可溶性内质网驻留蛋白(蛋白二硫化物异构酶和葡萄糖-6-磷酸酶)。在用亲脂染料DiOC6标记的活细胞中也发现了核通道。DiOC6标记细胞的时间推移成像显示，在几分钟的时间尺度上，通道在间期核内经历了形态和空间分布的变化。通道壁中细胞质核心和核孔复合体的存在表明这些结构在核质运输中可能发挥作用。这些结构的一个子集与核仁的明确关联也将与这种运输作用相一致。
The nuclear envelope consists of a doublemembraned extension of the rough endoplasmic reticulum. In this report we describe long, dynamic tubular channels, derived from the nuclear envelope, that extend deep into the nucleoplasm. These channels show cell-type specific morphologies ranging from single short stubs to multiple, complex, branched structures. Some channels transect the nucleus entirely, opening at two separate points on the nuclear surface, while others terminate at or close to nucleoli. These channels are distinct from other topological features of the nuclear envelope, such as lobes or folds. The channel wall consists of two membranes continuous with the nuclear envelope, studded with features indistinguishable from nuclear pore complexes, and decorated on the nucleoplasmic surface with lamins. The enclosed core is continuous with the cytoplasm, and the lumenal space between the membranes contains soluble ER-resident proteins (protein disulphide isomerase and glucose-6-phosphatase). Nuclear channels are also found in live cells labeled with the lipophilic dye DiOC6. Time-lapse imaging of DiOC6-labeled cells shows that the channels undergo changes in morphology and spatial distribution within the interphase nucleus on a timescale of minutes. The presence of a cytoplasmic core and nuclear pore complexes in the channel walls suggests a possible role for these structures in nucleo–cytoplasmic transport. The clear association of a subset of these structures with nucleoli would also be consistent with such a transport role.