School of Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK.
Biochem J. 2011 May 1;435(3):661-7. doi: 10.1042/BJ20101769.
Behaviour of the NE (nuclear envelope) during open mitosis has been explored extensively in metazoans, but lack of native markers has limited similar investigations in plants. In the present study, carried out using living synchronized tobacco BY-2 suspension cultures, the non-functional NE marker LBR (lamin B receptor)-GFP (green fluorescent protein) and two native, functional NE proteins, AtSUN1 [Arapidopsis thaliana SUN (Sad1/UNC84) 1] and AtSUN2, we provide evidence that the ER (endoplasmic reticulum)-retention theory for NE membranes is applicable in plants. We also observe two apparently unique plant features: location of the NE-membrane components in close proximity to chromatin throughout division, and spatially distinct reformation of the NE commencing at the chromatin surface facing the spindle poles and concluding at the surface facing the cell plate. Mobility of the proteins was investigated in the interphase NE, during NE breakdown and reformation, in the spindle membranes and the cell plate. A role for AtSUN2 in nuclear envelope breakdown is suggested.
在后生动物中，已经广泛研究了核膜（NE）在有丝分裂中的行为，但由于缺乏天然标记物，类似的研究在植物中受到限制。本研究使用活的同步烟草 BY-2 悬浮培养物，利用非功能的 NE 标记物 LBR（lamin B receptor）-GFP（绿色荧光蛋白）和两种天然、功能性的 NE 蛋白 AtSUN1（Arapidopsis thaliana SUN（Sad1/UNC84）1）和 AtSUN2，提供了 ER（内质网）保留理论适用于植物的证据。我们还观察到两个明显的植物特有特征：在整个分裂过程中，NE 膜成分与染色质紧密接近；以及在纺锤体两极朝向的染色质表面开始并在面向细胞板的表面结束的 NE 重新形成的空间上明显的分离。在有丝分裂的核膜、核膜解体和重建期间、纺锤体膜和细胞板中，研究了蛋白质的流动性。AtSUN2 在核膜解体中的作用。
