Department of Cell Biology, University of Potsdam, Institute for Biochemistry and Biology, Potsdam-Golm, Germany.
Department of Cell Biology, LMU Munich, Biomedical Center, Planegg-Martinsried, Germany.
Nucleus. 2022 Dec;13(1):144-154. doi: 10.1080/19491034.2022.2047289.
Dictyostelium amoebae perform a semi-closed mitosis, in which the nuclear envelope is fenestrated at the insertion sites of the mitotic centrosomes and around the central spindle during karyokinesis. During late telophase the centrosome relocates to the cytoplasmic side of the nucleus, the central spindle disassembles and the nuclear fenestrae become closed. Our data indicate that Dictyostelium spastin (DdSpastin) is a microtubule-binding and severing type I membrane protein that plays a role in this process. Its mitotic localization is in agreement with a requirement for the removal of microtubules that would hinder closure of the fenestrae. Furthermore, DdSpastin interacts with the HeH/ LEM-family protein Src1 in BioID analyses as well as the inner nuclear membrane protein Sun1, and shows subcellular co-localizations with Src1, Sun1, the ESCRT component CHMP7 and the IST1-like protein filactin, suggesting that the principal pathway of mitotic nuclear envelope remodeling is conserved between animals and Dictyostelium amoebae.
粘菌变形虫进行半封闭有丝分裂，在核纤层上有丝分裂中心体的插入部位和在有丝分裂细胞分裂过程中纺锤体的中部有孔。在末期后期，中心体迁移到细胞核的细胞质侧，中部纺锤体解体，核孔关闭。我们的数据表明，粘菌 spastin（DdSpastin）是一种微管结合和切割的 I 型膜蛋白，在这个过程中发挥作用。它的有丝分裂定位与去除微管的要求一致，微管会阻碍孔的关闭。此外，DdSpastin 在 BioID 分析中与 HeH/LEM 家族蛋白 Src1 相互作用，以及与内核膜蛋白 Sun1 相互作用，并与 Src1、Sun1、ESCRT 成分 CHMP7 和 IST1 样蛋白 filactin 有亚细胞共定位，表明有丝分裂核膜重塑的主要途径在动物和粘菌变形虫之间是保守的。
