Intracellular curvature-generating proteins in cell-to-cell fusion.
Intracellular curvature-generating proteins in cell-to-cell fusion.
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DOI：
10.1042/bj20111243
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发表时间：
2011-12-01
期刊：
影响因子：
--
通讯作者：
Chernomordik LV
中科院分区：
文献类型：
--
作者：
Richard JP;Leikina E;Langen R;Henne WM;Popova M;Balla T;McMahon HT;Kozlov MM;Chernomordik LV
细胞间融合在正常生理和不同病理条件下起着重要作用。由特化蛋白介导的早期融合阶段并产生融合孔，随后是依赖于细胞代谢和尚未鉴定的机制的孔扩张阶段。由于在融合孔边缘和高度弯曲的细胞内膜隔室中的膜弯曲的相似性，在本研究中，我们探讨了产生这些隔室的蛋白质的活性的变化是否影响流感病毒和杆状病毒的蛋白质融合体启动的细胞融合。我们通过表达或显微注射epsin的ENTH（epsin N-末端同源性）结构域或通过表达GRAF 1（与粘着斑激酶1相关的GT3调节剂）BAR（Bin/两栖physin/Rvs）结构域或FCHo 2（FCH结构域蛋白2）F-BAR结构域来提高细胞中弯曲产生蛋白的细胞内浓度。这些处理均促进合胞体形成。细胞融合程度也受到针对另一种曲率生成蛋白发动蛋白功能的治疗的影响。穿透细胞膜的动力蛋白GT3抑制剂阻断融合孔的扩张，而动力蛋白的显性失活突变体影响合胞体的形成程度。我们还报告说，合胞体的形成被抑制试剂降低PtdIns（4，5）P2，细胞内膜重塑的重要调节剂的内容和可访问性。我们的研究结果表明，在细胞与细胞融合的后期阶段的融合孔扩张介导，直接或间接，由细胞内膜成形蛋白。
Cell-to-cell fusion plays an important role in normal physiology and in different pathological conditions. Early fusion stages mediated by specialized proteins and yielding fusion pores are followed by a pore expansion stage that is dependent on cell metabolism and yet unidentified machinery. Because of a similarity of membrane bending in the fusion pore rim and in highly curved intracellular membrane compartments, in the present study we explored whether changes in the activity of the proteins that generate these compartments affect cell fusion initiated by protein fusogens of influenza virus and baculovirus. We raised the intracellular concentration of curvature-generating proteins in cells by either expressing or microinjecting the ENTH (epsin N-terminal homology) domain of epsin or by expressing the GRAF1 (GTPase regulator associated with focal adhesion kinase 1) BAR (Bin/amphiphysin/Rvs) domain or the FCHo2 (FCH domain-only protein 2) F-BAR domain. Each of these treatments promoted syncytium formation. Cell fusion extents were also influenced by treatments targeting the function of another curvature-generating protein, dynamin. Cell-membrane-permeant inhibitors of dynamin GTPase blocked expansion of fusion pores and dominant-negative mutants of dynamin influenced the syncytium formation extents. We also report that syncytium formation is inhibited by reagents lowering the content and accessibility of PtdIns(4,5)P2, an important regulator of intracellular membrane remodelling. Our findings indicate that fusion pore expansion at late stages of cell-to-cell fusion is mediated, directly or indirectly, by intracellular membrane-shaping proteins.
DOI：
10.1083/jcb.83.2.320
发表时间：
1979-11
期刊：
The Journal of cell biology
影响因子：
--
作者：
Wang E;Cross RK;Choppin PW
通讯作者：
Choppin PW