An analysis of the role of the target membrane on the Gp64-induced fusion pore.
An analysis of the role of the target membrane on the Gp64-induced fusion pore.
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DOI：
10.1006/viro.1998.9493
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发表时间：
1999-01
期刊：
影响因子：
3.7
通讯作者：
I. Plonsky;M. Cho;A. Oomens;G. Blissard;J. Zimmerberg
中科院分区：
文献类型：
--
作者：
I. Plonsky;M. Cho;A. Oomens;G. Blissard;J. Zimmerberg
在介导表达这些融合蛋白的宿主细胞和靶细胞之间的融合时，流感血凝素(HA)和多壳核多角体病毒的GP64诱导出显著不同的初始融合孔(Plonsky和Zimmerberg，1996；Spruce等人，1989,1991；Zimmerberg等人，1994)。然而，在这些实验中，宿主膜和靶膜的变化混淆了对融合反应的主要成分在确定初始孔特征中所起作用的分析。为了确定靶细胞质膜对融合孔表型的贡献，我们研究了GP64诱导的稳定表达细胞(Sf9(Op1D))与红细胞(RBC)或Sf9细胞的融合。Sf9(Op1D)/RBC和Sf9(Op1D)/Sf9细胞对的初始融合孔具有相同的电导，并且在两种细胞组合中都没有观察到孔闪烁。这表明目标细胞既不决定初始孔的大小也不决定其可逆性。然而，靶细胞确实影响孔形成的动力学。与Sf9(Op1D)/Sf9对相比，Sf9(Op1D)/RBC融合从触发到出现毛孔的等待时间更短。气孔等待时间与电导率之间没有相关性。这与假设由非固定数量的组分聚集的孔壁作为GP64融合孔形成的速率限制步骤的分子模型相反。
Influenza hemagglutinin (HA) and GP64 of the baculovirus Autographa californica multicapsid nuclear polyhedrosis virus induce strikingly different initial fusion pores when mediating fusion between host cells that express these fusion proteins and target cells (Plonsky and Zimmerberg, 1996; Spruce et al., 1989, 1991; Zimmerberg et al., 1994). However, in these experiments, variations in host and target membranes confounded the analysis of the role that major components of the fusion reaction play in determining initial pore characteristics. To determine the contribution of the target cell plasma membrane to the fusion pore phenotype, we studied GP64-induced fusion of stably transfected cells (Sf9(Op1D)) to either red blood cells (RBCs) or Sf9 cells. Initial fusion pores in Sf9(Op1D)/RBC and Sf9(Op1D)/Sf9 cell pairs exhibited the same conductance, and pore flickering was not observed in either combination of cells. This indicates that the target cell determines neither the size nor the reversibility of the initial pore. However, the target cell does influence the kinetics of pore formation. The waiting time between triggering and pore appearance was shorter for Sf9(Op1D)/RBC fusion than for Sf9(Op1D)/Sf9 pairs. No correlation between pore waiting time and conductance was found. This argues against a molecular model that assumes aggregation of the pore wall from a nonfixed number of components as the rate-limiting step in GP64 fusion pore formation.