Roles of cellular NSF protein in entry and nuclear egress of budded virions of Autographa californica multiple nucleopolyhedrovirus

　　論文信息：Ya Guo, Qi Yue, Jinli Gao, Zhe Wang, Yun-Ru Chen, Gary W. Blissard, Tong-Xian Liu and Zhaofei Li. Roles of cellular NSF protein in entry and nuclear egress of budded virions of Autographa californica multiple nucleopolyhedrovirus. J Virol (2017). doi:10.1128/JVI.01111-17

　　中科院二區(qū)，IF = 4.663

　　論文摘要：In eukaryotic cells, the soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor (SNARE) proteins comprise the minimal machinery that triggers fusion of transport vesicles with their target membranes. Comparative studies revealed that genes encoding the components of the SNARE system are highly conserved in yeast, insect, and human genomes. Upon infection of insect cells by the virus AcMNPV, the transcript levels of most SNARE genes were initially up-regulated. We found that overexpression of dominant-negative (DN) forms of NSF or knock-down of the expression of NSF, the key regulator of the SNARE system, significantly affected the infectious AcMNPV production. In cells expressing DN NSF,  entering virions were trapped in the cytoplasm or transported to the nucleus with low efficiency. The presence of DN NSF also moderately reduced trafficking of the viral envelope glycoprotein GP64 to the plasma membrane but dramatically inhibited production of infectious BV. TEM analysis of infections in cells expressing DN NSF revealed that progeny nucleocapsids were retained in a perinuclear space surrounded by inner and outer nuclear membranes. Several baculovirus conserved (core) proteins (Ac76, Ac78, GP41, Ac93, and Ac103) that are important for infectious budded virion production, were found to associate with NSF, and NSF was detected within the assembled BV. Together, these data indicate that the cellular SNARE system is involved in AcMNPV infection and that NSF is required for efficient entry and nuclear egress of budded virions of AcMNPV.